The commit is pushed to "branch-rh7-3.10.0-327.36.1.vz7.19.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git after rh7-3.10.0-327.36.1.vz7.19.9 ------> commit 4e92c1145557efd8aeb0a425b1809e65327de540 Author: Paolo Bonzini <pbonz...@redhat.com> Date: Wed Nov 16 16:46:04 2016 +0400
ms/KVM: x86: drop TSC offsetting kvm_x86_ops to fix KVM_GET/SET_CLOCK Since commit a545ab6a0085 ("kvm: x86: add tsc_offset field to struct kvm_vcpu_arch", 2016-09-07) the offset between host and L1 TSC is cached and need not be fished out of the VMCS or VMCB. This means that we can implement adjust_tsc_offset_guest and read_l1_tsc entirely in generic code. The simplification is particularly significant for VMX code, where vmx->nested.vmcs01_tsc_offset was duplicating what is now in vcpu->arch.tsc_offset. Therefore the vmcs01_tsc_offset can be dropped completely. More importantly, this fixes KVM_GET_CLOCK/KVM_SET_CLOCK which, after commit 108b249c453d ("KVM: x86: introduce get_kvmclock_ns", 2016-09-01) called read_l1_tsc while the VMCS was not loaded. It thus returned bogus values on Intel CPUs. Fixes: 108b249c453dd7132599ab6dc7e435a7036c193f Reported-by: Roman Kagan <rka...@virtuozzo.com> Reviewed-by: Radim KrÄmáŠ<rkrc...@redhat.com> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> (cherry-picked from commit ea26e4ec08d4727e3a9e48a6b74695861effcbd9) modifications to hyperv.c added fix #PSBM-54338 Signed-off-by: Denis Plotnikov <dplotni...@virtuozzo.com> Signed-off-by: Roman Kagan <rka...@virtuozzo.com> --- arch/x86/include/asm/kvm_host.h | 3 --- arch/x86/kvm/hyperv.c | 2 +- arch/x86/kvm/svm.c | 23 ----------------------- arch/x86/kvm/vmx.c | 39 +++------------------------------------ arch/x86/kvm/x86.c | 8 ++++---- 5 files changed, 8 insertions(+), 67 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index aa86551..2348a55 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -821,7 +821,6 @@ struct kvm_x86_ops { int (*get_lpage_level)(void); bool (*rdtscp_supported)(void); bool (*invpcid_supported)(void); - void (*adjust_tsc_offset_guest)(struct kvm_vcpu *vcpu, s64 adjustment); void (*set_tdp_cr3)(struct kvm_vcpu *vcpu, unsigned long cr3); @@ -831,8 +830,6 @@ struct kvm_x86_ops { void (*write_tsc_offset)(struct kvm_vcpu *vcpu, u64 offset); - u64 (*read_l1_tsc)(struct kvm_vcpu *vcpu, u64 host_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/hyperv.c b/arch/x86/kvm/hyperv.c index b5ebcaf..9a5df5c 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -398,7 +398,7 @@ static u64 get_time_ref_counter(struct kvm *kvm) return div_u64(get_kvmclock_ns(kvm), 100); vcpu = kvm_get_vcpu(kvm, 0); - tsc = kvm_x86_ops->read_l1_tsc(vcpu, native_read_tsc()); + tsc = kvm_read_l1_tsc(vcpu, native_read_tsc()); return mul_u64_u64_shr(tsc, hv->tsc_ref.tsc_scale, 64) + hv->tsc_ref.tsc_offset; } diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 9021e79..3e51a1f 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -975,21 +975,6 @@ static void svm_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) mark_dirty(svm->vmcb, VMCB_INTERCEPTS); } -static void svm_adjust_tsc_offset_guest(struct kvm_vcpu *vcpu, s64 adjustment) -{ - struct vcpu_svm *svm = to_svm(vcpu); - - svm->vmcb->control.tsc_offset += adjustment; - if (is_guest_mode(vcpu)) - svm->nested.hsave->control.tsc_offset += adjustment; - else - trace_kvm_write_tsc_offset(vcpu->vcpu_id, - svm->vmcb->control.tsc_offset - adjustment, - svm->vmcb->control.tsc_offset); - - mark_dirty(svm->vmcb, VMCB_INTERCEPTS); -} - static void init_vmcb(struct vcpu_svm *svm) { struct vmcb_control_area *control = &svm->vmcb->control; @@ -2961,12 +2946,6 @@ static int cr8_write_interception(struct vcpu_svm *svm) return 0; } -static u64 svm_read_l1_tsc(struct kvm_vcpu *vcpu, u64 host_tsc) -{ - struct vmcb *vmcb = get_host_vmcb(to_svm(vcpu)); - return vmcb->control.tsc_offset + host_tsc; -} - static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) { struct vcpu_svm *svm = to_svm(vcpu); @@ -4341,8 +4320,6 @@ static struct kvm_x86_ops svm_x86_ops = { .has_wbinvd_exit = svm_has_wbinvd_exit, .write_tsc_offset = svm_write_tsc_offset, - .adjust_tsc_offset_guest = svm_adjust_tsc_offset_guest, - .read_l1_tsc = svm_read_l1_tsc, .set_tdp_cr3 = set_tdp_cr3, diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 45007f1..6497232 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -396,7 +396,6 @@ struct nested_vmx { /* vmcs02_list cache of VMCSs recently used to run L2 guests */ struct list_head vmcs02_pool; int vmcs02_num; - u64 vmcs01_tsc_offset; /* L2 