Re: [libvirt] [PATCH 20/20] qemu: Add support for hot/cold-(un)plug of shmem devices

This is needed in order to migrate with ivshmem role='peer' as that is not allowed to migrate. Signed-off-by: Martin Kletzander <mkletzan(a)redhat.com&gt; --- src/qemu/qemu_driver.c | 39 +++- src/qemu/qemu_hotplug.c | 247 ++++++++++++++++++++- src/qemu/qemu_hotplug.h | 6 + tests/qemuhotplugtest.c | 21 ++ .../qemuhotplug-ivshmem-doorbell-detach.xml | 7 + .../qemuhotplug-ivshmem-doorbell.xml | 4 + .../qemuhotplug-ivshmem-plain-detach.xml | 6 + .../qemuhotplug-ivshmem-plain.xml | 3 + ...muhotplug-base-live+ivshmem-doorbell-detach.xml | 1 + .../qemuhotplug-base-live+ivshmem-doorbell.xml | 65 ++++++ .../qemuhotplug-base-live+ivshmem-plain-detach.xml | 1 + .../qemuhotplug-base-live+ivshmem-plain.xml | 58 +++++ 12 files changed, 453 insertions(+), 5 deletions(-) create mode 100644 tests/qemuhotplugtestdevices/qemuhotplug-ivshmem-doorbell-detach.xml create mode 100644 tests/qemuhotplugtestdevices/qemuhotplug-ivshmem-doorbell.xml create mode 100644 tests/qemuhotplugtestdevices/qemuhotplug-ivshmem-plain-detach.xml create mode 100644 tests/qemuhotplugtestdevices/qemuhotplug-ivshmem-plain.xml create mode 120000 tests/qemuhotplugtestdomains/qemuhotplug-base-live+ivshmem-doorbell-detach.xml create mode 100644 tests/qemuhotplugtestdomains/qemuhotplug-base-live+ivshmem-doorbell.xml create mode 120000 tests/qemuhotplugtestdomains/qemuhotplug-base-live+ivshmem-plain-detach.xml create mode 100644 tests/qemuhotplugtestdomains/qemuhotplug-base-live+ivshmem-plain.xml

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c index 72dd93bbe467..e70bf577139b 100644 --- a/src/qemu/qemu_hotplug.c +++ b/src/qemu/qemu_hotplug.c @@ -2242,6 +2242,141 @@ qemuDomainAttachHostDevice(virConnectPtr conn, return -1; } + +int +qemuDomainAttachShmemDevice(virQEMUDriverPtr driver, + virDomainObjPtr vm, + virDomainShmemDefPtr shmem) +{ + int ret = -1; + char *shmstr = NULL; + char *charAlias = NULL; + char *memAlias = NULL; + bool release_backing = false; + bool release_address = true; + bool supported = false; + virErrorPtr orig_err = NULL; + virJSONValuePtr props = NULL; + qemuDomainObjPrivatePtr priv = vm->privateData; +

+ + switch (shmem->model) { + case VIR_DOMAIN_SHMEM_MODEL_IVSHMEM_PLAIN: + supported = virQEMUCapsGet(priv->qemuCaps, + QEMU_CAPS_DEVICE_IVSHMEM_PLAIN); + break; + + case VIR_DOMAIN_SHMEM_MODEL_IVSHMEM_DOORBELL: + supported = virQEMUCapsGet(priv->qemuCaps, + QEMU_CAPS_DEVICE_IVSHMEM_DOORBELL); + break; + + default:

+ virReportError(VIR_ERR_OPERATION_UNSUPPORTED, + _("live attach of shmem model '%s' is not supported"), + virDomainShmemModelTypeToString(shmem->model)); + return -1; + } + + if (!supported) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("Device '%s' is not supported by this version of qemu"), + virDomainShmemModelTypeToString(shmem->model)); + return -1; + } + + if (qemuAssignDeviceShmemAlias(vm->def, shmem, -1) < 0) + return -1; + + if (qemuDomainPrepareShmemChardev(shmem) < 0) + return -1; + + if (VIR_REALLOC_N(vm->def->shmems, vm->def->nshmems + 1) < 0) + return -1;

