[libvirt] [PowerPC PATCH 0/3 v4] Libvirt CPU enhancements for Power KVM
This patch series is a collection of enhancements for PowerPC CPUs on PowerKVM. Series Summary: ========== Patch 1/3 : Introduce a new architecture 'ppc64le' for libvirt. Patch 2/3 : Add libvirt support for VMs running in 'compat' mode on Power KVM. Patch 3/3 : Improve PVR handling to fall back to cpu generation. Detail: ==== * PowerPC has traditionally been a Big-endian architecture. However, with PowerPC ISA version 2.07, it can run in Little-endian mode as well. IBM Power8 processors, compliant with ISA 2.07 allow launching VMs in little-endian mode. This is signified by 'ppc64le' architecture. Patch 1 adds this support to libvirt, to allow running VMs based on ppc64le architecture. * Patch 2,3 tweak libvirt to correctly model PowerPC CPUs based on recent PowerKVM implementation. PowerKVM permits VMs with vcpus in the following allowed modes : i) Host native mode: where the vcpu seen in the VM belongs to the same processor generation as the host. Example: A POWER7 host, conforming to PowerISA version 2.06, will run VMs with "power7" vcpus. ii) Binary Compatibility ("compat") mode: PowerISA allows processors to run VMs in binary compatibility ("compat") mode supporting an older version of ISA. As an example: In compatibility mode, a POWER7 host can run a "power6" VM, conforming to power ISA v2.05. Similarly, a POWER8 host can run a "power7" VM conforming to PowerISA v2.06. QEMU has recently added support to explicitly denote a VM running in compatibility mode through commits 6d9412ea & 8dfa3a5e85. Henceforth, VMs of type (i) will be invoked with the QEMU invocation "-cpu host", while VMs of type (ii) will be invoked using "-cpu host, compat=power6". Now, an explicit cpu selection using "-cpu POWER6" is not valid. Instead, the recommended practice is to use the matching compat mode, if the requested cpu type differs from the host. Patches 2-3 address various aspects of this change. * Patch 2 : Adds support for generating the correct command line for QEMU. New xml semantics are introduced to signify this type. Corresponding documentation is also added. * Patch 3 : PowerKVM vCPUs differ uniquely across generations ( such as power6, power7, power8). Each generation signifies a new PowerISA version that exhibits features unique to that generation. The higher order 16 bits of PVR denote the processor generation and the lower order 16 bits denote the cpu chip (sub)version. For all practical purposes of launching a VM, we care about the generation the vCPU will belong to, and not specifically the chip version. In fact, PowerKVM does not seek out specification of a unique chip version(such as POWER7_v2.3) for running a vCPU. This patch updates the libvirt PVR check to reflect this relationship. Changelog: ========= v1 : https://www.redhat.com/archives/libvir-list/2014-June/msg01338.html v2 : http://www.redhat.com/archives/libvir-list/2014-October/msg00351.html v3 : http://www.mail-archive.com/libvir-list@redhat.com/msg104010.html Changes since v3: i) Added documentation for describing 'compat' mode to formatdomain.html.in ( Thanks for pointing this out, Michal ) ii) Minor corrections ( Indentation fix; Added check for PPC64LE in virDomainVideoDefaultType ) Regards, -- Prerna Saxena Linux Technology Centre, IBM Systems and Technology Lab, Bangalore, India
From cddaae164145043dd57546fa93ab49ada0e25ec1 Mon Sep 17 00:00:00 2001 From: "Pradipta Kr. Banerjee" <bpradip@in.ibm.com> Date: Tue, 28 Oct 2014 14:41:59 +0530
