diff options
| 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 /arch/x86/kvm/x86.c | |
| 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 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 579ce34e7904..1d5a7f418795 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -87,6 +87,11 @@ EXPORT_SYMBOL_GPL(kvm_x86_ops); int ignore_msrs = 0; module_param_named(ignore_msrs, ignore_msrs, bool, S_IRUGO | S_IWUSR); +bool kvm_has_tsc_control; +EXPORT_SYMBOL_GPL(kvm_has_tsc_control); +u32 kvm_max_guest_tsc_khz; +EXPORT_SYMBOL_GPL(kvm_max_guest_tsc_khz); + #define KVM_NR_SHARED_MSRS 16 struct kvm_shared_msrs_global { @@ -1986,6 +1991,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_X86_ROBUST_SINGLESTEP: case KVM_CAP_XSAVE: case KVM_CAP_ASYNC_PF: + case KVM_CAP_GET_TSC_KHZ: r = 1; break; case KVM_CAP_COALESCED_MMIO: @@ -2012,6 +2018,9 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_XCRS: r = cpu_has_xsave; break; + case KVM_CAP_TSC_CONTROL: + r = kvm_has_tsc_control; + break; default: r = 0; break; @@ -3045,6 +3054,32 @@ long kvm_arch_vcpu_ioctl(struct file *filp, r = kvm_vcpu_ioctl_x86_set_xcrs(vcpu, u.xcrs); break; } + case KVM_SET_TSC_KHZ: { + u32 user_tsc_khz; + + r = -EINVAL; + if (!kvm_has_tsc_control) + break; + + user_tsc_khz = (u32)arg; + + if (user_tsc_khz >= kvm_max_guest_tsc_khz) + goto out; + + kvm_x86_ops->set_tsc_khz(vcpu, user_tsc_khz); + + r = 0; + goto out; + } + case KVM_GET_TSC_KHZ: { + r = -EIO; + if (check_tsc_unstable()) + goto out; + + r = vcpu_tsc_khz(vcpu); + + goto out; + } default: r = -EINVAL; } |