This is a note to let you know that I've just added the patch titled KVM: x86: handle !lapic_in_kernel case in kvm_cpu_*_extint to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-x86-handle-lapic_in_kernel-case-in-kvm_cpu_-_extint.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 72c3bcdcda494cbd600712a32e67702cdee60c07 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini@xxxxxxxxxx> Date: Fri, 27 Nov 2020 08:53:52 +0100 Subject: KVM: x86: handle !lapic_in_kernel case in kvm_cpu_*_extint From: Paolo Bonzini <pbonzini@xxxxxxxxxx> commit 72c3bcdcda494cbd600712a32e67702cdee60c07 upstream. Centralize handling of interrupts from the userspace APIC in kvm_cpu_has_extint and kvm_cpu_get_extint, since userspace APIC interrupts are handled more or less the same as ExtINTs are with split irqchip. This removes duplicated code from kvm_cpu_has_injectable_intr and kvm_cpu_has_interrupt, and makes the code more similar between kvm_cpu_has_{extint,interrupt} on one side and kvm_cpu_get_{extint,interrupt} on the other. Cc: stable@xxxxxxxxxxxxxxx Reviewed-by: Filippo Sironi <sironi@xxxxxxxxx> Reviewed-by: David Woodhouse <dwmw@xxxxxxxxxxxx> Tested-by: David Woodhouse <dwmw@xxxxxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kvm/irq.c | 83 ++++++++++++++++++++------------------------------- arch/x86/kvm/lapic.c | 2 - 2 files changed, 34 insertions(+), 51 deletions(-) --- a/arch/x86/kvm/irq.c +++ b/arch/x86/kvm/irq.c @@ -54,27 +54,8 @@ static int pending_userspace_extint(stru */ static int kvm_cpu_has_extint(struct kvm_vcpu *v) { - u8 accept = kvm_apic_accept_pic_intr(v); - - if (accept) { - if (irqchip_split(v->kvm)) - return pending_userspace_extint(v); - else - return v->kvm->arch.vpic->output; - } else - return 0; -} - -/* - * check if there is injectable interrupt: - * when virtual interrupt delivery enabled, - * interrupt from apic will handled by hardware, - * we don't need to check it here. - */ -int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v) -{ /* - * FIXME: interrupt.injected represents an interrupt that it's + * FIXME: interrupt.injected represents an interrupt whose * side-effects have already been applied (e.g. bit from IRR * already moved to ISR). Therefore, it is incorrect to rely * on interrupt.injected to know if there is a pending @@ -87,6 +68,23 @@ int kvm_cpu_has_injectable_intr(struct k if (!lapic_in_kernel(v)) return v->arch.interrupt.injected; + if (!kvm_apic_accept_pic_intr(v)) + return 0; + + if (irqchip_split(v->kvm)) + return pending_userspace_extint(v); + else + return v->kvm->arch.vpic->output; +} + +/* + * check if there is injectable interrupt: + * when virtual interrupt delivery enabled, + * interrupt from apic will handled by hardware, + * we don't need to check it here. + */ +int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v) +{ if (kvm_cpu_has_extint(v)) return 1; @@ -102,20 +100,6 @@ int kvm_cpu_has_injectable_intr(struct k */ int kvm_cpu_has_interrupt(struct kvm_vcpu *v) { - /* - * FIXME: interrupt.injected represents an interrupt that it's - * side-effects have already been applied (e.g. bit from IRR - * already moved to ISR). Therefore, it is incorrect to rely - * on interrupt.injected to know if there is a pending - * interrupt in the user-mode LAPIC. - * This leads to nVMX/nSVM not be able to distinguish - * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on - * pending interrupt or should re-inject an injected - * interrupt. - */ - if (!lapic_in_kernel(v)) - return v->arch.interrupt.injected; - if (kvm_cpu_has_extint(v)) return 1; @@ -129,16 +113,21 @@ EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt) */ static int kvm_cpu_get_extint(struct kvm_vcpu *v) { - if (kvm_cpu_has_extint(v)) { - if (irqchip_split(v->kvm)) { - int vector = v->arch.pending_external_vector; - - v->arch.pending_external_vector = -1; - return vector; - } else - return kvm_pic_read_irq(v->kvm); /* PIC */ - } else + if (!kvm_cpu_has_extint(v)) { + WARN_ON(!lapic_in_kernel(v)); return -1; + } + + if (!lapic_in_kernel(v)) + return v->arch.interrupt.nr; + + if (irqchip_split(v->kvm)) { + int vector = v->arch.pending_external_vector; + + v->arch.pending_external_vector = -1; + return vector; + } else + return kvm_pic_read_irq(v->kvm); /* PIC */ } /* @@ -146,13 +135,7 @@ static int kvm_cpu_get_extint(struct kvm */ int kvm_cpu_get_interrupt(struct kvm_vcpu *v) { - int vector; - - if (!lapic_in_kernel(v)) - return v->arch.interrupt.nr; - - vector = kvm_cpu_get_extint(v); - + int vector = kvm_cpu_get_extint(v); if (vector != -1) return vector; /* PIC */ --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2284,7 +2284,7 @@ int kvm_apic_has_interrupt(struct kvm_vc struct kvm_lapic *apic = vcpu->arch.apic; u32 ppr; - if (!kvm_apic_hw_enabled(apic)) + if (!kvm_apic_present(vcpu)) return -1; __apic_update_ppr(apic, &ppr); Patches currently in stable-queue which might be from pbonzini@xxxxxxxxxx are queue-4.19/kvm-x86-fix-split-irqchip-vs-interrupt-injection-window-request.patch queue-4.19/kvm-x86-handle-lapic_in_kernel-case-in-kvm_cpu_-_extint.patch