# HG changeset patch # User Boris Ostrovsky # Date 1335358394 -3600 # Node ID ed9c557f8a35a6deb7e6df0679f24a2121fd1172 # Parent 7ba11d9b1d23633b5c42fadddad17b6dcb686141 svm: Do not intercept RDTSC(P) when TSC scaling is supported by hardware When running in TSC_MODE_ALWAYS_EMULATE mode on processors that support TSC scaling we don't need to intercept RDTSC/RDTSCP instructions. Signed-off-by: Boris Ostrovsky Acked-by: Wei Huang Tested-by: Wei Huang Committed-by: Keir Fraser --- a/xen/arch/x86/hvm/svm/svm.c +++ b/xen/arch/x86/hvm/svm/svm.c @@ -633,12 +633,19 @@ static void svm_set_rdtsc_exiting(struct { struct vmcb_struct *vmcb = v->arch.hvm_svm.vmcb; u32 general1_intercepts = vmcb_get_general1_intercepts(vmcb); + u32 general2_intercepts = vmcb_get_general2_intercepts(vmcb); general1_intercepts &= ~GENERAL1_INTERCEPT_RDTSC; - if ( enable ) + general2_intercepts &= ~GENERAL2_INTERCEPT_RDTSCP; + + if ( enable && !cpu_has_tsc_ratio ) + { general1_intercepts |= GENERAL1_INTERCEPT_RDTSC; + general2_intercepts |= GENERAL2_INTERCEPT_RDTSCP; + } vmcb_set_general1_intercepts(vmcb, general1_intercepts); + vmcb_set_general2_intercepts(vmcb, general2_intercepts); } static unsigned int svm_get_insn_bytes(struct vcpu *v, uint8_t *buf)