From 857e40999e35906baa367a79137019912cfb5434 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 25 Mar 2011 09:44:50 +0100 Subject: [PATCH] KVM: X86: Delegate tsc-offset calculation to architecture code With TSC scaling in SVM the tsc-offset needs to be calculated differently. This patch propagates this calculation into the architecture specific modules so that this complexity can be handled there. Signed-off-by: Joerg Roedel Signed-off-by: Avi Kivity --- arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/svm.c | 10 ++++++++++ arch/x86/kvm/vmx.c | 6 ++++++ arch/x86/kvm/x86.c | 10 +++++----- 4 files changed, 23 insertions(+), 5 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index f3a7116..da0a8ce 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -609,6 +609,8 @@ struct kvm_x86_ops { void (*set_tsc_khz)(struct kvm_vcpu *vcpu, u32 user_tsc_khz); void (*write_tsc_offset)(struct kvm_vcpu *vcpu, u64 offset); + u64 (*compute_tsc_offset)(struct kvm_vcpu *vcpu, u64 target_tsc); + void (*get_exit_info)(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2); int (*check_intercept)(struct kvm_vcpu *vcpu, diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index a39fde4..8c4549b 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -943,6 +943,15 @@ static void svm_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment) mark_dirty(svm->vmcb, VMCB_INTERCEPTS); } +static u64 svm_compute_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc) +{ + u64 tsc; + + tsc = svm_scale_tsc(vcpu, native_read_tsc()); + + return target_tsc - tsc; +} + static void init_vmcb(struct vcpu_svm *svm) { struct vmcb_control_area *control = &svm->vmcb->control; @@ -4194,6 +4203,7 @@ static struct kvm_x86_ops svm_x86_ops = { .set_tsc_khz = svm_set_tsc_khz, .write_tsc_offset = svm_write_tsc_offset, .adjust_tsc_offset = svm_adjust_tsc_offset, + .compute_tsc_offset = svm_compute_tsc_offset, .set_tdp_cr3 = set_tdp_cr3, diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index e19c7a5..aabe333 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1184,6 +1184,11 @@ static void vmx_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment) vmcs_write64(TSC_OFFSET, offset + adjustment); } +static u64 vmx_compute_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc) +{ + return target_tsc - native_read_tsc(); +} + /* * Reads an msr value (of 'msr_index') into 'pdata'. * Returns 0 on success, non-0 otherwise. @@ -4510,6 +4515,7 @@ static struct kvm_x86_ops vmx_x86_ops = { .set_tsc_khz = vmx_set_tsc_khz, .write_tsc_offset = vmx_write_tsc_offset, .adjust_tsc_offset = vmx_adjust_tsc_offset, + .compute_tsc_offset = vmx_compute_tsc_offset, .set_tdp_cr3 = vmx_set_cr3, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index fcce29b..579ce34 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -977,7 +977,7 @@ static u64 vcpu_tsc_khz(struct kvm_vcpu *vcpu) return __this_cpu_read(cpu_tsc_khz); } -static inline u64 nsec_to_cycles(u64 nsec) +static inline u64 nsec_to_cycles(struct kvm_vcpu *vcpu, u64 nsec) { u64 ret; @@ -985,7 +985,7 @@ static inline u64 nsec_to_cycles(u64 nsec) if (kvm_tsc_changes_freq()) printk_once(KERN_WARNING "kvm: unreliable cycle conversion on adjustable rate TSC\n"); - ret = nsec * __this_cpu_read(cpu_tsc_khz); + ret = nsec * vcpu_tsc_khz(vcpu); do_div(ret, USEC_PER_SEC); return ret; } @@ -1015,7 +1015,7 @@ void kvm_write_tsc(struct kvm_vcpu *vcpu, u64 data) s64 sdiff; raw_spin_lock_irqsave(&kvm->arch.tsc_write_lock, flags); - offset = data - native_read_tsc(); + offset = kvm_x86_ops->compute_tsc_offset(vcpu, data); ns = get_kernel_ns(); elapsed = ns - kvm->arch.last_tsc_nsec; sdiff = data - kvm->arch.last_tsc_write; @@ -1031,13 +1031,13 @@ void kvm_write_tsc(struct kvm_vcpu *vcpu, u64 data) * In that case, for a reliable TSC, we can match TSC offsets, * or make a best guest using elapsed value. */ - if (sdiff < nsec_to_cycles(5ULL * NSEC_PER_SEC) && + if (sdiff < nsec_to_cycles(vcpu, 5ULL * NSEC_PER_SEC) && elapsed < 5ULL * NSEC_PER_SEC) { if (!check_tsc_unstable()) { offset = kvm->arch.last_tsc_offset; pr_debug("kvm: matched tsc offset for %llu\n", data); } else { - u64 delta = nsec_to_cycles(elapsed); + u64 delta = nsec_to_cycles(vcpu, elapsed); offset += delta; pr_debug("kvm: adjusted tsc offset by %llu\n", delta); } -- 2.7.4