Pardon my ignorance... "Naveen N Rao (AMD)" <[email protected]> writes:
> Add support for configuring the TSC frequency when Secure TSC is enabled > in SEV-SNP guests through a new "tsc-frequency" property on SEV-SNP > guest objects, similar to the vCPU-specific property used by regular > guests and TDX. Which property exactly? > A new property is needed since SEV-SNP guests require > the TSC frequency to be specified during early SNP_LAUNCH_START command > before any vCPUs are created. Sounds awkward. Do the two properties set the same thing at different times? > The user-provided TSC frequency is set through KVM_SET_TSC_KHZ before > issuing KVM_SEV_SNP_LAUNCH_START. > > Attempts to set TSC frequency on both the SEV_SNP object and the cpu > object result in an error from KVM (on the vCPU ioctl), so do not add > separate checks for the same. > > Sample command-line: > -machine q35,confidential-guest-support=sev0 \ > -object > sev-snp-guest,id=sev0,cbitpos=51,reduced-phys-bits=1,secure-tsc=on,tsc-frequency=2500000000 > > Co-developed-by: Ketan Chaturvedi <[email protected]> > Signed-off-by: Ketan Chaturvedi <[email protected]> > Co-developed-by: Nikunj A Dadhania <[email protected]> > Signed-off-by: Nikunj A Dadhania <[email protected]> > Signed-off-by: Naveen N Rao (AMD) <[email protected]> [...] > diff --git a/qapi/qom.json b/qapi/qom.json > index c7dd2dd1b095..5daaf065b6b7 100644 > --- a/qapi/qom.json > +++ b/qapi/qom.json > @@ -1104,6 +1104,9 @@ > # @secure-tsc: enable Secure TSC > # (default: false) (since 10.2) > # > +# @tsc-frequency: set secure TSC frequency. Only valid if Secure TSC > +# is enabled (default: zero) (since 10.2) Is this likely to remain the only property that's only valied when @secure-tsc is true? > +# > # Since: 9.1 > ## > { 'struct': 'SevSnpGuestProperties', > @@ -1116,7 +1119,8 @@ > '*author-key-enabled': 'bool', > '*host-data': 'str', > '*vcek-disabled': 'bool', > - '*secure-tsc': 'bool' } } > + '*secure-tsc': 'bool', > + '*tsc-frequency': 'uint32' } } > > ## > # @TdxGuestProperties:
