From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37435) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cUdUp-000520-Iq for qemu-devel@nongnu.org; Fri, 20 Jan 2017 13:01:08 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cUdUm-0002e6-HV for qemu-devel@nongnu.org; Fri, 20 Jan 2017 13:01:07 -0500 Received: from mx1.redhat.com ([209.132.183.28]:53396) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cUdUm-0002dT-CB for qemu-devel@nongnu.org; Fri, 20 Jan 2017 13:01:04 -0500 Date: Fri, 20 Jan 2017 11:01:01 -0700 From: Alex Williamson Message-ID: <20170120110101.538bed72@t450s.home> In-Reply-To: <5881A858.2020203@cn.fujitsu.com> References: <1483175588-17006-1-git-send-email-caoj.fnst@cn.fujitsu.com> <1483175588-17006-5-git-send-email-caoj.fnst@cn.fujitsu.com> <20170118153621.75d8b83d@t450s.home> <5881A858.2020203@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH RFC v11 4/4] vfio: add 'aer' property to expose aercap List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Cao jin Cc: qemu-devel@nongnu.org, mst@redhat.com, izumi.taku@jp.fujitsu.com, Dou Liyang On Fri, 20 Jan 2017 14:04:08 +0800 Cao jin wrote: > On 01/19/2017 06:36 AM, Alex Williamson wrote: > > On Sat, 31 Dec 2016 17:13:08 +0800 > > Cao jin wrote: > > > >> From: Chen Fan > >> > >> Add 'aer' property, let user choose whether expose the aer capability > >> or not. > > > > But that's not what it does, it only controls the behavior in response > > to non-fatal errors, the capability is exposed regardless. > > > > This commit log is legacy, and defaults to off is a result of the > configuration restriction & your previous discussion, right? > > In current version, if 'aer' property is off, we just allocate the > config space via pcie_add_capability(), we don't init the AER > capability, the value is all 0s there, so does that still mean > "capability is exposed regardless"? The design has changed, we no longer require a matching host and guest topology, we can more easily transparently enable non-fatal error correction. We need to reevaluate whether previous decisions are still valid, we cannot blindly assume that a requirement for a previous design still applies. Thanks, Alex > >> Should disable aer feature by default, because only non-fatal > >> error is supported now. > > > > Why does that mean it should be disabled by default? What bad thing > > happens if we enable this opportunistically? > > > >> Signed-off-by: Chen Fan > >> Signed-off-by: Dou Liyang > >> Signed-off-by: Cao jin > >> --- > >> hw/vfio/pci.c | 2 ++ > >> 1 file changed, 2 insertions(+) > >> > >> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c > >> index 9861f72..fc9db66 100644 > >> --- a/hw/vfio/pci.c > >> +++ b/hw/vfio/pci.c > >> @@ -3057,6 +3057,8 @@ static Property vfio_pci_dev_properties[] = { > >> DEFINE_PROP_UINT32("x-pci-sub-device-id", VFIOPCIDevice, > >> sub_device_id, PCI_ANY_ID), > >> DEFINE_PROP_UINT32("x-igd-gms", VFIOPCIDevice, igd_gms, 0), > >> + DEFINE_PROP_BIT("aer", VFIOPCIDevice, features, > >> + VFIO_FEATURE_ENABLE_AER_BIT, false), > >> /* > >> * TODO - support passed fds... is this necessary? > >> * DEFINE_PROP_STRING("vfiofd", VFIOPCIDevice, vfiofd_name), > > > > > > > > . > > >