| Message ID | 20180904075652.127619-1-liran.alon@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: nVMX: Wake blocked vCPU in guest-mode if pending interrupt in virtual APICv | expand |
On Tue, Sep 4, 2018 at 12:57 AM Liran Alon <liran.alon@oracle.com> wrote: > > In case L1 do not intercept L2 HLT or enter L2 in HLT activity-state, > it is possible for a vCPU to be blocked while it is in guest-mode. > > According to Intel SDM 26.6.5 Interrupt-Window Exiting and > Virtual-Interrupt Delivery: "These events wake the logical processor > if it just entered the HLT state because of a VM entry". > Therefore, if L1 enters L2 in HLT activity-state and L2 has a pending > deliverable interrupt in vmcs12->guest_intr_status.RVI, then the vCPU > should be waken from the HLT state and injected with the interrupt. > > In addition, if while the vCPU is blocked (while it is in guest-mode), > it receives a nested posted-interrupt, then the vCPU should also be > waken and injected with the posted interrupt. > > To handle these cases, this patch enhances kvm_vcpu_has_events() to also > check if there is a pending interrupt in L2 virtual APICv provided by > L1. That is, it evaluates if there is a pending virtual interrupt for L2 > by checking RVI[7:4] > VPPR[7:4] as specified in Intel SDM 29.2.1 > Evaluation of Pending Interrupts. > > Note that this also handles the case of nested posted-interrupt by the > fact RVI is updated in vmx_complete_nested_posted_interrupt() which is > called from kvm_vcpu_check_block() -> kvm_arch_vcpu_runnable() -> > kvm_vcpu_running() -> vmx_check_nested_events() -> > vmx_complete_nested_posted_interrupt(). > > Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> > Reviewed-by: Darren Kenny <darren.kenny@oracle.com> > Signed-off-by: Liran Alon <liran.alon@oracle.com> > --- > arch/x86/include/asm/kvm_host.h | 1 + > arch/x86/kvm/vmx.c | 22 ++++++++++++++++++++++ > arch/x86/kvm/x86.c | 10 +++++++++- > 3 files changed, 32 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 00ddb0c9e612..456a3f9aa544 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -1022,6 +1022,7 @@ struct kvm_x86_ops { > void (*refresh_apicv_exec_ctrl)(struct kvm_vcpu *vcpu); > void (*hwapic_irr_update)(struct kvm_vcpu *vcpu, int max_irr); > void (*hwapic_isr_update)(struct kvm_vcpu *vcpu, int isr); > + bool (*guest_apic_has_interrupt)(struct kvm_vcpu *vcpu); > void (*load_eoi_exitmap)(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap); > void (*set_virtual_apic_mode)(struct kvm_vcpu *vcpu); > void (*set_apic_access_page_addr)(struct kvm_vcpu *vcpu, hpa_t hpa); > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index d687c20e7634..bed75118111c 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -6183,6 +6183,27 @@ static void vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu) > nested_mark_vmcs12_pages_dirty(vcpu); > } > > +static bool vmx_guest_apic_has_interrupt(struct kvm_vcpu *vcpu) > +{ > + struct vcpu_vmx *vmx = to_vmx(vcpu); > + void *vapic_page; > + u32 vppr; > + int rvi; > + > + if (WARN_ON_ONCE(!is_guest_mode(vcpu)) || > + !nested_cpu_has_vid(get_vmcs12(vcpu)) || > + WARN_ON_ONCE(!vmx->nested.virtual_apic_page)) > + return false; Here I am, late to the party as usual... Immediately after a live migration, is it possible that this code might be called while KVM_REQ_GET_VMCS12_PAGES is still pending, and vmx->nested.virtual_apic_page is NULL?
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 00ddb0c9e612..456a3f9aa544 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1022,6 +1022,7 @@ struct kvm_x86_ops { void (*refresh_apicv_exec_ctrl)(struct kvm_vcpu *vcpu); void (*hwapic_irr_update)(struct kvm_vcpu *vcpu, int max_irr); void (*hwapic_isr_update)(struct kvm_vcpu *vcpu, int isr); + bool (*guest_apic_has_interrupt)(struct kvm_vcpu *vcpu); void (*load_eoi_exitmap)(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap); void (*set_virtual_apic_mode)(struct kvm_vcpu *vcpu); void (*set_apic_access_page_addr)(struct kvm_vcpu *vcpu, hpa_t hpa); diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index d687c20e7634..bed75118111c 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6183,6 +6183,27 @@ static void vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu) nested_mark_vmcs12_pages_dirty(vcpu); } +static bool vmx_guest_apic_has_interrupt(struct kvm_vcpu *vcpu) +{ + struct vcpu_vmx *vmx = to_vmx(vcpu); + void *vapic_page; + u32 vppr; + int rvi; + + if (WARN_ON_ONCE(!is_guest_mode(vcpu)) || + !nested_cpu_has_vid(get_vmcs12(vcpu)) || + WARN_ON_ONCE(!vmx->nested.virtual_apic_page)) + return false; + + rvi = vmcs_read16(GUEST_INTR_STATUS) & 0xff; + + vapic_page = kmap(vmx->nested.virtual_apic_page); + vppr = *((u32 *)(vapic_page + APIC_PROCPRI)); + kunmap(vmx->nested.virtual_apic_page); + + return ((rvi & 0xf0) > (vppr & 0xf0)); +} + static inline bool kvm_vcpu_trigger_posted_interrupt(struct kvm_vcpu *vcpu, bool nested) { @@ -14100,6 +14121,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = { .apicv_post_state_restore = vmx_apicv_post_state_restore, .hwapic_irr_update = vmx_hwapic_irr_update, .hwapic_isr_update = vmx_hwapic_isr_update, + .guest_apic_has_interrupt = vmx_guest_apic_has_interrupt, .sync_pir_to_irr = vmx_sync_pir_to_irr, .deliver_posted_interrupt = vmx_deliver_posted_interrupt, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 506bd2b4b8bb..805c1df7c77e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9182,6 +9182,13 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm, kvm_page_track_flush_slot(kvm, slot); } +static inline bool kvm_guest_apic_has_interrupt(struct kvm_vcpu *vcpu) +{ + return (is_guest_mode(vcpu) && + kvm_x86_ops->guest_apic_has_interrupt && + kvm_x86_ops->guest_apic_has_interrupt(vcpu)); +} + static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu) { if (!list_empty_careful(&vcpu->async_pf.done)) @@ -9206,7 +9213,8 @@ static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu) return true; if (kvm_arch_interrupt_allowed(vcpu) && - kvm_cpu_has_interrupt(vcpu)) + (kvm_cpu_has_interrupt(vcpu) || + kvm_guest_apic_has_interrupt(vcpu))) return true; if (kvm_hv_has_stimer_pending(vcpu))