On Wed, Jan 30, 2013 at 09:03:11PM -0200, Marcelo Tosatti wrote: > On Fri, Jan 25, 2013 at 12:40:21AM +0000, Zhang, Yang Z wrote: > > Marcelo Tosatti wrote on 2013-01-25: > > > On Thu, Dec 13, 2012 at 03:29:40PM +0800, Yang Zhang wrote: > > >> From: Yang Zhang <yang.z.zh...@intel.com> > > >> > > >> Posted Interrupt allows APIC interrupts to inject into guest directly > > >> without any vmexit. > > >> > > >> - When delivering a interrupt to guest, if target vcpu is running, > > >> update Posted-interrupt requests bitmap and send a notification event > > >> to the vcpu. Then the vcpu will handle this interrupt automatically, > > >> without any software involvemnt. > > >> - If target vcpu is not running or there already a notification event > > >> pending in the vcpu, do nothing. The interrupt will be handled by > > >> next vm entry. > > >> Signed-off-by: Yang Zhang <yang.z.zh...@intel.com> > > >> --- > > >> arch/x86/include/asm/entry_arch.h | 1 + > > >> arch/x86/include/asm/hw_irq.h | 1 + arch/x86/include/asm/irq.h > > >> | 1 + arch/x86/include/asm/irq_vectors.h | 4 + > > >> arch/x86/include/asm/kvm_host.h | 3 + arch/x86/include/asm/vmx.h > > >> | 4 + arch/x86/kernel/entry_64.S | 2 + > > >> arch/x86/kernel/irq.c | 25 +++++++ > > >> arch/x86/kernel/irqinit.c | 2 + arch/x86/kvm/lapic.c > > >> | 16 +++- arch/x86/kvm/lapic.h | 1 + > > >> arch/x86/kvm/vmx.c | 133 > > >> +++++++++++++++++++++++++++++++++--- 12 files changed, 180 > > >> insertions(+), 13 deletions(-) > > >> diff --git a/arch/x86/include/asm/entry_arch.h > > >> b/arch/x86/include/asm/entry_arch.h index 40afa00..7b0a29e 100644 --- > > >> a/arch/x86/include/asm/entry_arch.h +++ > > >> b/arch/x86/include/asm/entry_arch.h @@ -18,6 +18,7 @@ > > >> BUILD_INTERRUPT(reboot_interrupt,REBOOT_VECTOR) > > >> #endif > > >> > > >> BUILD_INTERRUPT(x86_platform_ipi, X86_PLATFORM_IPI_VECTOR) > > >> +BUILD_INTERRUPT(posted_intr_ipi, POSTED_INTR_VECTOR) > > >> > > >> /* > > >> * every pentium local APIC has two 'local interrupts', with a > > >> diff --git a/arch/x86/include/asm/hw_irq.h > > >> b/arch/x86/include/asm/hw_irq.h > > >> index eb92a6e..ee61af3 100644 > > >> --- a/arch/x86/include/asm/hw_irq.h > > >> +++ b/arch/x86/include/asm/hw_irq.h > > >> @@ -28,6 +28,7 @@ > > >> /* Interrupt handlers registered during init_IRQ */ extern void > > >> apic_timer_interrupt(void); extern void x86_platform_ipi(void); > > >> +extern void posted_intr_ipi(void); extern void error_interrupt(void); > > >> extern void irq_work_interrupt(void); > > >> diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h > > >> index ba870bb..cff9933 100644 > > >> --- a/arch/x86/include/asm/irq.h > > >> +++ b/arch/x86/include/asm/irq.h > > >> @@ -30,6 +30,7 @@ extern void irq_force_complete_move(int); > > >> #endif > > >> > > >> extern void (*x86_platform_ipi_callback)(void); +extern void > > >> (*posted_intr_callback)(void); extern void native_init_IRQ(void); > > >> extern bool handle_irq(unsigned irq, struct pt_regs *regs); > > >> diff --git a/arch/x86/include/asm/irq_vectors.h > > >> b/arch/x86/include/asm/irq_vectors.h index 1508e51..8f2e383 100644 --- > > >> a/arch/x86/include/asm/irq_vectors.h +++ > > >> b/arch/x86/include/asm/irq_vectors.h @@ -102,6 +102,10 @@ > > >> */ > > >> #define X86_PLATFORM_IPI_VECTOR 0xf7 > > >> +#ifdef CONFIG_HAVE_KVM > > >> +#define POSTED_INTR_VECTOR 0xf2 > > >> +#endif > > >> + > > >> /* > > >> * IRQ work vector: > > >> */ > > >> diff --git a/arch/x86/include/asm/kvm_host.h > > >> b/arch/x86/include/asm/kvm_host.h index 7e26d1a..82423a8 100644 --- > > >> a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h > > >> @@ -700,6 +700,9 @@ struct kvm_x86_ops { > > >> int (*has_virtual_interrupt_delivery)(struct kvm_vcpu *vcpu); > > >> void (*update_irq)(struct kvm_vcpu *vcpu); > > >> void (*update_eoi_exitmap)(struct kvm_vcpu *vcpu, int vector, > > >> bool set); > > >> + int (*has_posted_interrupt)(struct kvm_vcpu *vcpu); > > >> + int (*send_nv)(struct kvm_vcpu *vcpu, int vector); > > >> + void (*update_irr)(struct kvm_vcpu *vcpu); > > >> int (*set_tss_addr)(struct kvm *kvm, unsigned int addr); > > >> int (*get_tdp_level)(void); > > >> u64 (*get_mt_mask)(struct kvm_vcpu *vcpu, gfn_t gfn, bool > > >> is_mmio); > > >> diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h > > >> index 1003341..7b9e1d0 100644 > > >> --- a/arch/x86/include/asm/vmx.h > > >> +++ b/arch/x86/include/asm/vmx.h > > >> @@ -152,6 +152,7 @@ > > >> #define PIN_BASED_EXT_INTR_MASK 0x00000001 > > >> #define PIN_BASED_NMI_EXITING 0x00000008 > > >> #define PIN_BASED_VIRTUAL_NMIS 0x00000020 > > >> +#define PIN_BASED_POSTED_INTR 0x00000080 > > >> > > >> #define VM_EXIT_SAVE_DEBUG_CONTROLS 0x00000002 #define > > >> VM_EXIT_HOST_ADDR_SPACE_SIZE 0x00000200 @@ -174,6 +175,7 @@ > > >> /* VMCS Encodings */ enum vmcs_field { VIRTUAL_PROCESSOR_ID > > >> = 0x00000000, + POSTED_INTR_NV = 0x00000002, > > >> GUEST_ES_SELECTOR = 0x00000800, > > >> GUEST_CS_SELECTOR > > >> = 0x00000802, GUEST_SS_SELECTOR = 0x00000804, > > >> @@ -208,6 +210,8 @@ enum vmcs_field { VIRTUAL_APIC_PAGE_ADDR_HIGH > > >> = 0x00002013, APIC_ACCESS_ADDR = 0x00002014, > > >> APIC_ACCESS_ADDR_HIGH = 0x00002015, > > >> + POSTED_INTR_DESC_ADDR = 0x00002016, > > >> + POSTED_INTR_DESC_ADDR_HIGH = 0x00002017, > > >> EPT_POINTER = 0x0000201a, > > >> EPT_POINTER_HIGH = 0x0000201b, > > >> EOI_EXIT_BITMAP0 = 0x0000201c, > > >> diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S > > >> index b51b2c7..d06eea1 100644 > > >> --- a/arch/x86/kernel/entry_64.S > > >> +++ b/arch/x86/kernel/entry_64.S > > >> @@ -1160,6 +1160,8 @@ apicinterrupt LOCAL_TIMER_VECTOR \ > > >> apic_timer_interrupt smp_apic_timer_interrupt > > >> apicinterrupt X86_PLATFORM_IPI_VECTOR \ > > >> x86_platform_ipi smp_x86_platform_ipi > > >> +apicinterrupt POSTED_INTR_VECTOR \ > > >> + posted_intr_ipi smp_posted_intr_ipi > > >> > > >> apicinterrupt THRESHOLD_APIC_VECTOR \ > > >> threshold_interrupt smp_threshold_interrupt > > >> diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c > > >> index e4595f1..781d324 100644 > > >> --- a/arch/x86/kernel/irq.c > > >> +++ b/arch/x86/kernel/irq.c > > >> @@ -22,6 +22,9 @@ atomic_t irq_err_count; > > >> > > >> /* Function pointer for generic interrupt vector handling */ > > >> void (*x86_platform_ipi_callback)(void) = NULL; > > >> +/* Function pointer for posted interrupt vector handling */ > > >> +void (*posted_intr_callback)(void) = NULL; > > >> +EXPORT_SYMBOL_GPL(posted_intr_callback); > > >> > > >> /* > > >> * 'what should we do if we get a hw irq event on an illegal vector'. > > >> @@ -228,6 +231,28 @@ void smp_x86_platform_ipi(struct pt_regs *regs) > > >> set_irq_regs(old_regs); > > >> } > > >> +/* > > >> + * Handler for POSTED_INTERRUPT_VECTOR. > > >> + */ > > >> +void smp_posted_intr_ipi(struct pt_regs *regs) > > >> +{ > > >> + struct pt_regs *old_regs = set_irq_regs(regs); > > >> + > > >> + ack_APIC_irq(); > > >> + > > >> + irq_enter(); > > >> + > > >> + exit_idle(); > > >> + > > >> + if (posted_intr_callback) > > >> + posted_intr_callback(); > > >> + > > >> + irq_exit(); > > >> + > > >> + set_irq_regs(old_regs); > > >> +} > > >> + > > >> + > > >> EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq); > > >> > > >> #ifdef CONFIG_HOTPLUG_CPU > > >> diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c > > >> index 6e03b0d..d15ca4f 100644 > > >> --- a/arch/x86/kernel/irqinit.c > > >> +++ b/arch/x86/kernel/irqinit.c > > >> @@ -205,6 +205,8 @@ static void __init apic_intr_init(void) > > >> > > >> /* IPI for X86 platform specific use */ > > >> alloc_intr_gate(X86_PLATFORM_IPI_VECTOR, x86_platform_ipi); > > >> + /* IPI for posted interrupt use */ > > >> + alloc_intr_gate(POSTED_INTR_VECTOR, posted_intr_ipi); > > >> > > >> /* IPI vectors for APIC spurious and error interrupts */ > > >> alloc_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt); > > >> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c > > >> index 2109a6a..d660b9d 100644 > > >> --- a/arch/x86/kvm/lapic.c > > >> +++ b/arch/x86/kvm/lapic.c > > >> @@ -350,6 +350,7 @@ static inline int apic_find_highest_irr(struct > > >> kvm_lapic > > > *apic) > > >> if (!apic->irr_pending) > > >> return -1; > > >> + kvm_x86_ops->update_irr(apic->vcpu); > > >> result = apic_search_irr(apic); > > >> ASSERT(result == -1 || result >= 16); > > >> @@ -725,18 +726,25 @@ static int __apic_accept_irq(struct kvm_lapic > > >> *apic, int > > > delivery_mode, > > >> if (trig_mode) { > > >> apic_debug("level trig mode for vector %d", > > >> vector); > > >> apic_set_vector(vector, apic->regs + APIC_TMR); > > >> - } else > > >> + } else { > > >> apic_clear_vector(vector, apic->regs + > > >> APIC_TMR); > > >> - > > >> + if (kvm_x86_ops->has_posted_interrupt(vcpu)) { > > >> + result = 1; > > >> + apic->irr_pending = true; > > >> + kvm_x86_ops->send_nv(vcpu, vector); > > >> + goto out; > > >> + } > > > > > > Hi, > > > > > > Steps 4, 5 and 6 of section 29.6 are executed in both VMX root/non-root > > > modes, or only non-root mode? > > SDM doesn't tell. But we don't need know this in software level. > > > > > > > > > > > If only non-root mode, there is a problem if target vcpu<->pcpu vm-exits > > > before receiving and acking the interrupt. In that case PIR set bits are > > > not transferred to VIRR. > > > > > > It would be necessary to read notification bit on VM-exit and, if set, > > > do PIR->VIRR transfer in software. The downside, is lack of an atomic > > In current implementation, it will sync PIR to VIRR before vmentry. > > > > > (VIRR |= PIR; PIR = 0) in software. So it would require synchronization > > > to KVM APIC injection (which ATM relies on atomic test_and_set of IRR). > > Some comments: > > Enable ack-on-exit feature patch: > 1) Value of register VM_EXIT_INTR_INFO is available at > vmx->exit_intr_info. See commit > 887864758580c80710947c38a4692032163777df. > > Posted interrupt patch: > 2) Must move IN_GUEST_MODE assignment after local_irq_disable, in > vcpu_enter_guest function. Otherwise: > > cpu0 vcpu1<->cpu1 > > vcpu->mode = IN_GUEST_MODE > > if IN_GUEST_MODE == true > send IPI > local_irq_disable > > PIR not transferred to VIRR, misses interrupt. > > 3) Must check outstanding PIR notification bit unconditionally on > every VM-entry, because: > > 1. local_irq_disable > 2. vcpu->mode = IN_GUEST_MODE > 3. vmenter > 4. vmexit > 5. vcpu->mode = OUTSIDE_GUEST_MODE > > If PIR-IPI-interrupt is sent between an event which triggers VM-exit > (for example, an external interrupt due to a device), and step 5 > (assignment of vcpu->mode), the PIR->VIRR transfer before vmentry must > be made.
Check for outstanding PIR notification bit must be made after disabling local interrupts, in vcpu_enter_guest. If PIR notification bit is set, should set KVM_REQ_EVENT in vcpu->requests, so that ->run is not executed, and vcpu_enter_guest reexecuted. Then the PIR->VIRR SW transfer can be made in KVM_REQ_EVENT processing (in a separate function please, not from get_interrupt). -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html