path: root/Documentation/virtual/kvm/cpuid.txt
diff options
authorAnton Arapov <>2012-08-07 11:21:50 +0200
committerAnton Arapov <>2012-08-07 12:52:25 +0200
commit1d44b6f3fcf6058fb7c960b7558766967e8028f7 (patch)
tree53d88547c973ba048d233091a3f91f3173ad01df /Documentation/virtual/kvm/cpuid.txt
parentd91eda5d7b0383e6a0c83e0146ff141ff3b1355b (diff)
fedora kernel: 222b075b3ff0d9e88aa9353e3c80667756ed7361v3.5.0-4
Signed-off-by: Anton Arapov <>
Diffstat (limited to 'Documentation/virtual/kvm/cpuid.txt')
1 files changed, 5 insertions, 1 deletions
diff --git a/Documentation/virtual/kvm/cpuid.txt b/Documentation/virtual/kvm/cpuid.txt
index 882068538c9..83afe65d496 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 maximum 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.