From: Masayoshi Mizuma <m.mizuma@xxxxxxxxxxxxxx>
Add qemuHotplugCreateDisksTransient() to make <transient/> disk
sharable.
The procedure is followings.
First, create the overlay disk with the original disk is set as the
backingStore. Then, blockdev-del the StorageProgs and FormatProgs of
the disk. That's because to fix the bootindex of the disk.
Lastly, device_add the disks.
Signed-off-by: Masayoshi Mizuma <m.mizuma@xxxxxxxxxxxxxx>
---
src/qemu/qemu_command.c | 3 +
src/qemu/qemu_hotplug.c | 285 ++++++++++++++++++++++++++++++++++++++++
src/qemu/qemu_hotplug.h | 3 +
3 files changed, 291 insertions(+)
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 1ec302d4ac..81a27703c5 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -2139,6 +2139,9 @@ qemuBuildDisksCommandLine(virCommandPtr cmd,
bootCD = 0;
break;
case VIR_DOMAIN_DISK_DEVICE_DISK:
+ /* to use bootindex later for transient disk */
+ disk->info.bootIndex = bootDisk;
+ G_GNUC_FALLTHROUGH;
case VIR_DOMAIN_DISK_DEVICE_LUN:
bootindex = bootDisk;
bootDisk = 0;
diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index a2535949b7..5d0445538d 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -6710,3 +6710,288 @@ qemuDomainSetVcpuInternal(virQEMUDriverPtr driver,
virBitmapFree(livevcpus);
return ret;
}
+
+struct _qemuHotplugTransientDiskContext {
+ virDomainDeviceDefPtr trandev;
+ virDomainDiskDefPtr *domdisk;
+ size_t ndd;
+};
+
+typedef struct _qemuHotplugTransientDiskContext qemuHotplugTransientDiskContext;
+typedef qemuHotplugTransientDiskContext *qemuHotplugTransientDiskContextPtr;
+
+static qemuHotplugTransientDiskContextPtr
+qemuHotplugTransientDiskContextNew(size_t ndisks)
+{
+ qemuHotplugTransientDiskContextPtr ret = g_new0(qemuHotplugTransientDiskContext, 1);
+
+ ret->trandev = g_new0(virDomainDeviceDef, ndisks);
+ ret->domdisk = g_new0(virDomainDiskDefPtr, ndisks);
+
+ return ret;
+}
+
+static void
+qemuHotplugTransientDiskCleanup(virDomainDeviceDefPtr data,
+ virDomainDiskDefPtr *domdisk)
+{
+ VIR_FREE(data);
+ VIR_FREE(domdisk);
+
+ return;
+}
+
+static void
+qemuHotplugTransientDiskContextCleanup(qemuHotplugTransientDiskContextPtr hptctxt)
+{
+ if (!hptctxt)
+ return;
+
+ qemuHotplugTransientDiskCleanup(hptctxt->trandev, hptctxt->domdisk);
+
+ g_free(hptctxt);
+}
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(qemuHotplugTransientDiskContext, qemuHotplugTransientDiskContextCleanup);
+
+static int
+qemuHotplugDiskPrepareOneBlockdev(virQEMUDriverPtr driver,
+ virDomainObjPtr vm,
+ virQEMUDriverConfigPtr cfg,
+ virDomainDiskDefPtr domdisk,
+ virDomainDiskDefPtr trandisk,
+ GHashTable *blockNamedNodeData,
+ qemuDomainAsyncJob asyncJob)
+{
+ qemuDomainObjPrivatePtr priv = vm->privateData;
+ g_autoptr(qemuBlockStorageSourceChainData) data = NULL;
+ g_autoptr(virStorageSource) terminator = NULL;
+
+ terminator = virStorageSourceNew();
+
+ if (qemuDomainPrepareStorageSourceBlockdev(trandisk, trandisk->src,
+ priv, cfg) < 0)
+ return -1;
+
+ if (!(data = qemuBuildStorageSourceChainAttachPrepareBlockdevTop(trandisk->src,
+ terminator,
+ priv->qemuCaps)))
+ return -1;
+
+ if (qemuBlockStorageSourceCreateDetectSize(blockNamedNodeData,
+ trandisk->src, domdisk->src) < 0)
+ return -1;
+
