From: =?UTF-8?q?Jan=20H=2E=20Sch=C3=B6nherr?= <jschoenh@amazon.de>
Date: Wed, 6 Sep 2017 18:34:06 +0200
Subject: KVM: x86: Fix immediate_exit handling for uninitialized AP
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Git-commit: 2f173d2688559a6f85643d38a2ad6f45eb420c42
Patch-mainline: v4.14-rc1
References: bsc#1061813

When user space sets kvm_run->immediate_exit, KVM is supposed to
return quickly. However, when a vCPU is in KVM_MP_STATE_UNINITIALIZED,
the value is not considered and the vCPU blocks.

Fix that oversight.

Fixes: 460df4c1fc7c008 ("KVM: race-free exit from KVM_RUN without POSIX signals")
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
 arch/x86/kvm/x86.c | 4 ++++
 1 file changed, 4 insertions(+)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7194,6 +7194,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_v
 		sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
 
 	if (unlikely(vcpu->arch.mp_state == KVM_MP_STATE_UNINITIALIZED)) {
+		if (kvm_run->immediate_exit) {
+			r = -EINTR;
+			goto out;
+		}
 		kvm_vcpu_block(vcpu);
 		kvm_apic_accept_events(vcpu);
 		kvm_clear_request(KVM_REQ_UNHALT, vcpu);