Re: [PART1 RFC v2 07/10] svm: Add VMEXIT handlers for AVIC

From: Suravee Suthikulpanit
Date: Wed Mar 16 2016 - 23:58:36 EST

Hi Radim,

On 03/10/2016 03:55 AM, Radim KrÄmÃÅ wrote:
>+ pr_debug("%s: offset=%#x, rw=%#x, vector=%#x, vcpu_id=%#x, cpu=%#x\n",
>+ __func__, offset, rw, vector, svm->vcpu.vcpu_id, svm->vcpu.cpu);
>+ BUG_ON(offset >= 0x400);
These are valid faulting registers, so our implementation has to handle
them. (And the rule is to never BUG if a recovery is simple.)

Just want to clarify the part that you mentioned "to handle them". IIUC, offet 0x400 and above are for x2APIC stuff, which AVIC does not currently support. Also, since I have only advertised as xAPIC when enabling AVIC, if we run into the situation that the VM is trying to access these register, we should just ignore it (and not BUG). Do I understand that correctly?