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Diffstat (limited to 'arch/x86/kvm/x86.c')
-rw-r--r--arch/x86/kvm/x86.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d2f1b4746903..96e897d38a63 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -190,6 +190,8 @@ u64 __read_mostly host_efer;
EXPORT_SYMBOL_GPL(host_efer);
static u64 __read_mostly host_xss;
+u64 __read_mostly supported_xss;
+EXPORT_SYMBOL_GPL(supported_xss);
struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "pf_fixed", VCPU_STAT(pf_fixed) },
@@ -2827,7 +2829,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
* IA32_XSS[bit 8]. Guests have to use RDMSR/WRMSR rather than
* XSAVES/XRSTORS to save/restore PT MSRs.
*/
- if (data != 0)
+ if (data & ~supported_xss)
return 1;
vcpu->arch.ia32_xss = data;
break;
@@ -9617,10 +9619,16 @@ int kvm_arch_hardware_setup(void)
rdmsrl_safe(MSR_EFER, &host_efer);
+ if (boot_cpu_has(X86_FEATURE_XSAVES))
+ rdmsrl(MSR_IA32_XSS, host_xss);
+
r = kvm_x86_ops->hardware_setup();
if (r != 0)
return r;
+ if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES))
+ supported_xss = 0;
+
cr4_reserved_bits = kvm_host_cr4_reserved_bits(&boot_cpu_data);
if (kvm_has_tsc_control) {
@@ -9637,9 +9645,6 @@ int kvm_arch_hardware_setup(void)
kvm_default_tsc_scaling_ratio = 1ULL << kvm_tsc_scaling_ratio_frac_bits;
}
- if (boot_cpu_has(X86_FEATURE_XSAVES))
- rdmsrl(MSR_IA32_XSS, host_xss);
-
kvm_init_msr_list();
return 0;
}