Merge remote-tracking branch 'aneesh/for-upstream-6' into staging

Conflicts:
	trace-events

22 files changed, 852 insertions, 883 deletions

diff --git a/Makefile.objs b/Makefile.objs
index 44d9bb9043..9e2077833e 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -305,7 +305,7 @@ sound-obj-$(CONFIG_HDA) += intel-hda.o hda-audio.o
 adlib.o fmopl.o: QEMU_CFLAGS += -DBUILD_Y8950=0
 hw-obj-$(CONFIG_SOUND) += $(sound-obj-y)
 
-9pfs-nested-$(CONFIG_VIRTFS)  = virtio-9p.o virtio-9p-debug.o
+9pfs-nested-$(CONFIG_VIRTFS)  = virtio-9p.o
 9pfs-nested-$(CONFIG_VIRTFS) += virtio-9p-local.o virtio-9p-xattr.o
 9pfs-nested-$(CONFIG_VIRTFS) += virtio-9p-xattr-user.o virtio-9p-posix-acl.o
 9pfs-nested-$(CONFIG_VIRTFS) += virtio-9p-coth.o cofs.o codir.o cofile.o
diff --git a/configure b/configure
index 9b4fe34fce..4f87e0a43b 100755
--- a/configure
+++ b/configure
@@ -2557,6 +2557,31 @@ EOF
 fi
 
 ##########################################
+# check if we have open_by_handle_at
+
+open_by_hande_at=no
+cat > $TMPC << EOF
+#include <fcntl.h>
+int main(void) { struct file_handle *fh; open_by_handle_at(0, fh, 0); }
+EOF
+if compile_prog "" "" ; then
+    open_by_handle_at=yes
+fi
+
+########################################
+# check if we have linux/magic.h
+
+linux_magic_h=no
+cat > $TMPC << EOF
+#include <linux/magic.h>
+int main(void) {
+}
+EOF
+if compile_prog "" "" ; then
+    linux_magic_h=yes
+fi
+
+##########################################
 # End of CC checks
 # After here, no more $cc or $ld runs
 
@@ -3035,6 +3060,14 @@ if test "$ucontext_coroutine" = "yes" ; then
   echo "CONFIG_UCONTEXT_COROUTINE=y" >> $config_host_mak
 fi
 
+if test "$open_by_handle_at" = "yes" ; then
+  echo "CONFIG_OPEN_BY_HANDLE=y" >> $config_host_mak
+fi
+
+if test "$linux_magic_h" = "yes" ; then
+  echo "CONFIG_LINUX_MAGIC_H=y" >> $config_host_mak
+fi
+
 # USB host support
 case "$usb" in
 linux)
diff --git a/fsdev/file-op-9p.h b/fsdev/file-op-9p.h
index 8de8abfd5b..908e2a5edc 100644
--- a/fsdev/file-op-9p.h
+++ b/fsdev/file-op-9p.h
@@ -23,23 +23,6 @@
 #define SM_LOCAL_MODE_BITS    0600
 #define SM_LOCAL_DIR_MODE_BITS    0700
 
-typedef enum
-{
-    /*
-     * Server will try to set uid/gid.
-     * On failure ignore the error.
-     */
-    SM_NONE = 0,
-    /*
-     * uid/gid set on fileserver files
-     */
-    SM_PASSTHROUGH = 1,
-    /*
-     * uid/gid part of xattr
-     */
-    SM_MAPPED,
-} SecModel;
-
 typedef struct FsCred
 {
     uid_t   fc_uid;
@@ -49,17 +32,41 @@ typedef struct FsCred
 } FsCred;
 
 struct xattr_operations;
+struct FsContext;
+struct V9fsPath;
 
-/* FsContext flag values */
-#define PATHNAME_FSCONTEXT 0x1
+typedef struct extended_ops {
+    int (*get_st_gen)(struct FsContext *, struct V9fsPath *,
+                      mode_t, uint64_t *);
+} extended_ops;
+
+/* export flags */
+#define V9FS_IMMEDIATE_WRITEOUT     0x00000001
+#define V9FS_PATHNAME_FSCONTEXT     0x00000002
+/*
+ * uid/gid set on fileserver files
+ */
+#define V9FS_SM_PASSTHROUGH         0x00000004
+/*
+ * uid/gid part of xattr
+ */
+#define V9FS_SM_MAPPED              0x00000008
+/*
+ * Server will try to set uid/gid.
+ * On failure ignore the error.
+ */
+#define V9FS_SM_NONE                0x00000010
+
+
+#define V9FS_SEC_MASK               0x0000001C
 
 typedef struct FsContext
 {
-    int flags;
-    char *fs_root;
-    SecModel fs_sm;
     uid_t uid;
+    char *fs_root;
+    int export_flags;
     struct xattr_operations **xops;
+    struct extended_ops exops;
     /* fs driver specific data */
     void *private;
 } FsContext;
diff --git a/fsdev/qemu-fsdev.c b/fsdev/qemu-fsdev.c
index 768819f575..5977bcca4c 100644
--- a/fsdev/qemu-fsdev.c
+++ b/fsdev/qemu-fsdev.c
@@ -18,46 +18,55 @@
 #include "qemu-common.h"
 #include "qemu-config.h"
 
-static QTAILQ_HEAD(FsTypeEntry_head, FsTypeListEntry) fstype_entries =
-    QTAILQ_HEAD_INITIALIZER(fstype_entries);
+static QTAILQ_HEAD(FsDriverEntry_head, FsDriverListEntry) fsdriver_entries =
+    QTAILQ_HEAD_INITIALIZER(fsdriver_entries);
 
-static FsTypeTable FsTypes[] = {
+static FsDriverTable FsDrivers[] = {
     { .name = "local", .ops = &local_ops},
     { .name = "handle", .ops = &handle_ops},
 };
 
 int qemu_fsdev_add(QemuOpts *opts)
 {
-    struct FsTypeListEntry *fsle;
+    struct FsDriverListEntry *fsle;
     int i;
     const char *fsdev_id = qemu_opts_id(opts);
-    const char *fstype = qemu_opt_get(opts, "fstype");
+    const char *fsdriver = qemu_opt_get(opts, "fsdriver");
     const char *path = qemu_opt_get(opts, "path");
     const char *sec_model = qemu_opt_get(opts, "security_model");
+    const char *writeout = qemu_opt_get(opts, "writeout");
+
 
     if (!fsdev_id) {
         fprintf(stderr, "fsdev: No id specified\n");
         return -1;
     }
 
-    if (fstype) {
-        for (i = 0; i < ARRAY_SIZE(FsTypes); i++) {
-            if (strcmp(FsTypes[i].name, fstype) == 0) {
+    if (fsdriver) {
+        for (i = 0; i < ARRAY_SIZE(FsDrivers); i++) {
+            if (strcmp(FsDrivers[i].name, fsdriver) == 0) {
                 break;
             }
         }
 
-        if (i == ARRAY_SIZE(FsTypes)) {
-            fprintf(stderr, "fsdev: fstype %s not found\n", fstype);
+        if (i == ARRAY_SIZE(FsDrivers)) {
+            fprintf(stderr, "fsdev: fsdriver %s not found\n", fsdriver);
             return -1;
         }
     } else {
-        fprintf(stderr, "fsdev: No fstype specified\n");
+        fprintf(stderr, "fsdev: No fsdriver specified\n");
+        return -1;
+    }
+
+    if (!strcmp(fsdriver, "local") && !sec_model) {
+        fprintf(stderr, "security model not specified, "
+                "local fs needs security model\nvalid options are:"
+                "\tsecurity_model=[passthrough|mapped|none]\n");
         return -1;
     }
 
-    if (!sec_model) {
-        fprintf(stderr, "fsdev: No security_model specified.\n");
+    if (strcmp(fsdriver, "local") && sec_model) {
+        fprintf(stderr, "only local fs driver needs security model\n");
         return -1;
     }
 
@@ -70,20 +79,40 @@ int qemu_fsdev_add(QemuOpts *opts)
 
     fsle->fse.fsdev_id = g_strdup(fsdev_id);
     fsle->fse.path = g_strdup(path);
-    fsle->fse.security_model = g_strdup(sec_model);
-    fsle->fse.ops = FsTypes[i].ops;
+    fsle->fse.ops = FsDrivers[i].ops;
+    fsle->fse.export_flags = 0;
+    if (writeout) {
+        if (!strcmp(writeout, "immediate")) {
+            fsle->fse.export_flags |= V9FS_IMMEDIATE_WRITEOUT;
+        }
+    }
 
-    QTAILQ_INSERT_TAIL(&fstype_entries, fsle, next);
-    return 0;
+    if (strcmp(fsdriver, "local")) {
+        goto done;
+    }
 
+    if (!strcmp(sec_model, "passthrough")) {
+        fsle->fse.export_flags |= V9FS_SM_PASSTHROUGH;
+    } else if (!strcmp(sec_model, "mapped")) {
+        fsle->fse.export_flags |= V9FS_SM_MAPPED;
+    } else if (!strcmp(sec_model, "none")) {
+        fsle->fse.export_flags |= V9FS_SM_NONE;
+    } else {
+        fprintf(stderr, "Invalid security model %s specified, valid options are"
+                "\n\t [passthrough|mapped|none]\n", sec_model);
+        return -1;
+    }
+done:
+    QTAILQ_INSERT_TAIL(&fsdriver_entries, fsle, next);
+    return 0;
 }
 
-FsTypeEntry *get_fsdev_fsentry(char *id)
+FsDriverEntry *get_fsdev_fsentry(char *id)
 {
     if (id) {
-        struct FsTypeListEntry *fsle;
+        struct FsDriverListEntry *fsle;
 
-        QTAILQ_FOREACH(fsle, &fstype_entries, next) {
+        QTAILQ_FOREACH(fsle, &fsdriver_entries, next) {
             if (strcmp(fsle->fse.fsdev_id, id) == 0) {
                 return &fsle->fse;
             }
diff --git a/fsdev/qemu-fsdev.h b/fsdev/qemu-fsdev.h
index e04931a58d..5099085720 100644
--- a/fsdev/qemu-fsdev.h
+++ b/fsdev/qemu-fsdev.h
@@ -29,28 +29,28 @@
  * -----------------
  *  etc
  */
-typedef struct FsTypeTable {
+typedef struct FsDriverTable {
     const char *name;
     FileOperations *ops;
-} FsTypeTable;
+} FsDriverTable;
 
 /*
  * Structure to store the various fsdev's passed through command line.
  */
-typedef struct FsTypeEntry {
+typedef struct FsDriverEntry {
     char *fsdev_id;
     char *path;
-    char *security_model;
+    int export_flags;
     FileOperations *ops;
-} FsTypeEntry;
+} FsDriverEntry;
 
-typedef struct FsTypeListEntry {
-    FsTypeEntry fse;
-    QTAILQ_ENTRY(FsTypeListEntry) next;
-} FsTypeListEntry;
+typedef struct FsDriverListEntry {
+    FsDriverEntry fse;
+    QTAILQ_ENTRY(FsDriverListEntry) next;
+} FsDriverListEntry;
 
 int qemu_fsdev_add(QemuOpts *opts);
-FsTypeEntry *get_fsdev_fsentry(char *id);
+FsDriverEntry *get_fsdev_fsentry(char *id);
 extern FileOperations local_ops;
 extern FileOperations handle_ops;
 #endif
diff --git a/hw/9pfs/cofile.c b/hw/9pfs/cofile.c
index 7ad4bec005..692811e5ab 100644
--- a/hw/9pfs/cofile.c
+++ b/hw/9pfs/cofile.c
@@ -17,6 +17,30 @@
 #include "qemu-coroutine.h"
 #include "virtio-9p-coth.h"
 
+int v9fs_co_st_gen(V9fsPDU *pdu, V9fsPath *path, mode_t st_mode,
+                   V9fsStatDotl *v9stat)
+{
+    int err = 0;
+    V9fsState *s = pdu->s;
+
+    if (v9fs_request_cancelled(pdu)) {
+        return -EINTR;
+    }
+    if (s->ctx.exops.get_st_gen) {
+        v9fs_path_read_lock(s);
+        v9fs_co_run_in_worker(
+            {
+                err = s->ctx.exops.get_st_gen(&s->ctx, path, st_mode,
+                                              &v9stat->st_gen);
+                if (err < 0) {
+                    err = -errno;
+                }
+            });
+        v9fs_path_unlock(s);
+    }
+    return err;
+}
+
 int v9fs_co_lstat(V9fsPDU *pdu, V9fsPath *path, struct stat *stbuf)
 {
     int err;
diff --git a/hw/9pfs/cofs.c b/hw/9pfs/cofs.c
index 68745add1e..83f125bd47 100644
--- a/hw/9pfs/cofs.c
+++ b/hw/9pfs/cofs.c
@@ -323,7 +323,7 @@ int v9fs_co_name_to_path(V9fsPDU *pdu, V9fsPath *dirpath,
     int err;
     V9fsState *s = pdu->s;
 
