Merge remote-tracking branch 'remotes/sstabellini/tags/xen-20170421-v2-tag' into staging

Xen 2017/04/21 + fix

# gpg: Signature made Tue 25 Apr 2017 19:10:37 BST
# gpg:                using RSA key 0x894F8F4870E1AE90
# gpg: Good signature from "Stefano Stabellini <stefano.stabellini@eu.citrix.com>"
# gpg:                 aka "Stefano Stabellini <sstabellini@kernel.org>"
# Primary key fingerprint: D04E 33AB A51F 67BA 07D3  0AEA 894F 8F48 70E1 AE90

* remotes/sstabellini/tags/xen-20170421-v2-tag: (21 commits)
  move xen-mapcache.c to hw/i386/xen/
  move xen-hvm.c to hw/i386/xen/
  move xen-common.c to hw/xen/
  add xen-9p-backend to MAINTAINERS under Xen
  xen/9pfs: build and register Xen 9pfs backend
  xen/9pfs: send responses back to the frontend
  xen/9pfs: implement in/out_iov_from_pdu and vmarshal/vunmarshal
  xen/9pfs: receive requests from the frontend
  xen/9pfs: connect to the frontend
  xen/9pfs: introduce Xen 9pfs backend
  9p: introduce a type for the 9p header
  xen: import ring.h from xen
  configure: use pkg-config for obtaining xen version
  xen: additionally restrict xenforeignmemory operations
  xen: use libxendevice model to restrict operations
  xen: use 5 digit xen versions
  xen: use libxendevicemodel when available
  configure: detect presence of libxendevicemodel
  xen: create wrappers for all other uses of xc_hvm_XXX() functions
  xen: rename xen_modified_memory() to xen_hvm_modified_memory()
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

5 files changed, 469 insertions, 5 deletions

diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h
index b7e836251e..5312d8a424 100644
--- a/hw/9pfs/9p.h
+++ b/hw/9pfs/9p.h
@@ -119,6 +119,12 @@ static inline char *rpath(FsContext *ctx, const char *path)
 typedef struct V9fsPDU V9fsPDU;
 struct V9fsState;
 
+typedef struct {
+    uint32_t size_le;
+    uint8_t id;
+    uint16_t tag_le;
+} QEMU_PACKED P9MsgHeader;
+
 struct V9fsPDU
 {
     uint32_t size;
diff --git a/hw/9pfs/Makefile.objs b/hw/9pfs/Makefile.objs
index 32197e6671..cab5e942ed 100644
--- a/hw/9pfs/Makefile.objs
+++ b/hw/9pfs/Makefile.objs
@@ -5,5 +5,6 @@ common-obj-y += coth.o cofs.o codir.o cofile.o
 common-obj-y += coxattr.o 9p-synth.o
 common-obj-$(CONFIG_OPEN_BY_HANDLE) +=  9p-handle.o
 common-obj-y += 9p-proxy.o
+common-obj-$(CONFIG_XEN) += xen-9p-backend.o
 
 obj-y += virtio-9p-device.o
diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
index 27a4a32f5c..3782f43702 100644
--- a/hw/9pfs/virtio-9p-device.c
+++ b/hw/9pfs/virtio-9p-device.c
@@ -46,11 +46,7 @@ static void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq)
     VirtQueueElement *elem;
 
     while ((pdu = pdu_alloc(s))) {
-        struct {
-            uint32_t size_le;
-            uint8_t id;
-            uint16_t tag_le;
-        } QEMU_PACKED out;
+        P9MsgHeader out;
 
         elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
         if (!elem) {
diff --git a/hw/9pfs/xen-9p-backend.c b/hw/9pfs/xen-9p-backend.c
new file mode 100644
index 0000000000..9c7f41af99
--- /dev/null
+++ b/hw/9pfs/xen-9p-backend.c
@@ -0,0 +1,440 @@
+/*
+ * Xen 9p backend
+ *
+ * Copyright Aporeto 2017
+ *
+ * Authors:
+ *  Stefano Stabellini <stefano@aporeto.com>
+ *
+ */
+
+#include "qemu/osdep.h"
+
+#include "hw/hw.h"
+#include "hw/9pfs/9p.h"
+#include "hw/xen/xen_backend.h"
+#include "hw/9pfs/xen-9pfs.h"
+#include "qemu/config-file.h"
+#include "fsdev/qemu-fsdev.h"
+
+#define VERSIONS "1"
+#define MAX_RINGS 8
+#define MAX_RING_ORDER 8
+
+typedef struct Xen9pfsRing {
+    struct Xen9pfsDev *priv;
+
+    int ref;
+    xenevtchn_handle   *evtchndev;
+    int evtchn;
+    int local_port;
+    int ring_order;
+    struct xen_9pfs_data_intf *intf;
+    unsigned char *data;
+    struct xen_9pfs_data ring;
+
+    struct iovec *sg;
+    QEMUBH *bh;
+
+    /* local copies, so that we can read/write PDU data directly from
+     * the ring */
+    RING_IDX out_cons, out_size, in_cons;
+    bool inprogress;
+} Xen9pfsRing;
+
+typedef struct Xen9pfsDev {
+    struct XenDevice xendev;  /* must be first */
+    V9fsState state;
+    char *path;
+    char *security_model;
+    char *tag;
+    char *id;
+
+    int num_rings;
+    Xen9pfsRing *rings;
+} Xen9pfsDev;
+
+static void xen_9pfs_in_sg(Xen9pfsRing *ring,
+                           struct iovec *in_sg,
+                           int *num,
+                           uint32_t idx,
+                           uint32_t size)
+{
+    RING_IDX cons, prod, masked_prod, masked_cons;
+
+    cons = ring->intf->in_cons;
+    prod = ring->intf->in_prod;
+    xen_rmb();
+    masked_prod = xen_9pfs_mask(prod, XEN_FLEX_RING_SIZE(ring->ring_order));
+    masked_cons = xen_9pfs_mask(cons, XEN_FLEX_RING_SIZE(ring->ring_order));
+
+    if (masked_prod < masked_cons) {
+        in_sg[0].iov_base = ring->ring.in + masked_prod;
+        in_sg[0].iov_len = masked_cons - masked_prod;
+        *num = 1;
+    } else {
+        in_sg[0].iov_base = ring->ring.in + masked_prod;
+        in_sg[0].iov_len = XEN_FLEX_RING_SIZE(ring->ring_order) - masked_prod;
+        in_sg[1].iov_base = ring->ring.in;
+        in_sg[1].iov_len = masked_cons;
+        *num = 2;
+    }
+}
+
+static void xen_9pfs_out_sg(Xen9pfsRing *ring,
+                            struct iovec *out_sg,
+                            int *num,
+                            uint32_t idx)
+{
+    RING_IDX cons, prod, masked_prod, masked_cons;
+
+    cons = ring->intf->out_cons;
+    prod = ring->intf->out_prod;
+    xen_rmb();
+    masked_prod = xen_9pfs_mask(prod, XEN_FLEX_RING_SIZE(ring->ring_order));
+    masked_cons = xen_9pfs_mask(cons, XEN_FLEX_RING_SIZE(ring->ring_order));
+
+    if (masked_cons < masked_prod) {
+        out_sg[0].iov_base = ring->ring.out + masked_cons;
+        out_sg[0].iov_len = ring->out_size;
+        *num = 1;
+    } else {
+        if (ring->out_size >
+            (XEN_FLEX_RING_SIZE(ring->ring_order) - masked_cons)) {
+            out_sg[0].iov_base = ring->ring.out + masked_cons;
+            out_sg[0].iov_len = XEN_FLEX_RING_SIZE(ring->ring_order) -
+                                masked_cons;
+            out_sg[1].iov_base = ring->ring.out;
+            out_sg[1].iov_len = ring->out_size -
+                                (XEN_FLEX_RING_SIZE(ring->ring_order) -
+                                 masked_cons);
+            *num = 2;
+        } else {
+            out_sg[0].iov_base = ring->ring.out + masked_cons;
+            out_sg[0].iov_len = ring->out_size;
+            *num = 1;
+        }
+    }
+}
+
+static ssize_t xen_9pfs_pdu_vmarshal(V9fsPDU *pdu,
+                                     size_t offset,
