Re: [PATCH 5/6] qemu: add support for Direct Mode for Hyper-V Synthetic timers

[Ján Tomko <jtomko@xxxxxxxxxx>]

On Thu, Jul 25, 2019 at 03:52:17PM +0200, Vitaly Kuznetsov wrote:
> QEMU-4.1 supports 'Direct Mode' for Hyper-V synthetic timers
> (hv-stimer-direct CPU flag): Windows guests can request that timer
> expiration notifications are delivered as normal interrupts (and not
> VMBus messages). This is used by Hyper-V on KVM.
>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> ---
> src/qemu/qemu_command.c             | 22 ++++++++++++++--
> src/qemu/qemu_process.c             | 39 +++++++++++++++++++++++++++--
> tests/qemuxml2argvdata/hyperv.args  |  4 +--
> tests/qemuxml2argvdata/hyperv.xml   |  4 ++-
> tests/qemuxml2xmloutdata/hyperv.xml |  4 ++-
> 5 files changed, 65 insertions(+), 8 deletions(-)
>
> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> index 1cf165079f..12229e879e 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -7096,7 +7096,7 @@ qemuBuildCpuCommandLine(virCommandPtr cmd,
>     int ret = -1;
>     virBuffer cpu_buf = VIR_BUFFER_INITIALIZER;
>     virBuffer buf = VIR_BUFFER_INITIALIZER;
> -    size_t i;
> +    size_t i, j;
>
>     if (def->cpu &&
>         (def->cpu->mode != VIR_CPU_MODE_CUSTOM || def->cpu->model)) {
> @@ -7158,7 +7158,6 @@ qemuBuildCpuCommandLine(virCommandPtr cmd,
>             case VIR_DOMAIN_HYPERV_VPINDEX:
>             case VIR_DOMAIN_HYPERV_RUNTIME:
>             case VIR_DOMAIN_HYPERV_SYNIC:
> -            case VIR_DOMAIN_HYPERV_STIMER:
>             case VIR_DOMAIN_HYPERV_RESET:
>             case VIR_DOMAIN_HYPERV_FREQUENCIES:
>             case VIR_DOMAIN_HYPERV_REENLIGHTENMENT:
> @@ -7170,6 +7169,25 @@ qemuBuildCpuCommandLine(virCommandPtr cmd,
>                                       virDomainHypervTypeToString(i));
>                 break;
>
> +            case VIR_DOMAIN_HYPERV_STIMER:
> +                if (def->hyperv_features[i] == VIR_TRISTATE_SWITCH_ON)
> +                    virBufferAsprintf(&buf, ",hv_%s",
> +                                      virDomainHypervTypeToString(i));



> +                for (j = 0; j < VIR_DOMAIN_HYPERV_STIMER_LAST; j++) {
> +                    switch ((virDomainHypervStimer) j) {
> +                    case VIR_DOMAIN_HYPERV_STIMER_DIRECT:
> +                        if (def->hyperv_stimer_features[j] == VIR_TRISTATE_SWITCH_ON)
> +                            virBufferAsprintf(&buf, ",hv_stimer_%s",
> +                                              virDomainHypervStimerTypeToString(j));
> +                        break;
> +
> +                        /* coverity[dead_error_begin] */
> +                    case VIR_DOMAIN_HYPERV_STIMER_LAST:
> +                        break;
> +                    }
> +                }

if (def->hyperv_stimer_direct == VIR_TRISTATE_SWITCH_ON)
   virBufferAddLit(&buf, "hv-stimer-direct");

> +                break;
> +
>             case VIR_DOMAIN_HYPERV_SPINLOCKS:
>                 if (def->hyperv_features[i] == VIR_TRISTATE_SWITCH_ON)
>                     virBufferAsprintf(&buf, ",hv_spinlocks=0x%x",
> diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
> index 75205bc121..0235cfd022 100644
> --- a/src/qemu/qemu_process.c
> +++ b/src/qemu/qemu_process.c
> @@ -4111,10 +4111,45 @@ qemuProcessVerifyHypervFeatures(virDomainDefPtr def,
>         rc = virCPUDataCheckFeature(cpu, cpuFeature);
>         VIR_FREE(cpuFeature);
>
> -        if (rc < 0)
> +        if (rc < 0) {
>             return -1;
> -        else if (rc == 1)
> +        } else if (rc == 1) {
> +            if ((i == VIR_DOMAIN_HYPERV_STIMER)) {
> +                size_t j;
> +

Fails compilation with my Clang:
qemu/qemu_process.c:4117:20: error: equality comparison with extraneous parentheses [-Werror,-Wparentheses-equality]
           if ((i == VIR_DOMAIN_HYPERV_STIMER)) {
                ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
qemu/qemu_process.c:4117:20: note: remove extraneous parentheses around the comparison to silence this warning
           if ((i == VIR_DOMAIN_HYPERV_STIMER)) {
               ~  ^                          ~
qemu/qemu_process.c:4117:20: note: use '=' to turn this equality comparison into an assignment
           if ((i == VIR_DOMAIN_HYPERV_STIMER)) {
                  ^~
                  =
1 error generated.
make[5]: *** [Makefile:11191: qemu/libvirt_driver_qemu_impl_la-qemu_process.lo] Error 1

> +                for (j = 0; j < VIR_DOMAIN_HYPERV_STIMER_LAST; j++) {
> +                    switch ((virDomainHypervStimer) j) {
> +                    case VIR_DOMAIN_HYPERV_STIMER_DIRECT:
> +                        if (def->hyperv_stimer_features[j] != VIR_TRISTATE_SWITCH_ON)
> +                            continue;
> +
> +                        if (virAsprintf(&cpuFeature, "__kvm_hv_stimer_%s",
> +                                        virDomainHypervStimerTypeToString(j)) < 0)
> +                            return -1;
> +
> +                        rc = virCPUDataCheckFeature(cpu, cpuFeature);
> +                        VIR_FREE(cpuFeature);
> +
> +                        if (rc < 0)
> +                            return -1;
> +                        else if (rc == 1)
> +                            continue;
> +
> +                        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> +                                       _("host doesn't support hyperv stimer '%s' feature"),
> +                                       virDomainHypervStimerTypeToString(i));
> +                        return -1;
> +
> +                        /* coverity[dead_error_begin] */
> +                    case VIR_DOMAIN_HYPERV_STIMER_LAST:
> +                        break;
> +                    }
> +                }
> +
> +            }
> +
>             continue;
> +        }
>
>         switch ((virDomainHyperv) i) {
>         case VIR_DOMAIN_HYPERV_RELAXED:

Jano

Attachment: signature.asc
Description: PGP signature

--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list