s390x: vmstatify config migration for virtio-ccw

Let's vmstatify virtio_ccw_save_config and virtio_ccw_load_config for
flexibility (extending using subsections) and for fun.

To achieve this we need to hack the config_vector, which is VirtIODevice
(that is common virtio) state, in the middle of the VirtioCcwDevice state
representation.  This is somewhat ugly, but we have no choice because the
stream format needs to be preserved.

Almost no changes in behavior. Exception is everything that comes with
vmstate like extra bookkeeping about what's in the stream, and maybe some
extra checks and better error reporting.

Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-Id: <20170703213414.94298-1-pasic@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

1 files changed, 222 insertions, 156 deletions

diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index 599805d275..d67fffae30 100644
--- a/hw/s390x/css.c
+++ b/hw/s390x/css.c
@@ -22,6 +22,7 @@
 #include "hw/s390x/css.h"
 #include "trace.h"
 #include "hw/s390x/s390_flic.h"
+#include "hw/s390x/s390-virtio-ccw.h"
 
 typedef struct CrwContainer {
     CRW crw;
@@ -40,6 +41,181 @@ typedef struct SubchSet {
     unsigned long devnos_used[BITS_TO_LONGS(MAX_SCHID + 1)];
 } SubchSet;
 
+static const VMStateDescription vmstate_scsw = {
+    .name = "s390_scsw",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT16(flags, SCSW),
+        VMSTATE_UINT16(ctrl, SCSW),
+        VMSTATE_UINT32(cpa, SCSW),
+        VMSTATE_UINT8(dstat, SCSW),
+        VMSTATE_UINT8(cstat, SCSW),
+        VMSTATE_UINT16(count, SCSW),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription vmstate_pmcw = {
+    .name = "s390_pmcw",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(intparm, PMCW),
+        VMSTATE_UINT16(flags, PMCW),
+        VMSTATE_UINT16(devno, PMCW),
+        VMSTATE_UINT8(lpm, PMCW),
+        VMSTATE_UINT8(pnom, PMCW),
+        VMSTATE_UINT8(lpum, PMCW),
+        VMSTATE_UINT8(pim, PMCW),
+        VMSTATE_UINT16(mbi, PMCW),
+        VMSTATE_UINT8(pom, PMCW),
+        VMSTATE_UINT8(pam, PMCW),
+        VMSTATE_UINT8_ARRAY(chpid, PMCW, 8),
+        VMSTATE_UINT32(chars, PMCW),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription vmstate_schib = {
+    .name = "s390_schib",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_STRUCT(pmcw, SCHIB, 0, vmstate_pmcw, PMCW),
+        VMSTATE_STRUCT(scsw, SCHIB, 0, vmstate_scsw, SCSW),
+        VMSTATE_UINT64(mba, SCHIB),
+        VMSTATE_UINT8_ARRAY(mda, SCHIB, 4),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+
+static const VMStateDescription vmstate_ccw1 = {
+    .name = "s390_ccw1",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(cmd_code, CCW1),
+        VMSTATE_UINT8(flags, CCW1),
+        VMSTATE_UINT16(count, CCW1),
+        VMSTATE_UINT32(cda, CCW1),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription vmstate_ciw = {
+    .name = "s390_ciw",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(type, CIW),
+        VMSTATE_UINT8(command, CIW),
+        VMSTATE_UINT16(count, CIW),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription vmstate_sense_id = {
+    .name = "s390_sense_id",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(reserved, SenseId),
+        VMSTATE_UINT16(cu_type, SenseId),
+        VMSTATE_UINT8(cu_model, SenseId),
+        VMSTATE_UINT16(dev_type, SenseId),
+        VMSTATE_UINT8(dev_model, SenseId),
+        VMSTATE_UINT8(unused, SenseId),
+        VMSTATE_STRUCT_ARRAY(ciw, SenseId, MAX_CIWS, 0, vmstate_ciw, CIW),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static int subch_dev_post_load(void *opaque, int version_id);
+static void subch_dev_pre_save(void *opaque);
+
+const char err_hint_devno[] = "Devno mismatch, tried to load wrong section!"
+    " Likely reason: some sequences of plug and unplug  can break"
+    " migration for machine versions prior to  2.7 (known design flaw).";
+
+const VMStateDescription vmstate_subch_dev = {
+    .name = "s390_subch_dev",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .post_load = subch_dev_post_load,
+    .pre_save = subch_dev_pre_save,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8_EQUAL(cssid, SubchDev, "Bug!"),
+        VMSTATE_UINT8_EQUAL(ssid, SubchDev, "Bug!"),
+        VMSTATE_UINT16(migrated_schid, SubchDev),
+        VMSTATE_UINT16_EQUAL(devno, SubchDev, err_hint_devno),
+        VMSTATE_BOOL(thinint_active, SubchDev),
+        VMSTATE_STRUCT(curr_status, SubchDev, 0, vmstate_schib, SCHIB),
+        VMSTATE_UINT8_ARRAY(sense_data, SubchDev, 32),
+        VMSTATE_UINT64(channel_prog, SubchDev),
+        VMSTATE_STRUCT(last_cmd, SubchDev, 0, vmstate_ccw1, CCW1),
+        VMSTATE_BOOL(last_cmd_valid, SubchDev),
+        VMSTATE_STRUCT(id, SubchDev, 0, vmstate_sense_id, SenseId),
+        VMSTATE_BOOL(ccw_fmt_1, SubchDev),
+        VMSTATE_UINT8(ccw_no_data_cnt, SubchDev),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+typedef struct IndAddrPtrTmp {
+    IndAddr **parent;
+    uint64_t addr;
+    int32_t len;
+} IndAddrPtrTmp;
+
+static int post_load_ind_addr(void *opaque, int version_id)
+{
+    IndAddrPtrTmp *ptmp = opaque;
+    IndAddr **ind_addr = ptmp->parent;
+
+    if (ptmp->len != 0) {
+        *ind_addr = get_indicator(ptmp->addr, ptmp->len);
+    } else {
+        *ind_addr = NULL;
+    }
+    return 0;
+}
+
+static void pre_save_ind_addr(void *opaque)
+{
+    IndAddrPtrTmp *ptmp = opaque;
+    IndAddr *ind_addr = *(ptmp->parent);
+
+    if (ind_addr != NULL) {
+        ptmp->len = ind_addr->len;
+        ptmp->addr = ind_addr->addr;
+    } else {
+        ptmp->len = 0;
+        ptmp->addr = 0L;
+    }
+}
+
+const VMStateDescription vmstate_ind_addr_tmp = {
+    .name = "s390_ind_addr_tmp",
+    .pre_save = pre_save_ind_addr,
+    .post_load = post_load_ind_addr,
+
+    .fields = (VMStateField[]) {
+        VMSTATE_INT32(len, IndAddrPtrTmp),
+        VMSTATE_UINT64(addr, IndAddrPtrTmp),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+const VMStateDescription vmstate_ind_addr = {
+    .name = "s390_ind_addr_tmp",
+    .fields = (VMStateField[]) {
+        VMSTATE_WITH_TMP(IndAddr*, IndAddrPtrTmp, vmstate_ind_addr_tmp),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 typedef struct CssImage {
     SubchSet *sch_set[MAX_SSID + 1];
     ChpInfo chpids[MAX_CHPID + 1];
@@ -77,6 +253,52 @@ static ChannelSubSys channel_subsys = {
         QTAILQ_HEAD_INITIALIZER(channel_subsys.indicator_addresses),
 };
 