This adds support for PowerPC Little Endian architecture., and allows libvirt to spawn VMs based on 'ppc64le' architecture. Signed-off-by: Pradipta Kr. Banerjee <bpradip@in.ibm.com> Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com> --- src/conf/domain_conf.c | 2 +- src/cpu/cpu_powerpc.c | 2 +- src/qemu/qemu_capabilities.c | 6 +++--- src/qemu/qemu_command.c | 22 +++++++++++----------- src/qemu/qemu_domain.c | 1 + src/util/virarch.h | 3 +++ 6 files changed, 20 insertions(+), 16 deletions(-) diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 39befb0..1d3b864 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -10032,7 +10032,7 @@ virDomainVideoDefaultType(const virDomainDef *def) (STREQ(def->os.type, "xen") || STREQ(def->os.type, "linux"))) return VIR_DOMAIN_VIDEO_TYPE_XEN; - else if (def->os.arch == VIR_ARCH_PPC64) + else if ARCH_IS_PPC64(def->os.arch) return VIR_DOMAIN_VIDEO_TYPE_VGA; else return VIR_DOMAIN_VIDEO_TYPE_CIRRUS; diff --git a/src/cpu/cpu_powerpc.c b/src/cpu/cpu_powerpc.c index 67cb9ff..d591c18 100644 --- a/src/cpu/cpu_powerpc.c +++ b/src/cpu/cpu_powerpc.c @@ -38,7 +38,7 @@ VIR_LOG_INIT("cpu.cpu_powerpc"); -static const virArch archs[] = { VIR_ARCH_PPC64 }; +static const virArch archs[] = { VIR_ARCH_PPC64, VIR_ARCH_PPC64LE }; struct ppc_vendor { char *name; diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index 6fcb5c7..bb59a36 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -633,7 +633,7 @@ virQEMUCapsProbeCPUModels(virQEMUCapsPtr qemuCaps, uid_t runUid, gid_t runGid) if (qemuCaps->arch == VIR_ARCH_I686 || qemuCaps->arch == VIR_ARCH_X86_64) { parse = virQEMUCapsParseX86Models; - } else if (qemuCaps->arch == VIR_ARCH_PPC64) { + } else if ARCH_IS_PPC64(qemuCaps->arch) { parse = virQEMUCapsParsePPCModels; } else { VIR_DEBUG("don't know how to parse %s CPU models", @@ -2003,7 +2003,7 @@ bool virQEMUCapsHasPCIMultiBus(virQEMUCapsPtr qemuCaps, return true; if (def->os.arch == VIR_ARCH_PPC || - def->os.arch == VIR_ARCH_PPC64) { + ARCH_IS_PPC64(def->os.arch)) { /* * Usage of pci.0 naming: * @@ -3573,7 +3573,7 @@ virQEMUCapsSupportsChardev(virDomainDefPtr def, !virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE)) return false; - if ((def->os.arch == VIR_ARCH_PPC) || (def->os.arch == VIR_ARCH_PPC64)) { + if ((def->os.arch == VIR_ARCH_PPC) || ARCH_IS_PPC64(def->os.arch)) { /* only pseries need -device spapr-vty with -chardev */ return (chr->deviceType == VIR_DOMAIN_CHR_DEVICE_TYPE_SERIAL && chr->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_SPAPRVIO); diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 2e5af4f..d60f274 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -713,7 +713,7 @@ qemuSetSCSIControllerModel(virDomainDefPtr def, return -1; } } else { - if ((def->os.arch == VIR_ARCH_PPC64) && + if (ARCH_IS_PPC64(def->os.arch) && STRPREFIX(def->os.machine, "pseries")) { *model = VIR_DOMAIN_CONTROLLER_MODEL_SCSI_IBMVSCSI; } else if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_SCSI_LSI)) { @@ -1264,7 +1264,7 @@ int qemuDomainAssignSpaprVIOAddresses(virDomainDefPtr def, for (i = 0; i < def->nserials; i++) { if (def->serials[i]->deviceType == VIR_DOMAIN_CHR_DEVICE_TYPE_SERIAL && - (def->os.arch == VIR_ARCH_PPC64) && + ARCH_IS_PPC64(def->os.arch) && STRPREFIX(def->os.machine, "pseries")) def->serials[i]->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_SPAPRVIO; if (qemuAssignSpaprVIOAddress(def, &def->serials[i]->info, @@ -1273,7 +1273,7 @@ int qemuDomainAssignSpaprVIOAddresses(virDomainDefPtr def, } if (def->nvram) { - if (def->os.arch == VIR_ARCH_PPC64 && + if (ARCH_IS_PPC64(def->os.arch) && STRPREFIX(def->os.machine, "pseries")) def->nvram->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_SPAPRVIO; if (qemuAssignSpaprVIOAddress(def, &def->nvram->info, @@ -4195,7 +4195,7 @@ qemuBuildUSBControllerDevStr(virDomainDefPtr domainDef, model = def->model; if (model == -1) { - if (domainDef->os.arch == VIR_ARCH_PPC64) + if