-    if (s->ctx.flags & PATHNAME_FSCONTEXT) {
+    if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
         err = s->ops->name_to_path(&s->ctx, dirpath, name, path);
         if (err < 0) {
             err = -errno;
diff --git a/hw/9pfs/virtio-9p-coth.h b/hw/9pfs/virtio-9p-coth.h
index 4630080e53..ca96b9cf2f 100644
--- a/hw/9pfs/virtio-9p-coth.h
+++ b/hw/9pfs/virtio-9p-coth.h
@@ -101,4 +101,7 @@ extern int v9fs_co_preadv(V9fsPDU *, V9fsFidState *,
                           struct iovec *, int, int64_t);
 extern int v9fs_co_name_to_path(V9fsPDU *, V9fsPath *,
                                 const char *, V9fsPath *);
+extern int v9fs_co_st_gen(V9fsPDU *pdu, V9fsPath *path, mode_t,
+                          V9fsStatDotl *v9stat);
+
 #endif
diff --git a/hw/9pfs/virtio-9p-debug.c b/hw/9pfs/virtio-9p-debug.c
deleted file mode 100644
index 96925f04a4..0000000000
--- a/hw/9pfs/virtio-9p-debug.c
+++ /dev/null
@@ -1,646 +0,0 @@
-/*
- * Virtio 9p PDU debug
- *
- * Copyright IBM, Corp. 2010
- *
- * Authors:
- *  Anthony Liguori   <aliguori@us.ibm.com>
- *
- * This work is licensed under the terms of the GNU GPL, version 2.  See
- * the COPYING file in the top-level directory.
- *
- */
-
-#include "hw/virtio.h"
-#include "hw/pc.h"
-#include "virtio-9p.h"
-#include "virtio-9p-debug.h"
-
-#define BUG_ON(cond) assert(!(cond))
-
-static FILE *llogfile;
-
-static struct iovec *get_sg(V9fsPDU *pdu, int rx)
-{
-    if (rx) {
-        return pdu->elem.in_sg;
-    }
-    return pdu->elem.out_sg;
-}
-
-static int get_sg_count(V9fsPDU *pdu, int rx)
-{
-    if (rx) {
-        return pdu->elem.in_num;
-    }
-    return pdu->elem.out_num;
-
-}
-
-static void pprint_int8(V9fsPDU *pdu, int rx, size_t *offsetp,
-                        const char *name)
-{
-    size_t copied;
-    int count = get_sg_count(pdu, rx);
-    size_t offset = *offsetp;
-    struct iovec *sg = get_sg(pdu, rx);
-    int8_t value;
-
-    copied = do_pdu_unpack(&value, sg, count, offset, sizeof(value));
-
-    BUG_ON(copied != sizeof(value));
-    offset += sizeof(value);
-    fprintf(llogfile, "%s=0x%x", name, value);
-    *offsetp = offset;
-}
-
-static void pprint_int16(V9fsPDU *pdu, int rx, size_t *offsetp,
-                        const char *name)
-{
-    size_t copied;
-    int count = get_sg_count(pdu, rx);
-    struct iovec *sg = get_sg(pdu, rx);
-    size_t offset = *offsetp;
-    int16_t value;
-
-
-    copied = do_pdu_unpack(&value, sg, count, offset, sizeof(value));
-
-    BUG_ON(copied != sizeof(value));
-    offset += sizeof(value);
-    fprintf(llogfile, "%s=0x%x", name, value);
-    *offsetp = offset;
-}
-
-static void pprint_int32(V9fsPDU *pdu, int rx, size_t *offsetp,
-                        const char *name)
-{
-    size_t copied;
-    int count = get_sg_count(pdu, rx);
-    struct iovec *sg = get_sg(pdu, rx);
-    size_t offset = *offsetp;
-    int32_t value;
-
-
-    copied = do_pdu_unpack(&value, sg, count, offset, sizeof(value));
-
-    BUG_ON(copied != sizeof(value));
-    offset += sizeof(value);
-    fprintf(llogfile, "%s=0x%x", name, value);
-    *offsetp = offset;
-}
-
-static void pprint_int64(V9fsPDU *pdu, int rx, size_t *offsetp,
-                        const char *name)
-{
-    size_t copied;
-    int count = get_sg_count(pdu, rx);
-    struct iovec *sg = get_sg(pdu, rx);
-    size_t offset = *offsetp;
-    int64_t value;
-
-
-    copied = do_pdu_unpack(&value, sg, count, offset, sizeof(value));
-
-    BUG_ON(copied != sizeof(value));
-    offset += sizeof(value);
-    fprintf(llogfile, "%s=0x%" PRIx64, name, value);
-    *offsetp = offset;
-}
-
-static void pprint_str(V9fsPDU *pdu, int rx, size_t *offsetp, const char *name)
-{
-    int sg_count = get_sg_count(pdu, rx);
-    struct iovec *sg = get_sg(pdu, rx);
-    size_t offset = *offsetp;
-    uint16_t tmp_size, size;
-    size_t result;
-    size_t copied = 0;
-    int i = 0;
-
-    /* get the size */
-    copied = do_pdu_unpack(&tmp_size, sg, sg_count, offset, sizeof(tmp_size));
-    BUG_ON(copied != sizeof(tmp_size));
-    size = le16_to_cpupu(&tmp_size);
-    offset += copied;
-
-    fprintf(llogfile, "%s=", name);
-    for (i = 0; size && i < sg_count; i++) {
-        size_t len;
-        if (offset >= sg[i].iov_len) {
-            /* skip this sg */
-            offset -= sg[i].iov_len;
-            continue;
-        } else {
-            len = MIN(sg[i].iov_len - offset, size);
-            result = fwrite(sg[i].iov_base + offset, 1, len, llogfile);
-            BUG_ON(result != len);
-            size -= len;
-            copied += len;
-            if (size) {
-                offset = 0;
-                continue;
-            }
-        }
-    }
-    *offsetp += copied;
-}
-
-static void pprint_qid(V9fsPDU *pdu, int rx, size_t *offsetp, const char *name)
-{
-    fprintf(llogfile, "%s={", name);
-    pprint_int8(pdu, rx, offsetp, "type");
-    pprint_int32(pdu, rx, offsetp, ", version");
-    pprint_int64(pdu, rx, offsetp, ", path");
-    fprintf(llogfile, "}");
-}
-
-static void pprint_stat(V9fsPDU *pdu, int rx, size_t *offsetp, const char *name)
-{
-    fprintf(llogfile, "%s={", name);
-    pprint_int16(pdu, rx, offsetp, "size");
-    pprint_int16(pdu, rx, offsetp, ", type");
-    pprint_int32(pdu, rx, offsetp, ", dev");
-    pprint_qid(pdu, rx, offsetp, ", qid");
-    pprint_int32(pdu, rx, offsetp, ", mode");
-    pprint_int32(pdu, rx, offsetp, ", atime");
-    pprint_int32(pdu, rx, offsetp, ", mtime");
-    pprint_int64(pdu, rx, offsetp, ", length");
-    pprint_str(pdu, rx, offsetp, ", name");
-    pprint_str(pdu, rx, offsetp, ", uid");
-    pprint_str(pdu, rx, offsetp, ", gid");
-    pprint_str(pdu, rx, offsetp, ", muid");
-    pprint_str(pdu, rx, offsetp, ", extension");
-    pprint_int32(pdu, rx, offsetp, ", uid");
-    pprint_int32(pdu, rx, offsetp, ", gid");
-    pprint_int32(pdu, rx, offsetp, ", muid");
-    fprintf(llogfile, "}");
-}
-
-static void pprint_stat_dotl(V9fsPDU *pdu, int rx, size_t *offsetp,
-                                                  const char *name)
-{
-    fprintf(llogfile, "%s={", name);
-    pprint_qid(pdu, rx, offsetp, "qid");
-    pprint_int32(pdu, rx, offsetp, ", st_mode");
-    pprint_int64(pdu, rx, offsetp, ", st_nlink");
-    pprint_int32(pdu, rx, offsetp, ", st_uid");
-    pprint_int32(pdu, rx, offsetp, ", st_gid");
-    pprint_int64(pdu, rx, offsetp, ", st_rdev");
-    pprint_int64(pdu, rx, offsetp, ", st_size");
-    pprint_int64(pdu, rx, offsetp, ", st_blksize");
-    pprint_int64(pdu, rx, offsetp, ", st_blocks");
-    pprint_int64(pdu, rx, offsetp, ", atime");
-    pprint_int64(pdu, rx, offsetp, ", atime_nsec");
-    pprint_int64(pdu, rx, offsetp, ", mtime");
-    pprint_int64(pdu, rx, offsetp, ", mtime_nsec");
-    pprint_int64(pdu, rx, offsetp, ", ctime");
-    pprint_int64(pdu, rx, offsetp, ", ctime_nsec");
-    fprintf(llogfile, "}");
-}
-
-
-
-static void pprint_strs(V9fsPDU *pdu, int rx, size_t *offsetp, const char *name)
-{
-    int sg_count = get_sg_count(pdu, rx);
-    struct iovec *sg = get_sg(pdu, rx);
-    size_t offset = *offsetp;
-    uint16_t tmp_count, count, i;
-    size_t copied = 0;
-
-    fprintf(llogfile, "%s={", name);
-
-    /* Get the count */
-    copied = do_pdu_unpack(&tmp_count, sg, sg_count, offset, sizeof(tmp_count));
-    BUG_ON(copied != sizeof(tmp_count));
-    count = le16_to_cpupu(&tmp_count);
-    offset += copied;
-
-    for (i = 0; i < count; i++) {
-        char str[512];
-        if (i) {
-            fprintf(llogfile, ", ");
-        }
-        snprintf(str, sizeof(str), "[%d]", i);
-        pprint_str(pdu, rx, &offset, str);
-    }
-
-    fprintf(llogfile, "}");
-
-    *offsetp = offset;
-}
-
-static void pprint_qids(V9fsPDU *pdu, int rx, size_t *offsetp, const char *name)
-{
-    int sg_count = get_sg_count(pdu, rx);
-    struct iovec *sg = get_sg(pdu, rx);
-    size_t offset = *offsetp;
-    uint16_t tmp_count, count, i;
-    size_t copied = 0;
-
-    fprintf(llogfile, "%s={", name);
-
-    copied = do_pdu_unpack(&tmp_count, sg, sg_count, offset, sizeof(tmp_count));
-    BUG_ON(copied != sizeof(tmp_count));
-    count = le16_to_cpupu(&tmp_count);
-    offset += copied;
-
-    for (i = 0; i < count; i++) {
-        char str[512];
-        if (i) {
-            fprintf(llogfile, ", ");
-        }
-        snprintf(str, sizeof(str), "[%d]", i);
-        pprint_qid(pdu, rx, &offset, str);
-    }
-
-    fprintf(llogfile, "}");
-
-    *offsetp = offset;
-}
-
-static void pprint_sg(V9fsPDU *pdu, int rx, size_t *offsetp, const char *name)
-{
-    struct iovec *sg = get_sg(pdu, rx);
-    unsigned int count;
-    int i;
-
-    if (rx) {
-        count = pdu->elem.in_num;
-    } else {
-        count = pdu->elem.out_num;
-    }
-
-    fprintf(llogfile, "%s={", name);
-    for (i = 0; i < count; i++) {
-        if (i) {
-            fprintf(llogfile, ", ");
-        }
-        fprintf(llogfile, "(%p, 0x%zx)", sg[i].iov_base, sg[i].iov_len);
-    }
-    fprintf(llogfile, "}");
-}
-
-/* FIXME: read from a directory fid returns serialized stat_t's */
-#ifdef DEBUG_DATA
-static void pprint_data(V9fsPDU *pdu, int rx, size_t *offsetp, const char *name)
-{
-    struct iovec *sg = get_sg(pdu, rx);
-    size_t offset = *offsetp;
-    unsigned int count;
-    int32_t size;
-    int total, i, j;
-    ssize_t len;
-
-    if (rx) {
-        count = pdu->elem.in_num;
-    } else {
-        count = pdu->elem.out_num;
-    }
-
-    BUG_ON((offset + sizeof(size)) > sg[0].iov_len);
-
-    memcpy(&size, sg[0].iov_base + offset, sizeof(size));
-    offset += sizeof(size);
-
-    fprintf(llogfile, "size: %x\n", size);
-
-    sg[0].iov_base += 11; /* skip header */
-    sg[0].iov_len -= 11;
-
-    total = 0;
-    for (i = 0; i < count; i++) {
-        total += sg[i].iov_len;
-        if (total >= size) {
-            /* trim sg list so writev does the right thing */
-            sg[i].iov_len -= (total - size);
-            i++;
-            break;
-        }
-    }
-
-    fprintf(llogfile, "%s={\"", name);
-    fflush(llogfile);
-    for (j = 0; j < i; j++) {
-        if (j) {
-            fprintf(llogfile, "\", \"");
-            fflush(llogfile);
-        }
-
-        do {
-            len = writev(fileno(llogfile), &sg[j], 1);
-        } while (len == -1 && errno == EINTR);
-        fprintf(llogfile, "len == %ld: %m\n", len);
-        BUG_ON(len != sg[j].iov_len);
-    }
-    fprintf(llogfile, "\"}");
-
-    sg[0].iov_base -= 11;
-    sg[0].iov_len += 11;
-
-}
-#endif
-
-void pprint_pdu(V9fsPDU *pdu)
-{
-    size_t offset = 7;
-
-    if (llogfile == NULL) {
-        llogfile = fopen("/tmp/pdu.log", "w");
-    }
-
-    BUG_ON(!llogfile);
-
-    switch (pdu->id) {
-    case P9_TREADDIR:
-        fprintf(llogfile, "TREADDIR: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        pprint_int64(pdu, 0, &offset, ", initial offset");
-        pprint_int32(pdu, 0, &offset, ", max count");
-        break;
-    case P9_RREADDIR:
-        fprintf(llogfile, "RREADDIR: (");
-        pprint_int32(pdu, 1, &offset, "count");
-#ifdef DEBUG_DATA
-        pprint_data(pdu, 1, &offset, ", data");
-#endif
-        break;
-    case P9_TMKDIR:
-        fprintf(llogfile, "TMKDIR: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        pprint_str(pdu, 0, &offset, "name");
-        pprint_int32(pdu, 0, &offset, "mode");
-        pprint_int32(pdu, 0, &offset, "gid");
-        break;
-    case P9_RMKDIR:
-        fprintf(llogfile, "RMKDIR: (");
-        pprint_qid(pdu, 0, &offset, "qid");
-        break;
-    case P9_TVERSION:
-        fprintf(llogfile, "TVERSION: (");
-        pprint_int32(pdu, 0, &offset, "msize");
-        pprint_str(pdu, 0, &offset, ", version");
-        break;
-    case P9_RVERSION:
-        fprintf(llogfile, "RVERSION: (");
-        pprint_int32(pdu, 1, &offset, "msize");
-        pprint_str(pdu, 1, &offset, ", version");
-        break;
-    case P9_TGETATTR:
-        fprintf(llogfile, "TGETATTR: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        break;
-    case P9_RGETATTR:
-        fprintf(llogfile, "RGETATTR: (");
-        pprint_stat_dotl(pdu, 1, &offset, "getattr");
-        break;
-    case P9_TAUTH:
-        fprintf(llogfile, "TAUTH: (");
-        pprint_int32(pdu, 0, &offset, "afid");
-        pprint_str(pdu, 0, &offset, ", uname");
-        pprint_str(pdu, 0, &offset, ", aname");
-        pprint_int32(pdu, 0, &offset, ", n_uname");
-        break;
-    case P9_RAUTH:
-        fprintf(llogfile, "RAUTH: (");
-        pprint_qid(pdu, 1, &offset, "qid");
-        break;
-    case P9_TATTACH:
-        fprintf(llogfile, "TATTACH: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        pprint_int32(pdu, 0, &offset, ", afid");
-        pprint_str(pdu, 0, &offset, ", uname");
-        pprint_str(pdu, 0, &offset, ", aname");
-        pprint_int32(pdu, 0, &offset, ", n_uname");
-        break;
-    case P9_RATTACH:
-        fprintf(llogfile, "RATTACH: (");
-        pprint_qid(pdu, 1, &offset, "qid");
-        break;
-    case P9_TERROR:
-        fprintf(llogfile, "TERROR: (");
-        break;
-    case P9_RERROR:
-        fprintf(llogfile, "RERROR: (");
-        pprint_str(pdu, 1, &offset, "ename");
-        pprint_int32(pdu, 1, &offset, ", ecode");
-        break;
-    case P9_TFLUSH:
-        fprintf(llogfile, "TFLUSH: (");
-        pprint_int16(pdu, 0, &offset, "oldtag");
-        break;
-    case P9_RFLUSH:
-        fprintf(llogfile, "RFLUSH: (");
-        break;
-    case P9_TWALK:
-        fprintf(llogfile, "TWALK: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        pprint_int32(pdu, 0, &offset, ", newfid");
-        pprint_strs(pdu, 0, &offset, ", wnames");
-        break;
-    case P9_RWALK:
-        fprintf(llogfile, "RWALK: (");
-        pprint_qids(pdu, 1, &offset, "wqids");
-        break;
-    case P9_TOPEN:
-        fprintf(llogfile, "TOPEN: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        pprint_int8(pdu, 0, &offset, ", mode");
-        break;
-    case P9_ROPEN:
-        fprintf(llogfile, "ROPEN: (");
-        pprint_qid(pdu, 1, &offset, "qid");
-        pprint_int32(pdu, 1, &offset, ", iounit");
-        break;
-    case P9_TCREATE:
-        fprintf(llogfile, "TCREATE: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        pprint_str(pdu, 0, &offset, ", name");
-        pprint_int32(pdu, 0, &offset, ", perm");
-        pprint_int8(pdu, 0, &offset, ", mode");
-        pprint_str(pdu, 0, &offset, ", extension");
-        break;
-    case P9_RCREATE:
-        fprintf(llogfile, "RCREATE: (");
-        pprint_qid(pdu, 1, &offset, "qid");
-        pprint_int32(pdu, 1, &offset, ", iounit");
-        break;
-    case P9_TSYMLINK:
-        fprintf(llogfile, "TSYMLINK: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        pprint_str(pdu, 0, &offset, ", name");
-        pprint_str(pdu, 0, &offset, ", symname");
-        pprint_int32(pdu, 0, &offset, ", gid");
-        break;
-    case P9_RSYMLINK:
-        fprintf(llogfile, "RSYMLINK: (");
-        pprint_qid(pdu, 1, &offset, "qid");
-        break;
-    case P9_TLCREATE:
-        fprintf(llogfile, "TLCREATE: (");
-        pprint_int32(pdu, 0, &offset, "dfid");
-        pprint_str(pdu, 0, &offset, ", name");
-        pprint_int32(pdu, 0, &offset, ", flags");
-        pprint_int32(pdu, 0, &offset, ", mode");
-        pprint_int32(pdu, 0, &offset, ", gid");
-        break;
-    case P9_RLCREATE:
-        fprintf(llogfile, "RLCREATE: (");
-        pprint_qid(pdu, 1, &offset, "qid");
-        pprint_int32(pdu, 1, &offset, ", iounit");
-        break;
-    case P9_TMKNOD:
-	fprintf(llogfile, "TMKNOD: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        pprint_str(pdu, 0, &offset, "name");
-        pprint_int32(pdu, 0, &offset, "mode");
-        pprint_int32(pdu, 0, &offset, "major");
-        pprint_int32(pdu, 0, &offset, "minor");
-        pprint_int32(pdu, 0, &offset, "gid");
-        break;
-    case P9_RMKNOD:
-        fprintf(llogfile, "RMKNOD: )");
-        pprint_qid(pdu, 0, &offset, "qid");
-        break;
-    case P9_TREADLINK:
-	fprintf(llogfile, "TREADLINK: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        break;
-    case P9_RREADLINK:
-	fprintf(llogfile, "RREADLINK: (");
-        pprint_str(pdu, 0, &offset, "target");
-        break;
-    case P9_TREAD:
-        fprintf(llogfile, "TREAD: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        pprint_int64(pdu, 0, &offset, ", offset");
-        pprint_int32(pdu, 0, &offset, ", count");
-        pprint_sg(pdu, 0, &offset, ", sg");
-        break;
-    case P9_RREAD:
-        fprintf(llogfile, "RREAD: (");
-        pprint_int32(pdu, 1, &offset, "count");
-        pprint_sg(pdu, 1, &offset, ", sg");
-        offset = 7;
-#ifdef DEBUG_DATA
-        pprint_data(pdu, 1, &offset, ", data");
-#endif
-        break;
-    case P9_TWRITE:
-        fprintf(llogfile, "TWRITE: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        pprint_int64(pdu, 0, &offset, ", offset");
-        pprint_int32(pdu, 0, &offset, ", count");
-        break;
-    case P9_RWRITE:
-        fprintf(llogfile, "RWRITE: (");
-        pprint_int32(pdu, 1, &offset, "count");
-        break;
-    case P9_TCLUNK:
-        fprintf(llogfile, "TCLUNK: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        break;
-    case P9_RCLUNK:
-        fprintf(llogfile, "RCLUNK: (");
-        break;
-    case P9_TFSYNC:
-        fprintf(llogfile, "TFSYNC: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        break;
-    case P9_RFSYNC:
-        fprintf(llogfile, "RFSYNC: (");
-        break;
-    case P9_TLINK:
-        fprintf(llogfile, "TLINK: (");
-        pprint_int32(pdu, 0, &offset, "dfid");
-        pprint_int32(pdu, 0, &offset, ", fid");
-        pprint_str(pdu, 0, &offset, ", newpath");
-        break;
-    case P9_RLINK:
-        fprintf(llogfile, "RLINK: (");
-        break;
-    case P9_TREMOVE:
-        fprintf(llogfile, "TREMOVE: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        break;
-    case P9_RREMOVE:
-        fprintf(llogfile, "RREMOVE: (");
-        break;
-    case P9_TSTAT:
-        fprintf(llogfile, "TSTAT: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        break;
-    case P9_RSTAT:
-        fprintf(llogfile, "RSTAT: (");
-        offset += 2; /* ignored */
-        pprint_stat(pdu, 1, &offset, "stat");
-        break;
-    case P9_TWSTAT:
-        fprintf(llogfile, "TWSTAT: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        offset += 2; /* ignored */
-        pprint_stat(pdu, 0, &offset, ", stat");
-        break;
-    case P9_RWSTAT:
-        fprintf(llogfile, "RWSTAT: (");
-        break;
-    case P9_TXATTRWALK:
-        fprintf(llogfile, "TXATTRWALK: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        pprint_int32(pdu, 0, &offset, ", newfid");
-        pprint_str(pdu, 0, &offset, ", xattr name");
-        break;
-    case P9_RXATTRWALK:
-        fprintf(llogfile, "RXATTRWALK: (");
-        pprint_int64(pdu, 1, &offset, "xattrsize");
-    case P9_TXATTRCREATE:
-        fprintf(llogfile, "TXATTRCREATE: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        pprint_str(pdu, 0, &offset, ", name");
-        pprint_int64(pdu, 0, &offset, ", xattrsize");
-        pprint_int32(pdu, 0, &offset, ", flags");
-        break;
-    case P9_RXATTRCREATE:
-        fprintf(llogfile, "RXATTRCREATE: (");
-        break;
-    case P9_TLOCK:
-        fprintf(llogfile, "TLOCK: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        pprint_int8(pdu, 0, &offset, ", type");
-        pprint_int32(pdu, 0, &offset, ", flags");
-        pprint_int64(pdu, 0, &offset, ", start");
-        pprint_int64(pdu, 0, &offset, ", length");
-        pprint_int32(pdu, 0, &offset, ", proc_id");
-        pprint_str(pdu, 0, &offset, ", client_id");
-        break;
-    case P9_RLOCK:
-        fprintf(llogfile, "RLOCK: (");
-        pprint_int8(pdu, 0, &offset, "status");
-        break;
-    case P9_TGETLOCK:
-        fprintf(llogfile, "TGETLOCK: (");
-        pprint_int32(pdu, 0, &offset, "fid");
-        pprint_int8(pdu, 0, &offset, ", type");
-        pprint_int64(pdu, 0, &offset, ", start");
-        pprint_int64(pdu, 0, &offset, ", length");
-        pprint_int32(pdu, 0, &offset, ", proc_id");
-        pprint_str(pdu, 0, &offset, ", client_id");
-        break;
-    case P9_RGETLOCK:
-        fprintf(llogfile, "RGETLOCK: (");
-        pprint_int8(pdu, 0, &offset, "type");
-        pprint_int64(pdu, 0, &offset, ", start");
-        pprint_int64(pdu, 0, &offset, ", length");
-        pprint_int32(pdu, 0, &offset, ", proc_id");
-        pprint_str(pdu, 0, &offset, ", client_id");
-        break;
-    default:
-        fprintf(llogfile, "unknown(%d): (", pdu->id);
-        break;
-    }
-
-    fprintf(llogfile, ")\n");
-    /* Flush the log message out */
-    fflush(llogfile);
-}
diff --git a/hw/9pfs/virtio-9p-debug.h b/hw/9pfs/virtio-9p-debug.h
deleted file mode 100644
index d9a249118d..0000000000
--- a/hw/9pfs/virtio-9p-debug.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef _QEMU_VIRTIO_9P_DEBUG_H
-#define _QEMU_VIRTIO_9P_DEBUG_H
-
-void pprint_pdu(V9fsPDU *pdu);
-
-#endif
diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
index 513e181c82..bba4c54762 100644
--- a/hw/9pfs/virtio-9p-device.c
+++ b/hw/9pfs/virtio-9p-device.c
@@ -49,7 +49,8 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf)
     V9fsState *s;
     int i, len;
     struct stat stat;
-    FsTypeEntry *fse;
+    FsDriverEntry *fse;
+    V9fsPath path;
 