+static void subch_dev_pre_save(void *opaque)
+{
+    SubchDev *s = opaque;
+
+    /* Prepare remote_schid for save */
+    s->migrated_schid = s->schid;
+}
+
+static int subch_dev_post_load(void *opaque, int version_id)
+{
+
+    SubchDev *s = opaque;
+
+    /* Re-assign the subchannel to remote_schid if necessary */
+    if (s->migrated_schid != s->schid) {
+        if (css_find_subch(true, s->cssid, s->ssid, s->schid) == s) {
+            /*
+             * Cleanup the slot before moving to s->migrated_schid provided
+             * it still belongs to us, i.e. it was not changed by previous
+             * invocation of this function.
+             */
+            css_subch_assign(s->cssid, s->ssid, s->schid, s->devno, NULL);
+        }
+        /* It's OK to re-assign without a prior de-assign. */
+        s->schid = s->migrated_schid;
+        css_subch_assign(s->cssid, s->ssid, s->schid, s->devno, s);
+    }
+
+    /*
+     * Hack alert. If we don't migrate the channel subsystem status
+     * we still need to find out if the guest enabled mss/mcss-e.
+     * If the subchannel is enabled, it certainly was able to access it,
+     * so adjust the max_ssid/max_cssid values for relevant ssid/cssid
+     * values. This is not watertight, but better than nothing.
+     */
+    if (s->curr_status.pmcw.flags & PMCW_FLAGS_MASK_ENA) {
+        if (s->ssid) {
+            channel_subsys.max_ssid = MAX_SSID;
+        }
+        if (s->cssid != channel_subsys.default_cssid) {
+            channel_subsys.max_cssid = MAX_CSSID;
+        }
+    }
+    return 0;
+}
+
 IndAddr *get_indicator(hwaddr ind_addr, int len)
 {
     IndAddr *indicator;
@@ -1747,162 +1969,6 @@ int css_enable_mss(void)
     return 0;
 }
 
