[libvirt] [PATCH] qemu: cpu: fix fullCPU to include all emulatable qemu features
On Core i5 650 guest fail to start with error [1] if guest cpu config is taken from domcapabilities and check is set to partial. The problem is in qemu caps fullCPU calculation in virQEMUCapsInitHostCPUModel. It is supposed to include features emulated by qemu and missed on host. Some of such features may be not included however. For mentioned cpu host cpu is detected as Westmere and guest cpu as SandyBridge. x2apic is missed on host and provided by installed qemu. The feature is not mentioned in guest cpu features explicitly because SandyBridge model include it. As a result fullCPU does not include x2apic too. Solution is to expand guest cpu features before updating fullCPU features. [1] error: the CPU is incompatible with host CPU: Host CPU does not provide required features: x2apic, tsc-deadline --- src/qemu/qemu_capabilities.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index 9c1eeac..edba716 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -3475,6 +3475,7 @@ virQEMUCapsInitHostCPUModel(virQEMUCapsPtr qemuCaps, virDomainVirtType type) { virCPUDefPtr cpu = NULL; + virCPUDefPtr cpuExpanded = NULL; virCPUDefPtr migCPU = NULL; virCPUDefPtr hostCPU = NULL; virCPUDefPtr fullCPU = NULL; @@ -3504,9 +3505,13 @@ virQEMUCapsInitHostCPUModel(virQEMUCapsPtr qemuCaps, NULL, NULL))) goto error; - for (i = 0; i < cpu->nfeatures; i++) { - if (cpu->features[i].policy == VIR_CPU_FEATURE_REQUIRE && - virCPUDefUpdateFeature(fullCPU, cpu->features[i].name, + if (!(cpuExpanded = virCPUDefCopy(cpu)) || + virCPUExpandFeatures(qemuCaps->arch, cpuExpanded) < 0) + goto error; + + for (i = 0; i < cpuExpanded->nfeatures; i++) { + if (cpuExpanded->features[i].policy == VIR_CPU_FEATURE_REQUIRE && + virCPUDefUpdateFeature(fullCPU, cpuExpanded->features[i].name, VIR_CPU_FEATURE_REQUIRE) < 0) goto error; } @@ -3528,6 +3533,7 @@ virQEMUCapsInitHostCPUModel(virQEMUCapsPtr qemuCaps, virQEMUCapsSetHostModel(qemuCaps, type, cpu, migCPU, fullCPU); cleanup: + virCPUDefFree(cpuExpanded); virCPUDefFree(hostCPU); return; -- 1.8.3.1
ping On 20.11.2017 15:55, Nikolay Shirokovskiy wrote:
On Core i5 650 guest fail to start with error [1] if guest cpu config is taken from domcapabilities and check is set to partial.
The problem is in qemu caps fullCPU calculation in virQEMUCapsInitHostCPUModel. It is supposed to include features emulated by qemu and missed on host. Some of such features may be not included however.
For mentioned cpu host cpu is detected as Westmere and guest cpu as SandyBridge. x2apic is missed on host and provided by installed qemu. The feature is not mentioned in guest cpu features explicitly because SandyBridge model include it. As a result fullCPU does not include x2apic too.
Solution is to expand guest cpu features before updating fullCPU features.
[1] error: the CPU is incompatible with host CPU: Host CPU does not provide required features: x2apic, tsc-deadline --- src/qemu/qemu_capabilities.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index 9c1eeac..edba716 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -3475,6 +3475,7 @@ virQEMUCapsInitHostCPUModel(virQEMUCapsPtr qemuCaps, virDomainVirtType type) { virCPUDefPtr cpu = NULL; + virCPUDefPtr cpuExpanded = NULL; virCPUDefPtr migCPU = NULL; virCPUDefPtr hostCPU = NULL; virCPUDefPtr fullCPU = NULL; @@ -3504,9 +3505,13 @@ virQEMUCapsInitHostCPUModel(virQEMUCapsPtr qemuCaps, NULL, NULL))) goto error;
- for (i = 0; i < cpu->nfeatures; i++) { - if (cpu->features[i].policy == VIR_CPU_FEATURE_REQUIRE && - virCPUDefUpdateFeature(fullCPU, cpu->features[i].name, + if (!(cpuExpanded = virCPUDefCopy(cpu)) || + virCPUExpandFeatures(qemuCaps->arch, cpuExpanded) < 0) + goto error; + + for (i = 0; i < cpuExpanded->nfeatures; i++) { + if (cpuExpanded->features[i].policy == VIR_CPU_FEATURE_REQUIRE && + virCPUDefUpdateFeature(fullCPU, cpuExpanded->features[i].name, VIR_CPU_FEATURE_REQUIRE) < 0) goto error; } @@ -3528,6 +3533,7 @@ virQEMUCapsInitHostCPUModel(virQEMUCapsPtr qemuCaps, virQEMUCapsSetHostModel(qemuCaps, type, cpu, migCPU, fullCPU);
