Patchwork [04/12] cpuid: fix comments

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Submitter Andre Przywara
Date Sept. 10, 2009, 10:20 p.m.
Message ID <1252621257-26364-5-git-send-email-andre.przywara@amd.com>
Download mbox | patch
Permalink /patch/33393/
State Superseded
Headers show

Comments

Andre Przywara - Sept. 10, 2009, 10:20 p.m.
Some comments regarding CPUID features were not up-to-date.
- Nested SVM is supported in qemu-kvm, but not in upstream qemu (yet).
- We support syscall/sysenter emulation in KVM now, so the comment
  explaining the vendor string issue can be more relaxed.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
---
 target-i386/cpuid.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)

Patch

diff --git a/target-i386/cpuid.c b/target-i386/cpuid.c
index 9ed9fb2..7b69ff4 100644
--- a/target-i386/cpuid.c
+++ b/target-i386/cpuid.c
@@ -610,10 +610,12 @@  void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
         *edx = env->cpuid_vendor2;
         *ecx = env->cpuid_vendor3;
 
-        /* sysenter isn't supported on compatibility mode on AMD.  and syscall
-         * isn't supported in compatibility mode on Intel.  so advertise the
-         * actuall cpu, and say goodbye to migration between different vendors
-         * is you use compatibility mode. */
+        /* sysenter isn't supported on compatibility mode on AMD, syscall
+         * isn't supported in compatibility mode on Intel.
+         * Normally we advertise the actual cpu vendor, but you can override
+         * this if you want to use KVM's sysenter/syscall emulation
+         * in compatibility mode and when doing cross vendor migration
+         */
         if (kvm_enabled() && !env->cpuid_vendor_override)
             host_cpuid(0, 0, NULL, ebx, ecx, edx);
         break;
@@ -720,7 +722,7 @@  void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
         }
 
         if (kvm_enabled()) {
-            /* Nested SVM not yet supported in KVM */
+            /* Nested SVM not yet supported in upstream QEMU */
             *ecx &= ~CPUID_EXT3_SVM;
         } else {
             /* AMD 3DNow! is not supported in QEMU */