From d3f9dda2c9fd9fa7d2f7f1f1dd70ed7d83938101 Mon Sep 17 00:00:00 2001 From: Peter Krempa Date: Wed, 11 Jul 2018 18:26:12 +0200 Subject: [PATCH] qemu: hotplug: Prepare for multiple backing chain member hotplug MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Similarly to how we've intergrated data belonging to a single virStorageSource for purposes of attaching it to a qemu instance we will need to agregate data relevant for the whole disk. With blockdev there will be some disk-wide backing chain members such as the copy-on-read handler. Introduce qemuHotplugDiskSourceData which agregates the backing chain and other data relevant for the disk and functions which generate it and apply and rollback it. In addition to disk hotplug this will also be reused for media changing where we need to exchange the full disk backend. Signed-off-by: Peter Krempa Reviewed-by: Ján Tomko --- src/qemu/qemu_hotplug.c | 118 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 109 insertions(+), 9 deletions(-) diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c index 171d9ed50c..5ba72e792e 100644 --- a/src/qemu/qemu_hotplug.c +++ b/src/qemu/qemu_hotplug.c @@ -350,6 +350,110 @@ qemuDomainDiskAttachManagedPR(virDomainObjPtr vm, } +struct _qemuHotplugDiskSourceData { + qemuBlockStorageSourceAttachDataPtr *backends; + size_t nbackends; +}; +typedef struct _qemuHotplugDiskSourceData qemuHotplugDiskSourceData; +typedef qemuHotplugDiskSourceData *qemuHotplugDiskSourceDataPtr; + + +static void +qemuHotplugDiskSourceDataFree(qemuHotplugDiskSourceDataPtr data) +{ + size_t i; + + if (!data) + return; + + for (i = 0; i < data->nbackends; i++) + qemuBlockStorageSourceAttachDataFree(data->backends[i]); + + VIR_FREE(data); +} + + +/** + * qemuHotplugDiskSourceAttachPrepare: + * @disk: disk to generate attachment data for + * @qemuCaps: capabilities of the qemu process + * + * Prepares and returns qemuHotplugDiskSourceData structure filled with all data + * which will fully attach the source backend of the disk to a given VM. + */ +static qemuHotplugDiskSourceDataPtr +qemuHotplugDiskSourceAttachPrepare(virDomainDiskDefPtr disk, + virQEMUCapsPtr qemuCaps) +{ + qemuBlockStorageSourceAttachDataPtr backend; + qemuHotplugDiskSourceDataPtr data; + qemuHotplugDiskSourceDataPtr ret = NULL; + + if (VIR_ALLOC(data) < 0) + return NULL; + + if (!(backend = qemuBuildStorageSourceAttachPrepareDrive(disk, qemuCaps, false))) + goto cleanup; + + if (qemuBuildStorageSourceAttachPrepareCommon(disk->src, backend, qemuCaps) < 0) + goto cleanup; + + if (VIR_APPEND_ELEMENT(data->backends, data->nbackends, backend) < 0) + goto cleanup; + + VIR_STEAL_PTR(ret, data); + + cleanup: + qemuBlockStorageSourceAttachDataFree(backend); + qemuHotplugDiskSourceDataFree(data); + return ret; +} + + +/** + * qemuHotplugDiskSourceAttach: + * @mon: monitor object + * @data: disk backend data object describing what to remove + * + * Attach a disk source backend with all relevant pieces. Caller must enter the + * monitor context for @mon. + */ +static int +qemuHotplugDiskSourceAttach(qemuMonitorPtr mon, + qemuHotplugDiskSourceDataPtr data) +{ + size_t i; + + for (i = data->nbackends; i > 0; i--) { + if (qemuBlockStorageSourceAttachApply(mon, data->backends[i - 1]) < 0) + return -1; + } + + return 0; +} + + +/** + * qemuHotplugDiskSourceRemove: + * @mon: monitor object + * @data: disk backend data object describing what to remove + * + * Remove a disk source backend with all relevant pieces. This function + * preserves the error which was set prior to calling it. Caller must enter the + * monitor context for @mon. + */ +static void +qemuHotplugDiskSourceRemove(qemuMonitorPtr mon, + qemuHotplugDiskSourceDataPtr data) + +{ + size_t i; + + for (i = 0; i < data->nbackends; i++) + qemuBlockStorageSourceAttachRollback(mon, data->backends[i]); +} + + /** * qemuDomainAttachDiskGeneric: * @@ -362,7 +466,7 @@ qemuDomainAttachDiskGeneric(virQEMUDriverPtr driver, { int ret = -1; qemuDomainObjPrivatePtr priv = vm->privateData; - qemuBlockStorageSourceAttachDataPtr data = NULL; + qemuHotplugDiskSourceDataPtr diskdata = NULL; virErrorPtr orig_err; char *devstr = NULL; char *managedPrmgrAlias = NULL; @@ -381,11 +485,7 @@ qemuDomainAttachDiskGeneric(virQEMUDriverPtr driver, if (qemuDomainDiskAttachManagedPR(vm, disk, &managedPrmgrProps) < 0) goto error; - if (!(data = qemuBuildStorageSourceAttachPrepareDrive(disk, priv->qemuCaps, - false))) - goto error; - - if (qemuBuildStorageSourceAttachPrepareCommon(disk->src, data, priv->qemuCaps) < 0) + if (!(diskdata = qemuHotplugDiskSourceAttachPrepare(disk, priv->qemuCaps))) goto error; if (!(devstr = qemuBuildDiskDeviceStr(vm->def, disk, 0, priv->qemuCaps))) @@ -400,7 +500,7 @@ qemuDomainAttachDiskGeneric(virQEMUDriverPtr driver, qemuMonitorAddObject(priv->mon, &managedPrmgrProps, &managedPrmgrAlias) < 0) goto exit_monitor; - if (qemuBlockStorageSourceAttachApply(priv->mon, data) < 0) + if (qemuHotplugDiskSourceAttach(priv->mon, diskdata) < 0) goto exit_monitor; if (qemuMonitorAddDevice(priv->mon, devstr) < 0) @@ -417,7 +517,7 @@ qemuDomainAttachDiskGeneric(virQEMUDriverPtr driver, ret = 0; cleanup: - qemuBlockStorageSourceAttachDataFree(data); + qemuHotplugDiskSourceDataFree(diskdata); virJSONValueFree(managedPrmgrProps); qemuDomainSecretDiskDestroy(disk); VIR_FREE(managedPrmgrAlias); @@ -426,7 +526,7 @@ qemuDomainAttachDiskGeneric(virQEMUDriverPtr driver, return ret; exit_monitor: - qemuBlockStorageSourceAttachRollback(priv->mon, data); + qemuHotplugDiskSourceRemove(priv->mon, diskdata); virErrorPreserveLast(&orig_err); if (managedPrmgrAlias) -- GitLab