+                                     const char *fmt,
+                                     va_list ap)
+{
+    Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
+    struct iovec in_sg[2];
+    int num;
+
+    xen_9pfs_in_sg(&xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings],
+                   in_sg, &num, pdu->idx, ROUND_UP(offset + 128, 512));
+    return v9fs_iov_vmarshal(in_sg, num, offset, 0, fmt, ap);
+}
+
+static ssize_t xen_9pfs_pdu_vunmarshal(V9fsPDU *pdu,
+                                       size_t offset,
+                                       const char *fmt,
+                                       va_list ap)
+{
+    Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
+    struct iovec out_sg[2];
+    int num;
+
+    xen_9pfs_out_sg(&xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings],
+                    out_sg, &num, pdu->idx);
+    return v9fs_iov_vunmarshal(out_sg, num, offset, 0, fmt, ap);
+}
+
+static void xen_9pfs_init_out_iov_from_pdu(V9fsPDU *pdu,
+                                           struct iovec **piov,
+                                           unsigned int *pniov)
+{
+    Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
+    Xen9pfsRing *ring = &xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings];
+    int num;
+
+    g_free(ring->sg);
+
+    ring->sg = g_malloc0(sizeof(*ring->sg) * 2);
+    xen_9pfs_out_sg(ring, ring->sg, &num, pdu->idx);
+    *piov = ring->sg;
+    *pniov = num;
+}
+
+static void xen_9pfs_init_in_iov_from_pdu(V9fsPDU *pdu,
+                                          struct iovec **piov,
+                                          unsigned int *pniov,
+                                          size_t size)
+{
+    Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
+    Xen9pfsRing *ring = &xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings];
+    int num;
+
+    g_free(ring->sg);
+
+    ring->sg = g_malloc0(sizeof(*ring->sg) * 2);
+    xen_9pfs_in_sg(ring, ring->sg, &num, pdu->idx, size);
+    *piov = ring->sg;
+    *pniov = num;
+}
+
+static void xen_9pfs_push_and_notify(V9fsPDU *pdu)
+{
+    RING_IDX prod;
+    Xen9pfsDev *priv = container_of(pdu->s, Xen9pfsDev, state);
+    Xen9pfsRing *ring = &priv->rings[pdu->tag % priv->num_rings];
+
+    g_free(ring->sg);
+    ring->sg = NULL;
+
+    ring->intf->out_cons = ring->out_cons;
+    xen_wmb();
+
+    prod = ring->intf->in_prod;
+    xen_rmb();
+    ring->intf->in_prod = prod + pdu->size;
+    xen_wmb();
+
+    ring->inprogress = false;
+    xenevtchn_notify(ring->evtchndev, ring->local_port);
+
+    qemu_bh_schedule(ring->bh);
+}
+
+static const struct V9fsTransport xen_9p_transport = {
+    .pdu_vmarshal = xen_9pfs_pdu_vmarshal,
+    .pdu_vunmarshal = xen_9pfs_pdu_vunmarshal,
+    .init_in_iov_from_pdu = xen_9pfs_init_in_iov_from_pdu,
+    .init_out_iov_from_pdu = xen_9pfs_init_out_iov_from_pdu,
+    .push_and_notify = xen_9pfs_push_and_notify,
+};
+
+static int xen_9pfs_init(struct XenDevice *xendev)
+{
+    return 0;
+}
+
+static int xen_9pfs_receive(Xen9pfsRing *ring)
+{
+    P9MsgHeader h;
+    RING_IDX cons, prod, masked_prod, masked_cons;
+    V9fsPDU *pdu;
+
+    if (ring->inprogress) {
+        return 0;
+    }
+
+    cons = ring->intf->out_cons;
+    prod = ring->intf->out_prod;
+    xen_rmb();
+
+    if (xen_9pfs_queued(prod, cons, XEN_FLEX_RING_SIZE(ring->ring_order)) <
+        sizeof(h)) {
+        return 0;
+    }
+    ring->inprogress = true;
+
+    masked_prod = xen_9pfs_mask(prod, XEN_FLEX_RING_SIZE(ring->ring_order));
+    masked_cons = xen_9pfs_mask(cons, XEN_FLEX_RING_SIZE(ring->ring_order));
+
+    xen_9pfs_read_packet((uint8_t *) &h, ring->ring.out, sizeof(h),
+                         masked_prod, &masked_cons,
+                         XEN_FLEX_RING_SIZE(ring->ring_order));
+