     s = (V9fsState *)virtio_common_init("virtio-9p",
                                     VIRTIO_ID_9P,
@@ -82,55 +83,33 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf)
         exit(1);
     }
 
-    if (!strcmp(fse->security_model, "passthrough")) {
-        /* Files on the Fileserver set to client user credentials */
-        s->ctx.fs_sm = SM_PASSTHROUGH;
+    s->ctx.export_flags = fse->export_flags;
+    s->ctx.fs_root = g_strdup(fse->path);
+    s->ctx.exops.get_st_gen = NULL;
+
+    if (fse->export_flags & V9FS_SM_PASSTHROUGH) {
         s->ctx.xops = passthrough_xattr_ops;
-    } else if (!strcmp(fse->security_model, "mapped")) {
-        /* Files on the fileserver are set to QEMU credentials.
-         * Client user credentials are saved in extended attributes.
-         */
-        s->ctx.fs_sm = SM_MAPPED;
+    } else if (fse->export_flags & V9FS_SM_MAPPED) {
         s->ctx.xops = mapped_xattr_ops;
-    } else if (!strcmp(fse->security_model, "none")) {
-        /*
-         * Files on the fileserver are set to QEMU credentials.
-         */
-        s->ctx.fs_sm = SM_NONE;
-        s->ctx.xops = none_xattr_ops;
-    } else {
-        fprintf(stderr, "Default to security_model=none. You may want"
-                " enable advanced security model using "
-                "security option:\n\t security_model=passthrough\n\t "
-                "security_model=mapped\n");
-        s->ctx.fs_sm = SM_NONE;
+    } else if (fse->export_flags & V9FS_SM_NONE) {
         s->ctx.xops = none_xattr_ops;
     }
 
-    if (lstat(fse->path, &stat)) {
-        fprintf(stderr, "share path %s does not exist\n", fse->path);
-        exit(1);
-    } else if (!S_ISDIR(stat.st_mode)) {
-        fprintf(stderr, "share path %s is not a directory\n", fse->path);
-        exit(1);
-    }
-
-    s->ctx.fs_root = g_strdup(fse->path);
     len = strlen(conf->tag);
     if (len > MAX_TAG_LEN) {
-        len = MAX_TAG_LEN;
+        fprintf(stderr, "mount tag '%s' (%d bytes) is longer than "
+                "maximum (%d bytes)", conf->tag, len, MAX_TAG_LEN);
+        exit(1);
     }
     /* s->tag is non-NULL terminated string */
     s->tag = g_malloc(len);
     memcpy(s->tag, conf->tag, len);
     s->tag_len = len;
     s->ctx.uid = -1;
-    s->ctx.flags = 0;
 
     s->ops = fse->ops;
     s->vdev.get_features = virtio_9p_get_features;
-    s->config_size = sizeof(struct virtio_9p_config) +
-                        s->tag_len;
+    s->config_size = sizeof(struct virtio_9p_config) + s->tag_len;
     s->vdev.get_config = virtio_9p_get_config;
     s->fid_list = NULL;
     qemu_co_rwlock_init(&s->rename_lock);
@@ -144,6 +123,27 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf)
         fprintf(stderr, "worker thread initialization failed\n");
         exit(1);
     }
+
+    /*
+     * Check details of export path, We need to use fs driver
+     * call back to do that. Since we are in the init path, we don't
+     * use co-routines here.
+     */
+    v9fs_path_init(&path);
+    if (s->ops->name_to_path(&s->ctx, NULL, "/", &path) < 0) {
+        fprintf(stderr,
+                "error in converting name to path %s", strerror(errno));
+        exit(1);
+    }
+    if (s->ops->lstat(&s->ctx, &path, &stat)) {
+        fprintf(stderr, "share path %s does not exist\n", fse->path);
+        exit(1);
+    } else if (!S_ISDIR(stat.st_mode)) {
+        fprintf(stderr, "share path %s is not a directory\n", fse->path);
+        exit(1);
+    }
+    v9fs_path_free(&path);
+
     return &s->vdev;
 }
 
