Messages in this thread Patch in this message | | | From | Yang Weijiang <> | Subject | [PATCH v7 12/26] KVM: x86: Report XSS as to-be-saved if there are supported features | Date | Fri, 24 Nov 2023 00:53:16 -0500 |
| |
From: Sean Christopherson <seanjc@google.com>
Add MSR_IA32_XSS to list of MSRs reported to userspace if supported_xss is non-zero, i.e. KVM supports at least one XSS based feature.
Before enabling CET virtualization series, guest IA32_MSR_XSS is guaranteed to be 0, i.e., XSAVES/XRSTORS is executed in non-root mode with XSS == 0, which equals to the effect of XSAVE/XRSTOR.
Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Yang Weijiang <weijiang.yang@intel.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> --- arch/x86/kvm/x86.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 360f4b8a4944..f7d4cc61bc55 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1464,6 +1464,7 @@ static const u32 msrs_to_save_base[] = { MSR_IA32_UMWAIT_CONTROL, MSR_IA32_XFD, MSR_IA32_XFD_ERR, + MSR_IA32_XSS, }; static const u32 msrs_to_save_pmu[] = { @@ -7317,6 +7318,10 @@ static void kvm_probe_msr_to_save(u32 msr_index) if (!(kvm_get_arch_capabilities() & ARCH_CAP_TSX_CTRL_MSR)) return; break; + case MSR_IA32_XSS: + if (!kvm_caps.supported_xss) + return; + break; default: break; } -- 2.27.0
| |