From 62a193edaf90df38356e292f47a17f28e0cee3f1 Mon Sep 17 00:00:00 2001 From: Matt Gingell Date: Mon, 16 Nov 2015 15:26:07 -0800 Subject: [PATCH] KVM: x86: request interrupt window when IRQ chip is split Before this patch, we incorrectly enter the guest without requesting an interrupt window if the IRQ chip is split between user space and the kernel. Because lapic_in_kernel no longer implies the PIC is in the kernel, this patch tests pic_in_kernel to determining whether an interrupt window should be requested when entering the guest. If the APIC is in the kernel and we request an interrupt window the guest will return immediately. If the APIC is masked the guest will not not make forward progress and unmask it, leading to a loop when KVM reenters and requests again. This patch adds a check to ensure the APIC is ready to accept an interrupt before requesting a window. Reviewed-by: Steve Rutherford Signed-off-by: Matt Gingell [Use the other newly introduced functions. - Paolo] Fixes: 1c1a9ce973a7863dd46767226bce2a5f12d48bc6 Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f254e296d368..eed32283d22c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6360,8 +6360,10 @@ void kvm_arch_mmu_notifier_invalidate_page(struct kvm *kvm, static int vcpu_enter_guest(struct kvm_vcpu *vcpu) { int r; - bool req_int_win = !lapic_in_kernel(vcpu) && - vcpu->run->request_interrupt_window; + bool req_int_win = + dm_request_for_irq_injection(vcpu) && + kvm_cpu_accept_dm_intr(vcpu); + bool req_immediate_exit = false; if (vcpu->requests) { -- 2.39.2