| Message ID | 20200518201600.255669-2-makarandsonare@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fix VMX preemption timer migration | expand |
Makarand Sonare <makarandsonare@google.com> writes: > From: Peter Shier <pshier@google.com> > > Add new field to hold preemption timer expiration deadline > appended to struct kvm_vmx_nested_state_data. This is to prevent > the first VM-Enter after migration from incorrectly restarting the timer > with the full timer value instead of partially decayed timer value. > KVM_SET_NESTED_STATE restarts timer using migrated state regardless > of whether L1 sets VM_EXIT_SAVE_VMX_PREEMPTION_TIMER. > > Fixes: cf8b84f48a593 ("kvm: nVMX: Prepare for checkpointing L2 state") > > Signed-off-by: Peter Shier <pshier@google.com> > Signed-off-by: Makarand Sonare <makarandsonare@google.com> > Change-Id: I6446aba5a547afa667f0ef4620b1b76115bf3753 > --- > Documentation/virt/kvm/api.rst | 4 ++ > arch/x86/include/uapi/asm/kvm.h | 2 + > arch/x86/kvm/vmx/nested.c | 61 ++++++++++++++++++++++++--- > arch/x86/kvm/vmx/vmx.h | 1 + > arch/x86/kvm/x86.c | 3 +- > include/uapi/linux/kvm.h | 1 + > tools/arch/x86/include/uapi/asm/kvm.h | 2 + > 7 files changed, 67 insertions(+), 7 deletions(-) > > diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst > index d871dacb984e9..b410815772970 100644 > --- a/Documentation/virt/kvm/api.rst > +++ b/Documentation/virt/kvm/api.rst > @@ -4326,6 +4326,9 @@ Errors: > #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 > #define KVM_STATE_NESTED_EVMCS 0x00000004 > Not your fault but KVM_STATE_NESTED_MTF_PENDING seems to be missing here > + /* Available with KVM_CAP_NESTED_STATE_PREEMPTION_TIMER */ > + #define KVM_STATE_NESTED_PREEMPTION_TIMER 0x00000010 > + > #define KVM_STATE_NESTED_FORMAT_VMX 0 > #define KVM_STATE_NESTED_FORMAT_SVM 1 > > @@ -4346,6 +4349,7 @@ Errors: > struct kvm_vmx_nested_state_data { > __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; > __u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; > + __u64 preemption_timer_deadline; > }; > > This ioctl copies the vcpu's nested virtualization state from the kernel to > diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h > index 3f3f780c8c650..20d5832bab215 100644 > --- a/arch/x86/include/uapi/asm/kvm.h > +++ b/arch/x86/include/uapi/asm/kvm.h > @@ -391,6 +391,7 @@ struct kvm_sync_regs { > #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 > #define KVM_STATE_NESTED_EVMCS 0x00000004 > #define KVM_STATE_NESTED_MTF_PENDING 0x00000008 > +#define KVM_STATE_NESTED_PREEMPTION_TIMER 0x00000010 and here you don't have the "/* Available with KVM_CAP_NESTED_STATE_PREEMPTION_TIMER */" comment you put to api.rst. I think it would be better to keep them in sync. > > #define KVM_STATE_NESTED_SMM_GUEST_MODE 0x00000001 > #define KVM_STATE_NESTED_SMM_VMXON 0x00000002 > @@ -400,6 +401,7 @@ struct kvm_sync_regs { > struct kvm_vmx_nested_state_data { > __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; > __u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; > + __u64 preemption_timer_deadline; > }; > > struct kvm_vmx_nested_state_hdr { > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > index 51ebb60e1533a..badb82a39ac04 100644 > --- a/arch/x86/kvm/vmx/nested.c > +++ b/arch/x86/kvm/vmx/nested.c > @@ -2092,9 +2092,9 @@ static enum hrtimer_restart vmx_preemption_timer_fn(struct hrtimer *timer) > return HRTIMER_NORESTART; > } > > -static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu) > +static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu, > + u64 