From 0004d2f3b0c3b21336415a967d70b7e9c2d08f54 Mon Sep 17 00:00:00 2001

Message-Id: <0004d2f3b0c3b21336415a967d70b7e9c2d08f54@dist-git>

From: Jiri Denemark <jdenemar@redhat.com>

Date: Fri, 21 Jun 2019 09:26:09 +0200

Subject: [PATCH] cpu_x86: Read CPU features from IA32_ARCH_CAPABILITIES MSR

MIME-Version: 1.0

Content-Type: text/plain; charset=UTF-8

Content-Transfer-Encoding: 8bit

This is used by the host capabilities code to construct host CPU

definition.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

Reviewed-by: Ján Tomko <jtomko@redhat.com>

(cherry picked from commit 56b254dccc96b7339494812c9df07ccf6af3da95)

https://bugzilla.redhat.com/show_bug.cgi?id=1697627

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

Message-Id: <58ad207c48e0f2a6c44ff097b0881b649826ecd4.1561068591.git.jdenemar@redhat.com>

Reviewed-by: Ján Tomko <jtomko@redhat.com>

---

 src/cpu/cpu_x86.c | 22 ++++++++++++++++++++++

 1 file changed, 22 insertions(+)

diff --git a/src/cpu/cpu_x86.c b/src/cpu/cpu_x86.c

index ec0e408f98..0a520f07ff 100644

--- a/src/cpu/cpu_x86.c

+++ b/src/cpu/cpu_x86.c

@@ -2771,6 +2771,28 @@ virCPUx86GetHost(virCPUDefPtr cpu,

         cpuidSet(CPUX86_EXTENDED, cpuData) < 0)

         goto cleanup;

+    /* Read the IA32_ARCH_CAPABILITIES MSR (0x10a) if supported.

+     * This is best effort since there might be no way to read the MSR

+     * when we are not running as root. */

+    if (virCPUx86DataCheckFeature(cpuData, "arch-capabilities") == 1) {

+        uint64_t msr;

+        unsigned long index = 0x10a;

+

+        if (virHostCPUGetMSR(index, &msr) == 0) {

+            virCPUx86DataItem item = {

+                .type = VIR_CPU_X86_DATA_MSR,

+                .data.msr = {

+                    .index = index,

+                    .eax = msr & 0xffffffff,

+                    .edx = msr >> 32,

+                },

+            };

+

+            if (virCPUx86DataAdd(cpuData, &item) < 0)

+                return -1;

+        }

+    }

+

     ret = x86DecodeCPUData(cpu, cpuData, models);

     cpu->microcodeVersion = virHostCPUGetMicrocodeVersion();

-- 

2.22.0