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[47.55.120.4]) by smtp.gmail.com with ESMTPSA id af79cd13be357-8b2355e615bsm530534085a.19.2025.11.07.17.11.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Nov 2025 17:11:43 -0800 (PST) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1vHXUV-00000008NdU-17Dq; Fri, 07 Nov 2025 21:11:43 -0400 Date: Fri, 7 Nov 2025 21:11:43 -0400 From: Jason Gunthorpe To: "Tian, Kevin" Cc: "Winiarski, Michal" , Alex Williamson , "De Marchi, Lucas" , Thomas =?utf-8?Q?Hellstr=C3=B6m?= , "Vivi, Rodrigo" , Yishai Hadas , Shameer Kolothum , "intel-xe@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "Brost, Matthew" , "Wajdeczko, Michal" , "dri-devel@lists.freedesktop.org" , Jani Nikula , Joonas Lahtinen , Tvrtko Ursulin , David Airlie , Simona Vetter , "Laguna, Lukasz" , Christoph Hellwig , "Cabiddu, Giovanni" , Brett Creeley Subject: Re: [PATCH v4 28/28] vfio/xe: Add device specific vfio_pci driver variant for Intel graphics Message-ID: <20251108011143.GE1859178@ziepe.ca> References: <20251105151027.540712-1-michal.winiarski@intel.com> <20251105151027.540712-29-michal.winiarski@intel.com> <7dtl5qum4mfgjosj2mkfqu5u5tu7p2roi2et3env4lhrccmiqi@asemffaeeflr> <20251108004754.GD1859178@ziepe.ca> 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 Sat, Nov 08, 2025 at 01:05:55AM +0000, Tian, Kevin wrote: > > From: Jason Gunthorpe > > Sent: Saturday, November 8, 2025 8:48 AM > > > > On Fri, Nov 07, 2025 at 03:10:33AM +0000, Tian, Kevin wrote: > > > > To me, it looks like something generic, that will have impact on any > > > > device specific driver variant. > > > > What am I missing? > > > > > > > > I wonder if drivers that don't implement the deferred reset trick were > > > > ever executed with lockdep enabled. > > > > > > > > > > @Jason, @Yishai, @Shameer, @Giovanni, @Brett: > > > > > > Sounds it's a right thing to pull back the deferred reset trick into > > > every driver. anything overlooked? > > > > It does seem like we should probably do something in the core code to > > help this and remove the duplication. > > from backport p.o.v. it might be easier to first fix each driver > independently then remove the duplication in upstream? If it hasn't bothered anyone yet I wouldn't stress about backporting.. Maybe those drivers do work for some unknown reason? Plus it is *really* hard to actually hit this deadlock.. Jason