2017-09-06 18:34+0200, Jan H. Schönherr:
> 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@xxxxxxxxx>
> ---
> compile-time tested only
> ---
> arch/x86/kvm/x86.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 40039cd..a69a948 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -7199,6 +7199,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
> 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);
Without immediate_exit, we would also execute the following code, but I
think it's ok not to ... queued, thanks.
> kvm_apic_accept_events(vcpu);
> kvm_clear_request(KVM_REQ_UNHALT, vcpu);
> --
> 2.3.1.dirty
>
