From 4051b18801f5b47bb0369feefdc80e57819d0ddf Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 25 Mar 2011 09:44:49 +0100 Subject: [PATCH] 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 Signed-off-by: Avi Kivity --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/svm.c | 33 +++++++++++++++++++++++++++++++++ arch/x86/kvm/vmx.c | 11 +++++++++++ 3 files changed, 45 insertions(+) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index e3aaa02ca03..f3a7116f802 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -606,6 +606,7 @@ struct kvm_x86_ops { bool (*has_wbinvd_exit)(void); + void (*set_tsc_khz)(struct kvm_vcpu *vcpu, u32 user_tsc_khz); void (*write_tsc_offset)(struct kvm_vcpu *vcpu, u64 offset); void (*get_exit_info)(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2); diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 83015009995..a39fde4f5fe 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 3dfefe3bcd0..e19c7a5473d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1160,6 +1160,16 @@ static u64 guest_read_tsc(void) return host_tsc + tsc_offset; } +/* + * 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 */ @@ -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, -- 2.20.1