[libvirt] [PATCH v4 8/8] qemu_driver: hook up query-cpu-model-comparison

[Boris Fiuczynski]

Reviewed-by: Boris Fiuczynski <fiuczy at linux.ibm.com>

On 7/17/19 4:03 PM, Collin Walling wrote:
> This command is hooked into the virsh hypervisor-cpu-compare command.
> As such, the CPU model XML provided to the command will be compared
> to the hypervisor CPU contained in the QEMU capabilities file for the
> appropriate QEMU binary (for s390x, this CPU definition can be observed
> via virsh domcapabilities).
> 
> s390x can report that the first model (A) is a subset of the second
> (B). If A is the hypervisor CPU and a subset of B (the CPU contained
> in the XML), then B would not be able to run on this machine and thus
> we will report that CPU model B is incompatible.
> 
> Signed-off-by: Collin Walling <walling at linux.ibm.com>
> Reviewed-by: Daniel Henrique Barboza <danielh413 at gmail.com>
> ---
>   src/qemu/qemu_capabilities.c | 48 ++++++++++++++++++++++++++++++++++++++++++++
>   src/qemu/qemu_capabilities.h |  9 +++++++++
>   src/qemu/qemu_driver.c       | 11 ++++++++++
>   3 files changed, 68 insertions(+)
> 
> diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
> index a99ebcb..20cb82b 100644
> --- a/src/qemu/qemu_capabilities.c
> +++ b/src/qemu/qemu_capabilities.c
> @@ -5660,3 +5660,51 @@ virQEMUCapsCPUModelBaseline(virQEMUCapsPtr qemuCaps,
>       virCPUDefFree(cpu);
>       return baseline;
>   }
> +
> +virCPUCompareResult
> +virQEMUCapsCPUModelComparison(virQEMUCapsPtr qemuCaps,
> +                              const char *libDir,
> +                              uid_t runUid,
> +                              gid_t runGid,
> +                              virCPUDefPtr cpu_a,
> +                              virCPUDefPtr cpu_b,
> +                              bool failIncompatible)
> +{
> +    qemuProcessQMPPtr proc = NULL;
> +    qemuMonitorCPUModelInfoPtr result = NULL;
> +    int ret = -1;
> +
> +    if (!(proc = qemuProcessQMPNew(qemuCaps->binary, libDir,
> +                                   runUid, runGid, false)))
> +        goto cleanup;
> +
> +    if (qemuProcessQMPStart(proc) < 0)
> +        goto cleanup;
> +
> +    if (qemuMonitorGetCPUModelComparison(proc->mon, cpu_a->model,
> +                                         cpu_a->nfeatures, cpu_a->features,
> +                                         cpu_b->model, cpu_b->nfeatures,
> +                                         cpu_b->features, &result) < 0)
> +        goto cleanup;
> +
> +    if (STREQ(result->name, "incompatible") ||
> +        STREQ(result->name, "subset"))
> +        ret = VIR_CPU_COMPARE_INCOMPATIBLE;
> +    else if (STREQ(result->name, "identical"))
> +        ret = VIR_CPU_COMPARE_IDENTICAL;
> +    else if (STREQ(result->name, "superset"))
> +        ret = VIR_CPU_COMPARE_SUPERSET;
> +
> +    if (failIncompatible && ret == VIR_CPU_COMPARE_INCOMPATIBLE) {
> +        ret = VIR_CPU_COMPARE_ERROR;
> +        virReportError(VIR_ERR_CPU_INCOMPATIBLE, NULL);
> +    }
> +
> + cleanup:
> +    if (ret < 0)
> +        virQEMUCapsLogProbeFailure(qemuCaps->binary);
> +
> +    qemuMonitorCPUModelInfoFree(result);
> +    qemuProcessQMPFree(proc);
> +    return ret;
> +}
> diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
> index 8afa05c..a62499f 100644
> --- a/src/qemu/qemu_capabilities.h
> +++ b/src/qemu/qemu_capabilities.h
> @@ -673,3 +673,12 @@ virCPUDefPtr virQEMUCapsCPUModelBaseline(virQEMUCapsPtr qemuCaps,
>                                           gid_t runGid,
>                                           int ncpus,
>                                           virCPUDefPtr *cpus);
> +
> +virCPUCompareResult
> +virQEMUCapsCPUModelComparison(virQEMUCapsPtr qemuCaps,
> +                              const char *libDir,
> +                              uid_t runUid,
> +                              gid_t runGid,
> +                              virCPUDefPtr cpu_a,
> +                              virCPUDefPtr cpu_b,
> +                              bool failIncompatible);
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index 37b9c75..3e49c04 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -13446,9 +13446,11 @@ qemuConnectCompareHypervisorCPU(virConnectPtr conn,
>   {
>       int ret = VIR_CPU_COMPARE_ERROR;
>       virQEMUDriverPtr driver = conn->privateData;
> +    virQEMUDriverConfigPtr config = driver->config;
>       virQEMUCapsPtr qemuCaps = NULL;
>       bool failIncompatible;
>       virCPUDefPtr hvCPU;
> +    virCPUDefPtr cpu;
>       virArch arch;
>       virDomainVirtType virttype;
>   
> @@ -13483,6 +13485,14 @@ qemuConnectCompareHypervisorCPU(virConnectPtr conn,
>   
>       if (ARCH_IS_X86(arch)) {
>           ret = virCPUCompareXML(arch, hvCPU, xmlCPU, failIncompatible);
> +    } else if (ARCH_IS_S390(arch) &&
> +               virQEMUCapsGet(qemuCaps, QEMU_CAPS_QUERY_CPU_MODEL_COMPARISON)) {
> +        if (virCPUDefParseXMLHelper(xmlCPU, NULL, VIR_CPU_TYPE_AUTO, &cpu) < 0)
> +            goto cleanup;
> +
> +        ret = virQEMUCapsCPUModelComparison(qemuCaps, config->libDir,
> +                                            config->user, config->group,
> +                                            hvCPU, cpu, failIncompatible);
>       } else {
>           virReportError(VIR_ERR_OPERATION_UNSUPPORTED,
>                          _("comparing with the hypervisor CPU is not supported "
> @@ -13490,6 +13500,7 @@ qemuConnectCompareHypervisorCPU(virConnectPtr conn,
>       }
>   
>    cleanup:
> +    virCPUDefFree(cpu);
>       virObjectUnref(qemuCaps);
>       return ret;
>   }
> 


-- 
Mit freundlichen Grüßen/Kind regards
    Boris Fiuczynski

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