From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50997) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fEQI9-0007g2-HK for qemu-devel@nongnu.org; Thu, 03 May 2018 22:17:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fEQI7-0005j4-2Y for qemu-devel@nongnu.org; Thu, 03 May 2018 22:17:49 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:43886 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fEQI6-0005ih-TR for qemu-devel@nongnu.org; Thu, 03 May 2018 22:17:46 -0400 Date: Fri, 4 May 2018 10:17:34 +0800 From: Peter Xu Message-ID: <20180504021734.GJ29580@xz-mi> References: <20180503213458.2749.28566.stgit@gimli.home> <20180503214513.2749.30627.stgit@gimli.home> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20180503214513.2749.30627.stgit@gimli.home> Subject: Re: [Qemu-devel] [PATCH v3 6/6] vfio/quirks: Enable ioeventfd quirks to be handled by vfio directly List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Williamson Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, eric.auger@redhat.com On Thu, May 03, 2018 at 03:45:13PM -0600, Alex Williamson wrote: > With vfio ioeventfd support, we can program vfio-pci to perform a > specified BAR write when an eventfd is triggered. This allows the > KVM ioeventfd to be wired directly to vfio-pci, entirely avoiding > userspace handling for these events. On the same micro-benchmark > where the ioeventfd got us to almost 90% of performance versus > disabling the GeForce quirks, this gets us to within 95%. > > Signed-off-by: Alex Williamson Reviewed-by: Peter Xu -- Peter Xu