preemption_timeout) > { > - u64 preemption_timeout = get_vmcs12(vcpu)->vmx_preemption_timer_value; > struct vcpu_vmx *vmx = to_vmx(vcpu); > > /* > @@ -3353,8 +3353,24 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, > * the timer. > */ > vmx->nested.preemption_timer_expired = false; > - if (nested_cpu_has_preemption_timer(vmcs12)) > - vmx_start_preemption_timer(vcpu); > + if (nested_cpu_has_preemption_timer(vmcs12)) { > + u64 timer_value; > + u64 l1_tsc_value = kvm_read_l1_tsc(vcpu, rdtsc()); > + > + if (from_vmentry) { > + timer_value = vmcs12->vmx_preemption_timer_value; > + vmx->nested.preemption_timer_deadline = timer_value + > + (l1_tsc_value >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE); > + } else { > + if ((l1_tsc_value >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE) > > + vmx->nested.preemption_timer_deadline) > + timer_value = 0; > + else > + timer_value = vmx->nested.preemption_timer_deadline - > + (l1_tsc_value >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE); > + } > + vmx_start_preemption_timer(vcpu, timer_value); > + } > > /* > * Note no nested_vmx_succeed or nested_vmx_fail here. At this point > @@ -3962,9 +3978,11 @@ static void sync_vmcs02_to_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) > vmcs12->guest_activity_state = GUEST_ACTIVITY_ACTIVE; > > if (nested_cpu_has_preemption_timer(vmcs12) && > - vmcs12->vm_exit_controls & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER) > + !vmx->nested.nested_run_pending) { > + if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER) > vmcs12->vmx_preemption_timer_value = > vmx_get_preemption_timer_value(vcpu); > + } > > /* > * In some cases (usually, nested EPT), L2 is allowed to change its > @@ -5939,6 +5957,13 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, > > if (vmx->nested.mtf_pending) > kvm_state.flags |= KVM_STATE_NESTED_MTF_PENDING; > + > + if (nested_cpu_has_preemption_timer(vmcs12)) { > + kvm_state.flags |= > + KVM_STATE_NESTED_PREEMPTION_TIMER; > + kvm_state.size = offsetof(struct kvm_nested_state, data.vmx) + > + offsetofend(struct kvm_vmx_nested_state_data, preemption_timer_deadline); Hm, here we seem to drop all previous calculations for the kvm_state.size (like if shadow vmcs was present or not). I think this should just be kvm_state.size += sizeof(user_vmx_nested_state.preemption_timer_deadline); instead. > + } > } > } > > @@ -5970,6 +5995,9 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, > > BUILD_BUG_ON(sizeof(user_vmx_nested_state->vmcs12) < VMCS12_SIZE); > BUILD_BUG_ON(sizeof(user_vmx_nested_state->shadow_vmcs12) < VMCS12_SIZE); > + BUILD_BUG_ON(sizeof(user_vmx_nested_state->preemption_timer_deadline) > + != sizeof(vmx->nested.preemption_timer_deadline)); > + > > /* > * Copy over the full allocated size of vmcs12 rather than just the size > @@ -5985,6 +6013,12 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, > return -EFAULT; > } > > + if (kvm_state.flags & KVM_STATE_NESTED_PREEMPTION_TIMER) { > + if (put_user(vmx->nested.preemption_timer_deadline, > + &user_vmx_nested_state->preemption_timer_deadline)) > + return -EFAULT; > + } > + > out: > return kvm_state.size; > } > @@ -6056,7 +6090,8 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, > */ > if (is_smm(vcpu) ? > (kvm_state->flags & > - (KVM_STATE_NESTED_GUEST_MODE | KVM_STATE_NESTED_RUN_PENDING)) > + (KVM_STATE_NESTED_GUEST_MODE | KVM_STATE_NESTED_RUN_PENDING | > + KVM_STATE_NESTED_PREEMPTION_TIMER)) > : kvm_state->hdr.vmx.smm.flags) > return -EINVAL; > > @@ -6146,6 +6181,20 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, > goto error_guest_mode; > } > > + if (kvm_state->flags & KVM_STATE_NESTED_PREEMPTION_TIMER) { > + > + if (kvm_state->size < > + offsetof(struct kvm_nested_state, data.vmx) + > + offsetofend(struct kvm_vmx_nested_state_data, preemption_timer_deadline)) This also doesn't seem to be correct. E.g. what if there is no shadow vmcs data in the saved state? > + goto error_guest_mode; > + > + if (get_user(vmx->nested.preemption_timer_deadline, > + &user_vmx_nested_state->preemption_timer_deadline)) { > + ret = -EFAULT; > + goto error_guest_mode; > + } > + } > + > if (nested_vmx_check_controls(vcpu, vmcs12) || > nested_vmx_check_host_state(vcpu, vmcs12) || > nested_vmx_check_guest_state(vcpu, vmcs12, &ignored)) > diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h > index 298ddef79d009..db697400755fb 100644 > --- a/arch/x86/kvm/vmx/vmx.h > +++ b/arch/x86/kvm/vmx/vmx.h > @@ -169,6 +169,7 @@ struct nested_vmx { > u16 posted_intr_nv; > > struct hrtimer preemption_timer; > + u64 preemption_timer_deadline; > bool preemption_timer_expired; > > /* to migrate it to L2 if VM_ENTRY_LOAD_DEBUG_CONTROLS is off */ > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 471fccf7f8501..ba9e62ffbb4cd 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -3418,6 +3418,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) > case KVM_CAP_MSR_PLATFORM_INFO: > case KVM_CAP_EXCEPTION_PAYLOAD: > case KVM_CAP_SET_GUEST_DEBUG: > + case KVM_CAP_NESTED_STATE_PREEMPTION_TIMER: > r = 1; > break; > case KVM_CAP_SYNC_REGS: > @@ -4626,7 +4627,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp, > > if (kvm_state.flags & > ~(KVM_STATE_NESTED_RUN_PENDING | KVM_STATE_NESTED_GUEST_MODE > - | KVM_STATE_NESTED_EVMCS)) > + | KVM_STATE_NESTED_EVMCS | KVM_STATE_NESTED_PREEMPTION_TIMER)) > break; > > /* nested_run_pending implies guest_mode. */ > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index ac9eba0289d1b..0868dce12a715 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -1018,6 +1018,7 @@ struct kvm_ppc_resize_hpt { > #define KVM_CAP_S390_PROTECTED 180 > #define KVM_CAP_PPC_SECURE_GUEST 181 > #define KVM_CAP_HALT_POLL 182 > +#define KVM_CAP_NESTED_STATE_PREEMPTION_TIMER 183 > > #ifdef KVM_CAP_IRQ_ROUTING > > diff --git a/tools/arch/x86/include/uapi/asm/kvm.h b/tools/arch/x86/include/uapi/asm/kvm.h > index 3f3f780c8c650..60701178b9cc1 100644 > --- a/tools/arch/x86/include/uapi/asm/kvm.h > +++ b/tools/arch/x86/include/uapi/asm/kvm.h > @@ -391,6 +391,8 @@ struct kvm_sync_regs { > #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 > #define KVM_STATE_NESTED_EVMCS 0x00000004 > #define KVM_STATE_NESTED_MTF_PENDING 0x00000008 > +/* Available with KVM_CAP_NESTED_STATE_PREEMPTION_TIMER */ > +#define KVM_STATE_NESTED_PREEMPTION_TIMER 0x00000010 > > #define KVM_STATE_NESTED_SMM_GUEST_MODE 0x00000001 > #define KVM_STATE_NESTED_SMM_VMXON 0x00000002 It seems tools/arch/x86/include/uapi/asm/kvm.h is usually updated separately (not sure it's the right thing to do though..)
