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[80.230.68.31]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-493c63b6f8csm11868245e9.11.2026.07.01.21.03.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Jul 2026 21:03:32 -0700 (PDT) Date: Thu, 2 Jul 2026 00:03:28 -0400 From: "Michael S. Tsirkin" To: Alyssa Ross Cc: Sergio Lopez , Chia-I Wu , Jason Wang , Eugenio =?iso-8859-1?Q?P=E9rez?= , Xuan Zhuo , linux-kernel@vger.kernel.org, Simona Vetter , Dmitry Osipenko , Thomas Zimmermann , David Airlie , Gurchetan Singh , Gerd Hoffmann , virtualization@lists.linux.dev, dri-devel@lists.freedesktop.org, Maxime Ripard , Maarten Lankhorst Subject: Re: [PATCH v2 2/3] drm/virtio: honor blob_alignment requirements Message-ID: <20260702000144-mutt-send-email-mst@kernel.org> References: <20260428194450.518296-1-slp@redhat.com> <20260428194450.518296-3-slp@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Jul 01, 2026 at 01:10:30PM +0200, Alyssa Ross wrote: > On Tue, Apr 28, 2026 at 09:44:49PM +0200, Sergio Lopez wrote: > > If VIRTIO_GPU_F_BLOB_ALIGNMENT has been negotiated, blob size must be > > aligned to blob_alignment. Validate this in verify_blob() so that > > invalid requests are rejected early. > > > > Signed-off-by: Sergio Lopez > > FYI: this change breaks crosvm, which is squatting the 5 and 6 values > of VIRTIO_GPU_F_* with different meanings. I've reported it as a > crosvm bug, so hopefully it can be taken care of there. > > https://issuetracker.google.com/issues/529852979 Move fast and beak things, then it takes a wile to fix them) Do you understand who uses it maybe? Maybe if there's a PR for both sides it will be handled faster. > > --- > > drivers/gpu/drm/virtio/virtgpu_ioctl.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c > > index c33c057365f8..d0c4edf1eaf4 100644 > > --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c > > +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c > > @@ -489,6 +489,11 @@ static int verify_blob(struct virtio_gpu_device *vgdev, > > params->size = rc_blob->size; > > params->blob = true; > > params->blob_flags = rc_blob->blob_flags; > > + > > + if (vgdev->has_blob_alignment && > > + !IS_ALIGNED(params->size, vgdev->blob_alignment)) > > + return -EINVAL; > > + > > return 0; > > } > > > > -- > > 2.53.0 > >