From: Sean Christopherson <[email protected]> KVM supported XSS feature bits are designated in supported_xss, bits could be set/cleared dynamically, add helpers to facilitate the operation. Also add MSR_IA32_XSS to the list of MSRs reported to userspace if supported_xss is non-zero, i.e. KVM supports at least one XSS based feature.
Co-developed-by: Sean Christopherson <[email protected]> Signed-off-by: Sean Christopherson <[email protected]> Signed-off-by: Yang Weijiang <[email protected]> --- arch/x86/kvm/x86.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 397f599b20e5..528eba526c9c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1237,6 +1237,8 @@ static const u32 msrs_to_save_all[] = { MSR_ARCH_PERFMON_EVENTSEL0 + 12, MSR_ARCH_PERFMON_EVENTSEL0 + 13, MSR_ARCH_PERFMON_EVENTSEL0 + 14, MSR_ARCH_PERFMON_EVENTSEL0 + 15, MSR_ARCH_PERFMON_EVENTSEL0 + 16, MSR_ARCH_PERFMON_EVENTSEL0 + 17, + + MSR_IA32_XSS, }; static u32 msrs_to_save[ARRAY_SIZE(msrs_to_save_all)]; @@ -5728,6 +5730,10 @@ static void kvm_init_msr_list(void) min(INTEL_PMC_MAX_GENERIC, x86_pmu.num_counters_gp)) continue; break; + case MSR_IA32_XSS: + if (!supported_xss) + continue; + break; default: break; } @@ -10137,6 +10143,18 @@ void kvm_arch_hardware_disable(void) drop_user_return_notifiers(); } +static inline void __maybe_unused kvm_set_xss_bits(u32 low, u32 high) +{ + supported_xss |= low; + supported_xss |= ((u64)high) << 32; +} + +static inline void __maybe_unused kvm_clear_xss_bits(u32 low, u32 high) +{ + supported_xss &= ~low; + supported_xss &= ~(((u64)high) << 32); +} + int kvm_arch_hardware_setup(void *opaque) { struct kvm_x86_init_ops *ops = opaque; @@ -10155,6 +10173,8 @@ int kvm_arch_hardware_setup(void *opaque) if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES)) supported_xss = 0; + else + supported_xss &= host_xss; #define __kvm_cpu_cap_has(UNUSED_, f) kvm_cpu_cap_has(f) cr4_reserved_bits = __cr4_reserved_bits(__kvm_cpu_cap_has, UNUSED_); -- 2.17.2