On 5/18/20 1:15 PM, Makarand Sonare wrote: > From: Peter Shier <pshier@google.com> > > Add new field to hold preemption timer expiration deadline > appended to struct kvm_vmx_nested_state_data. This is to prevent > the first VM-Enter after migration from incorrectly restarting the timer > with the full timer value instead of partially decayed timer value. > KVM_SET_NESTED_STATE restarts timer using migrated state regardless > of whether L1 sets VM_EXIT_SAVE_VMX_PREEMPTION_TIMER. > > Fixes: cf8b84f48a593 ("kvm: nVMX: Prepare for checkpointing L2 state") > > Signed-off-by: Peter Shier <pshier@google.com> > Signed-off-by: Makarand Sonare <makarandsonare@google.com> > Change-Id: I6446aba5a547afa667f0ef4620b1b76115bf3753 > --- > Documentation/virt/kvm/api.rst | 4 ++ > arch/x86/include/uapi/asm/kvm.h | 2 + > arch/x86/kvm/vmx/nested.c | 61 ++++++++++++++++++++++++--- > arch/x86/kvm/vmx/vmx.h | 1 + > arch/x86/kvm/x86.c | 3 +- > include/uapi/linux/kvm.h | 1 + > tools/arch/x86/include/uapi/asm/kvm.h | 2 + > 7 files changed, 67 insertions(+), 7 deletions(-) > > diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst > index d871dacb984e9..b410815772970 100644 > --- a/Documentation/virt/kvm/api.rst > +++ b/Documentation/virt/kvm/api.rst > @@ -4326,6 +4326,9 @@ Errors: > #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 > #define KVM_STATE_NESTED_EVMCS 0x00000004 > > + /* Available with KVM_CAP_NESTED_STATE_PREEMPTION_TIMER */ > + #define KVM_STATE_NESTED_PREEMPTION_TIMER 0x00000010 > + > #define KVM_STATE_NESTED_FORMAT_VMX 0 > #define KVM_STATE_NESTED_FORMAT_SVM 1 > > @@ -4346,6 +4349,7 @@ Errors: > struct kvm_vmx_nested_state_data { > __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; > __u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; > + __u64 preemption_timer_deadline; > }; > > This ioctl copies the vcpu's nested virtualization state from the kernel to > diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h > index 3f3f780c8c650..20d5832bab215 100644 > --- a/arch/x86/include/uapi/asm/kvm.h > +++ b/arch/x86/include/uapi/asm/kvm.h > @@ -391,6 +391,7 @@ struct kvm_sync_regs { > #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 > #define KVM_STATE_NESTED_EVMCS 0x00000004 > #define KVM_STATE_NESTED_MTF_PENDING 0x00000008 > +#define KVM_STATE_NESTED_PREEMPTION_TIMER 0x00000010 > > #define KVM_STATE_NESTED_SMM_GUEST_MODE 0x00000001 > #define KVM_STATE_NESTED_SMM_VMXON 0x00000002 > @@ -400,6 +401,7 @@ struct kvm_sync_regs { > struct kvm_vmx_nested_state_data { > __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; > __u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; > + __u64 preemption_timer_deadline; > }; > > struct kvm_vmx_nested_state_hdr { > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > index 51ebb60e1533a..badb82a39ac04 100644 > --- a/arch/x86/kvm/vmx/nested.c > +++ b/arch/x86/kvm/vmx/nested.c > @@ -2092,9 +2092,9 @@ static enum hrtimer_restart vmx_preemption_timer_fn(struct hrtimer *timer) > return HRTIMER_NORESTART; > } > > -static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu) > +static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu, > + u64 preemption_timeout) > { > - u64 preemption_timeout = get_vmcs12(vcpu)->vmx_preemption_timer_value; > struct vcpu_vmx *vmx = to_vmx(vcpu); > > /* > @@ -3353,8 +3353,24 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, > * the timer. > */ > vmx->nested.preemption_timer_expired = false; > - if (nested_cpu_has_preemption_timer(vmcs12)) > - vmx_start_preemption_timer(vcpu); > + if (nested_cpu_has_preemption_timer(vmcs12)) { > + u64 timer_value; > + u64 l1_tsc_value = kvm_read_l1_tsc(vcpu, rdtsc()); > + > + if (from_vmentry) { > + timer_value = vmcs12->vmx_preemption_timer_value; > + vmx->nested.preemption_timer_deadline = timer_value + > + (l1_tsc_value >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE); > + } else { > + if ((l1_tsc_value >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE) > > + vmx->nested.preemption_timer_deadline) > + timer_value = 0; > + else > + timer_value = vmx->nested.preemption_timer_deadline - > + (l1_tsc_value >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE); A couple of code optimizations can be done here: 1. The inside if-else can be simplified by initializing 'timer_value' at the place where you have defined it: } else { + if (!((l1_tsc_value >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE) > + vmx->nested.preemption_timer_deadline)) + timer_value = vmx->nested.preemption_timer_deadline - + (l1_tsc_value >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE); + } 2. You can apply the right-shift operation on 'l1_tsc_value' right where you have defined it: u64 l1_tsc_value = kvm_read_l1_tsc(vcpu, rdtsc()) >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE > + } > + vmx_start_preemption_timer(vcpu, timer_value); > + } > > /* > * Note no nested_vmx_succeed or nested_vmx_fail here. At this point > @@ -3962,9 +3978,11 @@ static void sync_vmcs02_to_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) > vmcs12->guest_activity_state = GUEST_ACTIVITY_ACTIVE; > > if (nested_cpu_has_preemption_timer(vmcs12) && > - vmcs12->vm_exit_controls & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER) > + !vmx->nested.nested_run_pending) { > + if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER) > vmcs12->vmx_preemption_timer_value = > vmx_get_preemption_timer_value(vcpu); > + } > > /* > * In some cases (usually, nested EPT), L2 is allowed to change its > @@ -5939,6 +5957,13 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, > > if (vmx->nested.mtf_pending) > kvm_state.flags |= KVM_STATE_NESTED_MTF_PENDING; > + > + if (nested_cpu_has_preemption_timer(vmcs12)) { > + kvm_state.flags |= > + KVM_STATE_NESTED_PREEMPTION_TIMER; > + kvm_state.size = offsetof(struct kvm_nested_state, data.vmx) + 'size' is reset here instead of accumulating all previous sizes. Is that what is intended ? > + offsetofend(struct kvm_vmx_nested_state_data, preemption_timer_deadline); > + } > } > } > > @@ -5970,6 +5995,9 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, > > BUILD_BUG_ON(sizeof(user_vmx_nested_state->vmcs12) < VMCS12_SIZE); > BUILD_BUG_ON(sizeof(user_vmx_nested_state->shadow_vmcs12) < VMCS12_SIZE); > + BUILD_BUG_ON(sizeof(user_vmx_nested_state->preemption_timer_deadline) > + != sizeof(vmx->nested.preemption_timer_deadline)); > + > > /* > * Copy over the full allocated size of vmcs12 rather than just the size > @@ -5985,6 +6013,12 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, > return -EFAULT; > } > > + if (kvm_state.flags & KVM_STATE_NESTED_PREEMPTION_TIMER) { > + if (put_user(vmx->nested.preemption_timer_deadline, > + &user_vmx_nested_state->preemption_timer_deadline)) > + return -EFAULT; > + } > + > out: > return kvm_state.size; > } > @@ -6056,7 +6090,8 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, > */ > if (is_smm(vcpu) ? > (kvm_state->flags & > - (KVM_STATE_NESTED_GUEST_MODE | KVM_STATE_NESTED_RUN_PENDING)) > + (KVM_STATE_NESTED_GUEST_MODE | KVM_STATE_NESTED_RUN_PENDING | > + KVM_STATE_NESTED_PREEMPTION_TIMER)) > : kvm_state->hdr.vmx.smm.flags) > return -EINVAL; > > @@ -6146,6 +6181,20 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, > goto error_guest_mode; > } > > + if (kvm_state->flags & KVM_STATE_NESTED_PREEMPTION_TIMER) { > + > + if (kvm_state->size < > + offsetof(struct kvm_nested_state, data.vmx) + > + offsetofend(struct kvm_vmx_nested_state_data, preemption_timer_deadline)) > + goto error_guest_mode; > + > + if (get_user(vmx->nested.preemption_timer_deadline, > + &user_vmx_nested_state->preemption_timer_deadline)) { > + ret = -EFAULT; > + goto error_guest_mode; > + } > + } > + > if (nested_vmx_check_controls(vcpu, vmcs12) || > nested_vmx_check_host_state(vcpu, vmcs12) || > nested_vmx_check_guest_state(vcpu, vmcs12, &ignored)) > diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h > index 298ddef79d009..db697400755fb 100644 > --- a/arch/x86/kvm/vmx/vmx.h > +++ b/arch/x86/kvm/vmx/vmx.h > @@ -169,6 +169,7 @@ struct nested_vmx { > u16 posted_intr_nv; > > struct hrtimer preemption_timer; > + u64 preemption_timer_deadline; > bool preemption_timer_expired; > > /* to migrate it to L2 if VM_ENTRY_LOAD_DEBUG_CONTROLS is off */ > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 471fccf7f8501..ba9e62ffbb4cd 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -3418,6 +3418,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) > case KVM_CAP_MSR_PLATFORM_INFO: > case KVM_CAP_EXCEPTION_PAYLOAD: > case KVM_CAP_SET_GUEST_DEBUG: > + case KVM_CAP_NESTED_STATE_PREEMPTION_TIMER: > r = 1; > break; > case KVM_CAP_SYNC_REGS: > @@ -4626,7 +4627,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp, > > if (kvm_state.flags & > ~(KVM_STATE_NESTED_RUN_PENDING | KVM_STATE_NESTED_GUEST_MODE > - | KVM_STATE_NESTED_EVMCS)) > + | KVM_STATE_NESTED_EVMCS | KVM_STATE_NESTED_PREEMPTION_TIMER)) > break; > > /* nested_run_pending implies guest_mode. */ > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index ac9eba0289d1b..0868dce12a715 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -1018,6 +1018,7 @@ struct kvm_ppc_resize_hpt { > #define KVM_CAP_S390_PROTECTED 180 > #define KVM_CAP_PPC_SECURE_GUEST 181 > #define KVM_CAP_HALT_POLL 182 > +#define KVM_CAP_NESTED_STATE_PREEMPTION_TIMER 183 > > #ifdef KVM_CAP_IRQ_ROUTING > > diff --git a/tools/arch/x86/include/uapi/asm/kvm.h b/tools/arch/x86/include/uapi/asm/kvm.h > index 3f3f780c8c650..60701178b9cc1 100644 > --- a/tools/arch/x86/include/uapi/asm/kvm.h > +++ b/tools/arch/x86/include/uapi/asm/kvm.h > @@ -391,6 +391,8 @@ struct kvm_sync_regs { > #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 > #define KVM_STATE_NESTED_EVMCS 0x00000004 > #define KVM_STATE_NESTED_MTF_PENDING 0x00000008 > +/* Available with KVM_CAP_NESTED_STATE_PREEMPTION_TIMER */ > +#define KVM_STATE_NESTED_PREEMPTION_TIMER 0x00000010 > > #define KVM_STATE_NESTED_SMM_GUEST_MODE 0x00000001 > #define KVM_STATE_NESTED_SMM_VMXON 0x00000002
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index d871dacb984e9..b410815772970 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -4326,6 +4326,9 @@ Errors: #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 #define KVM_STATE_NESTED_EVMCS 0x00000004 + /* Available with KVM_CAP_NESTED_STATE_PREEMPTION_TIMER */ + #define KVM_STATE_NESTED_PREEMPTION_TIMER 0x00000010 + #define KVM_STATE_NESTED_FORMAT_VMX 0 #define KVM_STATE_NESTED_FORMAT_SVM 1 @@ -4346,6 +4349,7 @@ Errors: struct kvm_vmx_nested_state_data { __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; __u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; + __u64 preemption_timer_deadline; }; This ioctl copies the vcpu's nested virtualization state from