cleanup: + virCPUDefFree(cpuExpanded); virCPUDefFree(hostCPU); return;
I've checked against latest upstream version of libvirt. Issue is still not fixed. I guess I should provide cpu data for tests like in next patch: Author: Jiri Denemark <jdenemar@redhat.com> Date: Fri Jan 5 14:52:45 2018 +0100 cputest: Add data for Intel(R) Xeon(R) CPU E5-2609 v3 The CPU contains the updated microcode for CVE-2017-5715. Signed-off-by: Jiri Denemark <jdenemar@redhat.com> Reviewed-by: Pavel Hrdina <phrdina@redhat.com> tests/cputest.c | 1 + tests/cputestdata/x86_64-cpuid-Xeon-E5-2609-v3-disabled.xml | 6 + tests/cputestdata/x86_64-cpuid-Xeon-E5-2609-v3-enabled.xml | 8 + tests/cputestdata/x86_64-cpuid-Xeon-E5-2609-v3-guest.xml | 32 +++ tests/cputestdata/x86_64-cpuid-Xeon-E5-2609-v3-host.xml | 33 +++ tests/cputestdata/x86_64-cpuid-Xeon-E5-2609-v3-json.xml | 15 ++ tests/cputestdata/x86_64-cpuid-Xeon-E5-2609-v3.json | 726 ++++++++++++++++++++++++++++++++++++++++++++++++++ tests/cputestdata/x86_64-cpuid-Xeon-E5-2609-v3.xml | 37 +++ 8 files changed, 858 insertions(+) I just can not find a script in libvirt repo that generates them. On 20.11.2017 15:55, Nikolay Shirokovskiy wrote:
On Core i5 650 guest fail to start with error [1] if guest cpu config is taken from domcapabilities and check is set to partial.
The problem is in qemu caps fullCPU calculation in virQEMUCapsInitHostCPUModel. It is supposed to include features emulated by qemu and missed on host. Some of such features may be not included however.
For mentioned cpu host cpu is detected as Westmere and guest cpu as SandyBridge. x2apic is missed on host and provided by installed qemu. The feature is not mentioned in guest cpu features explicitly because SandyBridge model include it. As a result fullCPU does not include x2apic too.
Solution is to expand guest cpu features before updating fullCPU features.
[1] error: the CPU is incompatible with host CPU: Host CPU does not provide required features: x2apic, tsc-deadline --- src/qemu/qemu_capabilities.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index 9c1eeac..edba716 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -3475,6 +3475,7 @@ virQEMUCapsInitHostCPUModel(virQEMUCapsPtr qemuCaps, virDomainVirtType type) { virCPUDefPtr cpu = NULL; + virCPUDefPtr cpuExpanded = NULL; virCPUDefPtr migCPU = NULL; virCPUDefPtr hostCPU = NULL; virCPUDefPtr fullCPU = NULL; @@ -3504,9 +3505,13 @@ virQEMUCapsInitHostCPUModel(virQEMUCapsPtr qemuCaps, NULL, NULL))) goto error;
- for (i = 0; i < cpu->nfeatures; i++) { - if (cpu->features[i].policy == VIR_CPU_FEATURE_REQUIRE && - virCPUDefUpdateFeature(fullCPU, cpu->features[i].name, + if (!(cpuExpanded = virCPUDefCopy(cpu)) || + virCPUExpandFeatures(qemuCaps->arch, cpuExpanded) < 0) + goto error; + + for (i = 0; i < cpuExpanded->nfeatures; i++) { + if (cpuExpanded->features[i].policy == VIR_CPU_FEATURE_REQUIRE && + virCPUDefUpdateFeature(fullCPU, cpuExpanded->features[i].name, VIR_CPU_FEATURE_REQUIRE) < 0) goto error; } @@ -3528,6 +3533,7 @@ virQEMUCapsInitHostCPUModel(virQEMUCapsPtr qemuCaps, virQEMUCapsSetHostModel(qemuCaps, type, cpu, migCPU, fullCPU);
cleanup: + virCPUDefFree(cpuExpanded); virCPUDefFree(hostCPU); return;
On Thu, Apr 05, 2018 at 10:26:48 +0300, Nikolay Shirokovskiy wrote:
I've checked against latest upstream version of libvirt. Issue is still not fixed.
I guess I should provide cpu data for tests like in next patch:
Yeah, CPU data would be helpful to see more details about the CPU. You can generate them in tests/cputestdata using ./cpu-gather.sh | ./cpu-parse.sh You may need to install the cpuid tool before using them and ideally have a modern QEMU binary installed too. Jirka
participants (2)
-
Jiri Denemark -
Nikolay Shirokovskiy