* [PATCH] kvm: update eax documentation in signature cpuid
@ 2012-05-01 13:06 Michael S. Tsirkin
2012-05-01 13:24 ` Takuya Yoshikawa
0 siblings, 1 reply; 2+ messages in thread
From: Michael S. Tsirkin @ 2012-05-01 13:06 UTC (permalink / raw)
To: Avi Kivity
Cc: Marcelo Tosatti, Thomas Gleixner, Ingo Molnar, H. Peter Anvin,
x86, kvm, linux-kernel, davej
---
Pls apply on top of kvm cpuid bit.
diff --git a/Documentation/virtual/kvm/cpuid.txt b/Documentation/virtual/kvm/cpuid.txt
index 8820685..c6e85d8 100644
--- a/Documentation/virtual/kvm/cpuid.txt
+++ b/Documentation/virtual/kvm/cpuid.txt
@@ -10,11 +10,15 @@ a guest.
KVM cpuid functions are:
function: KVM_CPUID_SIGNATURE (0x40000000)
-returns : eax = 0,
+returns : eax = 0x40000001,
ebx = 0x4b4d564b,
ecx = 0x564b4d56,
edx = 0x4d.
Note that this value in ebx, ecx and edx corresponds to the string "KVMKVMKVM".
+The value in eax corresponds to the maximim cpuid function present in this leaf,
+and will be updated if more functions are added in the future.
+Note also that old hosts set eax value to 0x0. This should
+be interpreted as if the value was 0x40000001.
This function queries the presence of KVM cpuid leafs.
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] kvm: update eax documentation in signature cpuid
2012-05-01 13:06 [PATCH] kvm: update eax documentation in signature cpuid Michael S. Tsirkin
@ 2012-05-01 13:24 ` Takuya Yoshikawa
0 siblings, 0 replies; 2+ messages in thread
From: Takuya Yoshikawa @ 2012-05-01 13:24 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: Avi Kivity, Marcelo Tosatti, Thomas Gleixner, Ingo Molnar,
H. Peter Anvin, x86, kvm, linux-kernel, davej
On Tue, 1 May 2012 16:06:11 +0300
"Michael S. Tsirkin" <mst@redhat.com> wrote:
> Note that this value in ebx, ecx and edx corresponds to the string "KVMKVMKVM".
> +The value in eax corresponds to the maximim cpuid function present in this leaf,
maximum?
Takuya
> +and will be updated if more functions are added in the future.
> +Note also that old hosts set eax value to 0x0. This should
> +be interpreted as if the value was 0x40000001.
> This function queries the presence of KVM cpuid leafs.
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2012-05-01 13:06 [PATCH] kvm: update eax documentation in signature cpuid Michael S. Tsirkin
2012-05-01 13:24 ` Takuya Yoshikawa
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