1 files changed, 40 insertions, 3 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 8a3f9f64f86f..e7c3f3bd08fc 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -88,6 +88,14 @@ struct nested_state {
         /* A VMEXIT is required but not yet emulated */
         bool exit_required;
 
+        /*
+         * If we vmexit during an instruction emulation we need this to restore
+         * the l1 guest rip after the emulation
+         */
+        unsigned long vmexit_rip;
+        unsigned long vmexit_rsp;
+        unsigned long vmexit_rax;
+
         /* cache for intercepts of the guest */
         u16 intercept_cr_read;
         u16 intercept_cr_write;
@@ -1206,8 +1214,12 @@ static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
                 if (old == new) {
                         /* cr0 write with ts and mp unchanged */
                         svm->vmcb->control.exit_code = SVM_EXIT_CR0_SEL_WRITE;
-                        if (nested_svm_exit_handled(svm) == NESTED_EXIT_DONE)
+                        if (nested_svm_exit_handled(svm) == NESTED_EXIT_DONE) {
+                                svm->nested.vmexit_rip = kvm_rip_read(vcpu);
+                                svm->nested.vmexit_rsp = kvm_register_read(vcpu, VCPU_REGS_RSP);
+                                svm->nested.vmexit_rax = kvm_register_read(vcpu, VCPU_REGS_RAX);
                                 return;
+                        }
                 }
         }
 
@@ -2399,6 +2411,23 @@ static int emulate_on_interception(struct vcpu_svm *svm)
         return emulate_instruction(&svm->vcpu, 0, 0, 0) == EMULATE_DONE;
 }
 
+static int cr0_write_interception(struct vcpu_svm *svm)
+{
+        struct kvm_vcpu *vcpu = &svm->vcpu;
+        int r;
+
+        r = emulate_instruction(&svm->vcpu, 0, 0, 0);
+
+        if (svm->nested.vmexit_rip) {
+                kvm_register_write(vcpu, VCPU_REGS_RIP, svm->nested.vmexit_rip);
+                kvm_register_write(vcpu, VCPU_REGS_RSP, svm->nested.vmexit_rsp);
+                kvm_register_write(vcpu, VCPU_REGS_RAX, svm->nested.vmexit_rax);
+                svm->nested.vmexit_rip = 0;
+        }
+
+        return r == EMULATE_DONE;
+}
+
 static int cr8_write_interception(struct vcpu_svm *svm)
 {
         struct kvm_run *kvm_run = svm->vcpu.run;
@@ -2672,7 +2701,7 @@ static int (*svm_exit_handlers[])(struct vcpu_svm *svm) = {
         [SVM_EXIT_READ_CR4]                     = emulate_on_interception,
         [SVM_EXIT_READ_CR8]                     = emulate_on_interception,
         [SVM_EXIT_CR0_SEL_WRITE]                = emulate_on_interception,
-        [SVM_EXIT_WRITE_CR0]                    = emulate_on_interception,
+        [SVM_EXIT_WRITE_CR0]                    = cr0_write_interception,
         [SVM_EXIT_WRITE_CR3]                    = emulate_on_interception,
         [SVM_EXIT_WRITE_CR4]                    = emulate_on_interception,
         [SVM_EXIT_WRITE_CR8]                    = cr8_write_interception,
@@ -3252,6 +3281,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
         vcpu->arch.regs[VCPU_REGS_RIP] = svm->vmcb->save.rip;
 
         load_host_msrs(vcpu);
+        kvm_load_ldt(ldt_selector);
         loadsegment(fs, fs_selector);
 #ifdef CONFIG_X86_64
         load_gs_index(gs_selector);
@@ -3259,7 +3289,6 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
 #else
         loadsegment(gs, gs_selector);
 #endif
-        kvm_load_ldt(ldt_selector);
 
         reload_tss(vcpu);
 
@@ -3354,6 +3383,14 @@ static void svm_cpuid_update(struct kvm_vcpu *vcpu)
 static void svm_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry)
 {
         switch (func) {
+        case 0x00000001:
+                /* Mask out xsave bit as long as it is not supported by SVM */
+                entry->ecx &= ~(bit(X86_FEATURE_XSAVE));
+                break;
+        case 0x80000001:
+                if (nested)
+                        entry->ecx |= (1 << 2); /* Set SVM bit */
+                break;
         case 0x8000000A:
                 entry->eax = 1; /* SVM revision 1 */
                 entry->ebx = 8; /* Lets support 8 ASIDs in case we add proper