From 8b64571f3ce90fc14c571ea588f608bce4328d34 Mon Sep 17 00:00:00 2001

From: "plai@redhat.com" <plai@redhat.com>

Date: Wed, 3 Apr 2019 15:54:32 +0100

Subject: [PATCH 08/10] x86: define a new MSR based feature word --

 FEATURE_WORDS_ARCH_CAPABILITIES

RH-Author: plai@redhat.com

Message-id: <1554306874-28796-9-git-send-email-plai@redhat.com>

Patchwork-id: 85385

O-Subject: [RHEL8.1 qemu-kvm PATCH resend 08/10] x86: define a new MSR based feature word -- FEATURE_WORDS_ARCH_CAPABILITIES

Bugzilla: 1561761

RH-Acked-by: Eduardo Habkost <ehabkost@redhat.com>

RH-Acked-by: Igor Mammedov <imammedo@redhat.com>

RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>

From: Robert Hoo <robert.hu@linux.intel.com>

Note RSBA is specially treated -- no matter host support it or not, qemu

pretends it is supported.

Signed-off-by: Robert Hoo <robert.hu@linux.intel.com>

Message-Id: <1539578845-37944-4-git-send-email-robert.hu@linux.intel.com>

[ehabkost: removed automatic enabling of RSBA]

Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

(cherry picked from commit d86f963694df27f11b3681ffd225c9362de1b634)

Signed-off-by: Paul Lai <plai@redhat.com>

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 target/i386/cpu.c | 24 +++++++++++++++++++++++-

 target/i386/cpu.h |  8 ++++++++

 target/i386/kvm.c | 11 +++++++++++

 3 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c

index a0fdd3a..8750f64 100644

--- a/target/i386/cpu.c

+++ b/target/i386/cpu.c

@@ -1143,6 +1143,27 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = {

         },

         .tcg_features = ~0U,

     },

+    /*Below are MSR exposed features*/

+    [FEAT_ARCH_CAPABILITIES] = {

+        .type = MSR_FEATURE_WORD,

+        .feat_names = {

+            "rdctl-no", "ibrs-all", "rsba", "skip-l1dfl-vmentry",

+            "ssb-no", NULL, NULL, NULL,

+            NULL, NULL, NULL, NULL,

+            NULL, NULL, NULL, NULL,

+            NULL, NULL, NULL, NULL,

+            NULL, NULL, NULL, NULL,

+            NULL, NULL, NULL, NULL,

+            NULL, NULL, NULL, NULL,

+        },

+        .msr = {

+            .index = MSR_IA32_ARCH_CAPABILITIES,

+            .cpuid_dep = {

+                FEAT_7_0_EDX,

+                CPUID_7_0_EDX_ARCH_CAPABILITIES

+            }

+        },

+    },

 };

 typedef struct X86RegisterInfo32 {

@@ -3665,7 +3686,8 @@ static uint32_t x86_cpu_get_supported_feature_word(FeatureWord w,

                                                         wi->cpuid.reg);

             break;

         case MSR_FEATURE_WORD:

-            r = kvm_arch_get_supported_msr_feature(kvm_state, wi->msr.index);

+            r = kvm_arch_get_supported_msr_feature(kvm_state,

+                        wi->msr.index);

             break;

         }

     } else if (hvf_enabled()) {

diff --git a/target/i386/cpu.h b/target/i386/cpu.h

index dd4493e..63f692f 100644

--- a/target/i386/cpu.h

+++ b/target/i386/cpu.h

@@ -500,6 +500,7 @@ typedef enum FeatureWord {

     FEAT_6_EAX,         /* CPUID[6].EAX */

     FEAT_XSAVE_COMP_LO, /* CPUID[EAX=0xd,ECX=0].EAX */

     FEAT_XSAVE_COMP_HI, /* CPUID[EAX=0xd,ECX=0].EDX */

+    FEAT_ARCH_CAPABILITIES,

     FEATURE_WORDS,

 } FeatureWord;

@@ -729,6 +730,13 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS];

 #define CPUID_TOPOLOGY_LEVEL_SMT      (1U << 8)

 #define CPUID_TOPOLOGY_LEVEL_CORE     (2U << 8)

+/* MSR Feature Bits */

+#define MSR_ARCH_CAP_RDCL_NO    (1U << 0)

+#define MSR_ARCH_CAP_IBRS_ALL   (1U << 1)

+#define MSR_ARCH_CAP_RSBA       (1U << 2)

+#define MSR_ARCH_CAP_SKIP_L1DFL_VMENTRY (1U << 3)

+#define MSR_ARCH_CAP_SSB_NO     (1U << 4)

+

 #ifndef HYPERV_SPINLOCK_NEVER_RETRY

 #define HYPERV_SPINLOCK_NEVER_RETRY             0xFFFFFFFF

 #endif

diff --git a/target/i386/kvm.c b/target/i386/kvm.c

index 096ed24..f1626a4 100644

--- a/target/i386/kvm.c

+++ b/target/i386/kvm.c

@@ -1833,6 +1833,17 @@ static int kvm_put_msrs(X86CPU *cpu, int level)

     }

 #endif

+    /* If host supports feature MSR, write down. */

+    if (kvm_feature_msrs) {

+        int i;

+        for (i = 0; i < kvm_feature_msrs->nmsrs; i++)

+            if (kvm_feature_msrs->indices[i] == MSR_IA32_ARCH_CAPABILITIES) {

+                kvm_msr_entry_add(cpu, MSR_IA32_ARCH_CAPABILITIES,

+                              env->features[FEAT_ARCH_CAPABILITIES]);

+                break;

+            }

+    }

+

     /*

      * The following MSRs have side effects on the guest or are too heavy

      * for normal writeback. Limit them to reset or full state updates.

-- 

1.8.3.1