qemu/0033-i386-kvm-MSR_IA32_SPEC_CTRL-and-MSR.patch

From 386bbf8992317f3106d45dbfdb4b577029e9091f Mon Sep 17 00:00:00 2001
From: Wei Wang <wei.w.wang@intel.com>
Date: Tue, 7 Nov 2017 16:39:49 +0800
Subject: [PATCH] i386/kvm: MSR_IA32_SPEC_CTRL and MSR_IA32_PRED_CMD

CPUID(EAX=0X7,ECX=0).EDX[26]/[27] indicates the support of
MSR_IA32_SPEC_CTRL and MSR_IA32_PRED_CMD. Expose the CPUID
to the guest. Also add the support of transferring the MSRs during live
migration.

Signed-off-by: Wei Wang <wei.w.wang@intel.com>
[BR: BSC#1068032 CVE-2017-5715]
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 target/i386/cpu.c     |  3 ++-
 target/i386/cpu.h     |  4 ++++
 target/i386/kvm.c     | 14 +++++++++++++-
 target/i386/machine.c | 20 ++++++++++++++++++++
 4 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 045d66191f..4a403b1e7b 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -2880,13 +2880,14 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
     case 7:
         /* Structured Extended Feature Flags Enumeration Leaf */
         if (count == 0) {
+            host_cpuid(index, 0, eax, ebx, ecx, edx);
             *eax = 0; /* Maximum ECX value for sub-leaves */
             *ebx = env->features[FEAT_7_0_EBX]; /* Feature flags */
             *ecx = env->features[FEAT_7_0_ECX]; /* Feature flags */
             if ((*ecx & CPUID_7_0_ECX_PKU) && env->cr[4] & CR4_PKE_MASK) {
                 *ecx |= CPUID_7_0_ECX_OSPKE;
             }
-            *edx = env->features[FEAT_7_0_EDX]; /* Feature flags */
+            *edx = env->features[FEAT_7_0_EDX] | *edx;
         } else {
             *eax = 0;
             *ebx = 0;
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index cbdd631e2e..d9ecf7a368 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -335,6 +335,7 @@
 #define MSR_IA32_APICBASE_BASE          (0xfffffU<<12)
 #define MSR_IA32_FEATURE_CONTROL        0x0000003a
 #define MSR_TSC_ADJUST                  0x0000003b
+#define MSR_IA32_SPEC_CTRL              0x00000048
 #define MSR_IA32_TSCDEADLINE            0x6e0
 
 #define FEATURE_CONTROL_LOCKED                    (1<<0)
@@ -641,6 +642,8 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS];
 
 #define CPUID_7_0_EDX_AVX512_4VNNIW (1U << 2) /* AVX512 Neural Network Instructions */
 #define CPUID_7_0_EDX_AVX512_4FMAPS (1U << 3) /* AVX512 Multiply Accumulation Single Precision */
+#define CPUID_7_0_EDX_SPEC_CTRL     (1U << 26)
+#define CPUID_7_0_EDX_PRED_CMD      (1U << 27)
 
 #define CPUID_XSAVE_XSAVEOPT   (1U << 0)
 #define CPUID_XSAVE_XSAVEC     (1U << 1)
@@ -1183,6 +1186,7 @@ typedef struct CPUX86State {
 
     uint64_t xss;
 
+    uint64_t spec_ctrl;
     TPRAccess tpr_access_type;
 } CPUX86State;
 
diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index b1e32e95d3..d0041e6285 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -76,6 +76,7 @@ static bool has_msr_star;
 static bool has_msr_hsave_pa;
 static bool has_msr_tsc_aux;
 static bool has_msr_tsc_adjust;
+static bool has_msr_spec_ctrl;
 static bool has_msr_tsc_deadline;
 static bool has_msr_feature_control;
 static bool has_msr_misc_enable;
@@ -1108,6 +1109,9 @@ static int kvm_get_supported_msrs(KVMState *s)
                 case MSR_TSC_ADJUST:
                     has_msr_tsc_adjust = true;
                     break;
+		case MSR_IA32_SPEC_CTRL:
+                    has_msr_spec_ctrl = true;
+                    break;
                 case MSR_IA32_TSCDEADLINE:
                     has_msr_tsc_deadline = true;
                     break;
@@ -1626,6 +1630,9 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
     if (has_msr_xss) {
         kvm_msr_entry_add(cpu, MSR_IA32_XSS, env->xss);
     }
+    if (has_msr_spec_ctrl) {
+        kvm_msr_entry_add(cpu, MSR_IA32_SPEC_CTRL, env->spec_ctrl);
+    }
 #ifdef TARGET_X86_64
     if (lm_capable_kernel) {
         kvm_msr_entry_add(cpu, MSR_CSTAR, env->cstar);
@@ -1998,7 +2005,9 @@ static int kvm_get_msrs(X86CPU *cpu)
     if (has_msr_xss) {
         kvm_msr_entry_add(cpu, MSR_IA32_XSS, 0);
     }
-
+    if (has_msr_spec_ctrl) {
+        kvm_msr_entry_add(cpu, MSR_IA32_SPEC_CTRL, 0);
+    }
 
     if (!env->tsc_valid) {
         kvm_msr_entry_add(cpu, MSR_IA32_TSC, 0);
@@ -2220,6 +2229,9 @@ static int kvm_get_msrs(X86CPU *cpu)
         case MSR_IA32_XSS:
             env->xss = msrs[i].data;
             break;
+        case MSR_IA32_SPEC_CTRL:
+            env->spec_ctrl = msrs[i].data;
+            break;
         default:
             if (msrs[i].index >= MSR_MC0_CTL &&
                 msrs[i].index < MSR_MC0_CTL + (env->mcg_cap & 0xff) * 4) {
diff --git a/target/i386/machine.c b/target/i386/machine.c
index df5ec359eb..d561a65153 100644
--- a/target/i386/machine.c
+++ b/target/i386/machine.c
@@ -759,6 +759,25 @@ static const VMStateDescription vmstate_xss = {
     }
 };
 
+static bool spec_ctrl_needed(void *opaque)
+{
+    X86CPU *cpu = opaque;
+    CPUX86State *env = &cpu->env;
+
+    return env->spec_ctrl != 0;
+}
+
+static const VMStateDescription vmstate_spec_ctrl = {
+    .name = "cpu/spec_ctrl",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = spec_ctrl_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT64(env.spec_ctrl, X86CPU),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 #ifdef TARGET_X86_64
 static bool pkru_needed(void *opaque)
 {
@@ -932,6 +951,7 @@ VMStateDescription vmstate_x86_cpu = {
         &vmstate_msr_hyperv_stimer,
         &vmstate_avx512,
         &vmstate_xss,
+        &vmstate_spec_ctrl,
         &vmstate_tsc_khz,
 #ifdef TARGET_X86_64
         &vmstate_pkru,