qemu_process: detect updated video ram size values from QEMU

QEMU internally updates the size of video memory if the domain XML had
provided too low memory size or there are some dependencies for a QXL
devices 'vgamem' and 'ram' size. We need to know about the changes and
store them into the status XML to not break migration or managedsave
through different libvirt versions.

The values would be loaded only if the "vgamem_mb" property exists for
the device.  The presence of the "vgamem_mb" also tells that the
"ram_size" and "vram_size" exists for QXL devices.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>

diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index 55f07f3188b7646c0e699785a5a4318eec7e4e82..6882a50479e492fd1e12f38f08acedaf49da7920 100644 (file)
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -1154,6 +1154,40 @@ qemuMonitorFindBalloonObjectPath(qemuMonitorPtr mon,
     return ret;
 }
 
+
+/**
+ * To update video memory size in status XML we need to load correct values from
+ * QEMU.  This is supported only with JSON monitor.
+ *
+ * Returns 0 on success, -1 on failure and sets proper error message.
+ */
+int
+qemuMonitorUpdateVideoMemorySize(qemuMonitorPtr mon,
+                                 virDomainVideoDefPtr video,
+                                 const char *videoName)
+{
+    int ret = -1;
+    char *path = NULL;
+
+    if (mon->json) {
+        ret = qemuMonitorFindObjectPath(mon, "/", videoName, &path);
+        if (ret < 0) {
+            if (ret == -2)
+                virReportError(VIR_ERR_INTERNAL_ERROR,
+                               _("Failed to find QOM Object path for "
+                                 "device '%s'"), videoName);
+            return -1;
+        }
+
+        ret = qemuMonitorJSONUpdateVideoMemorySize(mon, video, path);
+        VIR_FREE(path);
+        return ret;
+    }
+
+    return 0;
+}
+
+
 int qemuMonitorHMPCommandWithFd(qemuMonitorPtr mon,
                                 const char *cmd,
                                 int scm_fd,

diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index edab66f8cb7ca41f61c832b91c213584ab2e949b..133d42d4bb7589e9027d6ec440236ec6738f224e 100644 (file)
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -243,6 +243,10 @@ virJSONValuePtr qemuMonitorGetOptions(qemuMonitorPtr mon)
     ATTRIBUTE_NONNULL(1);
 void qemuMonitorSetOptions(qemuMonitorPtr mon, virJSONValuePtr options)
     ATTRIBUTE_NONNULL(1);
+int qemuMonitorUpdateVideoMemorySize(qemuMonitorPtr mon,
+                                     virDomainVideoDefPtr video,
+                                     const char *videName)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3);
 int qemuMonitorHMPCommandWithFd(qemuMonitorPtr mon,
                                 const char *cmd,
                                 int scm_fd,

diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index e567aa772fa728a4a561d31cd4072f5eb86acdc0..da5c14d237790681f870c21f28c70ddf097851d4 100644 (file)
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -1300,6 +1300,75 @@ int qemuMonitorJSONGetVirtType(qemuMonitorPtr mon,
 }
 
 
+/**
+ * Loads correct video memory size values from QEMU and update the video
+ * definition.
+ *
+ * Return 0 on success, -1 on failure and set proper error message.
+ */
+int
+qemuMonitorJSONUpdateVideoMemorySize(qemuMonitorPtr mon,
+                                     virDomainVideoDefPtr video,
+                                     char *path)
+{
+    qemuMonitorJSONObjectProperty prop = {
+        QEMU_MONITOR_OBJECT_PROPERTY_ULONG,
+        {0}
+    };
+
+    switch (video->type) {
+    case VIR_DOMAIN_VIDEO_TYPE_VGA:
+        if (qemuMonitorJSONGetObjectProperty(mon, path, "vgamem_mb", &prop) < 0) {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("QOM Objext '%s' has no property 'vgamem_mb'"),
+                           path);
+            return -1;
+        }
+        video->vram = prop.val.ul * 1024;
+        break;
+    case VIR_DOMAIN_VIDEO_TYPE_QXL:
+        if (qemuMonitorJSONGetObjectProperty(mon, path, "vram_size", &prop) < 0) {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("QOM Objext '%s' has no property 'vram_size'"),
+                           path);
+            return -1;
+        }
+        video->vram = prop.val.ul / 1024;
+        if (qemuMonitorJSONGetObjectProperty(mon, path, "ram_size", &prop) < 0) {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("QOM Objext '%s' has no property 'ram_size'"),
+                           path);
+            return -1;
+        }
+        video->ram = prop.val.ul / 1024;
+        if (qemuMonitorJSONGetObjectProperty(mon, path, "vgamem_mb", &prop) < 0) {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("QOM Objext '%s' has no property 'vgamem_mb'"),
+                           path);
+            return -1;
+        }
+        video->vgamem = prop.val.ul * 1024;
+        break;
+    case VIR_DOMAIN_VIDEO_TYPE_VMVGA:
+        if (qemuMonitorJSONGetObjectProperty(mon, path, "vgamem_mb", &prop) < 0) {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("QOM Objext '%s' has no property 'vgamem_mb'"),
+                           path);
+            return -1;
+        }
+        video->vram = prop.val.ul * 1024;
+        break;
+    case VIR_DOMAIN_VIDEO_TYPE_CIRRUS:
+    case VIR_DOMAIN_VIDEO_TYPE_XEN:
+    case VIR_DOMAIN_VIDEO_TYPE_VBOX:
+    case VIR_DOMAIN_VIDEO_TYPE_LAST:
+        break;
+    }
+
+    return 0;
+}
+
+
 /*
  * Returns: 0 if balloon not supported, +1 if balloon query worked
  * or -1 on failure

diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h
index 222f11ee085a13332e1df2405b3dfb164ecec2c7..1da1a007ffc0dd712a65f2cb7946f8c5ff060eef 100644 (file)
--- a/src/qemu/qemu_monitor_json.h
+++ b/src/qemu/qemu_monitor_json.h
@@ -57,6 +57,9 @@ int qemuMonitorJSONGetCPUInfo(qemuMonitorPtr mon,
                               int **pids);
 int qemuMonitorJSONGetVirtType(qemuMonitorPtr mon,
                                int *virtType);
+int qemuMonitorJSONUpdateVideoMemorySize(qemuMonitorPtr mon,
+                                         virDomainVideoDefPtr video,
+                                         char *path);
 int qemuMonitorJSONGetBalloonInfo(qemuMonitorPtr mon,
                                   unsigned long long *currmem);
 int qemuMonitorJSONGetMemoryStats(qemuMonitorPtr mon,

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index c18204b1e86233fe8de319950b644d7201bbd992..6840fd4a309ca94bc8eb5271ad2cf2c755412dde 100644 (file)
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -3067,6 +3067,85 @@ qemuProcessCleanupChardevDevice(virDomainDefPtr def ATTRIBUTE_UNUSED,
 }
 
 
+/**
+ * Loads and update video memory size for video devices according to QEMU
+ * process as the QEMU will silently update the values that we pass to QEMU
+ * through command line.  We need to load these updated values and store them
+ * into the status XML.
+ *
+ * We will fail if for some reason the values cannot be loaded from QEMU because
+ * its mandatory to get the correct video memory size to status XML to not break
+ * migration.
+ */
+static int
+qemuProcessUpdateVideoRamSize(virQEMUDriverPtr driver,
+                              virDomainObjPtr vm,
+                              int asyncJob)
+{
+    int ret = -1;
+    ssize_t i;
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+    virDomainVideoDefPtr video = NULL;
+    virQEMUDriverConfigPtr cfg = NULL;
+
+    if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
+        return -1;
+
+    for (i = 0; i < vm->def->nvideos; i++) {
+        video = vm->def->videos[i];
+
+        switch (video->type) {
+        case VIR_DOMAIN_VIDEO_TYPE_VGA:
+            if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_VGA_VGAMEM)) {
+                if (qemuMonitorUpdateVideoMemorySize(priv->mon, video, "VGA") < 0)
+                    goto error;
+            }
+            break;
+        case VIR_DOMAIN_VIDEO_TYPE_QXL:
+            if (i == 0) {
+                if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_QXL_VGA_VGAMEM)) {
+                    if (qemuMonitorUpdateVideoMemorySize(priv->mon, video,
+                                                         "qxl-vga") < 0)
+                        goto error;
+                }
+            } else {
+                if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_QXL_VGAMEM)) {
+                    if (qemuMonitorUpdateVideoMemorySize(priv->mon, video,
+                                                         "qxl") < 0)
+                        goto error;
+                }
+            }
+            break;
+        case VIR_DOMAIN_VIDEO_TYPE_VMVGA:
+            if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_VMWARE_SVGA_VGAMEM)) {
+                if (qemuMonitorUpdateVideoMemorySize(priv->mon, video,
+                                                     "vmware-svga") < 0)
+                    goto error;
+            }
+            break;
+        case VIR_DOMAIN_VIDEO_TYPE_CIRRUS:
+        case VIR_DOMAIN_VIDEO_TYPE_XEN:
+        case VIR_DOMAIN_VIDEO_TYPE_VBOX:
+        case VIR_DOMAIN_VIDEO_TYPE_LAST:
+            break;
+        }
+
+    }
+
+    qemuDomainObjExitMonitor(driver, vm);
+
+    cfg = virQEMUDriverGetConfig(driver);
+    ret = virDomainSaveStatus(driver->xmlopt, cfg->stateDir, vm);
+    virObjectUnref(cfg);
+
+    return ret;
+
+ error:
+    qemuDomainObjExitMonitor(driver, vm);
+    return -1;
+}
+
+
 struct qemuProcessHookData {
     virConnectPtr conn;
     virDomainObjPtr vm;
@@ -4801,6 +4880,10 @@ int qemuProcessStart(virConnectPtr conn,
     }
     qemuDomainObjExitMonitor(driver, vm);
 
+    VIR_DEBUG("Detecting actual memory size for video device");
+    if (qemuProcessUpdateVideoRamSize(driver, vm, asyncJob) < 0)
+        goto cleanup;
+
     if (!(flags & VIR_QEMU_PROCESS_START_PAUSED)) {
         VIR_DEBUG("Starting domain CPUs");
         /* Allow the CPUS to start executing */