the kernel to diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h index 3f3f780c8c650..20d5832bab215 100644 --- a/arch/x86/include/uapi/asm/kvm.h +++ b/arch/x86/include/uapi/asm/kvm.h @@ -391,6 +391,7 @@ struct kvm_sync_regs { #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 #define KVM_STATE_NESTED_EVMCS 0x00000004 #define KVM_STATE_NESTED_MTF_PENDING 0x00000008 +#define KVM_STATE_NESTED_PREEMPTION_TIMER 0x00000010 #define KVM_STATE_NESTED_SMM_GUEST_MODE 0x00000001 #define KVM_STATE_NESTED_SMM_VMXON 0x00000002 @@ -400,6 +401,7 @@ struct kvm_sync_regs { struct kvm_vmx_nested_state_data { __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; __u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; + __u64 preemption_timer_deadline; }; struct kvm_vmx_nested_state_hdr { diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 51ebb60e1533a..badb82a39ac04 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2092,9 +2092,9 @@ static enum hrtimer_restart vmx_preemption_timer_fn(struct hrtimer *timer) return HRTIMER_NORESTART; } -static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu) +static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu, + u64 preemption_timeout) { - u64 preemption_timeout = get_vmcs12(vcpu)->vmx_preemption_timer_value; struct vcpu_vmx *vmx = to_vmx(vcpu); /* @@ -3353,8 +3353,24 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, * the timer. */ vmx->nested.preemption_timer_expired = false; - if (nested_cpu_has_preemption_timer(vmcs12)) - vmx_start_preemption_timer(vcpu); + if (nested_cpu_has_preemption_timer(vmcs12)) { + u64 timer_value; + u64 l1_tsc_value = kvm_read_l1_tsc(vcpu, rdtsc()); + + if (from_vmentry) { + timer_value = vmcs12->vmx_preemption_timer_value; + vmx->nested.preemption_timer_deadline = timer_value + + (l1_tsc_value >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE); + } else { + if ((l1_tsc_value >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE) > + vmx->nested.preemption_timer_deadline) + timer_value = 0; + else + timer_value = vmx->nested.preemption_timer_deadline - + (l1_tsc_value >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE); + } + vmx_start_preemption_timer(vcpu, timer_value); + } /* * Note no nested_vmx_succeed or nested_vmx_fail here. At this point @@ -3962,9 +3978,11 @@ static void sync_vmcs02_to_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) vmcs12->guest_activity_state = GUEST_ACTIVITY_ACTIVE; if (nested_cpu_has_preemption_timer(vmcs12) && - vmcs12->vm_exit_controls & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER) + !vmx->nested.nested_run_pending) { + if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER) vmcs12->vmx_preemption_timer_value = vmx_get_preemption_timer_value(vcpu); + } /* * In some cases (usually, nested EPT), L2 is allowed to change its @@ -5939,6 +5957,13 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, if (vmx->nested.mtf_pending) kvm_state.flags |= KVM_STATE_NESTED_MTF_PENDING; + + if (nested_cpu_has_preemption_timer(vmcs12)) { + kvm_state.flags |= + KVM_STATE_NESTED_PREEMPTION_TIMER; + kvm_state.size = offsetof(struct kvm_nested_state, data.vmx) + + offsetofend(struct kvm_vmx_nested_state_data, preemption_timer_deadline); + } } } @@ -5970,6 +5995,9 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, BUILD_BUG_ON(sizeof(user_vmx_nested_state->vmcs12) < VMCS12_SIZE); BUILD_BUG_ON(sizeof(user_vmx_nested_state->shadow_vmcs12) < VMCS12_SIZE); + BUILD_BUG_ON(sizeof(user_vmx_nested_state->preemption_timer_deadline) + != sizeof(vmx->nested.preemption_timer_deadline)); + /* * Copy over the full allocated size of vmcs12 rather than just the size @@ -5985,6 +6013,12 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, return -EFAULT; } + if (kvm_state.flags & KVM_STATE_NESTED_PREEMPTION_TIMER) { + if (put_user(vmx->nested.preemption_timer_deadline, + &user_vmx_nested_state->preemption_timer_deadline)) + return -EFAULT; + } + out: return kvm_state.size; } @@ -6056,7 +6090,8 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, */ if (is_smm(vcpu) ? (kvm_state->flags & - (KVM_STATE_NESTED_GUEST_MODE | KVM_STATE_NESTED_RUN_PENDING)) + (KVM_STATE_NESTED_GUEST_MODE | KVM_STATE_NESTED_RUN_PENDING | + KVM_STATE_NESTED_PREEMPTION_TIMER)) : kvm_state->hdr.vmx.smm.flags) return -EINVAL; @@ -6146,6 +6181,20 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, goto error_guest_mode; } + if (kvm_state->flags & KVM_STATE_NESTED_PREEMPTION_TIMER) { + + if (kvm_state->size < + offsetof(struct kvm_nested_state, data.vmx) + + offsetofend(struct kvm_vmx_nested_state_data, preemption_timer_deadline)) + goto error_guest_mode; + + if (get_user(vmx->nested.preemption_timer_deadline, + &user_vmx_nested_state->preemption_timer_deadline)) { + ret = -EFAULT; + goto error_guest_mode; + } + } + if (nested_vmx_check_controls(vcpu, vmcs12) || nested_vmx_check_host_state(vcpu, vmcs12) || nested_vmx_check_guest_state(vcpu, vmcs12, &ignored)) diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 298ddef79d009..db697400755fb 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -169,6 +169,7 @@ struct nested_vmx { u16 posted_intr_nv; struct hrtimer preemption_timer; + u64 preemption_timer_deadline; bool preemption_timer_expired; /* to migrate it to L2 if VM_ENTRY_LOAD_DEBUG_CONTROLS is off */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 471fccf7f8501..ba9e62ffbb4cd 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3418,6 +3418,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_MSR_PLATFORM_INFO: case KVM_CAP_EXCEPTION_PAYLOAD: case KVM_CAP_SET_GUEST_DEBUG: + case KVM_CAP_NESTED_STATE_PREEMPTION_TIMER: r = 1; break; case KVM_CAP_SYNC_REGS: @@ -4626,7 +4627,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp, if (kvm_state.flags & ~(KVM_STATE_NESTED_RUN_PENDING | KVM_STATE_NESTED_GUEST_MODE - | KVM_STATE_NESTED_EVMCS)) + | KVM_STATE_NESTED_EVMCS | KVM_STATE_NESTED_PREEMPTION_TIMER)) break; /* nested_run_pending implies guest_mode. */ diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index ac9eba0289d1b..0868dce12a715 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1018,6 +1018,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_S390_PROTECTED 180 #define KVM_CAP_PPC_SECURE_GUEST 181 #define KVM_CAP_HALT_POLL 182 +#define KVM_CAP_NESTED_STATE_PREEMPTION_TIMER 183 #ifdef KVM_CAP_IRQ_ROUTING diff --git a/tools/arch/x86/include/uapi/asm/kvm.h b/tools/arch/x86/include/uapi/asm/kvm.h index 3f3f780c8c650..60701178b9cc1 100644 --- a/tools/arch/x86/include/uapi/asm/kvm.h +++ b/tools/arch/x86/include/uapi/asm/kvm.h @@ -391,6 +391,8 @@ struct kvm_sync_regs { #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 #define KVM_STATE_NESTED_EVMCS 0x00000004 #define KVM_STATE_NESTED_MTF_PENDING 0x00000008 +/* Available with KVM_CAP_NESTED_STATE_PREEMPTION_TIMER */ +#define KVM_STATE_NESTED_PREEMPTION_TIMER 0x00000010 #define KVM_STATE_NESTED_SMM_GUEST_MODE 0x00000001 #define KVM_STATE_NESTED_SMM_VMXON 0x00000002