Re: [PATCH v2 1/2] qemu: add support for shmem-{plain, doorbell} role

Role(master or peer) controls how the domain behaves on migration. For more details about migration with ivshmem, see https://git.qemu.org/?p=qemu.git;a=blob_plain;f=docs/system/ivshmem.rst;h... It's a optional attribute in libvirt, and qemu will choose default role for ivshmem device if the user is not specified. With device property 'role', the value can be 'master' or 'peer'. - 'master' (means 'master=on' in qemu), the guest will copy the shared memory on migration to the destination host. - 'peer' (means 'master=off' in qemu), the migration is disabled. Signed-off-by: Martin Kletzander <mkletzan(a)redhat.com&gt;

Signed-off-by: Yang Hang <yanghang44(a)huawei.com&gt; Signed-off-by: Wang Xin <wangxinxin.wang(a)huawei.com&gt; diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index f5ee97de81..d4d90ad44d 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -9141,7 +9141,7 @@ qemu-kvm -net nic,model=? /dev/null <pre> ... &lt;devices&gt; - &lt;shmem name='my_shmem0'&gt; + &lt;shmem name='my_shmem0' role='peer'&gt; &lt;model type='ivshmem-plain'/&gt; &lt;size unit='M'&gt;4&lt;/size&gt; &lt;/shmem&gt; @@ -9159,9 +9159,15 @@ qemu-kvm -net nic,model=? /dev/null <dt><code>shmem</code></dt> <dd> The <code>shmem</code> element has one mandatory attribute, - <code>name</code> to identify the shared memory. This attribute cannot - be directory specific to <code>.</code> or <code>..</code> as well as - it cannot involve path separator <code>/</code>. + <code>name</code> to identify the shared memory. Optional attribute + <code>role</code> can be set to values "master" or "peer". The former + will mean that upon migration, the data in the shared memory is migrated + with the domain. There should be only one "master" per shared memory object. + Migration with "peer" role is disabled. If migration of such domain is required, + the shmem device needs to be unplugged before migration and plugged in at the + destination upon successful migration. This attribute cannot be directory + specific to <code>.</code> or <code>..</code> as well as it cannot involve path + separator <code>/</code>.

