From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
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 <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx>
---
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