-void subch_device_save(SubchDev *s, QEMUFile *f)
-{
-    int i;
-
-    qemu_put_byte(f, s->cssid);
-    qemu_put_byte(f, s->ssid);
-    qemu_put_be16(f, s->schid);
-    qemu_put_be16(f, s->devno);
-    qemu_put_byte(f, s->thinint_active);
-    /* SCHIB */
-    /*     PMCW */
-    qemu_put_be32(f, s->curr_status.pmcw.intparm);
-    qemu_put_be16(f, s->curr_status.pmcw.flags);
-    qemu_put_be16(f, s->curr_status.pmcw.devno);
-    qemu_put_byte(f, s->curr_status.pmcw.lpm);
-    qemu_put_byte(f, s->curr_status.pmcw.pnom);
-    qemu_put_byte(f, s->curr_status.pmcw.lpum);
-    qemu_put_byte(f, s->curr_status.pmcw.pim);
-    qemu_put_be16(f, s->curr_status.pmcw.mbi);
-    qemu_put_byte(f, s->curr_status.pmcw.pom);
-    qemu_put_byte(f, s->curr_status.pmcw.pam);
-    qemu_put_buffer(f, s->curr_status.pmcw.chpid, 8);
-    qemu_put_be32(f, s->curr_status.pmcw.chars);
-    /*     SCSW */
-    qemu_put_be16(f, s->curr_status.scsw.flags);
-    qemu_put_be16(f, s->curr_status.scsw.ctrl);
-    qemu_put_be32(f, s->curr_status.scsw.cpa);
-    qemu_put_byte(f, s->curr_status.scsw.dstat);
-    qemu_put_byte(f, s->curr_status.scsw.cstat);
-    qemu_put_be16(f, s->curr_status.scsw.count);
-    qemu_put_be64(f, s->curr_status.mba);
-    qemu_put_buffer(f, s->curr_status.mda, 4);
-    /* end SCHIB */
-    qemu_put_buffer(f, s->sense_data, 32);
-    qemu_put_be64(f, s->channel_prog);
-    /* last cmd */
-    qemu_put_byte(f, s->last_cmd.cmd_code);
-    qemu_put_byte(f, s->last_cmd.flags);
-    qemu_put_be16(f, s->last_cmd.count);
-    qemu_put_be32(f, s->last_cmd.cda);
-    qemu_put_byte(f, s->last_cmd_valid);
-    qemu_put_byte(f, s->id.reserved);
-    qemu_put_be16(f, s->id.cu_type);
-    qemu_put_byte(f, s->id.cu_model);
-    qemu_put_be16(f, s->id.dev_type);
-    qemu_put_byte(f, s->id.dev_model);
-    qemu_put_byte(f, s->id.unused);
-    for (i = 0; i < ARRAY_SIZE(s->id.ciw); i++) {
-        qemu_put_byte(f, s->id.ciw[i].type);
-        qemu_put_byte(f, s->id.ciw[i].command);
-        qemu_put_be16(f, s->id.ciw[i].count);
-    }
-    qemu_put_byte(f, s->ccw_fmt_1);
-    qemu_put_byte(f, s->ccw_no_data_cnt);
-}
-
-int subch_device_load(SubchDev *s, QEMUFile *f)
-{
-    SubchDev *old_s;
-    Error *err = NULL;
-    uint16_t old_schid = s->schid;
-    uint16_t old_devno = s->devno;
-    int i;
-
-    s->cssid = qemu_get_byte(f);
-    s->ssid = qemu_get_byte(f);
-    s->schid = qemu_get_be16(f);
-    s->devno = qemu_get_be16(f);
-    if (s->devno != old_devno) {
-        /* Only possible if machine < 2.7 (no css_dev_path) */
-
-        error_setg(&err, "%x != %x", old_devno,  s->devno);
-        error_append_hint(&err, "Devno mismatch, tried to load wrong section!"
-                          " Likely reason: some sequences of plug and unplug"
-                          " can break migration for machine versions prior to"
-                          " 2.7 (known design flaw).\n");
-        error_report_err(err);
-        return -EINVAL;
-    }
-    /* Re-assign subch. */
-    if (old_schid != s->schid) {
-        old_s = channel_subsys.css[s->cssid]->sch_set[s->ssid]->sch[old_schid];
