5 files changed, 95 insertions, 5 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 59cbc5b1d905..be3a0e7ecae4 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -55,6 +55,7 @@
 #define KVM_NUM_MMU_PAGES 256
 #define KVM_MIN_FREE_MMU_PAGES 5
 #define KVM_REFILL_PAGES 25
+#define KVM_MAX_CPUID_ENTRIES 40
 
 #define FX_IMAGE_SIZE 512
 #define FX_IMAGE_ALIGN 16
@@ -286,6 +287,9 @@ struct kvm_vcpu {
                         u32 ar;
                 } tr, es, ds, fs, gs;
         } rmode;
+
+        int cpuid_nent;
+        struct kvm_cpuid_entry cpuid_entries[KVM_MAX_CPUID_ENTRIES];
 };
 
 struct kvm_memory_slot {
@@ -446,6 +450,7 @@ void realmode_set_cr(struct kvm_vcpu *vcpu, int cr, unsigned long value,
 
 struct x86_emulate_ctxt;
 
+void kvm_emulate_cpuid(struct kvm_vcpu *vcpu);
 int emulate_invlpg(struct kvm_vcpu *vcpu, gva_t address);
 int emulate_clts(struct kvm_vcpu *vcpu);
 int emulator_get_dr(struct x86_emulate_ctxt* ctxt, int dr,
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index ff8bcfee76e5..caec54fbf07f 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1504,6 +1504,43 @@ void save_msrs(struct vmx_msr_entry *e, int n)
 }
 EXPORT_SYMBOL_GPL(save_msrs);
 
+void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
+{
+        int i;
+        u32 function;
+        struct kvm_cpuid_entry *e, *best;
+
+        kvm_arch_ops->cache_regs(vcpu);
+        function = vcpu->regs[VCPU_REGS_RAX];
+        vcpu->regs[VCPU_REGS_RAX] = 0;
+        vcpu->regs[VCPU_REGS_RBX] = 0;
+        vcpu->regs[VCPU_REGS_RCX] = 0;
+        vcpu->regs[VCPU_REGS_RDX] = 0;
+        best = NULL;
+        for (i = 0; i < vcpu->cpuid_nent; ++i) {
+                e = &vcpu->cpuid_entries[i];
+                if (e->function == function) {
+                        best = e;
+                        break;
+                }
+                /*
+                 * Both basic or both extended?
+                 */
+                if (((e->function ^ function) & 0x80000000) == 0)
+                        if (!best || e->function > best->function)
+                                best = e;
+        }
+        if (best) {
+                vcpu->regs[VCPU_REGS_RAX] = best->eax;
+                vcpu->regs[VCPU_REGS_RBX] = best->ebx;
+                vcpu->regs[VCPU_REGS_RCX] = best->ecx;
+                vcpu->regs[VCPU_REGS_RDX] = best->edx;
+        }
+        kvm_arch_ops->decache_regs(vcpu);
+        kvm_arch_ops->skip_emulated_instruction(vcpu);
+}
+EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);
+
 static void complete_pio(struct kvm_vcpu *vcpu)
 {
         struct kvm_io *io = &vcpu->run->io;
@@ -2075,6 +2112,26 @@ out:
         return r;
 }
 
+static int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
+                                    struct kvm_cpuid *cpuid,
+                                    struct kvm_cpuid_entry __user *entries)
+{
+        int r;
+
+        r = -E2BIG;
+        if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
+                goto out;
+        r = -EFAULT;
+        if (copy_from_user(&vcpu->cpuid_entries, entries,
+                           cpuid->nent * sizeof(struct kvm_cpuid_entry)))
+                goto out;
+        vcpu->cpuid_nent = cpuid->nent;
+        return 0;
+
+out:
+        return r;
+}
+
 static long kvm_vcpu_ioctl(struct file *filp,
                            unsigned int ioctl, unsigned long arg)
 {
@@ -2181,6 +2238,18 @@ static long kvm_vcpu_ioctl(struct file *filp,
         case KVM_SET_MSRS:
                 r = msr_io(vcpu, argp, do_set_msr, 0);
                 break;
+        case KVM_SET_CPUID: {
+                struct kvm_cpuid __user *cpuid_arg = argp;
+                struct kvm_cpuid cpuid;
+
+                r = -EFAULT;
+                if (copy_from_user(&cpuid, cpuid_arg, sizeof cpuid))
+                        goto out;
+                r = kvm_vcpu_ioctl_set_cpuid(vcpu, &cpuid, cpuid_arg->entries);
+                if (r)
+                        goto out;
+                break;
+        }
         default:
                 ;
         }
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index c35b8c83bf3f..d4b2936479d9 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -1101,8 +1101,8 @@ static int task_switch_interception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_r
 static int cpuid_interception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 {
         vcpu->svm->next_rip = vcpu->svm->vmcb->save.rip + 2;
-        kvm_run->exit_reason = KVM_EXIT_CPUID;
-        return 0;
+        kvm_emulate_cpuid(vcpu);
+        return 1;
 }
 
 static int emulate_on_interception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 4d5f40fcb651..71410a65bb90 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -1585,8 +1585,8 @@ static int handle_dr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 
 static int handle_cpuid(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 {
-        kvm_run->exit_reason = KVM_EXIT_CPUID;
-        return 0;
+        kvm_emulate_cpuid(vcpu);
+        return 1;
 }
 
 static int handle_rdmsr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 19aeb3385188..15e23bc06e8b 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -41,7 +41,6 @@ enum kvm_exit_reason {
         KVM_EXIT_UNKNOWN          = 0,
         KVM_EXIT_EXCEPTION        = 1,
         KVM_EXIT_IO               = 2,
-        KVM_EXIT_CPUID            = 3,
         KVM_EXIT_DEBUG            = 4,
         KVM_EXIT_HLT              = 5,
         KVM_EXIT_MMIO             = 6,
@@ -210,6 +209,22 @@ struct kvm_dirty_log {
         };
 };
 
+struct kvm_cpuid_entry {
+        __u32 function;
+        __u32 eax;
+        __u32 ebx;
+        __u32 ecx;
+        __u32 edx;
+        __u32 padding;
+};
+
+/* for KVM_SET_CPUID */
+struct kvm_cpuid {
+        __u32 nent;
+        __u32 padding;
+        struct kvm_cpuid_entry entries[0];
+};
+
 #define KVMIO 0xAE
 
 /*
@@ -243,5 +258,6 @@ struct kvm_dirty_log {
 #define KVM_DEBUG_GUEST           _IOW(KVMIO, 9, struct kvm_debug_guest)
 #define KVM_GET_MSRS              _IOWR(KVMIO, 13, struct kvm_msrs)
 #define KVM_SET_MSRS              _IOW(KVMIO, 14, struct kvm_msrs)
+#define KVM_SET_CPUID             _IOW(KVMIO, 17, struct kvm_cpuid)
 
 #endif