@@ -169,6 +169,8 @@ static PCIDeviceInfo virtio_9p_info = {
     .revision  = VIRTIO_PCI_ABI_VERSION,
     .class_id  = 0x2,
     .qdev.props = (Property[]) {
+        DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags,
+                        VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true),
         DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 2),
         DEFINE_VIRTIO_COMMON_FEATURES(VirtIOPCIProxy, host_features),
         DEFINE_PROP_STRING("mount_tag", VirtIOPCIProxy, fsconf.tag),
diff --git a/hw/9pfs/virtio-9p-handle.c b/hw/9pfs/virtio-9p-handle.c
index 5c8b5ed471..98809f1642 100644
--- a/hw/9pfs/virtio-9p-handle.c
+++ b/hw/9pfs/virtio-9p-handle.c
@@ -21,49 +21,56 @@
 #include <sys/un.h>
 #include <attr/xattr.h>
 #include <unistd.h>
-
-struct handle_data {
-    int mountfd;
-    int handle_bytes;
-};
-
-#if __GLIBC__ <= 2 && __GLIBC_MINOR__ < 14
-struct file_handle {
-        unsigned int handle_bytes;
-        int handle_type;
-        unsigned char handle[0];
-};
+#include <linux/fs.h>
+#ifdef CONFIG_LINUX_MAGIC_H
+#include <linux/magic.h>
 #endif
+#include <sys/ioctl.h>
 
-#ifndef AT_EMPTY_PATH
-#define AT_EMPTY_PATH   0x1000  /* Allow empty relative pathname */
+#ifndef XFS_SUPER_MAGIC
+#define XFS_SUPER_MAGIC  0x58465342
 #endif
-#ifndef O_PATH
-#define O_PATH    010000000
+#ifndef EXT2_SUPER_MAGIC
+#define EXT2_SUPER_MAGIC 0xEF53
 #endif
-
-#ifndef __NR_name_to_handle_at
-#if defined(__i386__)
-#define __NR_name_to_handle_at  341
-#define __NR_open_by_handle_at  342
-#elif defined(__x86_64__)
-#define __NR_name_to_handle_at  303
-#define __NR_open_by_handle_at  304
+#ifndef REISERFS_SUPER_MAGIC
+#define REISERFS_SUPER_MAGIC 0x52654973
 #endif
+#ifndef BTRFS_SUPER_MAGIC
+#define BTRFS_SUPER_MAGIC 0x9123683E
 #endif
 
-#ifdef __NR_name_to_handle_at
+struct handle_data {
+    int mountfd;
+    int handle_bytes;
+};
+
+#ifdef CONFIG_OPEN_BY_HANDLE
 static inline int name_to_handle(int dirfd, const char *name,
                                  struct file_handle *fh, int *mnt_id, int flags)
 {
-    return syscall(__NR_name_to_handle_at, dirfd, name, fh, mnt_id, flags);
+    return name_to_handle_at(dirfd, name, fh, mnt_id, flags);
 }
 
 static inline int open_by_handle(int mountfd, const char *fh, int flags)
 {
-    return syscall(__NR_open_by_handle_at, mountfd, fh, flags);
+    return open_by_handle_at(mountfd, (struct file_handle *)fh, flags);
 }
 #else
+
+struct file_handle {
+    unsigned int handle_bytes;
+    int handle_type;
+    unsigned char handle[0];
+};
+
+#ifndef AT_EMPTY_PATH
+#define AT_EMPTY_PATH   0x1000  /* Allow empty relative pathname */
+#endif
+#ifndef O_PATH
+#define O_PATH    010000000
+#endif
+
 static inline int name_to_handle(int dirfd, const char *name,
                                  struct file_handle *fh, int *mnt_id, int flags)
 {
@@ -192,16 +199,29 @@ static ssize_t handle_preadv(FsContext *ctx, int fd, const struct iovec *iov,
 static ssize_t handle_pwritev(FsContext *ctx, int fd, const struct iovec *iov,
                               int iovcnt, off_t offset)
 {
+    ssize_t ret;
 #ifdef CONFIG_PREADV
-    return pwritev(fd, iov, iovcnt, offset);
+    ret = pwritev(fd, iov, iovcnt, offset);
 #else
     int err = lseek(fd, offset, SEEK_SET);
     if (err == -1) {
         return err;
     } else {
-        return writev(fd, iov, iovcnt);
+        ret = writev(fd, iov, iovcnt);
     }
 #endif
+#ifdef CONFIG_SYNC_FILE_RANGE
+    if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
+        /*
+         * Initiate a writeback. This is not a data integrity sync.
+         * We want to ensure that we don't leave dirty pages in the cache
+         * after write when writeout=immediate is sepcified.
+         */
+        sync_file_range(fd, offset, ret,
+                        SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE);
+    }
+#endif
+    return ret;
 }
 
 static int handle_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
@@ -367,7 +387,9 @@ static int handle_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 static int handle_utimensat(FsContext *ctx, V9fsPath *fs_path,
                             const struct timespec *buf)
 {
-    int fd, ret;
+    int ret;
+#ifdef CONFIG_UTIMENSAT
+    int fd;
     struct handle_data *data = (struct handle_data *)ctx->private;
 
     fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
@@ -376,6 +398,10 @@ static int handle_utimensat(FsContext *ctx, V9fsPath *fs_path,
     }
     ret = futimens(fd, buf);
     close(fd);
+#else
+    ret = -1;
+    errno = ENOSYS;
+#endif
     return ret;
 }
 
@@ -546,16 +572,50 @@ static int handle_unlinkat(FsContext *ctx, V9fsPath *dir,
     return ret;
 }
 
+static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
+                                 mode_t st_mode, uint64_t *st_gen)
+{
+    int err, fd;
+
+    /*
+     * Do not try to open special files like device nodes, fifos etc
+     * We can get fd for regular files and directories only
+     */
+    if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
+            return 0;
+    }
+    fd = handle_open(ctx, path, O_RDONLY);
+    if (fd < 0) {
+        return fd;
+    }
+    err = ioctl(fd, FS_IOC_GETVERSION, st_gen);
+    handle_close(ctx, fd);
+    return err;
+}
+
 static int handle_init(FsContext *ctx)
 {
     int ret, mnt_id;
+    struct statfs stbuf;
     struct file_handle fh;
     struct handle_data *data = g_malloc(sizeof(struct handle_data));
+
     data->mountfd = open(ctx->fs_root, O_DIRECTORY);
     if (data->mountfd < 0) {
         ret = data->mountfd;
         goto err_out;
     }
+    ret = statfs(ctx->fs_root, &stbuf);
+    if (!ret) {
+        switch (stbuf.f_type) {
+        case EXT2_SUPER_MAGIC:
+        case BTRFS_SUPER_MAGIC:
+        case REISERFS_SUPER_MAGIC:
+        case XFS_SUPER_MAGIC:
+            ctx->exops.get_st_gen = handle_ioc_getversion;
+            break;
+        }
+    }
     memset(&fh, 0, sizeof(struct file_handle));
     ret = name_to_handle(data->mountfd, ".", &fh, &mnt_id, 0);
     if (ret && errno == EOVERFLOW) {
diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c
index 9559ff6550..d561de88f0 100644
--- a/hw/9pfs/virtio-9p-local.c
+++ b/hw/9pfs/virtio-9p-local.c
@@ -20,6 +20,24 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <attr/xattr.h>
+#include <linux/fs.h>
+#ifdef CONFIG_LINUX_MAGIC_H
+#include <linux/magic.h>
+#endif
+#include <sys/ioctl.h>
+
+#ifndef XFS_SUPER_MAGIC
+#define XFS_SUPER_MAGIC  0x58465342
+#endif
+#ifndef EXT2_SUPER_MAGIC
+#define EXT2_SUPER_MAGIC 0xEF53
+#endif
+#ifndef REISERFS_SUPER_MAGIC
+#define REISERFS_SUPER_MAGIC 0x52654973
+#endif
+#ifndef BTRFS_SUPER_MAGIC
+#define BTRFS_SUPER_MAGIC 0x9123683E
+#endif
 
 static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
 {
@@ -31,7 +49,7 @@ static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
     if (err) {
         return err;
     }
-    if (fs_ctx->fs_sm == SM_MAPPED) {
+    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
         /* Actual credentials are part of extended attrs */
         uid_t tmp_uid;
         gid_t tmp_gid;
@@ -106,7 +124,7 @@ static int local_post_create_passthrough(FsContext *fs_ctx, const char *path,
          * If we fail to change ownership and if we are
          * using security model none. Ignore the error
          */
-        if (fs_ctx->fs_sm != SM_NONE) {
+        if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
             return -1;
         }
     }
@@ -120,7 +138,7 @@ static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
     char buffer[PATH_MAX];
     char *path = fs_path->data;
 
-    if (fs_ctx->fs_sm == SM_MAPPED) {
+    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
         int fd;
         fd = open(rpath(fs_ctx, path, buffer), O_RDONLY);
         if (fd == -1) {
@@ -131,8 +149,8 @@ static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
         } while (tsize == -1 && errno == EINTR);
         close(fd);
         return tsize;
-    } else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
-               (fs_ctx->fs_sm == SM_NONE)) {
+    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
+               (fs_ctx->export_flags & V9FS_SM_NONE)) {
         tsize = readlink(rpath(fs_ctx, path, buffer), buf, bufsz);
     }
     return tsize;
@@ -203,16 +221,30 @@ static ssize_t local_preadv(FsContext *ctx, int fd, const struct iovec *iov,
 static ssize_t local_pwritev(FsContext *ctx, int fd, const struct iovec *iov,
                              int iovcnt, off_t offset)
 {
+    ssize_t ret
+;
 #ifdef CONFIG_PREADV
-    return pwritev(fd, iov, iovcnt, offset);
+    ret = pwritev(fd, iov, iovcnt, offset);
 #else
     int err = lseek(fd, offset, SEEK_SET);
     if (err == -1) {
         return err;
     } else {
-        return writev(fd, iov, iovcnt);
+        ret = writev(fd, iov, iovcnt);
     }
 #endif
+#ifdef CONFIG_SYNC_FILE_RANGE
+    if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
+        /*
+         * Initiate a writeback. This is not a data integrity sync.
+         * We want to ensure that we don't leave dirty pages in the cache
+         * after write when writeout=immediate is sepcified.
+         */
+        sync_file_range(fd, offset, ret,
+                        SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE);
+    }
+#endif
+    return ret;
 }
 
 static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
@@ -220,10 +252,10 @@ static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
     char buffer[PATH_MAX];
     char *path = fs_path->data;
 
-    if (fs_ctx->fs_sm == SM_MAPPED) {
+    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
         return local_set_xattr(rpath(fs_ctx, path, buffer), credp);
-    } else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
-               (fs_ctx->fs_sm == SM_NONE)) {
+    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
+               (fs_ctx->export_flags & V9FS_SM_NONE)) {
         return chmod(rpath(fs_ctx, path, buffer), credp->fc_mode);
     }
     return -1;
@@ -243,7 +275,7 @@ static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
     path = fullname.data;
 
     /* Determine the security model */
-    if (fs_ctx->fs_sm == SM_MAPPED) {
+    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
         err = mknod(rpath(fs_ctx, path, buffer),
                 SM_LOCAL_MODE_BITS|S_IFREG, 0);
         if (err == -1) {
@@ -254,8 +286,8 @@ static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
             serrno = errno;
             goto err_end;
         }
-    } else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
-               (fs_ctx->fs_sm == SM_NONE)) {
+    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
+               (fs_ctx->export_flags & V9FS_SM_NONE)) {
         err = mknod(rpath(fs_ctx, path, buffer), credp->fc_mode,
                 credp->fc_rdev);
         if (err == -1) {
@@ -291,7 +323,7 @@ static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
     path = fullname.data;
 
     /* Determine the security model */
-    if (fs_ctx->fs_sm == SM_MAPPED) {
+    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
         err = mkdir(rpath(fs_ctx, path, buffer), SM_LOCAL_DIR_MODE_BITS);
         if (err == -1) {
             goto out;
@@ -302,8 +334,8 @@ static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
             serrno = errno;
             goto err_end;
         }
-    } else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
-               (fs_ctx->fs_sm == SM_NONE)) {
+    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
+               (fs_ctx->export_flags & V9FS_SM_NONE)) {
         err = mkdir(rpath(fs_ctx, path, buffer), credp->fc_mode);
         if (err == -1) {
             goto out;
@@ -331,7 +363,7 @@ static int local_fstat(FsContext *fs_ctx, int fd, struct stat *stbuf)
     if (err) {
         return err;
     }
-    if (fs_ctx->fs_sm == SM_MAPPED) {
+    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
         /* Actual credentials are part of extended attrs */
         uid_t tmp_uid;
         gid_t tmp_gid;
@@ -369,7 +401,7 @@ static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
     path = fullname.data;
 
     /* Determine the security model */
-    if (fs_ctx->fs_sm == SM_MAPPED) {
+    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
         fd = open(rpath(fs_ctx, path, buffer), flags, SM_LOCAL_MODE_BITS);
         if (fd == -1) {
             err = fd;
@@ -382,8 +414,8 @@ static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
             serrno = errno;
             goto err_end;
         }
-    } else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
-               (fs_ctx->fs_sm == SM_NONE)) {
+    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
+               (fs_ctx->export_flags & V9FS_SM_NONE)) {
         fd = open(rpath(fs_ctx, path, buffer), flags, credp->fc_mode);
         if (fd == -1) {
             err = fd;
@@ -422,7 +454,7 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
     newpath = fullname.data;
 
