From 92a1f12d2598f429bd8639e21d89305e787115c5 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 25 Mar 2011 09:44:51 +0100 Subject: 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 Signed-off-by: Avi Kivity --- Documentation/kvm/api.txt | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'Documentation') diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt index 9bef4e4cec5..1b9eaa7e885 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 -- cgit v1.2.3-70-g09d2