ARCH_IS_PPC64(domainDef->os.arch) model = VIR_DOMAIN_CONTROLLER_MODEL_USB_PCI_OHCI; else model = VIR_DOMAIN_CONTROLLER_MODEL_USB_PIIX3_UHCI; @@ -8573,7 +8573,7 @@ qemuBuildCommandLine(virConnectPtr conn, !qemuDomainMachineIsQ35(def) && (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_PIIX3_USB_UHCI) || (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_PCI_OHCI) && - def->os.arch == VIR_ARCH_PPC64))) { + ARCH_IS_PPC64(def->os.arch)))) { if (usblegacy) { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", _("Multiple legacy USB controllers are " @@ -9771,7 +9771,7 @@ qemuBuildCommandLine(virConnectPtr conn, } if (def->nvram) { - if (def->os.arch == VIR_ARCH_PPC64 && + if (ARCH_IS_PPC64(def->os.arch) && STRPREFIX(def->os.machine, "pseries")) { if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_NVRAM)) { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", @@ -9894,7 +9894,7 @@ qemuBuildSerialChrDeviceStr(char **deviceStr, { virBuffer cmd = VIR_BUFFER_INITIALIZER; - if ((arch == VIR_ARCH_PPC64) && STRPREFIX(machine, "pseries")) { + if (ARCH_IS_PPC64(arch) && STRPREFIX(machine, "pseries")) { if (serial->deviceType == VIR_DOMAIN_CHR_DEVICE_TYPE_SERIAL && serial->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_SPAPRVIO) { virBufferAsprintf(&cmd, "spapr-vty,chardev=char%s", @@ -10316,7 +10316,7 @@ qemuParseCommandLineDisk(virDomainXMLOptionPtr xmlopt, if (VIR_ALLOC(def->src) < 0) goto error; - if (((dom->os.arch == VIR_ARCH_PPC64) && + if ((ARCH_IS_PPC64(dom->os.arch) && dom->os.machine && STRPREFIX(dom->os.machine, "pseries"))) def->bus = VIR_DOMAIN_DISK_BUS_SCSI; else @@ -10409,7 +10409,7 @@ qemuParseCommandLineDisk(virDomainXMLOptionPtr xmlopt, } else if (STREQ(keywords[i], "if")) { if (STREQ(values[i], "ide")) { def->bus = VIR_DOMAIN_DISK_BUS_IDE; - if (((dom->os.arch == VIR_ARCH_PPC64) && + if ((ARCH_IS_PPC64(dom->os.arch) && dom->os.machine && STRPREFIX(dom->os.machine, "pseries"))) { virReportError(VIR_ERR_INTERNAL_ERROR, _("pseries systems do not support ide devices '%s'"), val); @@ -11654,7 +11654,7 @@ qemuParseCommandLine(virCapsPtr qemuCaps, } if (STREQ(arg, "-cdrom")) { disk->device = VIR_DOMAIN_DISK_DEVICE_CDROM; - if (((def->os.arch == VIR_ARCH_PPC64) && + if ((ARCH_IS_PPC64(def->os.arch) && def->os.machine && STRPREFIX(def->os.machine, "pseries"))) disk->bus = VIR_DOMAIN_DISK_BUS_SCSI; if (VIR_STRDUP(disk->dst, "hdc") < 0) @@ -11670,7 +11670,7 @@ qemuParseCommandLine(virCapsPtr qemuCaps, disk->bus = VIR_DOMAIN_DISK_BUS_IDE; else disk->bus = VIR_DOMAIN_DISK_BUS_SCSI; - if (((def->os.arch == VIR_ARCH_PPC64) && + if ((ARCH_IS_PPC64(def->os.arch) && def->os.machine && STRPREFIX(def->os.machine, "pseries"))) disk->bus = VIR_DOMAIN_DISK_BUS_SCSI; } diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 76fccce..e4edf34 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -980,6 +980,7 @@ qemuDomainDefPostParse(virDomainDefPtr def, break; case VIR_ARCH_PPC64: + case VIR_ARCH_PPC64LE: addPCIRoot = true; addDefaultUSBKBD = true; addDefaultUSBMouse = true; diff --git a/src/util/virarch.h b/src/util/virarch.h index d395e58..3206ce2 100644 --- a/src/util/virarch.h +++ b/src/util/virarch.h @@ -79,6 +79,9 @@ typedef enum { (arch) == VIR_ARCH_PPC64LE ||\ (arch) == VIR_ARCH_PPCEMB) +# define ARCH_IS_PPC64(arch) ((arch) == VIR_ARCH_PPC64 ||\ + (arch) == VIR_ARCH_PPC64LE) + # define ARCH_IS_ARM(arch) ((arch) == VIR_ARCH_ARMV6L ||\ (arch) == VIR_ARCH_ARMV7L ||\ (arch) == VIR_ARCH_ARMV7B ||\ -- 1.9.3 -- Prerna Saxena Linux Technology Centre, IBM Systems and Technology Lab, Bangalore, India
From c3572e59f1e56322ba92ab35e31da48dd63b7cec Mon Sep 17 00:00:00 2001 From: Prerna Saxena <prerna@linux.vnet.ibm.com> Date: Tue, 21 Oct 2014 01:06:51 -0400
