The module parameter can be used to control the SEV feature support.
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: "Radim Krčmář" <rkrcmar@xxxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
---
arch/x86/kvm/svm.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 7e46aea59615..59abb9fe2f13 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -284,6 +284,10 @@ module_param(vls, int, 0444);
static int vgif = true;
module_param(vgif, int, 0444);
+/* enable/disable SEV support */
+static int sev = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
+module_param(sev, int, 0444);
+
static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0);
static void svm_flush_tlb(struct kvm_vcpu *vcpu);
static void svm_complete_interrupts(struct vcpu_svm *svm);
@@ -1049,6 +1053,15 @@ static int avic_ga_log_notifier(u32 ga_tag)
return 0;
}
+/*
+ * Get the maximum number of encrypted guests:
+ * Fn8001_001F[ECX][31:0]: Number of supported guests.
+ */
+static __init void sev_hardware_setup(void)
+{
+ max_sev_asid = cpuid_ecx(0x8000001F);
+}
+
static __init int svm_hardware_setup(void)
{
int cpu;
@@ -1084,6 +1097,16 @@ static __init int svm_hardware_setup(void)
kvm_enable_efer_bits(EFER_SVME | EFER_LMSLE);
}
+ if (sev) {
+ if (boot_cpu_has(X86_FEATURE_SEV) &&
+ IS_ENABLED(CONFIG_KVM_AMD_SEV)) {
+ sev_hardware_setup();
+ pr_info("SEV supported\n");
+ } else {
+ sev = false;
+ }
+ }
+
for_each_possible_cpu(cpu) {
r = svm_cpu_init(cpu);
if (r)
--
2.9.5
