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 | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 49 insertions(+)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index bff7ce727a78..ca63642517a7 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -37,6 +37,7 @@
#include <linux/amd-iommu.h>
#include <linux/hashtable.h>
#include <linux/frame.h>
+#include <linux/psp-sev.h>
#include <asm/apic.h>
#include <asm/perf_event.h>
@@ -284,6 +285,10 @@ 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 +1054,39 @@ static int avic_ga_log_notifier(u32 ga_tag)
return 0;
}
+static __init int sev_hardware_setup(void)
+{
+ struct sev_user_data_status *status;
+ int rc;
+
+ /* Maximum number of encrypted guests supported simultaneously */
+ max_sev_asid = cpuid_ecx(0x8000001F);
+
+ if (!max_sev_asid)
+ return 1;
+
+ status = kmalloc(sizeof(*status), GFP_KERNEL);
+ if (!status)
+ return 1;
+
+ /*
+ * Check SEV platform status.
+ *
+ * PLATFORM_STATUS can be called in any state, if we failed to query
+ * the PLATFORM status then either PSP firmware does not support SEV
+ * feature or SEV firmware is dead.
+ */
+ rc = sev_platform_status(status, NULL);
+ if (rc)
+ goto err;
+
+ pr_info("SEV supported\n");
+
+err:
+ kfree(status);
+ return rc;
+}
+
static __init int svm_hardware_setup(void)
{
int cpu;
@@ -1084,6 +1122,17 @@ 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)) {
+ r = sev_hardware_setup();
+ if (r)
+ sev = false;
+ } else {
+ sev = false;
+ }
+ }
+
for_each_possible_cpu(cpu) {
r = svm_cpu_init(cpu);
if (r)
--
2.9.5
