Re: [PATCH] KVM: SVM: fix task switch emulation on INTn instruction.

Maciej S. Szmigiero
2022-07-14T14:43:16Z

On 14.07.2022 14:44, Maxim Levitsky wrote:
> Recently KVM's SVM code switched to re-injecting software interrupt events,
> if something prevented their delivery.
>
> Task switch due to task gate in the IDT, however is an exception
> to this rule, because in this case, INTn instruction causes
> a task switch intercept and its emulation completes the INTn
> emulation as well.
>
> Add a missing case to task_switch_interception for that.
>
> This fixes 32 bit kvm unit test taskswitch2.
>
> Fixes: 7e5b5ef8dca322 ("KVM: SVM: Re-inject INTn instead of retrying the insn on "failure"")
>
> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
> ---

That's a good catch, your patch looks totally sensible to me.
People running Win 3.x or OS/2 on top of KVM will surely be grateful for it :)

Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>

Thanks,
Maciej