Re: [PATCH] KVM-USER: Fix for CPU interrupts in QEMU

[Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>]

Gregory Haskins wrote:
> QEMU-KVM has a bug where the interruptibility of the CPU is predicated on
> pending interrupts.  If the reason that a CPU is interrupted is because we
> need to inject interrupts, the current code will just keep looping and miss
> the event window.
>
> This doesnt seem to cause problems with in-trunk KVM.  However, once we turn
> on in-kernel HALTING, QEMU starts to have some serious problems that were
> attributed to this bug.
>
> Signed-off-by: Gregory Haskins <ghaskins-Et1tbQHTxzrQT0dZR+AlfA@public.gmane.org>
> ---
>
>  qemu/qemu-kvm.c |    5 +----
>  1 files changed, 1 insertions(+), 4 deletions(-)
>
> diff --git a/qemu/qemu-kvm.c b/qemu/qemu-kvm.c
> index 1849997..5b5c739 100644
> --- a/qemu/qemu-kvm.c
> +++ b/qemu/qemu-kvm.c
> @@ -452,11 +452,8 @@ void kvm_save_registers(CPUState *env)
>  int kvm_cpu_exec(CPUState *env)
>  {
>      int r;
> -    int pending = (!env->ready_for_interrupt_injection ||
> -                   ((env->interrupt_request & CPU_INTERRUPT_HARD) &&
> -		   (env->eflags & IF_MASK)));
>  
> -    if (!pending && (env->interrupt_request & CPU_INTERRUPT_EXIT)) {
> +    if (env->interrupt_request & CPU_INTERRUPT_EXIT) {
>          env->interrupt_request &= ~CPU_INTERRUPT_EXIT;
>          env->exception_index = EXCP_INTERRUPT;
>          cpu_loop_exit();
>
>   

When applied to current HEAD, this doesn't work.  Booting windows or 
Linux, quite soon during boot everything freezes.


-- 
error compiling committee.c: too many arguments to function


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