     /* Determine the security model */
-    if (fs_ctx->fs_sm == SM_MAPPED) {
+    if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
         int fd;
         ssize_t oldpath_size, write_size;
         fd = open(rpath(fs_ctx, newpath, buffer), O_CREAT|O_EXCL|O_RDWR,
@@ -451,8 +483,8 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
             serrno = errno;
             goto err_end;
         }
-    } else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
-               (fs_ctx->fs_sm == SM_NONE)) {
+    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
+               (fs_ctx->export_flags & V9FS_SM_NONE)) {
         err = symlink(oldpath, rpath(fs_ctx, newpath, buffer));
         if (err) {
             goto out;
@@ -464,7 +496,7 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
              * If we fail to change ownership and if we are
              * using security model none. Ignore the error
              */
-            if (fs_ctx->fs_sm != SM_NONE) {
+            if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
                 serrno = errno;
                 goto err_end;
             } else
@@ -519,13 +551,13 @@ static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
     char *path = fs_path->data;
 
     if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
-            (fs_ctx->fs_sm == SM_PASSTHROUGH)) {
+            (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH)) {
         return lchown(rpath(fs_ctx, path, buffer), credp->fc_uid,
                 credp->fc_gid);
-    } else if (fs_ctx->fs_sm == SM_MAPPED) {
+    } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
         return local_set_xattr(rpath(fs_ctx, path, buffer), credp);
-    } else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
-               (fs_ctx->fs_sm == SM_NONE)) {
+    } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
+               (fs_ctx->export_flags & V9FS_SM_NONE)) {
         return lchown(rpath(fs_ctx, path, buffer), credp->fc_uid,
                 credp->fc_gid);
     }
@@ -645,10 +677,44 @@ static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
     return ret;
 }
 
+static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
+                                mode_t st_mode, uint64_t *st_gen)
+{
+    int err, fd;
+    /*
+     * Do not try to open special files like device nodes, fifos etc
+     * We can get fd for regular files and directories only
+     */
+    if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
+            return 0;
+    }
+    fd = local_open(ctx, path, O_RDONLY);
+    if (fd < 0) {
+        return fd;
+    }
+    err = ioctl(fd, FS_IOC_GETVERSION, st_gen);
+    local_close(ctx, fd);
+    return err;
+}
+
 static int local_init(FsContext *ctx)
 {
-    ctx->flags |= PATHNAME_FSCONTEXT;
-    return 0;
+    int err;
+    struct statfs stbuf;
+
+    ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
+    err = statfs(ctx->fs_root, &stbuf);
+    if (!err) {
+        switch (stbuf.f_type) {
+        case EXT2_SUPER_MAGIC:
+        case BTRFS_SUPER_MAGIC:
+        case REISERFS_SUPER_MAGIC:
+        case XFS_SUPER_MAGIC:
+            ctx->exops.get_st_gen = local_ioc_getversion;
+            break;
+        }
+    }
+    return err;
 }
 
 FileOperations local_ops = {
diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index c01c31aa25..aab3bebcc7 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -17,11 +17,10 @@
 #include "hw/virtio-pci.h"
 #include "virtio-9p.h"
 #include "fsdev/qemu-fsdev.h"
-#include "virtio-9p-debug.h"
 #include "virtio-9p-xattr.h"
 #include "virtio-9p-coth.h"
+#include "trace.h"
 
-int debug_9p_pdu;
 int open_fd_hw;
 int total_open_fd;
 static int open_fd_rc;
@@ -72,6 +71,55 @@ static int omode_to_uflags(int8_t mode)
     return ret;
 }
 
+static int dotl_to_at_flags(int flags)
+{
+    int rflags = 0;
+    if (flags & P9_DOTL_AT_REMOVEDIR) {
+        rflags |= AT_REMOVEDIR;
+    }
+    return rflags;
+}
+
+struct dotl_openflag_map {
+    int dotl_flag;
+    int open_flag;
+};
+
+static int dotl_to_open_flags(int flags)
+{
+    int i;
+    /*
+     * We have same bits for P9_DOTL_READONLY, P9_DOTL_WRONLY
+     * and P9_DOTL_NOACCESS
+     */
+    int oflags = flags & O_ACCMODE;
+
+    struct dotl_openflag_map dotl_oflag_map[] = {
+        { P9_DOTL_CREATE, O_CREAT },
+        { P9_DOTL_EXCL, O_EXCL },
+        { P9_DOTL_NOCTTY , O_NOCTTY },
+        { P9_DOTL_TRUNC, O_TRUNC },
+        { P9_DOTL_APPEND, O_APPEND },
+        { P9_DOTL_NONBLOCK, O_NONBLOCK } ,
+        { P9_DOTL_DSYNC, O_DSYNC },
+        { P9_DOTL_FASYNC, FASYNC },
+        { P9_DOTL_DIRECT, O_DIRECT },
+        { P9_DOTL_LARGEFILE, O_LARGEFILE },
+        { P9_DOTL_DIRECTORY, O_DIRECTORY },
+        { P9_DOTL_NOFOLLOW, O_NOFOLLOW },
+        { P9_DOTL_NOATIME, O_NOATIME },
+        { P9_DOTL_SYNC, O_SYNC },
+    };
+
+    for (i = 0; i < ARRAY_SIZE(dotl_oflag_map); i++) {
+        if (flags & dotl_oflag_map[i].dotl_flag) {
+            oflags |= dotl_oflag_map[i].open_flag;
+        }
+    }
+
+    return oflags;
+}
+
 void cred_init(FsCred *credp)
 {
     credp->fc_uid = -1;
@@ -80,6 +128,21 @@ void cred_init(FsCred *credp)
     credp->fc_rdev = -1;
 }
 
+static int get_dotl_openflags(V9fsState *s, int oflags)
+{
+    int flags;
+    /*
+     * Filter the client open flags
+     */
+    flags = dotl_to_open_flags(oflags);
+    flags &= ~(O_NOCTTY | O_ASYNC | O_CREAT);
+    /*
+     * Ignore direct disk access hint until the server supports it.
+     */
+    flags &= ~O_DIRECT;
+    return flags;
+}
+
 void v9fs_string_init(V9fsString *str)
 {
     str->data = NULL;
@@ -621,9 +684,6 @@ static V9fsPDU *alloc_pdu(V9fsState *s)
 static void free_pdu(V9fsState *s, V9fsPDU *pdu)
 {
     if (pdu) {
-        if (debug_9p_pdu) {
-            pprint_pdu(pdu);
-        }
         /*
          * Cancelled pdu are added back to the freelist
          * by flush request .
@@ -909,6 +969,7 @@ static void complete_pdu(V9fsState *s, V9fsPDU *pdu, ssize_t len)
         if (s->proto_version == V9FS_PROTO_2000L) {
             id = P9_RLERROR;
         }
+        trace_complete_pdu(pdu->tag, pdu->id, err); /* Trace ERROR */
     }
 
     /* fill out the header */
@@ -1218,6 +1279,7 @@ static void v9fs_version(void *opaque)
     size_t offset = 7;
 
     pdu_unmarshal(pdu, offset, "ds", &s->msize, &version);
+    trace_v9fs_version(pdu->tag, pdu->id, s->msize, version.data);
 
     if (!strcmp(version.data, "9P2000.u")) {
         s->proto_version = V9FS_PROTO_2000U;
@@ -1228,6 +1290,8 @@ static void v9fs_version(void *opaque)
     }
 
     offset += pdu_marshal(pdu, offset, "ds", s->msize, &version);
+    trace_v9fs_version_return(pdu->tag, pdu->id, s->msize, version.data);
+
     complete_pdu(s, pdu, offset);
 
     v9fs_string_free(&version);
@@ -1246,6 +1310,7 @@ static void v9fs_attach(void *opaque)
     ssize_t err;
 
     pdu_unmarshal(pdu, offset, "ddssd", &fid, &afid, &uname, &aname, &n_uname);
+    trace_v9fs_attach(pdu->tag, pdu->id, fid, afid, uname.data, aname.data);
 
     fidp = alloc_fid(s, fid);
     if (fidp == NULL) {
@@ -1270,6 +1335,8 @@ static void v9fs_attach(void *opaque)
 out:
     put_fid(pdu, fidp);
 out_nofid:
+    trace_v9fs_attach_return(pdu->tag, pdu->id,
+                             qid.type, qid.version, qid.path);
     complete_pdu(s, pdu, err);
     v9fs_string_free(&uname);
     v9fs_string_free(&aname);
@@ -1287,6 +1354,7 @@ static void v9fs_stat(void *opaque)
     V9fsState *s = pdu->s;
 
     pdu_unmarshal(pdu, offset, "d", &fid);
+    trace_v9fs_stat(pdu->tag, pdu->id, fid);
 
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {
@@ -1307,6 +1375,9 @@ static void v9fs_stat(void *opaque)
 out:
     put_fid(pdu, fidp);
 out_nofid:
+    trace_v9fs_stat_return(pdu->tag, pdu->id, v9stat.mode,
+                           v9stat.atime, v9stat.mtime, v9stat.length);
+
     complete_pdu(s, pdu, err);
 }
 
@@ -1323,6 +1394,7 @@ static void v9fs_getattr(void *opaque)
     V9fsState *s = pdu->s;
 
     pdu_unmarshal(pdu, offset, "dq", &fid, &request_mask);
+    trace_v9fs_getattr(pdu->tag, pdu->id, fid, request_mask);
 
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {
@@ -1338,11 +1410,24 @@ static void v9fs_getattr(void *opaque)
         goto out;
     }
     stat_to_v9stat_dotl(s, &stbuf, &v9stat_dotl);
+
+    /*  fill st_gen if requested and supported by underlying fs */
+    if (request_mask & P9_STATS_GEN) {
+        retval = v9fs_co_st_gen(pdu, &fidp->path, stbuf.st_mode, &v9stat_dotl);
+        if (retval < 0) {
+            goto out;
+        }
+        v9stat_dotl.st_result_mask |= P9_STATS_GEN;
+    }
     retval = offset;
     retval += pdu_marshal(pdu, offset, "A", &v9stat_dotl);
 out:
     put_fid(pdu, fidp);
 out_nofid:
+    trace_v9fs_getattr_return(pdu->tag, pdu->id, v9stat_dotl.st_result_mask,
+                              v9stat_dotl.st_mode, v9stat_dotl.st_uid,
+                              v9stat_dotl.st_gid);
+
     complete_pdu(s, pdu, retval);
 }
 
@@ -1470,6 +1555,8 @@ static void v9fs_walk(void *opaque)
     offset += pdu_unmarshal(pdu, offset, "ddw", &fid,
                             &newfid, &nwnames);
 
+    trace_v9fs_walk(pdu->tag, pdu->id, fid, newfid, nwnames);
+
     if (nwnames && nwnames <= P9_MAXWELEM) {
         wnames = g_malloc0(sizeof(wnames[0]) * nwnames);
         qids   = g_malloc0(sizeof(qids[0]) * nwnames);
@@ -1526,6 +1613,7 @@ out:
     v9fs_path_free(&dpath);
     v9fs_path_free(&path);
 out_nofid:
+    trace_v9fs_walk_return(pdu->tag, pdu->id, nwnames, qids);
     complete_pdu(s, pdu, err);
     if (nwnames && nwnames <= P9_MAXWELEM) {
         for (name_idx = 0; name_idx < nwnames; name_idx++) {
@@ -1576,6 +1664,8 @@ static void v9fs_open(void *opaque)
     } else {
         pdu_unmarshal(pdu, offset, "db", &fid, &mode);
     }
+    trace_v9fs_open(pdu->tag, pdu->id, fid, mode);
+
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {
         err = -ENOENT;
@@ -1598,10 +1688,7 @@ static void v9fs_open(void *opaque)
         err = offset;
     } else {
         if (s->proto_version == V9FS_PROTO_2000L) {
-            flags = mode;
-            flags &= ~(O_NOCTTY | O_ASYNC | O_CREAT);
-            /* Ignore direct disk access hint until the server supports it. */
-            flags &= ~O_DIRECT;
+            flags = get_dotl_openflags(s, mode);
         } else {
             flags = omode_to_uflags(mode);
         }
@@ -1625,6 +1712,8 @@ static void v9fs_open(void *opaque)
 out:
     put_fid(pdu, fidp);
 out_nofid:
+    trace_v9fs_open_return(pdu->tag, pdu->id,
+                           qid.type, qid.version, qid.path, iounit);
     complete_pdu(s, pdu, err);
 }
 
@@ -1643,6 +1732,7 @@ static void v9fs_lcreate(void *opaque)
 
     pdu_unmarshal(pdu, offset, "dsddd", &dfid, &name, &flags,
                   &mode, &gid);
+    trace_v9fs_lcreate(pdu->tag, pdu->id, dfid, flags, mode, gid);
 
     fidp = get_fid(pdu, dfid);
     if (fidp == NULL) {
@@ -1650,8 +1740,7 @@ static void v9fs_lcreate(void *opaque)
         goto out_nofid;
     }
 
-    /* Ignore direct disk access hint until the server supports it. */
-    flags &= ~O_DIRECT;
+    flags = get_dotl_openflags(pdu->s, flags);
     err = v9fs_co_open2(pdu, fidp, &name, gid,
                         flags | O_CREAT, mode, &stbuf);
     if (err < 0) {
@@ -1673,6 +1762,8 @@ static void v9fs_lcreate(void *opaque)
 out:
     put_fid(pdu, fidp);
 out_nofid:
+    trace_v9fs_lcreate_return(pdu->tag, pdu->id,
+                              qid.type, qid.version, qid.path, iounit);
     complete_pdu(pdu->s, pdu, err);
     v9fs_string_free(&name);
 }
@@ -1688,6 +1779,8 @@ static void v9fs_fsync(void *opaque)
     V9fsState *s = pdu->s;
 
     pdu_unmarshal(pdu, offset, "dd", &fid, &datasync);
+    trace_v9fs_fsync(pdu->tag, pdu->id, fid, datasync);
+
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {
         err = -ENOENT;
@@ -1712,6 +1805,7 @@ static void v9fs_clunk(void *opaque)
     V9fsState *s = pdu->s;
 
     pdu_unmarshal(pdu, offset, "d", &fid);
+    trace_v9fs_clunk(pdu->tag, pdu->id, fid);
 
     fidp = clunk_fid(s, fid);
     if (fidp == NULL) {
@@ -1828,6 +1922,7 @@ static void v9fs_read(void *opaque)
     V9fsState *s = pdu->s;
 
     pdu_unmarshal(pdu, offset, "dqd", &fid, &off, &max_count);
+    trace_v9fs_read(pdu->tag, pdu->id, fid, off, max_count);
 
