In the unlikely case that L1 does not capture MSR_IA32_TSC, L0 needs to emulate this MSR write by L2 by modifying vmcs02.tsc_offset. We also need to set vmcs12.tsc_offset, for this change to survive the next nested entry (see prepare_vmcs02()).
Signed-off-by: Nadav Har'El <[email protected]> --- arch/x86/kvm/vmx.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- .before/arch/x86/kvm/vmx.c 2010-10-17 11:52:03.000000000 +0200 +++ .after/arch/x86/kvm/vmx.c 2010-10-17 11:52:03.000000000 +0200 @@ -1674,12 +1674,23 @@ static u64 guest_read_tsc(void) static void vmx_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) { vmcs_write64(TSC_OFFSET, offset); + if (to_vmx(vcpu)->nested.nested_mode) + /* + * We are only changing TSC_OFFSET when L2 is running if for + * some reason L1 chose not to trap the TSC MSR. Since + * prepare_vmcs12() does not copy tsc_offset, we need to also + * set the vmcs12 field here. + */ + get_vmcs12_fields(vcpu)->tsc_offset = offset - + to_vmx(vcpu)->nested.vmcs01_fields->tsc_offset; } static void vmx_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment) { u64 offset = vmcs_read64(TSC_OFFSET); vmcs_write64(TSC_OFFSET, offset + adjustment); + if (to_vmx(vcpu)->nested.nested_mode) + get_vmcs12_fields(vcpu)->tsc_offset += adjustment; } /* -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
