| Message ID | 1523564347-8896-1-git-send-email-karahmed@amazon.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 12/04/2018 22:19, KarimAllah Ahmed wrote: > Update 'tsc_offset' on vmenty/vmexit of L2 guests to ensure that it always > captures the TSC_OFFSET of the running guest whether it is the L1 or L2 > guest. > > Cc: Jim Mattson <jmattson@google.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Radim Krčmář <rkrcmar@redhat.com> > Cc: kvm@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Suggested-by: Paolo Bonzini <pbonzini@redhat.com> > Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> > --- > v1 -> v2: > > - Rewrote the patch to always update tsc_offset to represent the current > guest (pbonzini@) Yes, this is it, thanks. I'll test it tomorrow and if I have time look at AMD. Paolo > --- > arch/x86/include/asm/kvm_host.h | 1 + > arch/x86/kvm/vmx.c | 25 ++++++++++++++++++++----- > arch/x86/kvm/x86.c | 9 ++++++++- > 3 files changed, 29 insertions(+), 6 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 9fa4f57..3bedfef 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -1015,6 +1015,7 @@ struct kvm_x86_ops { > > bool (*has_wbinvd_exit)(void); > > + u64 (*read_l1_tsc_offset)(struct kvm_vcpu *vcpu); > 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/vmx.c b/arch/x86/kvm/vmx.c > index cff2f50..9e7dd39 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -2895,6 +2895,17 @@ static u64 guest_read_tsc(struct kvm_vcpu *vcpu) > return kvm_scale_tsc(vcpu, host_tsc) + tsc_offset; > } > > +static u64 vmx_read_l1_tsc_offset(struct kvm_vcpu *vcpu) > +{ > + struct vmcs12 *vmcs12 = get_vmcs12(vcpu); > + > + if (is_guest_mode(vcpu) && > + (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING)) > + return vcpu->arch.tsc_offset - vmcs12->tsc_offset; > + > + return vcpu->arch.tsc_offset; > +} > + > /* > * writes 'offset' into guest's timestamp counter offset register > */ > @@ -11163,11 +11174,8 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, > vmcs_write64(GUEST_IA32_PAT, vmx->vcpu.arch.pat); > } > > - if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING) > - vmcs_write64(TSC_OFFSET, > - vcpu->arch.tsc_offset + vmcs12->tsc_offset); > - else > - vmcs_write64(TSC_OFFSET, vcpu->arch.tsc_offset); > + vmcs_write64(TSC_OFFSET, vcpu->arch.tsc_offset); > + > if (kvm_has_tsc_control) > decache_tsc_multiplier(vmx); > > @@ -11469,6 +11477,9 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) > if (enable_shadow_vmcs) > copy_shadow_to_vmcs12(vmx); > > + if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING) > + vcpu->arch.tsc_offset += vmcs12->tsc_offset; > + > /* > * The nested entry process starts with enforcing various prerequisites > * on vmcs12 as required by the Intel SDM, and act appropriately when > @@ -12015,6 +12026,9 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, > > leave_guest_mode(vcpu); > > + if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING) > + vcpu->arch.tsc_offset -= vmcs12->tsc_offset; > + > if (likely(!vmx->fail)) { > if (exit_reason == -1) > sync_vmcs12(vcpu, vmcs12); > @@ -12688,6 +12702,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = { > > .has_wbinvd_exit = cpu_has_vmx_wbinvd_exit, > > + .read_l1_tsc_offset = vmx_read_l1_tsc_offset, > .write_tsc_offset = vmx_write_tsc_offset, > > .set_tdp_cr3 = vmx_set_cr3, > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index ac42c85..3fb1353 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -1532,7 +1532,14 @@ 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 vcpu->arch.tsc_offset + kvm_scale_tsc(vcpu, host_tsc); > + u64 tsc_offset; > + > + if (kvm_x86_ops->read_l1_tsc_offset) > + tsc_offset = kvm_x86_ops->read_l1_tsc_offset(vcpu); > + else > + tsc_offset = vcpu->arch.tsc_offset; > + > + return tsc_offset + kvm_scale_tsc(vcpu, host_tsc); > } > EXPORT_SYMBOL_GPL(kvm_read_l1_tsc); > >
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 9fa4f57..3bedfef 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1015,6 +1015,7 @@ struct kvm_x86_ops { bool (*has_wbinvd_exit)(void); + u64 (*read_l1_tsc_offset)(struct kvm_vcpu *vcpu); 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/vmx.c b/arch/x86/kvm/vmx.c index cff2f50..9e7dd39 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2895,6 +2895,17 @@ static u64 guest_read_tsc(struct kvm_vcpu *vcpu) return kvm_scale_tsc(vcpu, host_tsc) + tsc_offset; } +static u64 vmx_read_l1_tsc_offset(struct kvm_vcpu *vcpu) +{ + struct vmcs12 *vmcs12 = get_vmcs12(vcpu); + + if (is_guest_mode(vcpu) && + (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING)) + return vcpu->arch.tsc_offset - vmcs12->tsc_offset; + + return vcpu->arch.tsc_offset; +} + /* * writes 'offset' into guest's timestamp counter offset register */ @@ -11163,11 +11174,8 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, vmcs_write64(GUEST_IA32_PAT, vmx->vcpu.arch.pat); } - if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING) - vmcs_write64(TSC_OFFSET, - vcpu->arch.tsc_offset + vmcs12->tsc_offset); - else - vmcs_write64(TSC_OFFSET, vcpu->arch.tsc_offset); + vmcs_write64(TSC_OFFSET, vcpu->arch.tsc_offset); + if (kvm_has_tsc_control) decache_tsc_multiplier(vmx); @@ -11469,6 +11477,9 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) if (enable_shadow_vmcs) copy_shadow_to_vmcs12(vmx); + if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING) + vcpu->arch.tsc_offset += vmcs12->tsc_offset; + /* * The nested entry process starts with enforcing various prerequisites * on vmcs12 as required by the Intel SDM, and act appropriately when @@ -12015,6 +12026,9 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, leave_guest_mode(vcpu); + if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING) + vcpu->arch.tsc_offset -= vmcs12->tsc_offset; + if (likely(!vmx->fail)) { if (exit_reason == -1) sync_vmcs12(vcpu, vmcs12); @@ -12688,6 +12702,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = { .has_wbinvd_exit = cpu_has_vmx_wbinvd_exit, + .read_l1_tsc_offset = vmx_read_l1_tsc_offset, .write_tsc_offset = vmx_write_tsc_offset, .set_tdp_cr3 = vmx_set_cr3, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ac42c85..3fb1353 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1532,7 +1532,14 @@ 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 vcpu->arch.tsc_offset + kvm_scale_tsc(vcpu, host_tsc); + u64 tsc_offset; + + if (kvm_x86_ops->read_l1_tsc_offset) + tsc_offset = kvm_x86_ops->read_l1_tsc_offset(vcpu); + else + tsc_offset = vcpu->arch.tsc_offset; + + return tsc_offset + kvm_scale_tsc(vcpu, host_tsc); } EXPORT_SYMBOL_GPL(kvm_read_l1_tsc);
Update 'tsc_offset' on vmenty/vmexit of L2 guests to ensure that it always captures the TSC_OFFSET of the running guest whether it is the L1 or L2 guest. Cc: Jim Mattson <jmattson@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> --- v1 -> v2: - Rewrote the patch to always update tsc_offset to represent the current guest (pbonzini@) --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/vmx.c | 25 ++++++++++++++++++++----- arch/x86/kvm/x86.c | 9 ++++++++- 3 files changed, 29 insertions(+), 6 deletions(-)