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Mon, 03 Aug 2026 20:39:43 -0700 (PDT) Date: Mon, 3 Aug 2026 23:39:40 -0400 From: "Michael S. Tsirkin" To: Mike Christie Cc: Jia Jia , jasowangio@gmail.com, pbonzoni@redhat.com, stefanha@redhat.com, eperezma@redhat.com, virtualization@lists.linux.dev, kvm@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH] vhost-scsi: flush backend after device ioctls Message-ID: <20260803233841-mutt-send-email-mst@kernel.org> References: <20260721073639.1532488-1-physicalmtea@gmail.com> <3d2dfa19-42f8-4d1f-a411-c72669f4c4bc@oracle.com> <20260723105451.1563439-1-physicalmtea@gmail.com> <45a33302-0b28-4d00-8724-c3af6e1783f6@oracle.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <45a33302-0b28-4d00-8724-c3af6e1783f6@oracle.com> On Mon, Aug 03, 2026 at 07:02:43PM -0500, Mike Christie wrote: > On 7/23/26 5:54 AM, Jia Jia wrote: > > The owner must keep the old mappings valid until the ioctl returns. > > Remapping or dropping them from another userspace thread before then is > > outside the lifetime assumption of this transition barrier. > > Ok I get it now. For some reason I thought that was valid. > > For the patch we don't want to flush if vhost_dev_ioctl fails > and there's no reason to flush for operations like > VHOST_GET_FORK_FROM_OWNER or VHOST_SET_OWNER. > > Could vhost_dev_ioctl return when a flush is needed? I agree but also this is consistent with all other vhost devices. So I'm taking v2 of this, and we can iterate to optimize all devices with patches on top. -- MST