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

[Paolo Bonzini]

On 08/03/2016 23:05, Radim KrÄmÃÅ wrote:
>>> >> +	case AVIC_INCMP_IPI_ERR_INV_TARGET:
>>> >> +		pr_err("%s: Invalid IPI target (icr=%#08x:%08x, idx=%u)\n",
>>> >> +		       __func__, icrh, icrl, index);
>>> >> +		BUG();
>>> >> +		break;
>>> >> +	case AVIC_INCMP_IPI_ERR_INV_BK_PAGE:
>>> >> +		pr_err("%s: Invalid bk page (icr=%#08x:%08x, idx=%u)\n",
>>> >> +		       __func__, icrh, icrl, index);
>>> >> +		BUG();
>>> >> +		break;
>> > 
>> > Please use WARN(1, "%s: Invalid bk page (icr=%#08x:%08x, idx=%u)\n",
>> > __func__, icrh, icrl, index) (and likewise for invalid target) instead
>> > of BUG().
> I think that if we hit one of these, then WARNs would just flood the
> log.  I'd prefer WARN_ONCE on AVIC_INCMP_IPI_ERR_INV_BK_PAGE.
> (Btw. aren't icr and idx are pointless on this error?  and the function
>  name should be printed by WARN.)

Agreed.

> Invalid target is triggerable by the guest (by sending IPI to a
> non-existent LAPIC), so warning log level seems too severe.
> pr_info_ratelimited() or nothing would be better.

Definitely should be nothing.

Paolo