</dd> <dt><code>model</code></dt> <dd> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index a810f569c6..09d4ad3e96 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -4417,6 +4417,14 @@ <param name="pattern">[^/]*</param> </data> </attribute> + <optional> + <attribute name="role"> + <choice> + <value>master</value> + <value>peer</value> + </choice> + </attribute> + </optional> <interleave> <optional> <element name="model"> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 7ecd2818b9..6e67c7ebe0 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -1325,6 +1325,13 @@ VIR_ENUM_IMPL(virDomainShmemModel, "ivshmem-doorbell", ); +VIR_ENUM_IMPL(virDomainShmemRole, + VIR_DOMAIN_SHMEM_ROLE_LAST, + "default", + "master", + "peer", +); + VIR_ENUM_IMPL(virDomainLaunchSecurity, VIR_DOMAIN_LAUNCH_SECURITY_LAST, "", @@ -15357,6 +15364,19 @@ virDomainShmemDefParseXML(virDomainXMLOptionPtr xmlopt, goto cleanup; } + if (def->model != VIR_DOMAIN_SHMEM_MODEL_IVSHMEM) { + tmp = virXMLPropString(node, "role"); + if (tmp) { + if ((def->role = virDomainShmemRoleTypeFromString(tmp)) <= 0) { + virReportError(VIR_ERR_XML_ERROR, + _("Unknown shmem role type '%s'"), tmp); + goto cleanup; + } + + VIR_FREE(tmp); + } + } + if (virParseScaledValue("./size[1]", NULL, ctxt, &def->size, 1, ULLONG_MAX, false) < 0) goto cleanup; @@ -18579,6 +18599,9 @@ virDomainShmemDefEquals(virDomainShmemDefPtr src, if (src->model != dst->model) return false; + if (src->role != dst->role) + return false; + if (src->server.enabled != dst->server.enabled) return false; @@ -23758,6 +23781,15 @@ virDomainShmemDefCheckABIStability(virDomainShmemDefPtr src, return false; } + if (src->role != dst->role) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("Target shared memory role '%s' does not match " + "source role '%s'"), + virDomainShmemRoleTypeToString(dst->role), + virDomainShmemRoleTypeToString(src->role)); + return false; + } + if (src->model != dst->model) { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, _("Target shared memory model '%s' does not match " @@ -27408,8 +27440,12 @@ virDomainShmemDefFormat(virBufferPtr buf, virDomainShmemDefPtr def, unsigned int flags) { - virBufferEscapeString(buf, "<shmem name='%s'>\n", def->name); + virBufferEscapeString(buf, "<shmem name='%s'", def->name); + if (def->role) + virBufferEscapeString(buf, " role='%s'", + virDomainShmemRoleTypeToString(def->role)); + virBufferAddLit(buf, ">\n"); virBufferAdjustIndent(buf, 2); virBufferAsprintf(buf, "<model type='%s'/>\n", diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index 241149af24..855c144ddb 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -1771,10 +1771,19 @@ typedef enum { VIR_DOMAIN_SHMEM_MODEL_LAST } virDomainShmemModel; +typedef enum { + VIR_DOMAIN_SHMEM_ROLE_DEFAULT, + VIR_DOMAIN_SHMEM_ROLE_MASTER, + VIR_DOMAIN_SHMEM_ROLE_PEER, + + VIR_DOMAIN_SHMEM_ROLE_LAST +} virDomainShmemRole; + struct _virDomainShmemDef { char *name; unsigned long long size; int model; /* enum virDomainShmemModel */ + int role; /* enum virDomainShmemRole */ struct { bool enabled; virDomainChrSourceDef chr; @@ -3624,6 +3633,7 @@ VIR_ENUM_DECL(virDomainMemoryAllocation); VIR_ENUM_DECL(virDomainIOMMUModel); VIR_ENUM_DECL(virDomainVsockModel); VIR_ENUM_DECL(virDomainShmemModel); +VIR_ENUM_DECL(virDomainShmemRole); VIR_ENUM_DECL(virDomainLaunchSecurity); /* from libvirt.h */ VIR_ENUM_DECL(virDomainState); diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 73b72c9e10..3f28943575 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -597,6 +597,8 @@ virDomainShmemDefInsert; virDomainShmemDefRemove; virDomainShmemModelTypeFromString; virDomainShmemModelTypeToString; +virDomainShmemRoleTypeFromString; +virDomainShmemRoleTypeToString; virDomainShutdownReasonTypeFromString; virDomainShutdownReasonTypeToString; virDomainShutoffReasonTypeFromString; diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 839c93bfb4..0655d8359d 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -8539,11 +8539,24 @@ qemuBuildShmemDevStr(virDomainDefPtr def, virBufferAdd(&buf, virDomainShmemModelTypeToString(shmem->model), -1); virBufferAsprintf(&buf, ",id=%s", shmem->info.alias); - if (shmem->server.enabled) + if (shmem->server.enabled) { virBufferAsprintf(&buf, ",chardev=char%s", shmem->info.alias); - else + } else { virBufferAsprintf(&buf, ",memdev=shmmem-%s", shmem->info.alias); + switch ((virDomainShmemRole) shmem->role) { + case VIR_DOMAIN_SHMEM_ROLE_MASTER: + virBufferAddLit(&buf, ",master=on"); + break; + case VIR_DOMAIN_SHMEM_ROLE_PEER: + virBufferAddLit(&buf, ",master=off"); + break; + case VIR_DOMAIN_SHMEM_ROLE_DEFAULT: + case VIR_DOMAIN_SHMEM_ROLE_LAST: + break; + } + } + if (shmem->msi.vectors) virBufferAsprintf(&buf, ",vectors=%u", shmem->msi.vectors); if (shmem->msi.ioeventfd) { diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index 78e64344f6..5ae85c7ae7 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -1261,10 +1261,22 @@ qemuMigrationSrcIsAllowed(virQEMUDriverPtr driver, } } - if (vm->def->nshmems) { - virReportError(VIR_ERR_OPERATION_INVALID, "%s", - _("migration with shmem device is not supported")); - return false; + for (i = 0; i < vm->def->nshmems; i++) { + virDomainShmemDefPtr shmem = vm->def->shmems[i]; + + if (shmem->model == VIR_DOMAIN_SHMEM_MODEL_IVSHMEM) { + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("migration with legacy shmem device is not supported")); + return false; + } + if (shmem->role == VIR_DOMAIN_SHMEM_ROLE_PEER) { + virReportError(VIR_ERR_OPERATION_INVALID, + _("domain's shmem device '%s' has role='%s', " + "try unplugging it first"),