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Thu, 11 Sep 2025 10:59:37 +0000 (GMT) Message-ID: <1dcb569edd7f73f2df4019bf459fdcb35dcdf921.camel@linux.ibm.com> Subject: Re: [TECH TOPIC] UALink driver upstreaming From: Mimi Zohar To: "Sinyuk, Konstantin" , ksummit@lists.linux.dev In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Date: Thu, 11 Sep 2025 06:59:37 -0400 Precedence: bulk X-Mailing-List: ksummit@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Evolution 3.54.3 (3.54.3-1.fc41) X-TM-AS-GCONF: 00 X-Proofpoint-GUID: XER92urdckE2bgsxO83lfZKWTE1di6sK X-Proofpoint-ORIG-GUID: XER92urdckE2bgsxO83lfZKWTE1di6sK X-Authority-Analysis: v=2.4 cv=J52q7BnS c=1 sm=1 tr=0 ts=68c2aba1 cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=IkcTkHD0fZMA:10 a=yJojWOMRYYMA:10 a=tf-vCfap5zr9poDNSDAA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwOTA2MDAyNSBTYWx0ZWRfX6sFN++TlDxtl IUtTPogzBCWBr/gcty6LLWKk5Mq0L81iRG1FjvTfYr0Nd9jdyE+5Cw5e0XGPAjj+Tx+QGxvPjF/ Ch9ioOO3jlMspKfk9Go07TkfpqLD60Q1yVyQkSuK4YlyQN9vjPmY/E/2c3NUHraINvL6AuPSCH7 vkwgl4gH/3ZeAfogYGs7FCgYH+iFZWKTIPmPWXF+MO95ukkaIDBmF2RHvMSHHTG3WpVO/Yz773T Sg75uLAi+dXHxFFq3ahQ+gJzTKFRcgJNR4rmByB+aC9bqM3av56IThAMpuMKawBejFYn0V/gY4d 1rxVlYODRAzBiLJvHsXZBGKazcItiq80qmrx7oiXzURsQGZEuuYlK1UKXqq4agK7DQFNxs5SXJf cOYc8GhE 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=2025-09-10_04,2025-09-11_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 clxscore=1011 suspectscore=0 spamscore=0 phishscore=0 bulkscore=0 adultscore=0 malwarescore=0 priorityscore=1501 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2507300000 definitions=main-2509060025 On Wed, 2025-09-10 at 22:37 +0300, Sinyuk, Konstantin wrote: > Hi All, >=20 > The UALink Consortium is defining an open, vendor=E2=80=91neutral interco= nnect aimed > at scaling AI workloads with low=E2=80=91latency, memory=E2=80=91semantic= communication > beyond PCIe. Unlike proprietary solutions such as NVLink (NVIDIA) or > Infinity Fabric (AMD), UALink is a cross=E2=80=91vendor standard and was = recently > recognized at FMS 2025. >=20 > I would like to present a proposal on what UALink support could look like= in > the upstream Linux kernel. >=20 > Key areas for discussion: > - Core driver design: proposed start under drivers/misc/ual/ for discover= y, > =C2=A0 topology, and resource management. > - Memory semantics: same=E2=80=91OS and multi=E2=80=91OS rack scenarios, = leveraging dma_buf, > =C2=A0 HMM, and NUMA. > - Control path: AUX bus for vendor extensions, offloading real=E2=80=91ti= me sequences > =C2=A0 to device microcontrollers, generic UALink interface. > - Security: confidential compute support and a userspace daemon for topol= ogy > =C2=A0 and authentication. > - Upstreaming strategy: begin with a minimal core driver, then incrementa= lly > =C2=A0 extend toward MM integration, dma_buf support, security, and > =C2=A0 cross=E2=80=91subsystem work. >=20 > The goal is to decide how UALink should be represented as a first=E2=80= =91class > interconnect in Linux, complementing CXL while remaining vendor=E2=80=91n= eutral, > ABI=E2=80=91stable, and maintainable. Hi Konstantin, It would be nice to have all the Linux Security Module (LSM) hooks in all t= he right places from the beginning for integrity (e.g. signature verification)= . thanks, Mimi