KVM: SEV-ES: Use V_TSC_AUX if available instead of RDTSC/MSR_TSC_AUX intercepts
The TSC_AUX virtualization feature allows AMD SEV-ES guests to securely use TSC_AUX (auxiliary time stamp counter data) in the RDTSCP and RDPID instructions. The TSC_AUX value is set using the WRMSR instruction to the TSC_AUX MSR (0xC0000103). It is read by the RDMSR, RDTSCP and RDPID instructions. If the read/write of the TSC_AUX MSR is intercepted, then RDTSCP and RDPID must also be intercepted when TSC_AUX virtualization is present. However, the RDPID instruction can't be intercepted. This means that when TSC_AUX virtualization is present, RDTSCP and TSC_AUX MSR read/write must not be intercepted for SEV-ES (or SEV-SNP) guests. Signed-off-by:Babu Moger <babu.moger@amd.com> Message-Id: <165040164424.1399644.13833277687385156344.stgit@bmoger-ubuntu> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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