From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50401) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fkTmM-00043E-DA for qemu-devel@nongnu.org; Tue, 31 Jul 2018 08:29:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fkTmI-0004B0-DU for qemu-devel@nongnu.org; Tue, 31 Jul 2018 08:29:30 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:52642 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 1fkTmI-0004AS-6e for qemu-devel@nongnu.org; Tue, 31 Jul 2018 08:29:26 -0400 Date: Tue, 31 Jul 2018 15:29:17 +0300 From: "Michael S. Tsirkin" Message-ID: <20180731152716-mutt-send-email-mst@kernel.org> References: <153299204130.14411.11438396195753743913.stgit@gimli.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <153299204130.14411.11438396195753743913.stgit@gimli.home> Subject: Re: [Qemu-devel] [PATCH v2 0/4] Balloon inhibit enhancements, vfio restriction List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Williamson Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, peterx@redhat.com, cohuck@redhat.com, david@redhat.com On Mon, Jul 30, 2018 at 05:13:26PM -0600, Alex Williamson wrote: > v2: > - Use atomic ops for balloon inhibit counter (Peter) > - Allow endpoint driver opt-in for ballooning, vfio-ccw opt-in by > default, vfio-pci opt-in by device option, only allowed for mdev > devices, no support added for platform as there are no platform > mdev devices. > > See patch 3/4 for detailed explanation why ballooning and device > assignment typically don't mix. If this eventually changes, flags > on the iommu info struct or perhaps device info struct can inform > us for automatic opt-in. Thanks, > > Alex So this patch seems to block ballooning when vfio is added. But what if balloon is added and inflated first? I'd suggest making qemu_balloon_inhibit fail in that case, and then vfio realize will fail as well. > --- > > Alex Williamson (4): > balloon: Allow nested inhibits > kvm: Use inhibit to prevent ballooning without synchronous mmu > vfio: Inhibit ballooning based on group attachment to a container > vfio/ccw/pci: Allow devices to opt-in for ballooning > > > accel/kvm/kvm-all.c | 4 ++++ > balloon.c | 13 ++++++++++--- > hw/vfio/ccw.c | 9 +++++++++ > hw/vfio/common.c | 26 ++++++++++++++++++++++++++ > hw/vfio/pci.c | 26 +++++++++++++++++++++++++- > hw/vfio/trace-events | 1 + > hw/virtio/virtio-balloon.c | 4 +--- > include/hw/vfio/vfio-common.h | 2 ++ > 8 files changed, 78 insertions(+), 7 deletions(-)