+ if (qemuBlockStorageSourceCreate(vm, trandisk->src, domdisk->src,
+ NULL, data->srcdata[0],
+ asyncJob) < 0)
+ return -1;
+
+ /* blockdev-del the transient disk src. The disk is blockdev-add'ed
+ * while the disk is hot-added */
+ if (qemuBlockStorageSourceDetachOneBlockdev(driver, vm,
+ asyncJob, trandisk->src) < 0)
+ return -1;
+
+ return 0;
+}
+
+static int
+qemuHotplugDiskTransientPrepareOne(virDomainObjPtr vm,
+ virQEMUDriverConfigPtr cfg,
+ virDomainDiskDefPtr domdisk,
+ virDomainDiskDefPtr trandisk,
+ GHashTable *blockNamedNodeData,
+ qemuDomainAsyncJob asyncJob)
+{
+ qemuDomainObjPrivatePtr priv = vm->privateData;
+ virQEMUDriverPtr driver = priv->driver;
+ bool supportsCreate;
+
+ if (qemuDomainStorageSourceValidateDepth(trandisk->src, 1, trandisk->dst) < 0)
+ return -1;
+
+ if (virStorageSourceInitChainElement(trandisk->src, domdisk->src, false) < 0)
+ return -1;
+
+ trandisk->src->readonly = false;
+ supportsCreate = virStorageSourceSupportsCreate(trandisk->src);
+
+ if (supportsCreate) {
+ if (qemuDomainStorageFileInit(driver, vm, trandisk->src, NULL) < 0)
+ return -1;
+
+ if (virStorageSourceCreate(trandisk->src) < 0) {
+ virReportSystemError(errno, _("failed to create image file '%s'"),
+ NULLSTR(trandisk->src->path));
+ return -1;
+ }
+ }
+
+ if (qemuDomainStorageSourceAccessAllow(driver, vm, trandisk->src,
+ false, true, true) < 0)
+ return -1;
+
+ if (qemuHotplugDiskPrepareOneBlockdev(driver, vm, cfg, domdisk, trandisk,
+ blockNamedNodeData, asyncJob) < 0)
+ return -1;
+
+ return 0;
+}
+
+static qemuHotplugTransientDiskContextPtr
+qemuHotplugDiskPrepareDisksTransient(virDomainObjPtr vm,
+ virQEMUDriverConfigPtr cfg,
+ GHashTable *blockNamedNodeData,
+ qemuDomainAsyncJob asyncJob)
+{
+ g_autoptr(qemuHotplugTransientDiskContext) hptctxt = NULL;
+ qemuDomainObjPrivatePtr priv = vm->privateData;
+ virQEMUDriverPtr driver = priv->driver;
+ size_t i;
+
+ hptctxt = qemuHotplugTransientDiskContextNew(vm->def->ndisks);
+
+ for (i = 0; i < vm->def->ndisks; i++) {
+ virDomainDiskDefPtr domdisk = vm->def->disks[i];
+ virDomainDiskDefPtr trandisk;
+ virDomainDeviceDefPtr trandev;
+
+ if (!(trandisk = virDomainDiskDefNew(driver->xmlopt)))
+ return NULL;
+
+ trandev = hptctxt->trandev + hptctxt->ndd;
+ trandev->type = VIR_DOMAIN_DEVICE_DISK;
+
+ memcpy(&trandisk->info, &domdisk->info, sizeof(virDomainDeviceInfo));
+ trandisk->info.alias = NULL;
+ trandisk->info.romfile = NULL;
+
+ if (domdisk->transient) {
+ trandisk->src = virStorageSourceNew();
+ trandisk->src->type = VIR_STORAGE_TYPE_FILE;
+ trandisk->src->format = VIR_STORAGE_FILE_QCOW2;
+ trandisk->src->path = g_strdup_printf("%s.TRANSIENT-%s",
+ domdisk->src->path, vm->def->name);
+
+ if (!(trandisk->src->backingStore =
+ virStorageSourceCopy(domdisk->src, false)))
+ return NULL;
+
+ if (virFileExists(trandisk->src->path)) {
+ virReportError(VIR_ERR_OPERATION_UNSUPPORTED,
+ _("Overlay file '%s' for transient disk '%s' already exists"),
+ trandisk->src->path, domdisk->dst);
+ return NULL;
+ }
+
+ if (qemuHotplugDiskTransientPrepareOne(vm, cfg, domdisk, trandisk,
+ blockNamedNodeData,
+ asyncJob) < 0)
+ return NULL;
+ } else {
+ /* The disks without transient option will be device_add as well
+ * because to fix the bootindex */