PowerISA allows processors to run VMs in binary compatibility ("compat") mode supporting an older version of ISA. QEMU has recently added support to explicitly denote a VM running in compatibility mode through commit 6d9412ea & 8dfa3a5e85. Now, a "compat" mode VM can be run by invoking this qemu commandline on a POWER8 host: -cpu host,compat=power7. This patch allows libvirt to extend the "fallback" semantics of cpu model to describe this new mode for PowerKVM guests. As an example: When a user wants to request a power7 vm to run in compatibility mode on a Power8 host, this can be described in XML as follows : <cpu mode='host-model' match='exact'> <model fallback='compat'>power7</model> </cpu> Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com> Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com> Signed-off-by: Pradipta Kr. Banerjee <bpradip@in.ibm.com> --- docs/schemas/domaincommon.rng | 1 + src/conf/cpu_conf.c | 4 +++- src/conf/cpu_conf.h | 1 + src/cpu/cpu_powerpc.c | 14 ++++---------- src/qemu/qemu_command.c | 11 ++++++++++- 5 files changed, 19 insertions(+), 12 deletions(-) diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index 20d81ae..ebab482 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -4067,6 +4067,7 @@ <choice> <value>allow</value> <value>forbid</value> + <value>compat</value> </choice> </attribute> </optional> diff --git a/src/conf/cpu_conf.c b/src/conf/cpu_conf.c index 9b7fbb0..e12d3db 100644 --- a/src/conf/cpu_conf.c +++ b/src/conf/cpu_conf.c @@ -47,7 +47,8 @@ VIR_ENUM_IMPL(virCPUMatch, VIR_CPU_MATCH_LAST, VIR_ENUM_IMPL(virCPUFallback, VIR_CPU_FALLBACK_LAST, "allow", - "forbid") + "forbid", + "compat") VIR_ENUM_IMPL(virCPUFeaturePolicy, VIR_CPU_FEATURE_LAST, "force", @@ -619,6 +620,7 @@ virCPUDefFormatBuf(virBufferPtr buf, return 0; formatModel = (def->mode == VIR_CPU_MODE_CUSTOM || + def->mode == VIR_CPU_MODE_HOST_MODEL || (flags & VIR_DOMAIN_XML_UPDATE_CPU)); formatFallback = (def->type == VIR_CPU_TYPE_GUEST && (def->mode == VIR_CPU_MODE_HOST_MODEL || diff --git a/src/conf/cpu_conf.h b/src/conf/cpu_conf.h index d45210b..69d8584 100644 --- a/src/conf/cpu_conf.h +++ b/src/conf/cpu_conf.h @@ -65,6 +65,7 @@ VIR_ENUM_DECL(virCPUMatch) typedef enum { VIR_CPU_FALLBACK_ALLOW, VIR_CPU_FALLBACK_FORBID, + VIR_CPU_FALLBACK_COMPAT, VIR_CPU_FALLBACK_LAST } virCPUFallback; diff --git a/src/cpu/cpu_powerpc.c b/src/cpu/cpu_powerpc.c index d591c18..ad887fe 100644 --- a/src/cpu/cpu_powerpc.c +++ b/src/cpu/cpu_powerpc.c @@ -479,7 +479,8 @@ ppcDecode(virCPUDefPtr cpu, goto cleanup; } - if (!cpuModelIsAllowed(model->name, models, nmodels)) { + if (cpu->fallback != VIR_CPU_FALLBACK_COMPAT && + !cpuModelIsAllowed(model->name, models, nmodels)) { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, _("CPU model %s is not supported by hypervisor"), model->name); @@ -562,8 +563,8 @@ ppcUpdate(virCPUDefPtr guest, static virCPUDefPtr ppcBaseline(virCPUDefPtr *cpus, unsigned int ncpus, - const char **models, - unsigned int nmodels, + const char **models ATTRIBUTE_UNUSED, + unsigned int nmodels ATTRIBUTE_UNUSED, unsigned int flags) { struct ppc_map *map = NULL; @@ -583,13 +584,6 @@ ppcBaseline(virCPUDefPtr *cpus, goto error; } - if (!cpuModelIsAllowed(model->name, models, nmodels)) { - virReportError(VIR_ERR_CONFIG_UNSUPPORTED, - _("CPU model %s is not supported by hypervisor"), - model->name); - goto error; - } - for (i = 0; i < ncpus; i++) { const struct ppc_vendor *vnd; diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index d60f274..3143bd8 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -6221,7 +6221,9 @@ qemuBuildCpuModelArgStr(virQEMUDriverPtr driver, *hasHwVirt = hasSVM > 0 ? true : false; } - if (cpu->mode == VIR_CPU_MODE_HOST_PASSTHROUGH) { + if ((cpu->mode == VIR_CPU_MODE_HOST_PASSTHROUGH) || + ((cpu->mode == VIR_CPU_MODE_HOST_MODEL) && + ARCH_IS_PPC64(def->os.arch))) { const char *mode = virCPUModeTypeToString(cpu->mode); if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_CPU_HOST)) { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, @@ -6236,6 +6238,13 @@ qemuBuildCpuModelArgStr(virQEMUDriverPtr driver, goto cleanup; } virBufferAddLit(buf, "host"); + + if (ARCH_IS_PPC64(def->os.arch) && + cpu->mode == VIR_CPU_MODE_HOST_MODEL && + cpu->fallback == VIR_CPU_FALLBACK_COMPAT) { + virBufferAsprintf(buf, ",compat=%s", def->cpu->model); + } + } else { if (VIR_ALLOC(guest) < 0) goto cleanup; -- 1.8.3.1 -- Prerna Saxena Linux Technology Centre, IBM Systems and Technology Lab, Bangalore, India
Apologies, I accidentally posted the older version. Pls ignore the previously posted patch 2/3. The updated patch is here :
From a98d6787dc4f1d39ae36d78799ecf36018377ec7 Mon Sep 17 00:00:00 2001 From: Prerna Saxena <prerna@linux.vnet.ibm.com> Date: Tue, 28 Oct 2014 15:05:59 +0530 Subject: [PATCH 2/3] PowerPC : Add support for launching VMs in 'compat' mode.
PowerISA allows processors to run VMs in binary compatibility ("compat") mode supporting an older version of ISA. QEMU has recently added support to explicitly denote a VM running in compatibility mode through commit 6d9412ea & 8dfa3a5e85. Now, a "compat" mode VM can be run by invoking this qemu commandline on a POWER8 host: -cpu host,compat=power7. This patch allows libvirt to extend the "fallback" semantics of cpu model to describe this new mode for PowerKVM guests. As an example: When a user wants to request a power7 vm to run in compatibility mode on a Power8 host, this can be described in XML as follows : <cpu mode='host-model' match='exact'> <model fallback='compat'>power7</model> </cpu> Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com> Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com> Signed-off-by: Pradipta Kr. Banerjee <bpradip@in.ibm.com> --- docs/formatdomain.html.in | 17 ++++++++++++++++- docs/schemas/domaincommon.rng | 1 + src/conf/cpu_conf.c | 4 +++- src/conf/cpu_conf.h | 1 + src/cpu/cpu_powerpc.c | 14 ++++---------- src/qemu/qemu_command.c | 11 ++++++++++- 6 files changed, 35 insertions(+), 13 deletions(-) diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index 0099ce7..babca04 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -1047,7 +1047,22 @@ (such as CPUID level) that don't work. Until these issues are fixed, it's a good idea to avoid using <code>host-model</code> and use <code>custom</code> mode with just the CPU model from host - capabilities XML.</dd> + capabilities XML. + <span class="since">(Since 1.2.10)</span> Libvirt on ppc64 introduces + a new mode <code>compat</code> to model PowerPC cpus running in binary + compatibility mode. PowerISA allows processors to run VMs in binary + compatibility ("compat") mode supporting an older version of ISA. For + example, when a user wants to request a power7 vm to run in + compatibility mode on a power8 host, this can be described in XML + as follows : +<pre> + <cpu mode='host-model'> + <model fallback='compat'<power7 <model/> + <topology sockets='1' cores='2' threads='1'/> + </cpu> + ...