aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kvm/svm/sev.c
diff options
context:
space:
mode:
authorIngo Molnar <mingo@kernel.org>2024-01-08 12:57:28 +0100
committerIngo Molnar <mingo@kernel.org>2024-01-08 12:57:28 +0100
commitcdb3033e191fd03da2d7da23b9cd448dfa180a8e (patch)
treee863d55e63bea2bc9c18652e0d7291fec5e5cd23 /arch/x86/kvm/svm/sev.c
parentfbb66ce0b1d670c72def736a13ac9176b860df4e (diff)
parentf60a631ab9ed5df15e446269ea515f2b8948ba0c (diff)
Merge branch 'sched/urgent' into sched/core, to pick up pending v6.7 fixes for the v6.8 merge window
This fix didn't make it upstream in time, pick it up for the v6.8 merge window. Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kvm/svm/sev.c')
-rw-r--r--arch/x86/kvm/svm/sev.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 4900c078045a..6ee925d66648 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2972,6 +2972,25 @@ static void sev_es_vcpu_after_set_cpuid(struct vcpu_svm *svm)
set_msr_interception(vcpu, svm->msrpm, MSR_TSC_AUX, v_tsc_aux, v_tsc_aux);
}
+
+ /*
+ * For SEV-ES, accesses to MSR_IA32_XSS should not be intercepted if
+ * the host/guest supports its use.
+ *
+ * guest_can_use() checks a number of requirements on the host/guest to
+ * ensure that MSR_IA32_XSS is available, but it might report true even
+ * if X86_FEATURE_XSAVES isn't configured in the guest to ensure host
+ * MSR_IA32_XSS is always properly restored. For SEV-ES, it is better
+ * to further check that the guest CPUID actually supports
+ * X86_FEATURE_XSAVES so that accesses to MSR_IA32_XSS by misbehaved
+ * guests will still get intercepted and caught in the normal
+ * kvm_emulate_rdmsr()/kvm_emulated_wrmsr() paths.
+ */
+ if (guest_can_use(vcpu, X86_FEATURE_XSAVES) &&
+ guest_cpuid_has(vcpu, X86_FEATURE_XSAVES))
+ set_msr_interception(vcpu, svm->msrpm, MSR_IA32_XSS, 1, 1);
+ else
+ set_msr_interception(vcpu, svm->msrpm, MSR_IA32_XSS, 0, 0);
}
void sev_vcpu_after_set_cpuid(struct vcpu_svm *svm)