A SEV-enabled guest must use ASIDs from the defined subset, while non-SEV
guests can use the remaining ASID range. The range of allowed SEV guest
ASIDs is [1 - CPUID_8000_001F[ECX][31:0]].

Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: "H. Peter Anvin" <h...@zytor.com>
Cc: Paolo Bonzini <pbonz...@redhat.com>
Cc: "Radim Krčmář" <rkrc...@redhat.com>
Cc: Joerg Roedel <j...@8bytes.org>
Cc: Borislav Petkov <b...@suse.de>
Cc: Tom Lendacky <thomas.lenda...@amd.com>
Cc: x...@kernel.org
Cc: k...@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Improvements-by: Borislav Petkov <b...@suse.de>
Signed-off-by: Brijesh Singh <brijesh.si...@amd.com>
---
 arch/x86/kvm/svm.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index be2e98c01b22..d4b62536e305 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -323,6 +323,8 @@ enum {
 
 #define VMCB_AVIC_APIC_BAR_MASK                0xFFFFFFFFFF000ULL
 
+static unsigned int max_sev_asid;
+
 static inline void mark_all_dirty(struct vmcb *vmcb)
 {
        vmcb->control.clean = 0;
@@ -787,7 +789,7 @@ static int svm_hardware_enable(void)
        sd->asid_generation = 1;
        sd->max_asid = cpuid_ebx(SVM_CPUID_FUNC) - 1;
        sd->next_asid = sd->max_asid + 1;
-       sd->min_asid = 1;
+       sd->min_asid = max_sev_asid + 1;
 
        gdt = get_current_gdt_rw();
        sd->tss_desc = (struct kvm_ldttss_desc *)(gdt + GDT_ENTRY_TSS);
@@ -1054,6 +1056,15 @@ 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 +1095,16 @@ static __init int svm_hardware_setup(void)
                kvm_tsc_scaling_ratio_frac_bits = 32;
        }
 
+       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;
+               }
+       }
+
        if (nested) {
                printk(KERN_INFO "kvm: Nested Virtualization enabled\n");
                kvm_enable_efer_bits(EFER_SVME | EFER_LMSLE);
-- 
2.9.5

Reply via email to