linux-kernel - Re: [PATCH] virtio_ring: switch to dma

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180419210843-mutt-send-email-mst@kernel.org>
Date:   Thu, 19 Apr 2018 21:10:47 +0300
From:   "Michael S. Tsirkin" <mst@...hat.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     linux-kernel@...r.kernel.org, Ohad Ben-Cohen <ohad@...ery.com>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        linux-remoteproc@...r.kernel.org, Jason Wang <jasowang@...hat.com>,
        virtualization@...ts.linux-foundation.org
Subject: Re: [PATCH] virtio_ring: switch to dma_XX barriers for rpmsg

On Thu, Apr 19, 2018 at 07:48:24PM +0200, Paolo Bonzini wrote:
> On 19/04/2018 19:46, Michael S. Tsirkin wrote:
> >> This should be okay, but I wonder if there should be a virtio_wmb(...)
> >> or an "if (weak_barriers) wmb()" before the "writel" in vm_notify
> >> (drivers/virtio/virtio_mmio.c).
> >>
> >> Thanks,
> >>
> >> Paolo
> > That one uses weak barriers AFAIK.
> > 
> > IIUC you mean rproc_virtio_notify.
> > 
> > I suspect it works because specific kick callbacks have a barrier internally.
> 
> Yes, that one.  At least keystone_rproc_kick doesn't seem to have a barrier.
> 
> Paolo

Maybe it's wrong or not used with virtio then.
This patch won't change anything with respect to that though.

-- 
MST