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;
>
>
--
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