The patch below does not apply to the 4.3-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 127a457acb2131fdb31c68c98cf11eda8ba7b380 Mon Sep 17 00:00:00 2001 From: Matt Gingell <[email protected]> Date: Tue, 17 Nov 2015 17:32:05 +0100 Subject: [PATCH] KVM: x86: fix interrupt window handling in split IRQ chip case This patch ensures that dm_request_for_irq_injection and post_kvm_run_save are in sync, avoiding that an endless ping-pong between userspace (who correctly notices that IF=0) and the kernel (who insists that userspace handles its request for the interrupt window). To synchronize them, it also adds checks for kvm_arch_interrupt_allowed and !kvm_event_needs_reinjection. These are always needed, not just for in-kernel LAPIC. Signed-off-by: Matt Gingell <[email protected]> [A collage of two patches from Matt. - Paolo] Fixes: 1c1a9ce973a7863dd46767226bce2a5f12d48bc6 Cc: [email protected] Signed-off-by: Paolo Bonzini <[email protected]> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 00462bd63129..46ed8edad793 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2763,6 +2763,12 @@ static int kvm_vcpu_ioctl_set_lapic(struct kvm_vcpu *vcpu, return 0; } +static int kvm_cpu_accept_dm_intr(struct kvm_vcpu *vcpu) +{ + return (!lapic_in_kernel(vcpu) || + kvm_apic_accept_pic_intr(vcpu)); +} + static int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq) { @@ -5921,12 +5927,16 @@ static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu) if (!vcpu->run->request_interrupt_window || pic_in_kernel(vcpu->kvm)) return false; + if (!kvm_arch_interrupt_allowed(vcpu)) + return false; + if (kvm_cpu_has_interrupt(vcpu)) return false; - return (irqchip_split(vcpu->kvm) - ? kvm_apic_accept_pic_intr(vcpu) - : kvm_arch_interrupt_allowed(vcpu)); + if (kvm_event_needs_reinjection(vcpu)) + return false; + + return kvm_cpu_accept_dm_intr(vcpu); } static void post_kvm_run_save(struct kvm_vcpu *vcpu) @@ -5937,17 +5947,12 @@ static void post_kvm_run_save(struct kvm_vcpu *vcpu) kvm_run->flags = is_smm(vcpu) ? KVM_RUN_X86_SMM : 0; kvm_run->cr8 = kvm_get_cr8(vcpu); kvm_run->apic_base = kvm_get_apic_base(vcpu); - if (!irqchip_in_kernel(vcpu->kvm)) - kvm_run->ready_for_interrupt_injection = - kvm_arch_interrupt_allowed(vcpu) && - !kvm_cpu_has_interrupt(vcpu) && - !kvm_event_needs_reinjection(vcpu); - else if (!pic_in_kernel(vcpu->kvm)) - kvm_run->ready_for_interrupt_injection = - kvm_apic_accept_pic_intr(vcpu) && - !kvm_cpu_has_interrupt(vcpu); - else - kvm_run->ready_for_interrupt_injection = 1; + kvm_run->ready_for_interrupt_injection = + pic_in_kernel(vcpu->kvm) || + (kvm_arch_interrupt_allowed(vcpu) && + !kvm_cpu_has_interrupt(vcpu) && + !kvm_event_needs_reinjection(vcpu) && + kvm_cpu_accept_dm_intr(vcpu)); } static void update_cr8_intercept(struct kvm_vcpu *vcpu) -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