+ + if ((shmem->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE || + shmem->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI) && + (virDomainPCIAddressEnsureAddr(priv->pciaddrs, &shmem->info) < 0)) + return -1; + + if (!(shmstr = qemuBuildShmemDevStr(vm->def, shmem, priv->qemuCaps))) + goto cleanup; + + if (shmem->server.enabled) { + if (virAsprintf(&charAlias, "char%s", shmem->info.alias) < 0) + goto cleanup; + } else { + if (!(props = qemuBuildShmemBackendMemProps(shmem))) + goto cleanup; + + if (virAsprintf(&memAlias, "shmmem-%s", shmem->info.alias) < 0) + goto cleanup; + } + + if (virDomainShmemDefInsert(vm->def, shmem) < 0) + goto cleanup;

+ + qemuDomainObjEnterMonitor(driver, vm); + + if (shmem->server.enabled) { + if (qemuMonitorAttachCharDev(priv->mon, charAlias, + &shmem->server.chr) < 0) + goto audit; + } else { + if (qemuMonitorAddObject(priv->mon, "memory-backend-file", + memAlias, props) < 0) { + props = NULL; + goto audit; + } + props = NULL; + } + + release_backing = true; + + if (qemuMonitorAddDevice(priv->mon, shmstr) < 0) + goto audit; + + ret = 0; + release_address = false;

+ + audit: + virDomainAuditShmem(vm, shmem, "attach", ret == 0);

+ orig_err = virSaveLastError(); + if (ret < 0 && release_backing) { + if (shmem->server.enabled) { + if (qemuMonitorDetachCharDev(priv->mon, charAlias) < 0) { + VIR_WARN("Unable to remove backing chardev '%s' after failed " + "qemuMonitorAddDevice", charAlias); + } + } else { + if (qemuMonitorDelObject(priv->mon, memAlias) < 0) { + VIR_WARN("Unable to remove backing memory '%s' after failed " + "qemuMonitorAddDevice", memAlias); + } + } + } + + if (qemuDomainObjExitMonitor(driver, vm) < 0) + ret = -1; + + cleanup: + if (release_address) + qemuDomainReleaseDeviceAddress(vm, &shmem->info, NULL); + + if (orig_err) { + virSetError(orig_err); + virFreeError(orig_err); + } + + VIR_FREE(memAlias); + VIR_FREE(charAlias); + VIR_FREE(shmstr); + + return ret; +} + + static int qemuDomainChangeNetBridge(virDomainObjPtr vm, virDomainNetDefPtr olddev, @@ -3486,6 +3621,61 @@ qemuDomainRemoveRNGDevice(virQEMUDriverPtr driver, } +static int +qemuDomainRemoveShmemDevice(virQEMUDriverPtr driver, + virDomainObjPtr vm, + virDomainShmemDefPtr shmem) +{ + int ret = -1; + ssize_t idx = -1; + char *charAlias = NULL; + char *memAlias = NULL; + virObjectEventPtr event = NULL; + qemuDomainObjPrivatePtr priv = vm->privateData; + +

