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[79.176.41.183]) by smtp.gmail.com with ESMTPSA id h14sm84919qke.99.2020.02.12.01.15.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 12 Feb 2020 01:15:05 -0800 (PST) Date: Wed, 12 Feb 2020 04:15:01 -0500 From: "Michael S. Tsirkin" To: Jason Wang Cc: virtio-dev@lists.oasis-open.org, Zha Bin , slp@redhat.com, "Liu, Jing2" , linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, chao.p.peng@linux.intel.com, gerry@linux.alibaba.com Subject: Re: [virtio-dev] Re: [PATCH v2 4/5] virtio-mmio: add MSI interrupt feature support Message-ID: <20200212041317-mutt-send-email-mst@kernel.org> References: <5522f205-207b-b012-6631-3cc77dde3bfe@linux.intel.com> <45e22435-08d3-08fe-8843-d8db02fcb8e3@redhat.com> <20200211065319-mutt-send-email-mst@kernel.org> <20200211070523-mutt-send-email-mst@kernel.org> <20200211090003-mutt-send-email-mst@kernel.org> <4557a5e8-74eb-f238-1579-b7b558cb2969@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4557a5e8-74eb-f238-1579-b7b558cb2969@redhat.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 12, 2020 at 05:03:00PM +0800, Jason Wang wrote: > > On 2020/2/11 下午10:00, Michael S. Tsirkin wrote: > > > Yes, it can work but it may bring extra effort when you want to mask a > > > vector which is was shared by a lot of queues. > > > > > > Thanks > > > > > masking should be per vq too. > > > > -- > > > Yes, but if the vector is shard by e.g 16 queues, then all those virtqueues > needs to be masked which is expensive. > > Thanks I think that's ok - masking is rare. in fact if vectors can be changed atomically I'm no longer sure they are needed, maybe a destructive "disable" which can lose interrupts is enough. -- MST