Commit 60637aac authored by Jan Kiszka's avatar Jan Kiszka Committed by Avi Kivity
Browse files

KVM: VMX: Support for NMI task gates 



Properly set GUEST_INTR_STATE_NMI and reset nmi_injected when a
task-switch vmexit happened due to a task gate being used for handling
NMIs. Also avoid the false warning about valid vectoring info in
kvm_handle_exit.

Based on original patch by Gleb Natapov.

Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent e4a41889

arch/x86/kvm/vmx.c

+15 −3
Original line number Diff line number Diff line
@@ -2832,6 +2832,7 @@ static int handle_apic_access(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 


static int handle_task_switch(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)

{

	struct vcpu_vmx *vmx = to_vmx(vcpu);

	unsigned long exit_qualification;

	u16 tss_selector;

	int reason;
@@ -2839,6 +2840,15 @@ static int handle_task_switch(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	exit_qualification = vmcs_readl(EXIT_QUALIFICATION);



	reason = (u32)exit_qualification >> 30;

	if (reason == TASK_SWITCH_GATE && vmx->vcpu.arch.nmi_injected &&

	    (vmx->idt_vectoring_info & VECTORING_INFO_VALID_MASK) &&

	    (vmx->idt_vectoring_info & VECTORING_INFO_TYPE_MASK)

	    == INTR_TYPE_NMI_INTR) {

		vcpu->arch.nmi_injected = false;

		if (cpu_has_virtual_nmis())

			vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO,

				      GUEST_INTR_STATE_NMI);

	}

	tss_selector = exit_qualification;



	return kvm_task_switch(vcpu, tss_selector, reason);
@@ -3012,9 +3022,11 @@ static int kvm_handle_exit(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu) 


	if ((vectoring_info & VECTORING_INFO_VALID_MASK) &&

			(exit_reason != EXIT_REASON_EXCEPTION_NMI &&

			exit_reason != EXIT_REASON_EPT_VIOLATION))

		printk(KERN_WARNING "%s: unexpected, valid vectoring info and "

		       "exit reason is 0x%x\n", __func__, exit_reason);

			exit_reason != EXIT_REASON_EPT_VIOLATION &&

			exit_reason != EXIT_REASON_TASK_SWITCH))

		printk(KERN_WARNING "%s: unexpected, valid vectoring info "

		       "(0x%x) and exit reason is 0x%x\n",

		       __func__, vectoring_info, exit_reason);

	if (exit_reason < kvm_vmx_max_exit_handlers

	    && kvm_vmx_exit_handlers[exit_reason])

		return kvm_vmx_exit_handlers[exit_reason](vcpu, kvm_run);

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