+ VIR_DEBUG("Removing shmem device %s from domain %p %s", + shmem->info.alias, vm, vm->def->name); + + if (shmem->server.enabled) { + if (virAsprintf(&charAlias, "char%s", shmem->info.alias) < 0) + goto cleanup; + } else { + if (virAsprintf(&memAlias, "shmmem-%s", shmem->info.alias) < 0) + goto cleanup; + } + + qemuDomainObjEnterMonitor(driver, vm); + + if (shmem->server.enabled) + ret = qemuMonitorDetachCharDev(priv->mon, charAlias); + else + ret = qemuMonitorDelObject(priv->mon, memAlias); + + if (qemuDomainObjExitMonitor(driver, vm) < 0) + goto cleanup; + + virDomainAuditShmem(vm, shmem, "detach", ret == 0); + + if (ret < 0) + goto cleanup; + + event = virDomainEventDeviceRemovedNewFromObj(vm, shmem->info.alias); + qemuDomainEventQueue(driver, event); + + if ((idx = virDomainShmemDefFind(vm->def, shmem)) >= 0) + virDomainShmemDefRemove(vm->def, idx); + qemuDomainReleaseDeviceAddress(vm, &shmem->info, NULL); + + ret = 0; + cleanup: + VIR_FREE(charAlias); + VIR_FREE(memAlias); + + return ret; +} + + int qemuDomainRemoveDevice(virQEMUDriverPtr driver, virDomainObjPtr vm, @@ -3517,6 +3707,10 @@ qemuDomainRemoveDevice(virQEMUDriverPtr driver, ret = qemuDomainRemoveMemoryDevice(driver, vm, dev->data.memory); break; + case VIR_DOMAIN_DEVICE_SHMEM: + ret = qemuDomainRemoveShmemDevice(driver, vm, dev->data.shmem); + break; + case VIR_DOMAIN_DEVICE_NONE: case VIR_DOMAIN_DEVICE_LEASE: case VIR_DOMAIN_DEVICE_FS: @@ -3530,7 +3724,6 @@ qemuDomainRemoveDevice(virQEMUDriverPtr driver, case VIR_DOMAIN_DEVICE_SMARTCARD: case VIR_DOMAIN_DEVICE_MEMBALLOON: case VIR_DOMAIN_DEVICE_NVRAM: - case VIR_DOMAIN_DEVICE_SHMEM: case VIR_DOMAIN_DEVICE_TPM: case VIR_DOMAIN_DEVICE_PANIC: case VIR_DOMAIN_DEVICE_IOMMU: @@ -4105,6 +4298,58 @@ int qemuDomainDetachHostDevice(virQEMUDriverPtr driver, return qemuDomainDetachThisHostDevice(driver, vm, detach); } + +int +qemuDomainDetachShmemDevice(virQEMUDriverPtr driver, + virDomainObjPtr vm, + virDomainDeviceDefPtr dev) +{ + int ret = -1; + virErrorPtr orig_err = NULL; + virDomainShmemDefPtr shmem = dev->data.shmem; + qemuDomainObjPrivatePtr priv = vm->privateData; + +

+ switch (shmem->model) {

+ case VIR_DOMAIN_SHMEM_MODEL_IVSHMEM_PLAIN: + case VIR_DOMAIN_SHMEM_MODEL_IVSHMEM_DOORBELL: + break; + + default:

+ virReportError(VIR_ERR_OPERATION_UNSUPPORTED, + _("live detach of shmem model '%s' is not supported"), + virDomainShmemModelTypeToString(shmem->model)); + return -1; + } + + qemuDomainMarkDeviceForRemoval(vm, &shmem->info); + qemuDomainObjEnterMonitor(driver, vm); + + ret = qemuMonitorDelDevice(priv->mon, shmem->info.alias); + + if (ret < 0) + orig_err = virSaveLastError();

+ + if (qemuDomainObjExitMonitor(driver, vm) < 0) + ret = -1; + + if (ret == 0) { + if ((ret = qemuDomainWaitForDeviceRemoval(vm)) == 1) { + qemuDomainReleaseDeviceAddress(vm, &shmem->info, NULL); + ret = qemuDomainRemoveDevice(driver, vm, dev); + } + } + qemuDomainResetDeviceRemoval(vm); + + if (orig_err) { + virSetError(orig_err); + virFreeError(orig_err); + } + + return ret; +} + + int qemuDomainDetachNetDevice(virQEMUDriverPtr driver, virDomainObjPtr vm,