diff options
| author | Joerg Roedel <joerg.roedel@amd.com> | 2011-03-25 08:44:49 (GMT) |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-05-11 11:57:05 (GMT) |
| commit | 4051b18801f5b47bb0369feefdc80e57819d0ddf (patch) | |
| tree | ac0b50efc768bbf7bfe42fcd70e9d97bf46185b9 /arch/x86/kvm | |
| parent | 8f6055cbaf68cbd9ff2692a2cfa691b43629ccd4 (diff) | |
| download | linux-4051b18801f5b47bb0369feefdc80e57819d0ddf.tar.xz | |
KVM: X86: Implement call-back to propagate virtual_tsc_khz
This patch implements a call-back into the architecture code
to allow the propagation of changes to the virtual tsc_khz
of the vcpu.
On SVM it updates the tsc_ratio variable, on VMX it does
nothing.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/svm.c | 33 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx.c | 11 |
2 files changed, 44 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 8301500..a39fde4 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -885,6 +885,38 @@ static u64 svm_scale_tsc(struct kvm_vcpu *vcpu, u64 tsc) return _tsc; } +static void svm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz) +{ + struct vcpu_svm *svm = to_svm(vcpu); + u64 ratio; + u64 khz; + + /* TSC scaling supported? */ + if (!boot_cpu_has(X86_FEATURE_TSCRATEMSR)) + return; + + /* TSC-Scaling disabled or guest TSC same frequency as host TSC? */ + if (user_tsc_khz == 0) { + vcpu->arch.virtual_tsc_khz = 0; + svm->tsc_ratio = TSC_RATIO_DEFAULT; + return; + } + + khz = user_tsc_khz; + + /* TSC scaling required - calculate ratio */ + ratio = khz << 32; + do_div(ratio, tsc_khz); + + if (ratio == 0 || ratio & TSC_RATIO_RSVD) { + WARN_ONCE(1, "Invalid TSC ratio - virtual-tsc-khz=%u\n", + user_tsc_khz); + return; + } + vcpu->arch.virtual_tsc_khz = user_tsc_khz; + svm->tsc_ratio = ratio; +} + static void svm_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) { struct vcpu_svm *svm = to_svm(vcpu); @@ -4159,6 +4191,7 @@ static struct kvm_x86_ops svm_x86_ops = { .has_wbinvd_exit = svm_has_wbinvd_exit, + .set_tsc_khz = svm_set_tsc_khz, .write_tsc_offset = svm_write_tsc_offset, .adjust_tsc_offset = svm_adjust_tsc_offset, diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 3dfefe3..e19c7a5 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1161,6 +1161,16 @@ static u64 guest_read_tsc(void) } /* + * Empty call-back. Needs to be implemented when VMX enables the SET_TSC_KHZ + * ioctl. In this case the call-back should update internal vmx state to make + * the changes effective. + */ +static void vmx_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz) +{ + /* Nothing to do here */ +} + +/* * writes 'offset' into guest's timestamp counter offset register */ static void vmx_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) @@ -4497,6 +4507,7 @@ static struct kvm_x86_ops vmx_x86_ops = { .has_wbinvd_exit = cpu_has_vmx_wbinvd_exit, + .set_tsc_khz = vmx_set_tsc_khz, .write_tsc_offset = vmx_write_tsc_offset, .adjust_tsc_offset = vmx_adjust_tsc_offset, |