</pre> + </dd> + <dt><code>host-passthrough</code></dt> <dd>With this mode, the CPU visible to the guest should be exactly the same as the host CPU even in the aspects that libvirt does not diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index 20d81ae..ebab482 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -4067,6 +4067,7 @@ <choice> <value>allow</value> <value>forbid</value> + <value>compat</value> </choice> </attribute> </optional> diff --git a/src/conf/cpu_conf.c b/src/conf/cpu_conf.c index 9b7fbb0..e12d3db 100644 --- a/src/conf/cpu_conf.c +++ b/src/conf/cpu_conf.c @@ -47,7 +47,8 @@ VIR_ENUM_IMPL(virCPUMatch, VIR_CPU_MATCH_LAST, VIR_ENUM_IMPL(virCPUFallback, VIR_CPU_FALLBACK_LAST, "allow", - "forbid") + "forbid", + "compat") VIR_ENUM_IMPL(virCPUFeaturePolicy, VIR_CPU_FEATURE_LAST, "force", @@ -619,6 +620,7 @@ virCPUDefFormatBuf(virBufferPtr buf, return 0; formatModel = (def->mode == VIR_CPU_MODE_CUSTOM || + def->mode == VIR_CPU_MODE_HOST_MODEL || (flags & VIR_DOMAIN_XML_UPDATE_CPU)); formatFallback = (def->type == VIR_CPU_TYPE_GUEST && (def->mode == VIR_CPU_MODE_HOST_MODEL || diff --git a/src/conf/cpu_conf.h b/src/conf/cpu_conf.h index d45210b..69d8584 100644 --- a/src/conf/cpu_conf.h +++ b/src/conf/cpu_conf.h @@ -65,6 +65,7 @@ VIR_ENUM_DECL(virCPUMatch) typedef enum { VIR_CPU_FALLBACK_ALLOW, VIR_CPU_FALLBACK_FORBID, + VIR_CPU_FALLBACK_COMPAT, VIR_CPU_FALLBACK_LAST } virCPUFallback; diff --git a/src/cpu/cpu_powerpc.c b/src/cpu/cpu_powerpc.c index d591c18..abe9047 100644 --- a/src/cpu/cpu_powerpc.c +++ b/src/cpu/cpu_powerpc.c @@ -479,7 +479,8 @@ ppcDecode(virCPUDefPtr cpu, goto cleanup; } - if (!cpuModelIsAllowed(model->name, models, nmodels)) { + if (cpu->fallback != VIR_CPU_FALLBACK_COMPAT && + !cpuModelIsAllowed(model->name, models, nmodels)) { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, _("CPU model %s is not supported by hypervisor"), model->name); @@ -562,8 +563,8 @@ ppcUpdate(virCPUDefPtr guest, static virCPUDefPtr ppcBaseline(virCPUDefPtr *cpus, unsigned int ncpus, - const char **models, - unsigned int nmodels, + const char **models ATTRIBUTE_UNUSED, + unsigned int nmodels ATTRIBUTE_UNUSED, unsigned int flags) { struct ppc_map *map = NULL; @@ -583,13 +584,6 @@ ppcBaseline(virCPUDefPtr *cpus, goto error; } - if (!cpuModelIsAllowed(model->name, models, nmodels)) { - virReportError(VIR_ERR_CONFIG_UNSUPPORTED, - _("CPU model %s is not supported by hypervisor"), - model->name); - goto error; - } - for (i = 0; i < ncpus; i++) { const struct ppc_vendor *vnd; diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index d60f274..3143bd8 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -6221,7 +6221,9 @@ qemuBuildCpuModelArgStr(virQEMUDriverPtr driver, *hasHwVirt = hasSVM > 0 ? true : false; } - if (cpu->mode == VIR_CPU_MODE_HOST_PASSTHROUGH) { + if ((cpu->mode == VIR_CPU_MODE_HOST_PASSTHROUGH) || + ((cpu->mode == VIR_CPU_MODE_HOST_MODEL) && + ARCH_IS_PPC64(def->os.arch))) { const char *mode = virCPUModeTypeToString(cpu->mode); if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_CPU_HOST)) { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, @@ -6236,6 +6238,13 @@ qemuBuildCpuModelArgStr(virQEMUDriverPtr driver, goto cleanup; } virBufferAddLit(buf, "host"); + + if (ARCH_IS_PPC64(def->os.arch) && + cpu->mode == VIR_CPU_MODE_HOST_MODEL && + cpu->fallback == VIR_CPU_FALLBACK_COMPAT) { + virBufferAsprintf(buf, ",compat=%s", def->cpu->model); + } + } else { if (VIR_ALLOC(guest) < 0) goto cleanup; -- 1.9.3
On Tue, Oct 28, 2014 at 04:43:59PM +0530, Prerna Saxena wrote:
Apologies, I accidentally posted the older version. Pls ignore the previously posted patch 2/3. The updated patch is here :
From a98d6787dc4f1d39ae36d78799ecf36018377ec7 Mon Sep 17 00:00:00 2001 From: Prerna Saxena <prerna@linux.vnet.ibm.com> Date: Tue, 28 Oct 2014 15:05:59 +0530 Subject: [PATCH 2/3] PowerPC : Add support for launching VMs in 'compat' mode.
PowerISA allows processors to run VMs in binary compatibility ("compat") mode supporting an older version of ISA. QEMU has recently added support to explicitly denote a VM running in compatibility mode through commit 6d9412ea & 8dfa3a5e85. Now, a "compat" mode VM can be run by invoking this qemu commandline on a POWER8 host: -cpu host,compat=power7.