+    /* cannot fail, because we only handle one request per ring at a time */
+    pdu = pdu_alloc(&ring->priv->state);
+    pdu->size = le32_to_cpu(h.size_le);
+    pdu->id = h.id;
+    pdu->tag = le32_to_cpu(h.tag_le);
+    ring->out_size = le32_to_cpu(h.size_le);
+    ring->out_cons = cons + le32_to_cpu(h.size_le);
+
+    qemu_co_queue_init(&pdu->complete);
+    pdu_submit(pdu);
+
+    return 0;
+}
+
+static void xen_9pfs_bh(void *opaque)
+{
+    Xen9pfsRing *ring = opaque;
+    xen_9pfs_receive(ring);
+}
+
+static void xen_9pfs_evtchn_event(void *opaque)
+{
+    Xen9pfsRing *ring = opaque;
+    evtchn_port_t port;
+
+    port = xenevtchn_pending(ring->evtchndev);
+    xenevtchn_unmask(ring->evtchndev, port);
+
+    qemu_bh_schedule(ring->bh);
+}
+
+static int xen_9pfs_free(struct XenDevice *xendev)
+{
+    int i;
+    Xen9pfsDev *xen_9pdev = container_of(xendev, Xen9pfsDev, xendev);
+
+    g_free(xen_9pdev->id);
+    g_free(xen_9pdev->tag);
+    g_free(xen_9pdev->path);
+    g_free(xen_9pdev->security_model);
+
+    for (i = 0; i < xen_9pdev->num_rings; i++) {
+        if (xen_9pdev->rings[i].data != NULL) {
+            xengnttab_unmap(xen_9pdev->xendev.gnttabdev,
+                    xen_9pdev->rings[i].data,
+                    (1 << xen_9pdev->rings[i].ring_order));
+        }
+        if (xen_9pdev->rings[i].intf != NULL) {
+            xengnttab_unmap(xen_9pdev->xendev.gnttabdev,
+                    xen_9pdev->rings[i].intf,
+                    1);
+        }
+        if (xen_9pdev->rings[i].evtchndev > 0) {
+            qemu_set_fd_handler(xenevtchn_fd(xen_9pdev->rings[i].evtchndev),
+                    NULL, NULL, NULL);
+            xenevtchn_unbind(xen_9pdev->rings[i].evtchndev,
+                             xen_9pdev->rings[i].local_port);
+        }
+        if (xen_9pdev->rings[i].bh != NULL) {
+            qemu_bh_delete(xen_9pdev->rings[i].bh);
+        }
+    }
+    g_free(xen_9pdev->rings);
+    return 0;
+}
+
+static int xen_9pfs_connect(struct XenDevice *xendev)
+{
+    int i;
+    Xen9pfsDev *xen_9pdev = container_of(xendev, Xen9pfsDev, xendev);
+    V9fsState *s = &xen_9pdev->state;
+    QemuOpts *fsdev;
+
+    if (xenstore_read_fe_int(&xen_9pdev->xendev, "num-rings",
+                             &xen_9pdev->num_rings) == -1 ||
+        xen_9pdev->num_rings > MAX_RINGS || xen_9pdev->num_rings < 1) {
+        return -1;
+    }
+
+    xen_9pdev->rings = g_malloc0(xen_9pdev->num_rings * sizeof(Xen9pfsRing));
+    for (i = 0; i < xen_9pdev->num_rings; i++) {
+        char *str;
+        int ring_order;
+
+        xen_9pdev->rings[i].priv = xen_9pdev;
+        xen_9pdev->rings[i].evtchn = -1;
+        xen_9pdev->rings[i].local_port = -1;
+
+        str = g_strdup_printf("ring-ref%u", i);
+        if (xenstore_read_fe_int(&xen_9pdev->xendev, str,
+                                 &xen_9pdev->rings[i].ref) == -1) {
+            goto out;
+        }
+        g_free(str);
+        str = g_strdup_printf("event-channel-%u", i);
+        if (xenstore_read_fe_int(&xen_9pdev->xendev, str,
+                                 &xen_9pdev->rings[i].evtchn) == -1) {
+            goto out;
+        }
+        g_free(str);
+
+        xen_9pdev->rings[i].intf =  xengnttab_map_grant_ref(
+                xen_9pdev->xendev.gnttabdev,
+                xen_9pdev->xendev.dom,
+                xen_9pdev->rings[i].ref,
+                PROT_READ | PROT_WRITE);
+        if (!xen_9pdev->rings[i].intf) {
+            goto out;
+        }
+        ring_order = xen_9pdev->rings[i].intf->ring_order;
+        if (ring_order > MAX_RING_ORDER) {
+            goto out;
+        }
+        xen_9pdev->rings[i].ring_order = ring_order;
+        xen_9pdev->rings[i].data = xengnttab_map_domain_grant_refs(
+                xen_9pdev->xendev.gnttabdev,
+                (1 << ring_order),