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {
@@ -1886,6 +1981,7 @@ static void v9fs_read(void *opaque)
 out:
     put_fid(pdu, fidp);
 out_nofid:
+    trace_v9fs_read_return(pdu->tag, pdu->id, count, err);
     complete_pdu(s, pdu, err);
 }
 
@@ -1970,6 +2066,8 @@ static void v9fs_readdir(void *opaque)
 
     pdu_unmarshal(pdu, offset, "dqd", &fid, &initial_offset, &max_count);
 
+    trace_v9fs_readdir(pdu->tag, pdu->id, fid, initial_offset, max_count);
+
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {
         retval = -EINVAL;
@@ -1995,6 +2093,7 @@ static void v9fs_readdir(void *opaque)
 out:
     put_fid(pdu, fidp);
 out_nofid:
+    trace_v9fs_readdir_return(pdu->tag, pdu->id, count, retval);
     complete_pdu(s, pdu, retval);
 }
 
@@ -2059,6 +2158,7 @@ static void v9fs_write(void *opaque)
     V9fsState *s = pdu->s;
 
     pdu_unmarshal(pdu, offset, "dqdv", &fid, &off, &count, sg, &cnt);
+    trace_v9fs_write(pdu->tag, pdu->id, fid, off, count, cnt);
 
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {
@@ -2105,6 +2205,7 @@ static void v9fs_write(void *opaque)
 out:
     put_fid(pdu, fidp);
 out_nofid:
+    trace_v9fs_write_return(pdu->tag, pdu->id, total, err);
     complete_pdu(s, pdu, err);
 }
 
@@ -2129,6 +2230,8 @@ static void v9fs_create(void *opaque)
     pdu_unmarshal(pdu, offset, "dsdbs", &fid, &name,
                   &perm, &mode, &extension);
 
+    trace_v9fs_create(pdu->tag, pdu->id, fid, name.data, perm, mode);
+
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {
         err = -EINVAL;
@@ -2262,6 +2365,8 @@ static void v9fs_create(void *opaque)
 out:
     put_fid(pdu, fidp);
 out_nofid:
+   trace_v9fs_create_return(pdu->tag, pdu->id,
+                            qid.type, qid.version, qid.path, iounit);
    complete_pdu(pdu->s, pdu, err);
    v9fs_string_free(&name);
    v9fs_string_free(&extension);
@@ -2282,6 +2387,7 @@ static void v9fs_symlink(void *opaque)
     size_t offset = 7;
 
     pdu_unmarshal(pdu, offset, "dssd", &dfid, &name, &symname, &gid);
+    trace_v9fs_symlink(pdu->tag, pdu->id, dfid, name.data, symname.data, gid);
 
     dfidp = get_fid(pdu, dfid);
     if (dfidp == NULL) {
@@ -2298,6 +2404,8 @@ static void v9fs_symlink(void *opaque)
 out:
     put_fid(pdu, dfidp);
 out_nofid:
+    trace_v9fs_symlink_return(pdu->tag, pdu->id,
+                              qid.type, qid.version, qid.path);
     complete_pdu(pdu->s, pdu, err);
     v9fs_string_free(&name);
     v9fs_string_free(&symname);
@@ -2312,6 +2420,7 @@ static void v9fs_flush(void *opaque)
     V9fsState *s = pdu->s;
 
     pdu_unmarshal(pdu, offset, "w", &tag);
+    trace_v9fs_flush(pdu->tag, pdu->id, tag);
 
     QLIST_FOREACH(cancel_pdu, &s->active_list, next) {
         if (cancel_pdu->tag == tag) {
@@ -2342,6 +2451,7 @@ static void v9fs_link(void *opaque)
     int err = 0;
 
     pdu_unmarshal(pdu, offset, "dds", &dfid, &oldfid, &name);
+    trace_v9fs_link(pdu->tag, pdu->id, dfid, oldfid, name.data);
 
     dfidp = get_fid(pdu, dfid);
     if (dfidp == NULL) {
@@ -2375,6 +2485,7 @@ static void v9fs_remove(void *opaque)
     V9fsPDU *pdu = opaque;
 
     pdu_unmarshal(pdu, offset, "d", &fid);
+    trace_v9fs_remove(pdu->tag, pdu->id, fid);
 
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {
@@ -2382,7 +2493,7 @@ static void v9fs_remove(void *opaque)
         goto out_nofid;
     }
     /* if fs driver is not path based, return EOPNOTSUPP */
-    if (!pdu->s->ctx.flags & PATHNAME_FSCONTEXT) {
+    if (!(pdu->s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT)) {
         err = -EOPNOTSUPP;
         goto out_err;
     }
@@ -2417,6 +2528,7 @@ static void v9fs_unlinkat(void *opaque)
     V9fsPDU *pdu = opaque;
 
     pdu_unmarshal(pdu, offset, "dsd", &dfid, &name, &flags);
+    flags = dotl_to_at_flags(flags);
 
     dfidp = get_fid(pdu, dfid);
     if (dfidp == NULL) {
@@ -2528,7 +2640,7 @@ static void v9fs_rename(void *opaque)
     }
     BUG_ON(fidp->fid_type != P9_FID_NONE);
     /* if fs driver is not path based, return EOPNOTSUPP */
-    if (!pdu->s->ctx.flags & PATHNAME_FSCONTEXT) {
+    if (!(pdu->s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT)) {
         err = -EOPNOTSUPP;
         goto out;
     }
@@ -2601,7 +2713,7 @@ static int v9fs_complete_renameat(V9fsPDU *pdu, int32_t olddirfid,
     if (err < 0) {
         goto out;
     }
-    if (s->ctx.flags & PATHNAME_FSCONTEXT) {
+    if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
         /* Only for path based fid  we need to do the below fixup */
         v9fs_fix_fid_paths(pdu, &olddirfidp->path, old_name,
                            &newdirfidp->path, new_name);
@@ -2653,6 +2765,8 @@ static void v9fs_wstat(void *opaque)
     V9fsState *s = pdu->s;
 
     pdu_unmarshal(pdu, offset, "dwS", &fid, &unused, &v9stat);
+    trace_v9fs_wstat(pdu->tag, pdu->id, fid,
+                     v9stat.mode, v9stat.atime, v9stat.mtime);
 
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {
@@ -2821,6 +2935,7 @@ static void v9fs_mknod(void *opaque)
 
     pdu_unmarshal(pdu, offset, "dsdddd", &fid, &name, &mode,
                   &major, &minor, &gid);
+    trace_v9fs_mknod(pdu->tag, pdu->id, fid, mode, major, minor);
 
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {
@@ -2838,6 +2953,7 @@ static void v9fs_mknod(void *opaque)
 out:
     put_fid(pdu, fidp);
 out_nofid:
+    trace_v9fs_mknod_return(pdu->tag, pdu->id, qid.type, qid.version, qid.path);
     complete_pdu(s, pdu, err);
     v9fs_string_free(&name);
 }
@@ -2865,6 +2981,10 @@ static void v9fs_lock(void *opaque)
     pdu_unmarshal(pdu, offset, "dbdqqds", &fid, &flock->type,
                   &flock->flags, &flock->start, &flock->length,
                   &flock->proc_id, &flock->client_id);
+
+    trace_v9fs_lock(pdu->tag, pdu->id, fid,
+                    flock->type, flock->start, flock->length);
+
     status = P9_LOCK_ERROR;
 
     /* We support only block flag now (that too ignored currently) */
@@ -2887,6 +3007,7 @@ out:
 out_nofid:
     err = offset;
     err += pdu_marshal(pdu, offset, "b", status);
+    trace_v9fs_lock_return(pdu->tag, pdu->id, status);
     complete_pdu(s, pdu, err);
     v9fs_string_free(&flock->client_id);
     g_free(flock);
@@ -2911,6 +3032,9 @@ static void v9fs_getlock(void *opaque)
                   &glock->start, &glock->length, &glock->proc_id,
                   &glock->client_id);
 
+    trace_v9fs_getlock(pdu->tag, pdu->id, fid,
+                       glock->type, glock->start, glock->length);
+
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {
         err = -ENOENT;
@@ -2920,7 +3044,7 @@ static void v9fs_getlock(void *opaque)
     if (err < 0) {
         goto out;
     }
-    glock->type = F_UNLCK;
+    glock->type = P9_LOCK_TYPE_UNLCK;
     offset += pdu_marshal(pdu, offset, "bqqds", glock->type,
                           glock->start, glock->length, glock->proc_id,
                           &glock->client_id);
@@ -2928,6 +3052,9 @@ static void v9fs_getlock(void *opaque)
 out:
     put_fid(pdu, fidp);
 out_nofid:
+    trace_v9fs_getlock_return(pdu->tag, pdu->id, glock->type, glock->start,
+                              glock->length, glock->proc_id);
+
     complete_pdu(s, pdu, err);
     v9fs_string_free(&glock->client_id);
     g_free(glock);
@@ -2948,6 +3075,8 @@ static void v9fs_mkdir(void *opaque)
 
     pdu_unmarshal(pdu, offset, "dsdd", &fid, &name, &mode, &gid);
 
+    trace_v9fs_mkdir(pdu->tag, pdu->id, fid, name.data, mode, gid);
+
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {
         err = -ENOENT;
@@ -2963,6 +3092,8 @@ static void v9fs_mkdir(void *opaque)
 out:
     put_fid(pdu, fidp);
 out_nofid:
+    trace_v9fs_mkdir_return(pdu->tag, pdu->id,
+                            qid.type, qid.version, qid.path, err);
     complete_pdu(pdu->s, pdu, err);
     v9fs_string_free(&name);
 }
@@ -2980,6 +3111,8 @@ static void v9fs_xattrwalk(void *opaque)
     V9fsState *s = pdu->s;
 
     pdu_unmarshal(pdu, offset, "dds", &fid, &newfid, &name);
+    trace_v9fs_xattrwalk(pdu->tag, pdu->id, fid, newfid, name.data);
+
     file_fidp = get_fid(pdu, fid);
     if (file_fidp == NULL) {
         err = -ENOENT;
@@ -3056,6 +3189,7 @@ out:
         put_fid(pdu, xattr_fidp);
     }
 out_nofid:
+    trace_v9fs_xattrwalk_return(pdu->tag, pdu->id, size);
     complete_pdu(s, pdu, err);
     v9fs_string_free(&name);
 }
@@ -3075,6 +3209,7 @@ static void v9fs_xattrcreate(void *opaque)
 
     pdu_unmarshal(pdu, offset, "dsqd",
                   &fid, &name, &size, &flags);
+    trace_v9fs_xattrcreate(pdu->tag, pdu->id, fid, name.data, size, flags);
 
     file_fidp = get_fid(pdu, fid);
     if (file_fidp == NULL) {
@@ -3111,6 +3246,7 @@ static void v9fs_readlink(void *opaque)
     V9fsFidState *fidp;
 
     pdu_unmarshal(pdu, offset, "d", &fid);
+    trace_v9fs_readlink(pdu->tag, pdu->id, fid);
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {
         err = -ENOENT;
@@ -3128,6 +3264,7 @@ static void v9fs_readlink(void *opaque)
 out:
     put_fid(pdu, fidp);
 out_nofid:
+    trace_v9fs_readlink_return(pdu->tag, pdu->id, target.data);
     complete_pdu(pdu->s, pdu, err);
 }
 
@@ -3179,9 +3316,6 @@ static void submit_pdu(V9fsState *s, V9fsPDU *pdu)
     Coroutine *co;
     CoroutineEntry *handler;
 
-    if (debug_9p_pdu) {
-        pprint_pdu(pdu);
-    }
     if (pdu->id >= ARRAY_SIZE(pdu_co_handlers) ||
         (pdu_co_handlers[pdu->id] == NULL)) {
         handler = v9fs_op_not_supp;
diff --git a/hw/9pfs/virtio-9p.h b/hw/9pfs/virtio-9p.h
index 60b8a56e57..802f5809d1 100644
--- a/hw/9pfs/virtio-9p.h
+++ b/hw/9pfs/virtio-9p.h
@@ -352,6 +352,35 @@ typedef struct V9fsMkState {
     V9fsString fullname;
 } V9fsMkState;
 
+/* 9p2000.L open flags */
+#define P9_DOTL_RDONLY        00000000
+#define P9_DOTL_WRONLY        00000001
+#define P9_DOTL_RDWR          00000002
+#define P9_DOTL_NOACCESS      00000003
+#define P9_DOTL_CREATE        00000100
+#define P9_DOTL_EXCL          00000200
+#define P9_DOTL_NOCTTY        00000400
+#define P9_DOTL_TRUNC         00001000
+#define P9_DOTL_APPEND        00002000
+#define P9_DOTL_NONBLOCK      00004000
+#define P9_DOTL_DSYNC         00010000
+#define P9_DOTL_FASYNC        00020000
+#define P9_DOTL_DIRECT        00040000
+#define P9_DOTL_LARGEFILE     00100000
+#define P9_DOTL_DIRECTORY     00200000
+#define P9_DOTL_NOFOLLOW      00400000
+#define P9_DOTL_NOATIME       01000000
+#define P9_DOTL_CLOEXEC       02000000
+#define P9_DOTL_SYNC          04000000
+
+/* 9p2000.L at flags */
+#define P9_DOTL_AT_REMOVEDIR         0x200
+
+/* 9P2000.L lock type */
+#define P9_LOCK_TYPE_RDLCK 0
+#define P9_LOCK_TYPE_WRLCK 1
+#define P9_LOCK_TYPE_UNLCK 2
+
 #define P9_LOCK_SUCCESS 0
 #define P9_LOCK_BLOCKED 1
 #define P9_LOCK_ERROR 2
@@ -393,21 +422,21 @@ static inline size_t do_pdu_unpack(void *dst, struct iovec *sg, int sg_count,
 
 static inline void v9fs_path_write_lock(V9fsState *s)
 {
-    if (s->ctx.flags & PATHNAME_FSCONTEXT) {
+    if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
         qemu_co_rwlock_wrlock(&s->rename_lock);
     }
 }
 
 static inline void v9fs_path_read_lock(V9fsState *s)
 {
-    if (s->ctx.flags & PATHNAME_FSCONTEXT) {
+    if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
         qemu_co_rwlock_rdlock(&s->rename_lock);
     }
 }
 
 static inline void v9fs_path_unlock(V9fsState *s)
 {
-    if (s->ctx.flags & PATHNAME_FSCONTEXT) {
+    if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
         qemu_co_rwlock_unlock(&s->rename_lock);
     }
 }
diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index df27c198b0..ca5923c495 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -83,11 +83,6 @@
 /* Flags track per-device state like workarounds for quirks in older guests. */
 #define VIRTIO_PCI_FLAG_BUS_MASTER_BUG  (1 << 0)
 