+ if (!(trandisk->src = virStorageSourceCopy(domdisk->src, false)))
+ return NULL;
+ }
+
+ trandisk->bus = domdisk->bus;
+ trandisk->dst = g_strdup(domdisk->dst);
+ trandev->data.disk = trandisk;
+
+ hptctxt->domdisk[hptctxt->ndd] = domdisk;
+
+ hptctxt->ndd++;
+ }
+
+ return g_steal_pointer(&hptctxt);
+}
+
+static int
+qemuHotplugDiskTransientCreate(virDomainObjPtr vm,
+ qemuHotplugTransientDiskContextPtr hptctxt,
+ virQEMUDriverConfigPtr cfg,
+ qemuDomainAsyncJob asyncJob)
+{
+ qemuDomainObjPrivatePtr priv = vm->privateData;
+ virQEMUDriverPtr driver = priv->driver;
+ const char *alias = NULL;
+ size_t i;
+ int ret;
+
+ for (i = 0; i < hptctxt->ndd; i++) {
+ virDomainDeviceDefPtr trandev = hptctxt->trandev + i;
+ virDomainDiskDefPtr domdisk = hptctxt->domdisk[i];
+ bool transient = domdisk->transient;
+
+ /* transient disk doesn't support disk hotplug. Disable it here temporarily
+ * to remove it */
+ if (transient)
+ domdisk->transient = false;
+
+ /* blockdev-del StorageProgs and FormatProps of domdisk so that
+ * qemuDomainAttachDeviceDiskLiveInternal() can blockdev-add without
+ * write lock issue */
+ if (qemuDomainRemoveDiskDevice(driver, vm, domdisk, asyncJob) < 0)
+ return -1;
+
+ ret = qemuDomainAttachDeviceDiskLiveInternal(driver, vm, trandev, asyncJob);
+ if (!ret) {
+ alias = trandev->data.disk->info.alias;
+ if (transient) {
+ trandev->data.disk->transient = true;
+ }
+ } else {
+ VIR_DEBUG("Failed to attach disk %s (transient: %d) with disk hotplug.",
+ trandev->data.disk->dst, transient);
+ return -1;
+ }
+
+ if (alias) {
+ virObjectEventPtr event;
+ event = virDomainEventDeviceAddedNewFromObj(vm, alias);
+ virObjectEventStateQueue(driver->domainEventState, event);
+ }
+
+ if (qemuDomainUpdateDeviceList(driver, vm, asyncJob) < 0)
+ return -1;
+ }
+
+ if (virDomainObjSave(vm, driver->xmlopt, cfg->stateDir) < 0)
+ return -1;
+
+ return 0;
+}
+
+int
+qemuHotplugCreateDisksTransient(virDomainObjPtr vm,
+ qemuDomainAsyncJob asyncJob)
+{
+ qemuDomainObjPrivatePtr priv = vm->privateData;
+ virQEMUDriverPtr driver = priv->driver;
+ g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
+ g_autoptr(qemuHotplugTransientDiskContext) hptctxt = NULL;
+ g_autoptr(GHashTable) blockNamedNodeData = NULL;
+
+ if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV) &&
+ virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_PCIE_ROOT_PORT_HOTPLUG)) {
+
+ VIR_DEBUG("prepare transient disks with disk hotplug");
+
+ if (!(blockNamedNodeData = qemuBlockGetNamedNodeData(vm, asyncJob)))
+ return -1;
+
+ if (!(hptctxt = qemuHotplugDiskPrepareDisksTransient(vm, cfg,
+ blockNamedNodeData,
+ asyncJob)))
+ return -1;
+
+ if (qemuHotplugDiskTransientCreate(vm, hptctxt, cfg, asyncJob) < 0)
+ return -1;
+ }
+
+ priv->inhibitDiskTransientDelete = false;
+
+ return 0;
+}
diff --git a/src/qemu/qemu_hotplug.h b/src/qemu/qemu_hotplug.h
index 6287c5b5e8..baef2dba42 100644
--- a/src/qemu/qemu_hotplug.h
+++ b/src/qemu/qemu_hotplug.h
@@ -160,3 +160,6 @@ int qemuHotplugAttachDBusVMState(virQEMUDriverPtr driver,
int qemuHotplugRemoveDBusVMState(virQEMUDriverPtr driver,
virDomainObjPtr vm,
qemuDomainAsyncJob asyncJob);
+
+int qemuHotplugCreateDisksTransient(virDomainObjPtr vm,
+ qemuDomainAsyncJob asyncJob);
--
2.27.0