must run next, and mustn't decide to exit to L1. */ bool nested_run_pending; /* @@ -2189,20 +2188,6 @@ static u64 guest_read_tsc(struct kvm_vcpu *vcpu) } /* - * Like guest_read_tsc, but always returns L1's notion of the timestamp - * counter, even if a nested guest (L2) is currently running. - */ -static u64 vmx_read_l1_tsc(struct kvm_vcpu *vcpu, u64 host_tsc) -{ - u64 tsc_offset; - - tsc_offset = is_guest_mode(vcpu) ? - to_vmx(vcpu)->nested.vmcs01_tsc_offset : - vmcs_read64(TSC_OFFSET); - return host_tsc + tsc_offset; -} - -/* * writes 'offset' into guest's timestamp counter offset register */ static void vmx_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) @@ -2215,7 +2200,6 @@ static void vmx_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) * to the newly set TSC to get L2's TSC. */ struct vmcs12 *vmcs12; - to_vmx(vcpu)->nested.vmcs01_tsc_offset = offset; /* recalculate vmcs02.TSC_OFFSET: */ vmcs12 = get_vmcs12(vcpu); vmcs_write64(TSC_OFFSET, offset + @@ -2228,19 +2212,6 @@ static void vmx_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) } } -static void vmx_adjust_tsc_offset_guest(struct kvm_vcpu *vcpu, s64 adjustment) -{ - u64 offset = vmcs_read64(TSC_OFFSET); - - vmcs_write64(TSC_OFFSET, offset + adjustment); - if (is_guest_mode(vcpu)) { - /* Even when running L2, the adjustment needs to apply to L1 */ - to_vmx(vcpu)->nested.vmcs01_tsc_offset += adjustment; - } else - trace_kvm_write_tsc_offset(vcpu->vcpu_id, offset, - offset + adjustment); -} - static bool guest_cpuid_has_vmx(struct kvm_vcpu *vcpu) { struct kvm_cpuid_entry2 *best = kvm_find_cpuid_entry(vcpu, 1, 0); @@ -8924,9 +8895,9 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING) vmcs_write64(TSC_OFFSET, - vmx->nested.vmcs01_tsc_offset + vmcs12->tsc_offset); + vcpu->arch.tsc_offset + vmcs12->tsc_offset); else - vmcs_write64(TSC_OFFSET, vmx->nested.vmcs01_tsc_offset); + vmcs_write64(TSC_OFFSET, vcpu->arch.tsc_offset + vmcs12->tsc_offset); if (enable_vpid) { /* @@ -9138,8 +9109,6 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) enter_guest_mode(vcpu); - vmx->nested.vmcs01_tsc_offset = vmcs_read64(TSC_OFFSET); - if (!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS)) vmx->nested.vmcs01_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL); @@ -9651,7 +9620,7 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, load_vmcs12_host_state(vcpu, vmcs12); /* Update TSC_OFFSET if TSC was changed while L2 ran */ - vmcs_write64(TSC_OFFSET, vmx->nested.vmcs01_tsc_offset); + vmcs_write64(TSC_OFFSET, vcpu->arch.tsc_offset); /* This is needed for same reason as it was needed in prepare_vmcs02 */ vmx->host_rsp = 0; @@ -9851,8 +9820,6 @@ static struct kvm_x86_ops vmx_x86_ops = { .has_wbinvd_exit = cpu_has_vmx_wbinvd_exit, .write_tsc_offset = vmx_write_tsc_offset, - .adjust_tsc_offset_guest = vmx_adjust_tsc_offset_guest, - .read_l1_tsc = vmx_read_l1_tsc, .set_tdp_cr3 = vmx_set_cr3, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 5ec55b1..ea058a2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1381,7 +1381,7 @@ static u64 kvm_compute_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc) u64 kvm_read_l1_tsc(struct kvm_vcpu *vcpu, u64 host_tsc) { - return kvm_x86_ops->read_l1_tsc(vcpu, kvm_scale_tsc(vcpu, host_tsc)); + return vcpu->arch.tsc_offset + kvm_scale_tsc(vcpu, host_tsc); } EXPORT_SYMBOL_GPL(kvm_read_l1_tsc); @@ -1519,7 +1519,7 @@ EXPORT_SYMBOL_GPL(kvm_write_tsc); static inline void adjust_tsc_offset_guest(struct kvm_vcpu *vcpu, s64 adjustment) { - kvm_x86_ops->adjust_tsc_offset_guest(vcpu, adjustment); + kvm_vcpu_write_tsc_offset(vcpu, vcpu->arch.tsc_offset + adjustment); } static inline void adjust_tsc_offset_host(struct kvm_vcpu *vcpu, s64 adjustment) @@ -1527,7 +1527,7 @@ static inline void adjust_tsc_offset_host(struct kvm_vcpu *vcpu, s64 adjustment) if (vcpu->arch.tsc_scaling_ratio != kvm_default_tsc_scaling_ratio) WARN_ON(adjustment < 0); adjustment = kvm_scale_tsc(vcpu, (u64) adjustment); - kvm_x86_ops->adjust_tsc_offset_guest(vcpu, adjustment); + adjust_tsc_offset_guest(vcpu, adjustment); } #ifdef CONFIG_X86_64 @@ -1709,7 +1709,7 @@ static u64 __get_kvmclock_ns(struct kvm *kvm) u8 flags; if (vcpu->arch.hv_clock.flags & PVCLOCK_TSC_STABLE_BIT) { - u64 tsc = kvm_x86_ops->read_l1_tsc(vcpu, native_read_tsc()); + u64 tsc = kvm_read_l1_tsc(vcpu, native_read_tsc()); __pvclock_read_cycles(&vcpu->arch.hv_clock, &ns, &flags, tsc); } else { ns = ktime_to_ns(ktime_get_boottime()) + ka->kvmclock_offset;
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