-/* Performance improves when virtqueue kick processing is decoupled from the
- * vcpu thread using ioeventfd for some devices. */
-#define VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT 1
-#define VIRTIO_PCI_FLAG_USE_IOEVENTFD   (1 << VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT)
-
 /* QEMU doesn't strictly need write barriers since everything runs in
  * lock-step.  We'll leave the calls to wmb() in though to make it obvious for
  * KVM or if kqemu gets SMP support.
diff --git a/hw/virtio-pci.h b/hw/virtio-pci.h
index 14c10f7d67..f8404de92b 100644
--- a/hw/virtio-pci.h
+++ b/hw/virtio-pci.h
@@ -18,6 +18,11 @@
 #include "virtio-net.h"
 #include "virtio-serial.h"
 
+/* Performance improves when virtqueue kick processing is decoupled from the
+ * vcpu thread using ioeventfd for some devices. */
+#define VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT 1
+#define VIRTIO_PCI_FLAG_USE_IOEVENTFD   (1 << VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT)
+
 typedef struct {
     PCIDevice pci_dev;
     VirtIODevice *vdev;
diff --git a/qemu-config.c b/qemu-config.c
index 7a7854fd06..90b6b3e85b 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -165,11 +165,11 @@ static QemuOptsList qemu_chardev_opts = {
 
 QemuOptsList qemu_fsdev_opts = {
     .name = "fsdev",
-    .implied_opt_name = "fstype",
+    .implied_opt_name = "fsdriver",
     .head = QTAILQ_HEAD_INITIALIZER(qemu_fsdev_opts.head),
     .desc = {
         {
-            .name = "fstype",
+            .name = "fsdriver",
             .type = QEMU_OPT_STRING,
         }, {
             .name = "path",
@@ -177,6 +177,9 @@ QemuOptsList qemu_fsdev_opts = {
         }, {
             .name = "security_model",
             .type = QEMU_OPT_STRING,
+        }, {
+            .name = "writeout",
+            .type = QEMU_OPT_STRING,
         },
         { /*End of list */ }
     },
@@ -184,11 +187,11 @@ QemuOptsList qemu_fsdev_opts = {
 
 QemuOptsList qemu_virtfs_opts = {
     .name = "virtfs",
-    .implied_opt_name = "fstype",
+    .implied_opt_name = "fsdriver",
     .head = QTAILQ_HEAD_INITIALIZER(qemu_virtfs_opts.head),
     .desc = {
         {
-            .name = "fstype",
+            .name = "fsdriver",
             .type = QEMU_OPT_STRING,
         }, {
             .name = "path",
@@ -199,6 +202,9 @@ QemuOptsList qemu_virtfs_opts = {
         }, {
             .name = "security_model",
             .type = QEMU_OPT_STRING,
+        }, {
+            .name = "writeout",
+            .type = QEMU_OPT_STRING,
         },
 
         { /*End of list */ }
diff --git a/qemu-options.hx b/qemu-options.hx
index d4fe990e27..5d2a7765e8 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -522,73 +522,103 @@ possible drivers and properties, use @code{-device ?} and
 @code{-device @var{driver},?}.
 ETEXI
 
+DEFHEADING()
+
 DEFHEADING(File system options:)
 
 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
-    "-fsdev local,id=id,path=path,security_model=[mapped|passthrough|none]\n",
+    "-fsdev fsdriver,id=id,path=path,[security_model={mapped|passthrough|none}]\n"
+    "       [,writeout=immediate]\n",
     QEMU_ARCH_ALL)
 
 STEXI
 
-The general form of a File system device option is:
-@table @option
-
-@item -fsdev @var{fstype} ,id=@var{id} [,@var{options}]
+@item -fsdev @var{fsdriver},id=@var{id},path=@var{path},[security_model=@var{security_model}][,writeout=@var{writeout}]
 @findex -fsdev
-Fstype is one of:
-@option{local},
-The specific Fstype will determine the applicable options.
-
-Options to each backend are described below.
-
-@item -fsdev local ,id=@var{id} ,path=@var{path} ,security_model=@var{security_model}
-
-Create a file-system-"device" for local-filesystem.
-
-@option{local} is only available on Linux.
-
-@option{path} specifies the path to be exported. @option{path} is required.
-
-@option{security_model} specifies the security model to be followed.
-@option{security_model} is required.
+Define a new file system device. Valid options are:
+@table @option
+@item @var{fsdriver}
+This option specifies the fs driver backend to use.
+Currently "local" and "handle" file system drivers are supported.
+@item id=@var{id}
+Specifies identifier for this device
+@item path=@var{path}
+Specifies the export path for the file system device. Files under
+this path will be available to the 9p client on the guest.
+@item security_model=@var{security_model}
+Specifies the security model to be used for this export path.
+Supported security models are "passthrough", "mapped" and "none".
+In "passthrough" security model, files are stored using the same
+credentials as they are created on the guest. This requires qemu
+to run as root. In "mapped" security model, some of the file
+attributes like uid, gid, mode bits and link target are stored as
+file attributes. Directories exported by this security model cannot
+interact with other unix tools. "none" security model is same as
+passthrough except the sever won't report failures if it fails to
+set file attributes like ownership. Security model is mandatory
+only for local fsdriver. Other fsdrivers (like handle) don't take
+security model as a parameter.
+@item writeout=@var{writeout}
+This is an optional argument. The only supported value is "immediate".
+This means that host page cache will be used to read and write data but
+write notification will be sent to the guest only when the data has been
+reported as written by the storage subsystem.
+@end table
 
+-fsdev option is used along with -device driver "virtio-9p-pci".
+@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
+Options for virtio-9p-pci driver are:
+@table @option
+@item fsdev=@var{id}
+Specifies the id value specified along with -fsdev option
+@item mount_tag=@var{mount_tag}
+Specifies the tag name to be used by the guest to mount this export point
 @end table
+
 ETEXI
 
+DEFHEADING()
+
 DEFHEADING(Virtual File system pass-through options:)
 
 DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
-    "-virtfs local,path=path,mount_tag=tag,security_model=[mapped|passthrough|none]\n",
+    "-virtfs local,path=path,mount_tag=tag,security_model=[mapped|passthrough|none]\n"
+    "        [,writeout=immediate]\n",
     QEMU_ARCH_ALL)
 
 STEXI
 
-The general form of a Virtual File system pass-through option is:
-@table @option
-
-@item -virtfs @var{fstype} [,@var{options}]
+@item -virtfs @var{fsdriver},path=@var{path},mount_tag=@var{mount_tag},security_model=@var{security_model}[,writeout=@var{writeout}]
 @findex -virtfs
-Fstype is one of:
-@option{local},
-The specific Fstype will determine the applicable options.
-
-Options to each backend are described below.
-
-@item -virtfs local ,path=@var{path} ,mount_tag=@var{mount_tag} ,security_model=@var{security_model}
-
-Create a Virtual file-system-pass through for local-filesystem.
-
-@option{local} is only available on Linux.
-
-@option{path} specifies the path to be exported. @option{path} is required.
-
-@option{security_model} specifies the security model to be followed.
-@option{security_model} is required.
-
-
-@option{mount_tag} specifies the tag with which the exported file is mounted.
-@option{mount_tag} is required.
 
+The general form of a Virtual File system pass-through options are:
+@table @option
+@item @var{fsdriver}
+This option specifies the fs driver backend to use.
+Currently "local" and "handle" file system drivers are supported.
+@item id=@var{id}
+Specifies identifier for this device
+@item path=@var{path}
+Specifies the export path for the file system device. Files under
+this path will be available to the 9p client on the guest.
+@item security_model=@var{security_model}
+Specifies the security model to be used for this export path.
+Supported security models are "passthrough", "mapped" and "none".
+In "passthrough" security model, files are stored using the same
+credentials as they are created on the guest. This requires qemu
+to run as root. In "mapped" security model, some of the file
+attributes like uid, gid, mode bits and link target are stored as
+file attributes. Directories exported by this security model cannot
+interact with other unix tools. "none" security model is same as
+passthrough except the sever won't report failures if it fails to
+set file attributes like ownership. Security model is mandatory only
+for local fsdriver. Other fsdrivers (like handle) don't take security
+model as a parameter.
+@item writeout=@var{writeout}
+This is an optional argument. The only supported value is "immediate".
+This means that host page cache will be used to read and write data but
+write notification will be sent to the guest only when the data has been
+reported as written by the storage subsystem.
 @end table
 ETEXI
 