This patch allows libvirt to extend the "fallback" semantics of cpu model to describe this new mode for PowerKVM guests. As an example: When a user wants to request a power7 vm to run in compatibility mode on a Power8 host, this can be described in XML as follows : <cpu mode='host-model' match='exact'> <model fallback='compat'>power7</model>
I don't really see any point in adding the fallback='compat' attribute. That is basically always implied if you use mode=host-model in combination with a named model. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
On Tuesday 28 October 2014 05:32 PM, Daniel P. Berrange wrote:
On Tue, Oct 28, 2014 at 04:43:59PM +0530, Prerna Saxena wrote:
Apologies, I accidentally posted the older version. Pls ignore the previously posted patch 2/3. The updated patch is here :
From a98d6787dc4f1d39ae36d78799ecf36018377ec7 Mon Sep 17 00:00:00 2001 From: Prerna Saxena <prerna@linux.vnet.ibm.com> Date: Tue, 28 Oct 2014 15:05:59 +0530 Subject: [PATCH 2/3] PowerPC : Add support for launching VMs in 'compat' mode.
PowerISA allows processors to run VMs in binary compatibility ("compat") mode supporting an older version of ISA. QEMU has recently added support to explicitly denote a VM running in compatibility mode through commit 6d9412ea & 8dfa3a5e85. Now, a "compat" mode VM can be run by invoking this qemu commandline on a POWER8 host: -cpu host,compat=power7.
This patch allows libvirt to extend the "fallback" semantics of cpu model to describe this new mode for PowerKVM guests. As an example: When a user wants to request a power7 vm to run in compatibility mode on a Power8 host, this can be described in XML as follows : <cpu mode='host-model' match='exact'> <model fallback='compat'>power7</model> I don't really see any point in adding the fallback='compat' attribute. That is basically always implied if you use mode=host-model in combination with a named model. Hi Daniel, Running in compatibility mode is not identical to running natively on an older processor. Reproducing the example from : http://www.redhat.com/archives/libvir-list/2014-October/msg00359.html
On PowerKVM, we can run VMs in 2 possible vCPU configurations: 1) Host native mode: Where host is power7; guest VMs also see power7 vcpus. Required qemu command line : "-cpu host" 2) Compat mode: In this case, the host CPU is Power8, but it can run in binary compatibility mode with an older version of ISA(such as power7). So it will exhibit only those features that were available in an older generation of Power ISA. The guest will see a "power7" vCPU even though it is running on a physical "power8" chip. This is a hardware feature that is enabled via a qemu/kvm switch. Required QEMU command line for PowerKVM : "-cpu host,compat=power7" My patch attempts to define semantics for this second mode of execution. A VM running in compat mode will not just differ in terms of qemu command line, but also in behaviour when contrasted with the host native mode. In other words, applications running on "power7" native VM will see different CPU as compared to applications running on a compat-mode "power7" VM over a Power8 host. From a VM management perspective, this difference needs to be brought out in XML. Also, "compat" mode is one way of emulating an older processor chip, but it may not be the _only_ way. Hence the virtualization stack needs to explicitly distinguish a compat-mode VM. In my v2 post, you had suggested that model fallback 'compat' be based on "host-model" cpu mode in place of "custom". I have sent out v3 and v4 based on this suggestion. Hope this XML schema is acceptable: <cpu mode='host-model'> <model fallback='compat'>power7</model> </cpu> I am looking forward to community inputs on what is a good place to introduce "compat" tag in XML schema. Will be happy to spin a v5 if another place seems more appropriate for the "compat" CPU tag. Regards, -- Prerna Saxena Linux Technology Centre, IBM Systems and Technology Lab, Bangalore, India
On Wed, Oct 29, 2014 at 05:04:22PM +0530, Prerna Saxena wrote:
On Tuesday 28 October 2014 05:32 PM, Daniel P. Berrange wrote:
On Tue, Oct 28, 2014 at 04:43:59PM +0530, Prerna Saxena wrote:
This patch allows libvirt to extend the "fallback" semantics of cpu model to describe this new mode for PowerKVM guests. As an example: When a user wants to request a power7 vm to run in compatibility mode on a Power8 host, this can be described in XML as follows : <cpu mode='host-model' match='exact'> <model fallback='compat'>power7</model>
I don't really see any point in adding the fallback='compat' attribute. That is basically always implied if you use mode=host-model in combination with a named model. Hi Daniel, Running in compatibility mode is not identical to running natively on an older processor. Reproducing the example from : http://www.redhat.com/archives/libvir-list/2014-October/msg00359.html
On PowerKVM, we can run VMs in 2 possible vCPU configurations: 1) Host native mode: Where host is power7; guest VMs also see power7 vcpus. Required qemu command line : "-cpu host"
2) Compat mode: In this case, the host CPU is Power8, but it can run in binary compatibility mode with an older version of ISA(such as power7). So it will exhibit only those features that were available in an older generation of Power ISA. The guest will see a "power7" vCPU even though it is running on a physical "power8" chip. This is a hardware feature that is enabled via a qemu/kvm switch.
