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| author | Joerg Roedel <joerg.roedel@amd.com> | 2011-03-25 09:44:51 +0100 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-05-11 07:57:06 -0400 |
| commit | 92a1f12d2598f429bd8639e21d89305e787115c5 (patch) | |
| tree | 48a6b7d6c50b5583b5163185dd097db100a471c6 /Documentation | |
| parent | 857e40999e35906baa367a79137019912cfb5434 (diff) | |
KVM: X86: Implement userspace interface to set virtual_tsc_khz
This patch implements two new vm-ioctls to get and set the
virtual_tsc_khz if the machine supports tsc-scaling. Setting
the tsc-frequency is only possible before userspace creates
any vcpu.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/kvm/api.txt | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt index 9bef4e4cec50..1b9eaa7e8856 100644 --- a/Documentation/kvm/api.txt +++ b/Documentation/kvm/api.txt @@ -1263,6 +1263,29 @@ struct kvm_assigned_msix_entry { __u16 padding[3]; }; +4.54 KVM_SET_TSC_KHZ + +Capability: KVM_CAP_TSC_CONTROL +Architectures: x86 +Type: vcpu ioctl +Parameters: virtual tsc_khz +Returns: 0 on success, -1 on error + +Specifies the tsc frequency for the virtual machine. The unit of the +frequency is KHz. + +4.55 KVM_GET_TSC_KHZ + +Capability: KVM_CAP_GET_TSC_KHZ +Architectures: x86 +Type: vcpu ioctl +Parameters: none +Returns: virtual tsc-khz on success, negative value on error + +Returns the tsc frequency of the guest. The unit of the return value is +KHz. If the host has unstable tsc this ioctl returns -EIO instead as an +error. + 5. The kvm_run structure Application code obtains a pointer to the kvm_run structure by |