From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:55625) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gxDzZ-0007ry-4F for qemu-devel@nongnu.org; Fri, 22 Feb 2019 11:48:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gxDzY-0005Ed-Ex for qemu-devel@nongnu.org; Fri, 22 Feb 2019 11:48:05 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51478) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gxDzW-0004cT-Cb for qemu-devel@nongnu.org; Fri, 22 Feb 2019 11:48:02 -0500 Date: Fri, 22 Feb 2019 16:47:14 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20190222164713.GF2574@work-vm> References: <28e6b4ed-9afd-3a79-6267-86c7385c23ce@redhat.com> <20190222163735.GB2616@work-vm> <1f3243df-1037-235f-838f-4651df476ee3@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1f3243df-1037-235f-838f-4651df476ee3@redhat.com> Subject: Re: [Qemu-devel] [Qemu-block] Guest unresponsive after Virtqueue size exceeded error List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Stefan Hajnoczi , Fernando Casas =?iso-8859-1?Q?Sch=F6ssow?= , Richard Henderson , qemu-devel , Natanael Copa * Paolo Bonzini (pbonzini@redhat.com) wrote: > On 22/02/19 17:37, Dr. David Alan Gilbert wrote: > > Why does vring_avail_idx use virtio_ld*u*w_phys_cached? > > (similar for vring_avail_ring). > > There's no generically safe way to do unaligned atomic loads - don't we know > > in virtio that these are naturally aligned? > > u is for unsigned. :) We know that these are aligned and so they will > be atomic. Ah OK! Dave > Paolo -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK