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Tsirkin" , linux-kernel@vger.kernel.org Cc: Amit Shah , Arnd Bergmann , Greg Kroah-Hartman , virtualization@lists.linux.dev Date: Wed, 17 Sep 2025 11:49:39 +0200 In-Reply-To: <7d29cca832103f70584a9bd88c32b77f508e9045.camel@gmail.com> References: <7ebfa9a5ec3f07506b3d8f01cd4f2a35e2135679.1757666355.git.mst@redhat.com> <32bc2a49fabd619ea7dcafd7f5d50fca206b38ac.camel@linux.ibm.com> <7d29cca832103f70584a9bd88c32b77f508e9045.camel@gmail.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.54.3 (3.54.3-1.fc41) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: A2XWjbpHdOTtMPyz1CYcgiDm6YYA0VmK X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwOTE2MDIwNCBTYWx0ZWRfX8RXu9+rwCiTv lXlndl0+EfM47hLYeTTuthtK1nE5ySniGGQc+LMAOybSXB9B1N1IgyPRJoRAGMCgybBJYowcVX8 qar7FZGUwkFhl5taXwexyBh3Dhn3nSNnyY2EczcpN/52UQEPLUykERgQxl5s01WnnYMiBrVICnN uQZyVpHPFFu0Hrn9ZI5PgxBmxPtTZGPHs3BdKBr3ItpMv3oyFDqUrvChv5+iBcneM6H5S8cyf2O eGoQ0rjXmqQmO0M7WqohMHlrUpzi0iDzYy8HQ6lDEUEBhR53wp+67JppwESmbizKeFNUZYS2NIp sXmIf1QqF7I1nte5VN6spVXmuh7zDXlwba7Qv9PRA3J4dtQC1+8Q7wJHI0gkCCkqsRG/vDDyQWZ F5TNbCg5 X-Proofpoint-GUID: g2c-RVtScm76_BMVaKTADUTKz9OyiyLX X-Authority-Analysis: v=2.4 cv=co2bk04i c=1 sm=1 tr=0 ts=68ca8438 cx=c_pps a=aDMHemPKRhS1OARIsFnwRA==:117 a=aDMHemPKRhS1OARIsFnwRA==:17 a=IkcTkHD0fZMA:10 a=yJojWOMRYYMA:10 a=VwQbUJbxAAAA:8 a=KTf-2ZXJcRCJ3dXJ6e0A:9 a=QEXdDO2ut3YA:10 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1117,Hydra:6.1.9,FMLib:17.12.80.40 definitions=2025-09-17_01,2025-09-17_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 impostorscore=0 priorityscore=1501 suspectscore=0 adultscore=0 phishscore=0 malwarescore=0 spamscore=0 bulkscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2507300000 definitions=main-2509160204 On Mon, 2025-09-15 at 23:37 +0200, Filip Hejsek wrote: > Hi, >=20 > On Mon, 2025-09-15 at 18:44 +0200, Maximilian Immanuel Brandtner > wrote: > > [...] > > As I already mentioned in the QEMU discussion, I proposed the fix, > > because I was working on a similar implementation to bring resizing > > to > > QEMU. >=20 > I couldn't find any mention of your implementation on the QEMU ML. >=20 > > Unfortunately, the patch-set was stuck in limbo for a while and > > now that someone else has picked up the slack, I've descided that > > it's > > better to contribute to the patch-set that is upstream instead of > > sending a competing patch-set that does the same thing. >=20 > Would it be OK for me to take a look at your WIP patches? I would > like > to see if you did anything differently. >=20 For the stuff I can get clearance for anyways. The tl:dr of what's different about my patch-set is as follows: - introduce a new IOResizeHandler instead of using a chr backend event - dynamically add a QOM-property to every character device that supports resizing (instead of the qmp-command that you have implemented) - guest chardev implementations I also used a g_unix_signal_source instead of a signal notifier and it worked during testing, but I prefer your solution > Also, you mentioned before that you were also working on patches for > Libvirt. These will still be useful, because I won't be implementing > that part. >=20 I haven't properly implemented it for libvirt either. The libvirt patch -set would have to be somewhat sizeable as well as virStream currently doesn't implement a handle to perform hypervisor specific calls (which a resize QMP call would be). Accordingly, the virStream implementation would have to be changed on a deeper level which is why I just didn't come around to it (I would also need to familiarize myself first with libvirt more which I haven't done yet). > > [...] > > I don't really care if this discrepancy is fixed one way or the > > other, > > but it should most definitely be fixed. >=20 > I'm of the same opinion, but if it is fixed on the kernel side, then > (assuming no device implementation with the wrong order exists) I > think > maybe the fix should be backported to all widely used kernels. It > seems > that the patch hasn't been backported to the longterm kernels [1], > which I think Debian kernels are based on. >=20 > [1]: > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/log/driv= ers/char/virtio_console.c?h=3Dv6.12.47 >=20 Then I guess the patch-set should be backported > > Kind regards, > > Max Brandtner >=20 > Regards, > Filip Hejsek