+                xen_9pdev->xendev.dom,
+                xen_9pdev->rings[i].intf->ref,
+                PROT_READ | PROT_WRITE);
+        if (!xen_9pdev->rings[i].data) {
+            goto out;
+        }
+        xen_9pdev->rings[i].ring.in = xen_9pdev->rings[i].data;
+        xen_9pdev->rings[i].ring.out = xen_9pdev->rings[i].data +
+                                       XEN_FLEX_RING_SIZE(ring_order);
+
+        xen_9pdev->rings[i].bh = qemu_bh_new(xen_9pfs_bh, &xen_9pdev->rings[i]);
+        xen_9pdev->rings[i].out_cons = 0;
+        xen_9pdev->rings[i].out_size = 0;
+        xen_9pdev->rings[i].inprogress = false;
+
+
+        xen_9pdev->rings[i].evtchndev = xenevtchn_open(NULL, 0);
+        if (xen_9pdev->rings[i].evtchndev == NULL) {
+            goto out;
+        }
+        fcntl(xenevtchn_fd(xen_9pdev->rings[i].evtchndev), F_SETFD, FD_CLOEXEC);
+        xen_9pdev->rings[i].local_port = xenevtchn_bind_interdomain
+                                            (xen_9pdev->rings[i].evtchndev,
+                                             xendev->dom,
+                                             xen_9pdev->rings[i].evtchn);
+        if (xen_9pdev->rings[i].local_port == -1) {
+            xen_pv_printf(xendev, 0,
+                          "xenevtchn_bind_interdomain failed port=%d\n",
+                          xen_9pdev->rings[i].evtchn);
+            goto out;
+        }
+        xen_pv_printf(xendev, 2, "bind evtchn port %d\n", xendev->local_port);
+        qemu_set_fd_handler(xenevtchn_fd(xen_9pdev->rings[i].evtchndev),
+                xen_9pfs_evtchn_event, NULL, &xen_9pdev->rings[i]);
+    }
+
+    xen_9pdev->security_model = xenstore_read_be_str(xendev, "security_model");
+    xen_9pdev->path = xenstore_read_be_str(xendev, "path");
+    xen_9pdev->id = s->fsconf.fsdev_id =
+        g_strdup_printf("xen9p%d", xendev->dev);
+    xen_9pdev->tag = s->fsconf.tag = xenstore_read_fe_str(xendev, "tag");
+    v9fs_register_transport(s, &xen_9p_transport);
+    fsdev = qemu_opts_create(qemu_find_opts("fsdev"),
+            s->fsconf.tag,
+            1, NULL);
+    qemu_opt_set(fsdev, "fsdriver", "local", NULL);
+    qemu_opt_set(fsdev, "path", xen_9pdev->path, NULL);
+    qemu_opt_set(fsdev, "security_model", xen_9pdev->security_model, NULL);
+    qemu_opts_set_id(fsdev, s->fsconf.fsdev_id);
+    qemu_fsdev_add(fsdev);
+    v9fs_device_realize_common(s, NULL);
+
+    return 0;
+
+out:
+    xen_9pfs_free(xendev);
+    return -1;
+}
+
+static void xen_9pfs_alloc(struct XenDevice *xendev)
+{
+    xenstore_write_be_str(xendev, "versions", VERSIONS);
+    xenstore_write_be_int(xendev, "max-rings", MAX_RINGS);
+    xenstore_write_be_int(xendev, "max-ring-page-order", MAX_RING_ORDER);
+}
+
+static void xen_9pfs_disconnect(struct XenDevice *xendev)
+{
+    /* Dynamic hotplug of PV filesystems at runtime is not supported. */
+}
+
+struct XenDevOps xen_9pfs_ops = {
+    .size       = sizeof(Xen9pfsDev),
+    .flags      = DEVOPS_FLAG_NEED_GNTDEV,
+    .alloc      = xen_9pfs_alloc,
+    .init       = xen_9pfs_init,
+    .initialise = xen_9pfs_connect,
+    .disconnect = xen_9pfs_disconnect,
+    .free       = xen_9pfs_free,
+};
diff --git a/hw/9pfs/xen-9pfs.h b/hw/9pfs/xen-9pfs.h
new file mode 100644
index 0000000000..2d6ef7828c
--- /dev/null
+++ b/hw/9pfs/xen-9pfs.h
@@ -0,0 +1,21 @@
+/*
+ * Xen 9p backend
+ *
+ * Copyright Aporeto 2017
+ *
+ * Authors:
+ *  Stefano Stabellini <stefano@aporeto.com>
+ *
+ * This work is licensed under the terms of the GNU GPL version 2 or
+ * later. See the COPYING file in the top-level directory.
+ *
+ */
+
+#include <xen/io/protocols.h>
+#include "hw/xen/io/ring.h"
+
+/*
+ * Do not merge into xen-9p-backend.c: clang doesn't allow unused static
+ * inline functions in c files.
+ */
+DEFINE_XEN_FLEX_RING_AND_INTF(xen_9pfs);