-        /*
-         * (old_s != s) means that some other device has its correct
-         * subchannel already assigned (in load).
-         */
-        if (old_s == s) {
-            css_subch_assign(s->cssid, s->ssid, old_schid, s->devno, NULL);
-        }
-        /* It's OK to re-assign without a prior de-assign. */
-        css_subch_assign(s->cssid, s->ssid, s->schid, s->devno, s);
-    }
-    s->thinint_active = qemu_get_byte(f);
-    /* SCHIB */
-    /*     PMCW */
-    s->curr_status.pmcw.intparm = qemu_get_be32(f);
-    s->curr_status.pmcw.flags = qemu_get_be16(f);
-    s->curr_status.pmcw.devno = qemu_get_be16(f);
-    s->curr_status.pmcw.lpm = qemu_get_byte(f);
-    s->curr_status.pmcw.pnom  = qemu_get_byte(f);
-    s->curr_status.pmcw.lpum = qemu_get_byte(f);
-    s->curr_status.pmcw.pim = qemu_get_byte(f);
-    s->curr_status.pmcw.mbi = qemu_get_be16(f);
-    s->curr_status.pmcw.pom = qemu_get_byte(f);
-    s->curr_status.pmcw.pam = qemu_get_byte(f);
-    qemu_get_buffer(f, s->curr_status.pmcw.chpid, 8);
-    s->curr_status.pmcw.chars = qemu_get_be32(f);
-    /*     SCSW */
-    s->curr_status.scsw.flags = qemu_get_be16(f);
-    s->curr_status.scsw.ctrl = qemu_get_be16(f);
-    s->curr_status.scsw.cpa = qemu_get_be32(f);
-    s->curr_status.scsw.dstat = qemu_get_byte(f);
-    s->curr_status.scsw.cstat = qemu_get_byte(f);
-    s->curr_status.scsw.count = qemu_get_be16(f);
-    s->curr_status.mba = qemu_get_be64(f);
-    qemu_get_buffer(f, s->curr_status.mda, 4);
-    /* end SCHIB */
-    qemu_get_buffer(f, s->sense_data, 32);
-    s->channel_prog = qemu_get_be64(f);
-    /* last cmd */
-    s->last_cmd.cmd_code = qemu_get_byte(f);
-    s->last_cmd.flags = qemu_get_byte(f);
-    s->last_cmd.count = qemu_get_be16(f);
-    s->last_cmd.cda = qemu_get_be32(f);
-    s->last_cmd_valid = qemu_get_byte(f);
-    s->id.reserved = qemu_get_byte(f);
-    s->id.cu_type = qemu_get_be16(f);
-    s->id.cu_model = qemu_get_byte(f);
-    s->id.dev_type = qemu_get_be16(f);
-    s->id.dev_model = qemu_get_byte(f);
-    s->id.unused = qemu_get_byte(f);
-    for (i = 0; i < ARRAY_SIZE(s->id.ciw); i++) {
-        s->id.ciw[i].type = qemu_get_byte(f);
-        s->id.ciw[i].command = qemu_get_byte(f);
-        s->id.ciw[i].count = qemu_get_be16(f);
-    }
-    s->ccw_fmt_1 = qemu_get_byte(f);
-    s->ccw_no_data_cnt = qemu_get_byte(f);
-    /*
-     * Hack alert. We don't migrate the channel subsystem status (no
-     * device!), but we need to find out if the guest enabled mss/mcss-e.
-     * If the subchannel is enabled, it certainly was able to access it,
-     * so adjust the max_ssid/max_cssid values for relevant ssid/cssid
-     * values. This is not watertight, but better than nothing.
-     */
-    if (s->curr_status.pmcw.flags & PMCW_FLAGS_MASK_ENA) {
-        if (s->ssid) {
-            channel_subsys.max_ssid = MAX_SSID;
-        }
-        if (s->cssid != channel_subsys.default_cssid) {
-            channel_subsys.max_cssid = MAX_CSSID;
-        }
-    }
-    return 0;
-}
-
 void css_reset_sch(SubchDev *sch)
 {
     PMCW *p = &sch->curr_status.pmcw;