diff options
| author | Haozhong Zhang <haozhong.zhang@intel.com> | 2015-10-20 15:39:04 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-11-10 12:06:16 +0100 |
| commit | 381d585c80e34988269bd7901ad910981e900be1 (patch) | |
| tree | 771900b748040495069fdad4c517f658159e3d6c /arch/x86/kvm/x86.c | |
| parent | 35181e86df97e4223f4a28fb33e2bcf3b73de141 (diff) | |
KVM: x86: Replace call-back set_tsc_khz() with a common function
Both VMX and SVM propagate virtual_tsc_khz in the same way, so this
patch removes the call-back set_tsc_khz() and replaces it with a common
function.
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 46 |
1 files changed, 41 insertions, 5 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 1473e64cb744..c314e8d22a67 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1253,7 +1253,43 @@ static u32 adjust_tsc_khz(u32 khz, s32 ppm) return v; } -static void kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 this_tsc_khz) +static int set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale) +{ + u64 ratio; + + /* Guest TSC same frequency as host TSC? */ + if (!scale) { + vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio; + return 0; + } + + /* TSC scaling supported? */ + if (!kvm_has_tsc_control) { + if (user_tsc_khz > tsc_khz) { + vcpu->arch.tsc_catchup = 1; + vcpu->arch.tsc_always_catchup = 1; + return 0; + } else { + WARN(1, "user requested TSC rate below hardware speed\n"); + return -1; + } + } + + /* TSC scaling required - calculate ratio */ + ratio = mul_u64_u32_div(1ULL << kvm_tsc_scaling_ratio_frac_bits, + user_tsc_khz, tsc_khz); + + if (ratio == 0 || ratio >= kvm_max_tsc_scaling_ratio) { + WARN_ONCE(1, "Invalid TSC scaling ratio - virtual-tsc-khz=%u\n", + user_tsc_khz); + return -1; + } + + vcpu->arch.tsc_scaling_ratio = ratio; + return 0; +} + +static int kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 this_tsc_khz) { u32 thresh_lo, thresh_hi; int use_scaling = 0; @@ -1262,7 +1298,7 @@ static void kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 this_tsc_khz) if (this_tsc_khz == 0) { /* set tsc_scaling_ratio to a safe value */ vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio; - return; + return -1; } /* Compute a scale to convert nanoseconds in TSC cycles */ @@ -1283,7 +1319,7 @@ static void kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 this_tsc_khz) pr_debug("kvm: requested TSC rate %u falls outside tolerance [%u,%u]\n", this_tsc_khz, thresh_lo, thresh_hi); use_scaling = 1; } - kvm_x86_ops->set_tsc_khz(vcpu, this_tsc_khz, use_scaling); + return set_tsc_khz(vcpu, this_tsc_khz, use_scaling); } static u64 compute_guest_tsc(struct kvm_vcpu *vcpu, s64 kernel_ns) @@ -3353,9 +3389,9 @@ long kvm_arch_vcpu_ioctl(struct file *filp, if (user_tsc_khz == 0) user_tsc_khz = tsc_khz; - kvm_set_tsc_khz(vcpu, user_tsc_khz); + if (!kvm_set_tsc_khz(vcpu, user_tsc_khz)) + r = 0; - r = 0; goto out; } case KVM_GET_TSC_KHZ: { |