Re: [Qemu-devel] [PATCH] ioapic: kvm: Skip route updates for masked pins

[Peter Xu <peterx@redhat.com>]

On Sun, Jun 02, 2019 at 01:42:13PM +0200, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@siemens.com>
> 
> Masked entries will not generate interrupt messages, thus do no need to
> be routed by KVM. This is a cosmetic cleanup, just avoiding warnings of
> the kind
> 
> qemu-system-x86_64: vtd_irte_get: detected non-present IRTE (index=0, high=0xff00, low=0x100)
> 
> if the masked entry happens to reference a non-present IRTE.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

Reviewed-by: Peter Xu <peterx@redhat.com>

Thanks, Jan.

The "non-cosmetic" part of clearing of those entries (e.g. including
when the entries were not setup correctly rather than masked) was
never really implemented and that task has been on my todo list for
quite a while but with a very low priority (low enough to sink...).  I
hope I didn't overlook its importance since AFAICT general OSs should
hardly trigger those paths and so far I don't see it a very big issue.

Regards,

-- 
Peter Xu