On Wed, 2024-08-21 at 12:19 +0200, Martin Kletzander wrote:
> On Thu, Aug 15, 2024 at 03:57:35PM +0200, Tim Wiederhake wrote:
> > qemu supports this enlightenment since version 7.10.
> >
> > From the qemu commit:
> > The newly introduced enlightenment allow L0 (KVM) and L1 (Hyper-
> > V)
> > hypervisors to collaborate to avoid unnecessary updates to L2
> > MSR-Bitmap upon vmexits.
> >
> > Signed-off-by: Tim Wiederhake <twiederh@xxxxxxxxxx>
> > ---
> > docs/formatdomain.rst | 2 ++
> > src/conf/domain_conf.c | 4 ++++
> > src/conf/domain_conf.h | 1 +
> > src/conf/schemas/domaincommon.rng | 5 +++++
> > src/cpu/cpu_x86.c | 4 ++++
> > src/cpu/cpu_x86_data.h | 1 +
> > src/qemu/qemu_command.c | 5 +++++
> > src/qemu/qemu_process.c | 1 +
> > tests/domaincapsdata/qemu_8.0.0-q35.x86_64.xml | 1 +
> > tests/domaincapsdata/qemu_8.0.0-tcg.x86_64.xml | 1 +
> > tests/domaincapsdata/qemu_8.0.0.x86_64.xml | 1 +
> > tests/domaincapsdata/qemu_8.1.0-q35.x86_64.xml | 1 +
> > tests/domaincapsdata/qemu_8.1.0-tcg.x86_64.xml | 1 +
> > tests/domaincapsdata/qemu_8.1.0.x86_64.xml | 1 +
> > tests/domaincapsdata/qemu_8.2.0-q35.x86_64.xml | 1 +
> > tests/domaincapsdata/qemu_8.2.0-tcg.x86_64.xml | 1 +
> > tests/domaincapsdata/qemu_8.2.0.x86_64.xml | 1 +
> > tests/domaincapsdata/qemu_9.0.0-q35.x86_64.xml | 1 +
> > tests/domaincapsdata/qemu_9.0.0-tcg.x86_64.xml | 1 +
> > tests/domaincapsdata/qemu_9.0.0.x86_64.xml | 1 +
> > tests/domaincapsdata/qemu_9.1.0-q35.x86_64.xml | 1 +
> > tests/domaincapsdata/qemu_9.1.0-tcg.x86_64.xml | 1 +
> > tests/domaincapsdata/qemu_9.1.0.x86_64.xml | 1 +
> > tests/qemucapabilitiesdata/caps_8.0.0_x86_64.xml | 1 +
> > tests/qemucapabilitiesdata/caps_8.1.0_x86_64.xml | 1 +
> > tests/qemucapabilitiesdata/caps_8.2.0_x86_64.xml | 1 +
> > tests/qemucapabilitiesdata/caps_9.0.0_x86_64.xml | 1 +
> > tests/qemucapabilitiesdata/caps_9.1.0_x86_64.xml | 1 +
> > tests/qemuxmlconfdata/hyperv-off.x86_64-latest.xml | 1 +
> > tests/qemuxmlconfdata/hyperv-off.xml | 1 +
> > tests/qemuxmlconfdata/hyperv.x86_64-latest.args | 2 +-
> > tests/qemuxmlconfdata/hyperv.x86_64-latest.xml | 1 +
> > tests/qemuxmlconfdata/hyperv.xml | 1 +
> > 33 files changed, 48 insertions(+), 1 deletion(-)
> >
> > diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst
> > index e1e219bcb5..0cf3dc9deb 100644
> > --- a/docs/formatdomain.rst
> > +++ b/docs/formatdomain.rst
> > @@ -1989,6 +1989,7 @@ Hypervisors may allow certain CPU / machine
> > features to be toggled on/off.
> > <tlbflush state='on'/>
> > <ipi state='on'/>
> > <evmcs state='on'/>
> > + <emsr_bitmap state='on'/>
> > </hyperv>
> > <kvm>
> > <hidden state='on'/>
> > @@ -2076,6 +2077,7 @@ are:
> > ipi Enable PV IPI
> > support on,
> > off :since:`4.10.0 (QEMU 3.1)`
> > evmcs Enable Enlightened
> > VMCS on,
> > off :since:`4.10.0 (QEMU 3.1)`
> > avic Enable use Hyper-V SynIC with hardware
> > APICv/AVIC on,
> > off :since:`8.10.0 (QEMU 6.2)`
> > + emsr_bitmap Avoid unnecessary updates to L2 MSR Bitmap upon
> > vmexits. on, off
> > :since:`10.7.0 (QEMU 7.1)`
> > ===============
> > ===================================================================
> > === ============================================
> > =======================================================
> >
> > :since:`Since 8.0.0`, the hypervisor can be configured further
> > by setting
> > diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> > index d950921667..c88e885d07 100644
> > --- a/src/conf/domain_conf.c
> > +++ b/src/conf/domain_conf.c
> > @@ -211,6 +211,7 @@ VIR_ENUM_IMPL(virDomainHyperv,
> > "ipi",
> > "evmcs",
> > "avic",
> > + "emsr_bitmap",
> > );
> >
> > VIR_ENUM_IMPL(virDomainKVM,
> > @@ -16574,6 +16575,7 @@
> > virDomainFeaturesHyperVDefParse(virDomainDef *def,
> > case VIR_DOMAIN_HYPERV_IPI:
> > case VIR_DOMAIN_HYPERV_EVMCS:
> > case VIR_DOMAIN_HYPERV_AVIC:
> > + case VIR_DOMAIN_HYPERV_EMSR_BITMAP:
> > break;
> >
> > case VIR_DOMAIN_HYPERV_STIMER:
> > @@ -21020,6 +21022,7 @@
> > virDomainDefFeaturesCheckABIStability(virDomainDef *src,
> > case VIR_DOMAIN_HYPERV_IPI:
> > case VIR_DOMAIN_HYPERV_EVMCS:
> > case VIR_DOMAIN_HYPERV_AVIC:
> > + case VIR_DOMAIN_HYPERV_EMSR_BITMAP:
> > if (src->hyperv_features[i] != dst-
> > >hyperv_features[i]) {
> > virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> > _("State of HyperV enlightenment
> > feature '%1$s' differs: source: '%2$s', destination: '%3$s'"),
> > @@ -27761,6 +27764,7 @@ virDomainDefFormatFeatures(virBuffer *buf,
> > case VIR_DOMAIN_HYPERV_IPI:
> > case VIR_DOMAIN_HYPERV_EVMCS:
> > case VIR_DOMAIN_HYPERV_AVIC:
> > + case VIR_DOMAIN_HYPERV_EMSR_BITMAP:
> > virBufferAddLit(&childBuf, "/>\n");
> > break;
> >
> > diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
> > index eae621f900..332bcd0cf9 100644
> > --- a/src/conf/domain_conf.h
> > +++ b/src/conf/domain_conf.h
> > @@ -2203,6 +2203,7 @@ typedef enum {
> > VIR_DOMAIN_HYPERV_IPI,
> > VIR_DOMAIN_HYPERV_EVMCS,
> > VIR_DOMAIN_HYPERV_AVIC,
> > + VIR_DOMAIN_HYPERV_EMSR_BITMAP,
> >
> > VIR_DOMAIN_HYPERV_LAST
> > } virDomainHyperv;
> > diff --git a/src/conf/schemas/domaincommon.rng
> > b/src/conf/schemas/domaincommon.rng
> > index 05ba697924..6f81fc94c2 100644
> > --- a/src/conf/schemas/domaincommon.rng
> > +++ b/src/conf/schemas/domaincommon.rng
> > @@ -7962,6 +7962,11 @@
> > <ref name="featurestate"/>
> > </element>
> > </optional>
> > + <optional>
> > + <element name="emsr_bitmap">
> > + <ref name="featurestate"/>
> > + </element>
> > + </optional>
> > </interleave>
> > </group>
> > </choice>
> > diff --git a/src/cpu/cpu_x86.c b/src/cpu/cpu_x86.c
> > index fcbce0ec46..139ac48234 100644
> > --- a/src/cpu/cpu_x86.c
> > +++ b/src/cpu/cpu_x86.c
> > @@ -107,6 +107,9 @@ KVM_FEATURE_DEF(VIR_CPU_x86_HV_IPI,
> > KVM_FEATURE_DEF(VIR_CPU_x86_HV_EVMCS,
> > 0x40000004, 0x00004000, 0x0);
> >
> > +KVM_FEATURE_DEF(VIR_CPU_x86_HV_EMSR_BITMAP,
> > + 0x4000000A, 0x00080000, 0x0);
> > +
> > static virCPUx86Feature x86_kvm_features[] =
> > {
> > KVM_FEATURE(VIR_CPU_x86_KVM_PV_UNHALT),
> > @@ -124,6 +127,7 @@ static virCPUx86Feature x86_kvm_features[] =
> > KVM_FEATURE(VIR_CPU_x86_HV_IPI),
> > KVM_FEATURE(VIR_CPU_x86_HV_EVMCS),
> > KVM_FEATURE(VIR_CPU_x86_HV_STIMER_DIRECT),
> > + KVM_FEATURE(VIR_CPU_x86_HV_EMSR_BITMAP),
> > };
> >
> > typedef struct _virCPUx86Signature virCPUx86Signature;
> > diff --git a/src/cpu/cpu_x86_data.h b/src/cpu/cpu_x86_data.h
> > index d1ca63db6d..414643fe8d 100644
> > --- a/src/cpu/cpu_x86_data.h
> > +++ b/src/cpu/cpu_x86_data.h
> > @@ -62,6 +62,7 @@ struct _virCPUx86MSR {
> > #define VIR_CPU_x86_HV_IPI "hv-ipi"
> > #define VIR_CPU_x86_HV_EVMCS "hv-evmcs"
> > #define VIR_CPU_x86_HV_AVIC "hv-avic"
> > +#define VIR_CPU_x86_HV_EMSR_BITMAP "hv-emsr_bitmap"
> >
> > /* Hyper-V Synthetic Timer option */
> > #define VIR_CPU_x86_HV_STIMER_DIRECT "hv-stimer-direct"
> > diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> > index 28914c9c34..cac6fc57a5 100644
> > --- a/src/qemu/qemu_command.c
> > +++ b/src/qemu/qemu_command.c
> > @@ -6523,6 +6523,11 @@ qemuBuildCpuCommandLine(virCommand *cmd,
> > def->hyperv_vendor_id);
> > break;
> >
> > + case VIR_DOMAIN_HYPERV_EMSR_BITMAP:
> > + if (def->hyperv_features[i] ==
> > VIR_TRISTATE_SWITCH_ON)
> > + virBufferAsprintf(&buf, ",%s=on", "hv-emsr-
> > bitmap");
> > + break;
> > +
>
> What is the reason for us to only include the "on" state? Is it
> because
> qemu guarantees the default is (and always will be) off? If that is
> true, then
>
> Reviewed-by: Martin Kletzander <mkletzan@xxxxxxxxxx>
>
