From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:45326) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ghbq7-0001rn-Cl for qemu-devel@nongnu.org; Thu, 10 Jan 2019 10:01:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ghbq2-00064n-IG for qemu-devel@nongnu.org; Thu, 10 Jan 2019 10:01:47 -0500 Received: from mx1.redhat.com ([209.132.183.28]:1746) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ghbq2-00064I-9r for qemu-devel@nongnu.org; Thu, 10 Jan 2019 10:01:42 -0500 Date: Thu, 10 Jan 2019 15:01:25 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20190110150125.GF2589@work-vm> References: <20190110020259.8492-1-ehabkost@redhat.com> <20190110020259.8492-4-ehabkost@redhat.com> <20190110133123.GF4500@habkost.net> <20190110091140-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20190110091140-mutt-send-email-mst@kernel.org> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v2 3/3] virtio: Make disable-legacy/disable-modern compat properties optional List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Eduardo Habkost , =?iso-8859-1?Q?Marc-Andr=E9?= Lureau , QEMU , Thomas Huth , Cornelia Huck * Michael S. Tsirkin (mst@redhat.com) wrote: > On Thu, Jan 10, 2019 at 11:31:23AM -0200, Eduardo Habkost wrote: > > On Thu, Jan 10, 2019 at 12:35:26PM +0400, Marc-Andr=E9 Lureau wrote: > > > Hi > > >=20 > > > On Thu, Jan 10, 2019 at 6:05 AM Eduardo Habkost wrote: > > > > > > > > The disable-legacy and disable-modern properties apply only to > > > > some virtio-pci devices. Make those properties optional. > > > > > > > > This fixes the crash introduced by commit f6e501a28ef9 ("virtio: = Provide > > > > version-specific variants of virtio PCI devices"): > > > > > > > > $ qemu-system-x86_64 -machine pc-i440fx-2.6 \ > > > > -device virtio-net-pci-non-transitional > > > > Unexpected error in object_property_find() at qom/object.c:1092= : > > > > qemu-system-x86_64: -device virtio-net-pci-non-transitional: ca= n't apply \ > > > > global virtio-pci.disable-modern=3Don: Property '.disable-moder= n' not found > > > > Aborted (core dumped) > > > > > > > > Reported-by: Thomas Huth > > > > Fixes: f6e501a28ef9 ("virtio: Provide version-specific variants o= f virtio PCI devices") > > > > Signed-off-by: Eduardo Habkost > > > > --- > > > > hw/core/machine.c | 5 +++-- > > > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/hw/core/machine.c b/hw/core/machine.c > > > > index 5530b71981..a19143aa44 100644 > > > > --- a/hw/core/machine.c > > > > +++ b/hw/core/machine.c > > > > @@ -91,8 +91,9 @@ const size_t hw_compat_2_7_len =3D G_N_ELEMENTS= (hw_compat_2_7); > > > > > > > > GlobalProperty hw_compat_2_6[] =3D { > > > > { "virtio-mmio", "format_transport_address", "off" }, > > > > - { "virtio-pci", "disable-modern", "on" }, > > > > - { "virtio-pci", "disable-legacy", "off" }, > > > > + /* Optional because not all virtio-pci devices support legac= y mode */ > > > > + { "virtio-pci", "disable-modern", "on", .optional =3D true = }, > > > > + { "virtio-pci", "disable-legacy", "off", .optional =3D true = }, > > >=20 > > > Could the generic devices implement a specific interface instead? > > > virtio-pci-generic? > >=20 > > This is the kind of complexity I wanted to avoid. We already > > have too many interface names for subsets of PCI and virtio > > devices. > >=20 > > >=20 > > > Adding "optional" handling looks like it may hide some other errors= . > >=20 > > What if we just make "optional" mean "skip if the property > > doesn't exist", as suggested by Cornelia and Dave? >=20 > That's the more standard meaning of the word optional, isn't it? Well the word is a separate issue; 'optional' is probably a bad choice but that's less important than what it actually does. I'd go for skip_if_missing which is explicit. Dave >=20 > > --=20 > > Eduardo -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK