• Babu Moger's avatar
    KVM: SEV-ES: Use V_TSC_AUX if available instead of RDTSC/MSR_TSC_AUX intercepts · 296d5a17
    Babu Moger authored
    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: default avatarBabu Moger <babu.moger@amd.com>
    Message-Id: <165040164424.1399644.13833277687385156344.stgit@bmoger-ubuntu>
    Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
    296d5a17
cpufeatures.h 28.3 KB