Adds KVM_EXIT_IOAPIC_EOI which passes the interrupt vector up to userspace. Uses a per VCPU exit bitmap to decide whether or not the IOAPIC needs to be informed (which is identical to the EOI_EXIT_BITMAP field used by modern x86 processors, but can also be used to elide kvm IOAPIC EOI exits on older processors). [Note: A prototype using ResampleFDs found that decoupling the EOI from the VCPU's thread made it possible for the VCPU to not see a recent EOI after reentering the guest. This does not match real hardware.] Compile tested for Intel x86. Signed-off-by: Steve Rutherford <srutherford@xxxxxxxxxx> --- Documentation/virtual/kvm/api.txt | 10 ++++++++++ arch/x86/include/asm/kvm_host.h | 3 +++ arch/x86/kvm/lapic.c | 9 +++++++++ arch/x86/kvm/x86.c | 11 +++++++++++ include/linux/kvm_host.h | 1 + include/uapi/linux/kvm.h | 5 +++++ 6 files changed, 39 insertions(+) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 0744b4e..dd92996 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -3285,6 +3285,16 @@ Valid values for 'type' are: */ __u64 kvm_valid_regs; __u64 kvm_dirty_regs; + + /* KVM_EXIT_IOAPIC_EOI */ + struct { + __u8 vector; + } eoi; + +Indicates that an eoi of a level triggered IOAPIC interrupt on vector has +occurred, which should be handled by the userspace IOAPIC. Triggers when +the Irqchip has been split between userspace and the kernel. + union { struct kvm_sync_regs regs; char padding[1024]; diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 3ddc134..b1978f1 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -539,6 +539,9 @@ struct kvm_vcpu_arch { struct { bool pv_unhalted; } pv; + + u64 eoi_exit_bitmaps[4]; + int pending_ioapic_eoi; }; struct kvm_lpage_info { diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index bc392a6..42fada6f 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -860,6 +860,15 @@ int kvm_apic_compare_prio(struct kvm_vcpu *vcpu1, struct kvm_vcpu *vcpu2) static void kvm_ioapic_send_eoi(struct kvm_lapic *apic, int vector) { + if (irqchip_split(apic->vcpu->kvm)) { + if (test_bit(vector, + (void *) apic->vcpu->arch.eoi_exit_bitmaps)) { + apic->vcpu->arch.pending_ioapic_eoi = vector; + kvm_make_request(KVM_REQ_IOAPIC_EOI_EXIT, apic->vcpu); + } + return; + } + if (kvm_ioapic_handles_vector(apic->vcpu->kvm, vector)) { int trigger_mode; if (apic_test_vector(vector, apic->regs + APIC_TMR)) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 7505b39..cc27c35 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6324,6 +6324,17 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) kvm_handle_pmu_event(vcpu); if (kvm_check_request(KVM_REQ_PMI, vcpu)) kvm_deliver_pmi(vcpu); + if (kvm_check_request(KVM_REQ_IOAPIC_EOI_EXIT, vcpu)) { + BUG_ON(vcpu->arch.pending_ioapic_eoi > 255); + if (test_bit(vcpu->arch.pending_ioapic_eoi, + (void *) vcpu->arch.eoi_exit_bitmaps)) { + vcpu->run->exit_reason = KVM_EXIT_IOAPIC_EOI; + vcpu->run->eoi.vector = + vcpu->arch.pending_ioapic_eoi; + r = 0; + goto out; + } + } if (kvm_check_request(KVM_REQ_SCAN_IOAPIC, vcpu)) vcpu_scan_ioapic(vcpu); if (kvm_check_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu)) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 277b7a1..cef20ad 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -134,6 +134,7 @@ static inline bool is_error_page(struct page *page) #define KVM_REQ_ENABLE_IBS 23 #define KVM_REQ_DISABLE_IBS 24 #define KVM_REQ_APIC_PAGE_RELOAD 25 +#define KVM_REQ_IOAPIC_EOI_EXIT 26 #define KVM_USERSPACE_IRQ_SOURCE_ID 0 #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID 1 diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 7d06dc4..2305948 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -183,6 +183,7 @@ struct kvm_s390_skeys { #define KVM_EXIT_EPR 23 #define KVM_EXIT_SYSTEM_EVENT 24 #define KVM_EXIT_S390_STSI 25 +#define KVM_EXIT_IOAPIC_EOI 26 /* For KVM_EXIT_INTERNAL_ERROR */ /* Emulate instruction failed. */ @@ -329,6 +330,10 @@ struct kvm_run { __u8 sel1; __u16 sel2; } s390_stsi; + /* KVM_EXIT_IOAPIC_EOI */ + struct { + __u8 vector; + } eoi; /* Fix the size of the union. */ char padding[256]; }; -- 2.2.0.rc0.207.ga3a616c -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html