Required QEMU command line for PowerKVM : "-cpu host,compat=power7"
Sure, I don't debate that this is the QEMU command line syntax. I don't see any reason why the fact that QEMU uses 'compat' here requires the addition of 'compat' at the libvit XML level.
My patch attempts to define semantics for this second mode of execution.
A VM running in compat mode will not just differ in terms of qemu command line, but also in behaviour when contrasted with the host native mode. In other words, applications running on "power7" native VM will see different CPU as compared to applications running on a compat-mode "power7" VM over a Power8 host. From a VM management perspective, this difference needs to be brought out in XML.
Also, "compat" mode is one way of emulating an older processor chip, but it may not be the _only_ way.
Hence the virtualization stack needs to explicitly distinguish a compat-mode VM.
In my v2 post, you had suggested that model fallback 'compat' be based on "host-model" cpu mode in place of "custom". I have sent out v3 and v4 based on this suggestion.
Hope this XML schema is acceptable: <cpu mode='host-model'> <model fallback='compat'>power7</model> </cpu>
The current libvirt code only allows for <cpu mode="host-model"/> which maps to '-cpu host' Given this starting point, it is sufficient to just have <cpu mode='host-model'> <model>power7</model> </cpu> mapping to '-cpu host,compat=power7' ie the very existance of a <model> against host-model is sufficient. We don't need to invent a pointless fallback=compat attribute too. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
From 415fce714a8d7ca9113e6bf7168f910b171e86d8 Mon Sep 17 00:00:00 2001 From: Prerna Saxena <prerna@linux.vnet.ibm.com> Date: Tue, 28 Oct 2014 15:30:05 +0530
IBM Power processors differ uniquely across generations (such as power6, power7, power8). Each generation signifies a new PowerISA version that exhibits features unique to that generation. The higher 16 bits of PVR for IBM Power processors encode the CPU generation, while the CPU chip (sub)version is encoded in lower 16 bits. For all practical purposes of launching a VM, we care about the generation which the vCPU will belong to, and not specifically the chip version. This patch updates the libvirt PVR check to reflect this relationship. It allows libvirt to select the right CPU generation in case the exact match for a a specific CPU is not found. Hence, there will no longer be a need to add each PowerPC CPU model to cpu_map.xml; just adding entry for the matching ISA generation will suffice. It also contains changes to cpu_map.xml since processor generations as understood by QEMU compat mode go as "power6", "power7" or "power8" [Reference : QEMU commit 8dfa3a5e85 ] Signed-off-by: Pradipta Kr. Banerjee <bpradip@in.ibm.com> Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com> --- src/cpu/cpu_map.xml | 24 ++++++++++++++++++++++++ src/cpu/cpu_powerpc.c | 8 ++++++++ 2 files changed, 32 insertions(+) diff --git a/src/cpu/cpu_map.xml b/src/cpu/cpu_map.xml index 18c7b0d..f9d8d38 100644 --- a/src/cpu/cpu_map.xml +++ b/src/cpu/cpu_map.xml @@ -627,5 +627,29 @@ <pvr value='0x004b0100'/> </model> + <model name='power6'> + <vendor name='IBM'/> + <compat isa='2.05'/> + <pvr value='0x003e0000'/> + </model> + + <model name='power7'> + <vendor name='IBM'/> + <compat isa='2.06'/> + <pvr value='0x003f0000'/> + </model> + + <model name='power7+'> + <vendor name='IBM'/> + <compat isa='2.06B'/> + <pvr value='0x004a0000'/> + </model> + + <model name='power8'> + <vendor name='IBM'/> + <compat isa='2.07'/> + <pvr value='0x004b0000'/> + </model> + </arch> </cpus> diff --git a/src/cpu/cpu_powerpc.c b/src/cpu/cpu_powerpc.c index abe9047..25c028c 100644 --- a/src/cpu/cpu_powerpc.c +++ b/src/cpu/cpu_powerpc.c @@ -99,6 +99,14 @@ ppcModelFindPVR(const struct ppc_map *map, model = model->next; } + /* PowerPC Processor Version Register is interpreted as follows : + * Higher order 16 bits : Power ISA generation. + * Lower order 16 bits : CPU chip version number. + * If the exact CPU isnt found, return the nearest matching CPU generation + */ + if (pvr & 0x0000FFFFul) + return ppcModelFindPVR(map, (pvr & 0xFFFF0000ul)); + return NULL; } -- 1.9.3 -- Prerna Saxena Linux Technology Centre, IBM Systems and Technology Lab, Bangalore, India
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Daniel P. Berrange -
Prerna Saxena