[RFC PATCH 7/7] x86: Support XFD and AMX xsave data migration

[Yang Zhong <yang.zhong@intel.com>]

From: Zeng Guang <guang.zeng@intel.com>

XFD(eXtended Feature Disable) allows to enable a
feature on xsave state while preventing specific
user threads from using the feature.

Support save and restore XFD MSRs if CPUID.D.1.EAX[4]
enumerate to be valid. Likewise migrate the MSRs and
related xsave state necessarily.

Signed-off-by: Zeng Guang <guang.zeng@intel.com>
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
---
 target/i386/cpu.h     |  9 +++++++++
 target/i386/kvm/kvm.c | 18 ++++++++++++++++++
 target/i386/machine.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 69 insertions(+)

diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 6153c4ab1a..1627988790 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -505,6 +505,9 @@ typedef enum X86Seg {
 
 #define MSR_VM_HSAVE_PA                 0xc0010117
 
+#define MSR_IA32_XFD                    0x000001c4
+#define MSR_IA32_XFD_ERR                0x000001c5
+
 #define MSR_IA32_BNDCFGS                0x00000d90
 #define MSR_IA32_XSS                    0x00000da0
 #define MSR_IA32_UMWAIT_CONTROL         0xe1
@@ -866,6 +869,8 @@ typedef uint64_t FeatureWordArray[FEATURE_WORDS];
 #define CPUID_7_1_EAX_AVX_VNNI          (1U << 4)
 /* AVX512 BFloat16 Instruction */
 #define CPUID_7_1_EAX_AVX512_BF16       (1U << 5)
+/* XFD Extend Feature Disabled */
+#define CPUID_D_1_EAX_XFD               (1U << 4)
 
 /* Packets which contain IP payload have LIP values */
 #define CPUID_14_0_ECX_LIP              (1U << 31)
@@ -1608,6 +1613,10 @@ typedef struct CPUX86State {
     uint64_t msr_rtit_cr3_match;
     uint64_t msr_rtit_addrs[MAX_RTIT_ADDRS];
 
+    /* Per-VCPU XFD MSRs */
+    uint64_t msr_xfd;
+    uint64_t msr_xfd_err;
+
     /* exception/interrupt handling */
     int error_code;
     int exception_is_int;
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 97520e9dff..02d5cf1063 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -3192,6 +3192,13 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
                               env->msr_ia32_sgxlepubkeyhash[3]);
         }
 
+        if (env->features[FEAT_XSAVE] & CPUID_D_1_EAX_XFD) {
+            kvm_msr_entry_add(cpu, MSR_IA32_XFD,
+                              env->msr_xfd);
+            kvm_msr_entry_add(cpu, MSR_IA32_XFD_ERR,
+                              env->msr_xfd_err);
+        }
+
         /* Note: MSR_IA32_FEATURE_CONTROL is written separately, see
          *       kvm_put_msr_feature_control. */
     }
@@ -3548,6 +3555,11 @@ static int kvm_get_msrs(X86CPU *cpu)
         kvm_msr_entry_add(cpu, MSR_IA32_SGXLEPUBKEYHASH3, 0);
     }
 
+    if (env->features[FEAT_XSAVE] & CPUID_D_1_EAX_XFD) {
+        kvm_msr_entry_add(cpu, MSR_IA32_XFD, 0);
+        kvm_msr_entry_add(cpu, MSR_IA32_XFD_ERR, 0);
+    }
+
     ret = kvm_vcpu_ioctl(CPU(cpu), KVM_GET_MSRS, cpu->kvm_msr_buf);
     if (ret < 0) {
         return ret;
@@ -3844,6 +3856,12 @@ static int kvm_get_msrs(X86CPU *cpu)
             env->msr_ia32_sgxlepubkeyhash[index - MSR_IA32_SGXLEPUBKEYHASH0] =
                            msrs[i].data;
             break;
+        case MSR_IA32_XFD:
+            env->msr_xfd = msrs[i].data;
+            break;
+        case MSR_IA32_XFD_ERR:
+            env->msr_xfd_err = msrs[i].data;
+            break;
         }
     }
 
diff --git a/target/i386/machine.c b/target/i386/machine.c
index 83c2b91529..fdeb5bab50 100644
--- a/target/i386/machine.c
+++ b/target/i386/machine.c
@@ -1455,6 +1455,46 @@ static const VMStateDescription vmstate_msr_intel_sgx = {
     }
 };
 
+static bool xfd_msrs_needed(void *opaque)
+{
+    X86CPU *cpu = opaque;
+    CPUX86State *env = &cpu->env;
+
+    return !!(env->features[FEAT_XSAVE] & CPUID_D_1_EAX_XFD);
+}
+
+static const VMStateDescription vmstate_msr_xfd = {
+    .name = "cpu/msr_xfd",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = xfd_msrs_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT64(env.msr_xfd, X86CPU),
+        VMSTATE_UINT64(env.msr_xfd_err, X86CPU),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static bool amx_xtile_needed(void *opaque)
+{
+    X86CPU *cpu = opaque;
+    CPUX86State *env = &cpu->env;
+
+    return !!(env->features[FEAT_7_0_EDX] & CPUID_7_0_EDX_AMX_TILE);
+}
+
+static const VMStateDescription vmstate_amx_xtile = {
+    .name = "cpu/intel_amx_xtile",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = amx_xtile_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8_ARRAY(env.xtilecfg, X86CPU, 64),
+        VMSTATE_UINT8_ARRAY(env.xtiledata, X86CPU, 8192),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 const VMStateDescription vmstate_x86_cpu = {
     .name = "cpu",
     .version_id = 12,
@@ -1593,6 +1633,8 @@ const VMStateDescription vmstate_x86_cpu = {
 #endif
         &vmstate_msr_tsx_ctrl,
         &vmstate_msr_intel_sgx,
+        &vmstate_msr_xfd,
+        &vmstate_amx_xtile,
         NULL
     }
 };