[libvirt] [PATCH 1/4] qemu: Enable configuration of HPT resizing for pSeries guests

[John Ferlan]

On 11/06/2017 11:08 AM, Andrea Bolognani wrote:
> Most of the time it's okay to leave this up to negotiation between
> the guest and the host, but in some situations it can be useful to
> manually decide the behavior, especially to enforce its availability.
> 
> Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1308743
> 
> Signed-off-by: Andrea Bolognani <abologna at redhat.com>
> ---
>  docs/schemas/domaincommon.rng                    | 15 ++++++++
>  src/conf/domain_conf.c                           | 46 +++++++++++++++++++++++-
>  src/conf/domain_conf.h                           | 12 +++++++
>  src/libvirt_private.syms                         |  1 +
>  src/qemu/qemu_capabilities.c                     |  8 +++++
>  src/qemu/qemu_capabilities.h                     |  1 +
>  src/qemu/qemu_command.c                          | 20 +++++++++++
>  src/qemu/qemu_domain.c                           |  8 +++++
>  tests/qemucapabilitiesdata/caps_2.10.0.ppc64.xml |  1 +
>  9 files changed, 111 insertions(+), 1 deletion(-)
> 

[...]

> diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
> index 7cb091056..1badadbc2 100644
> --- a/src/qemu/qemu_capabilities.c
> +++ b/src/qemu/qemu_capabilities.c
> @@ -443,6 +443,7 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST,
>                /* 270 */
>                "vxhs",
>                "virtio-blk.num-queues",
> +              "machine.pseries.resize-hpt",
>      );
>  
>  
> @@ -4776,6 +4777,13 @@ virQEMUCapsInitQMPMonitor(virQEMUCapsPtr qemuCaps,
>      if (qemuCaps->version >= 2006000)
>          virQEMUCapsSet(qemuCaps, QEMU_CAPS_MACHINE_KERNEL_IRQCHIP_SPLIT);
>  
> +    /* HPT resizing is supported since QEMU 2.10 on ppc64; unfortunately
> +     * there's no sane way to probe for it */
> +    if (qemuCaps->version >= 2010000 &&
> +        ARCH_IS_PPC64(qemuCaps->arch)) {

This check differs slightly from qemuDomainDefVerifyFeatures

> +        virQEMUCapsSet(qemuCaps, QEMU_CAPS_MACHINE_PSERIES_RESIZE_HPT);
> +    }
> +
>      if (virQEMUCapsProbeQMPCommands(qemuCaps, mon) < 0)
>          goto cleanup;
>  

[...]

> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> index 8708b79ed..e8868a34a 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -7526,6 +7526,26 @@ qemuBuildMachineCommandLine(virCommandPtr cmd,
>              }
>          }
>  
> +        if (def->features[VIR_DOMAIN_FEATURE_HPT] == VIR_TRISTATE_SWITCH_ON) {
> +            const char *str;
> +
> +            if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_MACHINE_PSERIES_RESIZE_HPT)) {
> +                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> +                               _("HTP resizing is not supported by this "
> +                                 "QEMU binary"));
> +                goto cleanup;
> +            }
> +
> +            str = virDomainHPTResizingTypeToString(def->hpt_resizing);
> +            if (!str) {
> +                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> +                               _("Invalid setting for HPT resizing"));
> +                goto cleanup;
> +            }
> +
> +            virBufferAsprintf(&buf, ",resize-hpt=%s", str);

This one only cares about the capability...

> +        }
> +
>          if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_BOOTINDEX) &&
>              virQEMUCapsGet(qemuCaps, QEMU_CAPS_LOADPARM))
>              qemuAppendLoadparmMachineParm(&buf, def);
> diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
> index b248a3ddc..60e6da327 100644
> --- a/src/qemu/qemu_domain.c
> +++ b/src/qemu/qemu_domain.c
> @@ -3142,6 +3142,14 @@ qemuDomainDefVerifyFeatures(const virDomainDef *def)
>          return -1;
>      }
>  
> +    if (def->features[VIR_DOMAIN_FEATURE_HPT] == VIR_TRISTATE_SWITCH_ON &&
> +        !qemuDomainIsPSeries(def)) {

But this one adds the def->machine.os check...  I know it's post parse
so it should thus cause failure before building the command line occurs,
so the question is should capability use "&& qemuDomainIsPSeries"?  Your
call...

Reviewed-by: John Ferlan <jferlan at redhat.com>

John

> +        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> +                       "%s",
> +                       _("HPT tuning is only supported for pSeries guests"));
> +        return -1;
> +    }
> +
>      return 0;
>  }
>  
[...]