Re: [RFC PATCH] emulator: Fix task switch into/out of VM86

[Gleb Natapov <gleb@redhat.com>]

On Mon, Jan 09, 2012 at 09:10:10PM +0100, Kevin Wolf wrote:
> * This works with VMX, but with SVM I have an additional problem: When
>   trying to exit VM86 (usually by an exception) through a task gate in
>   the IDT, the code runs into the reason = TASK_SWITCH_CALL path. I
>   searched a bit in the documentation, but didn't find any obvious way
>   to fix this.
> 
Hmm, so exit_int_info is invalid during task switch exit even though
task switch was caused by an exception. I wonder is this the case when
vcpu is not in vm86 mode too? For vm86 we can change:

        else
                reason = TASK_SWITCH_CALL;

to
	else if (vcpu in vm86 mode)
		reason = TASK_SWITCH_GATE;
	else
		reason = TASK_SWITCH_CALL;

IIRC you can't change tasks by call in vm86 mode.

--
			Gleb.