diff --git a/scripts/analyse-9p-simpletrace.py b/scripts/analyse-9p-simpletrace.py
new file mode 100755
index 0000000000..4358d6b594
--- /dev/null
+++ b/scripts/analyse-9p-simpletrace.py
@@ -0,0 +1,142 @@
+#!/usr/bin/env python
+# Pretty print 9p simpletrace log
+# Usage: ./analyse-9p-simpletrace <trace-events> <trace-pid>
+#
+# Author: Harsh Prateek Bora
+
+import simpletrace
+
+class VirtFSRequestTracker(simpletrace.Analyzer):
+	def begin(self):
+		print "Pretty printing 9p simpletrace log ..."
+
+        def complete_pdu(self, tag, id, err):
+                print "ERROR (tag =", tag, ", id =", id, ",err =", err, ")"
+
+        def v9fs_version(self, tag, id, msize, version):
+                print "TVERSION (tag =", tag, ", msize =", msize, ", version =", version, ")"
+
+        def v9fs_version_return(self, tag, id, msize, version):
+                print "RVERSION (tag =", tag, ", msize =", msize, ", version =", version, ")"
+
+        def v9fs_attach(self, tag, id, fid, afid, uname, aname):
+                print "TATTACH (tag =", tag, ", fid =", fid, ", afid =", afid, ", uname =", uname, ", aname =", aname, ")"
+
+	def v9fs_attach_return(self, tag, id, type, verison, path):
+		print "RATTACH (tag =", tag, ", qid={type =", type, ", version =", version, ", path =", path, "})"
+
+	def v9fs_stat(self, tag, id, fid):
+		print "TSTAT (tag =", tag, ", fid =", fid, ")"
+
+	def v9fs_stat_return(self, tag, id, mode, atime, mtime, length):
+		print "RSTAT (tag =", tag, ", mode =", mode, ", atime =", atime, ", mtime =", mtime, ", length =", length, ")"
+
+	def v9fs_getattr(self, tag, id, fid, request_mask):
+		print "TGETATTR (tag =", tag, ", fid =", fid, ", request_mask =", hex(request_mask), ")"
+
+	def v9fs_getattr_return(self, tag, id, result_mask, mode, uid, gid):
+		print "RGETATTR (tag =", tag, ", result_mask =", hex(result_mask), ", mode =", oct(mode), ", uid =", uid, ", gid =", gid, ")"
+
+	def v9fs_walk(self, tag, id, fid, newfid, nwnames):
+		print "TWALK (tag =", tag, ", fid =", fid, ", newfid =", newfid, ", nwnames =", nwnames, ")"
+
+	def v9fs_walk_return(self, tag, id, nwnames, qids):
+		print "RWALK (tag =", tag, ", nwnames =", nwnames, ", qids =", hex(qids), ")"
+
+	def v9fs_open(self, tag, id, fid, mode):
+		print "TOPEN (tag =", tag, ", fid =", fid, ", mode =", oct(mode), ")"
+
+	def v9fs_open_return(self, tag, id, type, version, path, iounit):
+		print "ROPEN (tag =", tag,  ", qid={type =", type, ", version =", version, ", path =", path, "}, iounit =", iounit, ")"
+
+	def v9fs_lcreate(self, tag, id, dfid, flags, mode, gid):
+		print "TLCREATE (tag =", tag, ", dfid =", dfid, ", flags =", oct(flags), ", mode =", oct(mode), ", gid =", gid, ")"
+
+	def v9fs_lcreate_return(self, id, type, version, path, iounit):
+		print "RLCREATE (tag =", tag,  ", qid={type =", type, ", version =", version, ", path =", path, "}, iounit =", iounit, ")"
+
+	def v9fs_fsync(self, tag, id, fid, datasync):
+		print "TFSYNC (tag =", tag, ", fid =", fid, ", datasync =", datasync, ")"
+
+	def v9fs_clunk(self, tag, id, fid):
+		print "TCLUNK (tag =", tag, ", fid =", fid, ")"
+
+	def v9fs_read(self, tag, id, fid, off, max_count):
+		print "TREAD (tag =", tag, ", fid =", fid, ", off =", off, ", max_count =", max_count, ")"
+
+	def v9fs_read_return(self, tag, id, count, err):
+		print "RREAD (tag =", tag, ", count =", count, ", err =", err, ")"
+
+	def v9fs_readdir(self, tag, id, fid, offset, max_count):
+		print "TREADDIR (tag =", tag, ", fid =", fid, ", offset =", offset, ", max_count =", max_count, ")"
+
+	def v9fs_readdir_return(self, tag, id, count, retval):
+		print "RREADDIR (tag =", tag, ", count =", count, ", retval =", retval, ")"
+
+	def v9fs_write(self, tag, id, fid, off, count, cnt):
+		print "TWRITE (tag =", tag, ", fid =", fid, ", off =", off, ", count =", count, ", cnt =", cnt, ")"
+
+	def v9fs_write_return(self, tag, id, total, err):
+		print "RWRITE (tag =", tag, ", total =", total, ", err =", err, ")"
+
+	def v9fs_create(self, tag, id, fid, perm, name, mode):
+		print "TCREATE (tag =", tag, ", fid =", fid, ", perm =", oct(perm), ", name =", name, ", mode =", oct(mode), ")"
+
+	def v9fs_create_return(self, tag, id, type, verison, path, iounit):
+		print "RCREATE (tag =", tag,  ", qid={type =", type, ", version =", version, ", path =", path, "}, iounit =", iounit, ")"
+
+	def v9fs_symlink(self, tag, id, fid, name, symname, gid):
+		print "TSYMLINK (tag =", tag, ", fid =", fid, ", name =", name, ", symname =", symname, ", gid =", gid, ")"
+
+	def v9fs_symlink_return(self, tag, id, type, version, path):
+		print "RSYMLINK (tag =", tag,  ", qid={type =", type, ", version =", version, ", path =", path, "})"
+
+	def v9fs_flush(self, tag, id, flush_tag):
+		print "TFLUSH (tag =", tag, ", flush_tag =", flush_tag, ")"
+
+	def v9fs_link(self, tag, id, dfid, oldfid, name):
+		print "TLINK (tag =", tag, ", dfid =", dfid, ", oldfid =", oldfid, ", name =", name, ")"
+
+	def v9fs_remove(self, tag, id, fid):
+		print "TREMOVE (tag =", tag, ", fid =", fid, ")"
+
+	def v9fs_wstat(self, tag, id, fid, mode, atime, mtime):
+		print "TWSTAT (tag =", tag, ", fid =", fid, ", mode =", oct(mode), ", atime =", atime, "mtime =", mtime, ")"
+
+	def v9fs_mknod(self, tag, id, fid, mode, major, minor):
+		print "TMKNOD (tag =", tag, ", fid =", fid, ", mode =", oct(mode), ", major =", major, ", minor =", minor, ")"
+
+	def v9fs_lock(self, tag, id, fid, type, start, length):
+		print "TLOCK (tag =", tag, ", fid =", fid, "type =", type, ", start =", start, ", length =", length, ")"
+
+	def v9fs_lock_return(self, tag, id, status):
+		print "RLOCK (tag =", tag, ", status =", status, ")"
+
+	def v9fs_getlock(self, tag, id, fid, type, start, length):
+		print "TGETLOCK (tag =", tag, ", fid =", fid, "type =", type, ", start =", start, ", length =", length, ")"
+
+	def v9fs_getlock_return(self, tag, id, type, start, length, proc_id):
+		print "RGETLOCK (tag =", tag, "type =", type, ", start =", start, ", length =", length, ", proc_id =", proc_id,  ")"
+
+	def v9fs_mkdir(self, tag, id, fid, name, mode, gid):
+		print "TMKDIR (tag =", tag, ", fid =", fid, ", name =", name, ", mode =", mode, ", gid =", gid, ")"
+
+	def v9fs_mkdir_return(self, tag, id, type, version, path, err):
+		print "RMKDIR (tag =", tag,  ", qid={type =", type, ", version =", version, ", path =", path, "}, err =", err, ")"
+
+	def v9fs_xattrwalk(self, tag, id, fid, newfid, name):
+		print "TXATTRWALK (tag =", tag, ", fid =", fid, ", newfid =", newfid, ", xattr name =", name, ")"
+
+	def v9fs_xattrwalk_return(self, tag, id, size):
+		print "RXATTRWALK (tag =", tag, ", xattrsize  =", size, ")"
+
+	def v9fs_xattrcreate(self, tag, id, fid, name, size, flags):
+		print "TXATTRCREATE (tag =", tag, ", fid =", fid, ", name =", name, ", xattrsize =", size, ", flags =", flags, ")"
+
+	def v9fs_readlink(self, tag, id, fid):
+		print "TREADLINK (tag =", tag, ", fid =", fid, ")"
+
+	def v9fs_readlink_return(self, tag, id, target):
+		print "RREADLINK (tag =", tag, ", target =", target, ")"
+
+simpletrace.run(VirtFSRequestTracker())
diff --git a/trace-events b/trace-events
index a06c6c5282..fc13733250 100644
--- a/trace-events
+++ b/trace-events
@@ -552,3 +552,49 @@ open_eth_reg_read(uint32_t addr, uint32_t v) "MAC[%02x] -> %08x"
 open_eth_reg_write(uint32_t addr, uint32_t v) "MAC[%02x] <- %08x"
 open_eth_desc_read(uint32_t addr, uint32_t v) "DESC[%04x] -> %08x"
 open_eth_desc_write(uint32_t addr, uint32_t v) "DESC[%04x] <- %08x"
+
+# hw/9pfs/virtio-9p.c
+complete_pdu(uint16_t tag, uint8_t id, int err) "tag %d id %d err %d"
+v9fs_version(uint16_t tag, uint8_t id, int32_t msize, char* version) "tag %d id %d msize %d version %s"
+v9fs_version_return(uint16_t tag, uint8_t id, int32_t msize, char* version) "tag %d id %d msize %d version %s"
+v9fs_attach(uint16_t tag, uint8_t id, int32_t fid, int32_t afid, char* uname, char* aname) "tag %d id %d fid %d afid %d aname %s"
+v9fs_attach_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path) "tag %d id %d type %d version %d path %"PRId64""
+v9fs_stat(uint16_t tag, uint8_t id, int32_t fid) "tag %d id %d fid %d"
+v9fs_stat_return(uint16_t tag, uint8_t id, int32_t mode, int32_t atime, int32_t mtime, int64_t length) "tag %d id %d stat={mode %d atime %d mtime %d length %"PRId64"}"
+v9fs_getattr(uint16_t tag, uint8_t id, int32_t fid, uint64_t request_mask) "tag %d id %d fid %d request_mask %"PRIu64""
+v9fs_getattr_return(uint16_t tag, uint8_t id, uint64_t result_mask, uint32_t mode, uint32_t uid, uint32_t gid) "tag %d id %d getattr={result_mask %"PRId64" mode %u uid %u gid %u}"
+v9fs_walk(uint16_t tag, uint8_t id, int32_t fid, int32_t newfid, uint16_t nwnames) "tag %d id %d fid %d newfid %d nwnames %d"
+v9fs_walk_return(uint16_t tag, uint8_t id, uint16_t nwnames, void* qids) "tag %d id %d nwnames %d qids %p"
+v9fs_open(uint16_t tag, uint8_t id, int32_t fid, int32_t mode) "tag %d id %d fid %d mode %d"
+v9fs_open_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path, int iounit) "tag %d id %d qid={type %d version %d path %"PRId64"} iounit %d"
+v9fs_lcreate(uint16_t tag, uint8_t id, int32_t dfid, int32_t flags, int32_t mode, uint32_t gid) "tag %d id %d dfid %d flags %d mode %d gid %u"
+v9fs_lcreate_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path, int32_t iounit) "tag %d id %d qid={type %d version %d path %"PRId64"} iounit %d"
+v9fs_fsync(uint16_t tag, uint8_t id, int32_t fid, int datasync) "tag %d id %d fid %d datasync %d"
+v9fs_clunk(uint16_t tag, uint8_t id, int32_t fid) "tag %d id %d fid %d"
+v9fs_read(uint16_t tag, uint8_t id, int32_t fid, int64_t off, int32_t max_count) "tag %d id %d fid %d off %"PRId64" max_count %d"
+v9fs_read_return(uint16_t tag, uint8_t id, int32_t count, ssize_t err) "tag %d id %d count %d err %zd"
+v9fs_readdir(uint16_t tag, uint8_t id, int32_t fid, int64_t offset, int32_t max_count) "tag %d id %d fid %d offset %"PRId64" max_count %d"
+v9fs_readdir_return(uint16_t tag, uint8_t id, int32_t count, ssize_t retval) "tag %d id %d count %d retval %zd"
+v9fs_write(uint16_t tag, uint8_t id, int32_t fid, int64_t off, int32_t count, int cnt) "tag %d id %d fid %d off %"PRId64" count %d cnt %d"
+v9fs_write_return(uint16_t tag, uint8_t id, int32_t total, ssize_t err) "tag %d id %d total %d err %zd"
+v9fs_create(uint16_t tag, uint8_t id, int32_t fid, char* name, int32_t perm, int8_t mode) "tag %d id %d fid %d name %s perm %d mode %d"
+v9fs_create_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path, int iounit) "tag %d id %d qid={type %d version %d path %"PRId64"} iounit %d"
+v9fs_symlink(uint16_t tag, uint8_t id, int32_t fid,  char* name, char* symname, uint32_t gid) "tag %d id %d fid %d name %s symname %s gid %u"
+v9fs_symlink_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path) "tag %d id %d qid={type %d version %d path %"PRId64"}"
+v9fs_flush(uint16_t tag, uint8_t id, int16_t flush_tag) "tag %d id %d flush_tag %d"
+v9fs_link(uint16_t tag, uint8_t id, int32_t dfid, int32_t oldfid, char* name) "tag %d id %d dfid %d oldfid %d name %s"
+v9fs_remove(uint16_t tag, uint8_t id, int32_t fid) "tag %d id %d fid %d"
+v9fs_wstat(uint16_t tag, uint8_t id, int32_t fid, int32_t mode, int32_t atime, int32_t mtime) "tag %d id %d fid %d stat={mode %d atime %d mtime}"
+v9fs_mknod(uint16_t tag, uint8_t id, int32_t fid, int mode, int major, int minor) "tag %d id %d fid %d mode %d major %d minor %d"
+v9fs_mknod_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path) "tag %d id %d qid={type %d version %d path %"PRId64"}"
+v9fs_lock(uint16_t tag, uint8_t id, int32_t fid, uint8_t type, uint64_t start, uint64_t length) "tag %d id %d fid %d type %d start %"PRIu64" length %"PRIu64""
+v9fs_lock_return(uint16_t tag, uint8_t id, int8_t status) "tag %d id %d status %d"
+v9fs_getlock(uint16_t tag, uint8_t id, int32_t fid, uint8_t type, uint64_t start, uint64_t length)"tag %d id %d fid %d type %d start %"PRIu64" length %"PRIu64""
+v9fs_getlock_return(uint16_t tag, uint8_t id, uint8_t type, uint64_t start, uint64_t length, uint32_t proc_id) "tag %d id %d type %d start %"PRIu64" length %"PRIu64" proc_id %u"
+v9fs_mkdir(uint16_t tag, uint8_t id, int32_t fid, char* name, int mode, uint32_t gid) "tag %d id %d fid %d name %s mode %d"
+v9fs_mkdir_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path, int err) "tag %d id %d qid={type %d version %d path %"PRId64"}"
+v9fs_xattrwalk(uint16_t tag, uint8_t id, int32_t fid, int32_t newfid, char* name) "tag %d id %d fid %d newfid %d name %s"
+v9fs_xattrwalk_return(uint16_t tag, uint8_t id, int64_t size) "tag %d id %d size %"PRId64""
+v9fs_xattrcreate(uint16_t tag, uint8_t id, int32_t fid, char* name, int64_t size, int flags) "tag %d id %d fid %d name %s size %"PRId64" flags %d"
+v9fs_readlink(uint16_t tag, uint8_t id, int32_t fid) "tag %d id %d fid %d"
+v9fs_readlink_return(uint16_t tag, uint8_t id, char* target) "tag %d id %d name %s"
diff --git a/vl.c b/vl.c
index fff2b4c80f..66f70fb6ae 100644
--- a/vl.c
+++ b/vl.c
@@ -2783,6 +2783,7 @@ int main(int argc, char **argv, char **envp)
             case QEMU_OPTION_virtfs: {
                 QemuOpts *fsdev;
                 QemuOpts *device;
+                const char *writeout;
 
                 olist = qemu_find_opts("virtfs");
                 if (!olist) {
@@ -2795,16 +2796,14 @@ int main(int argc, char **argv, char **envp)
                     exit(1);
                 }
 
-                if (qemu_opt_get(opts, "fstype") == NULL ||
+                if (qemu_opt_get(opts, "fsdriver") == NULL ||
                         qemu_opt_get(opts, "mount_tag") == NULL ||
-                        qemu_opt_get(opts, "path") == NULL ||
-                        qemu_opt_get(opts, "security_model") == NULL) {
-                    fprintf(stderr, "Usage: -virtfs fstype,path=/share_path/,"
-                            "security_model=[mapped|passthrough|none],"
+                        qemu_opt_get(opts, "path") == NULL) {
+                    fprintf(stderr, "Usage: -virtfs fsdriver,path=/share_path/,"
+                            "[security_model={mapped|passthrough|none}],"
                             "mount_tag=tag.\n");
                     exit(1);
                 }
-
                 fsdev = qemu_opts_create(qemu_find_opts("fsdev"),
                                          qemu_opt_get(opts, "mount_tag"), 1);
                 if (!fsdev) {
@@ -2812,7 +2811,18 @@ int main(int argc, char **argv, char **envp)
                             qemu_opt_get(opts, "mount_tag"));
                     exit(1);
                 }
-                qemu_opt_set(fsdev, "fstype", qemu_opt_get(opts, "fstype"));
+
+                writeout = qemu_opt_get(opts, "writeout");
+                if (writeout) {
+#ifdef CONFIG_SYNC_FILE_RANGE
+                    qemu_opt_set(fsdev, "writeout", writeout);
+#else
+                    fprintf(stderr, "writeout=immediate not supported on "
+                            "this platform\n");
+                    exit(1);
+#endif
+                }
+                qemu_opt_set(fsdev, "fsdriver", qemu_opt_get(opts, "fsdriver"));
                 qemu_opt_set(fsdev, "path", qemu_opt_get(opts, "path"));
                 qemu_opt_set(fsdev, "security_model",
                              qemu_opt_get(opts, "security_model"));