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[159.2.73.22]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-50d4b8d9f7bsm21034241cf.30.2026.04.02.04.59.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Apr 2026 04:59:59 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1w8GiM-0000000Blwf-23a0; Thu, 02 Apr 2026 08:59:58 -0300 Date: Thu, 2 Apr 2026 08:59:58 -0300 From: Jason Gunthorpe To: Tudor Ambarus Cc: Joerg Roedel , Will Deacon , Robin Murphy , Lorenzo Pieralisi , "Rob Herring (Arm)" , Joerg Roedel , Bjorn Helgaas , iommu@lists.linux.dev, linux-kernel@vger.kernel.org, peter.griffin@linaro.org, andre.draszik@linaro.org, willmcvicker@google.com, jyescas@google.com, kernel-team@android.com, stable@vger.kernel.org Subject: Re: [PATCH] iommu: Fix bypass of IOMMU readiness check for multi-IOMMU devices Message-ID: <20260402115958.GA2551565@ziepe.ca> References: <20260323-iommu-ready-check-v1-1-5f6fef8f9f59@linaro.org> <20260323135414.GA8437@ziepe.ca> <1062b66d-e4d0-4eee-8fc2-dbb65491a01b@linaro.org> <20260323173138.GB8437@ziepe.ca> <9892a17b-022e-41df-af1c-a2d684aa8db1@linaro.org> 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: <9892a17b-022e-41df-af1c-a2d684aa8db1@linaro.org> On Thu, Apr 02, 2026 at 02:25:54PM +0300, Tudor Ambarus wrote: > I can probably track whether all instances are ready, and defer if any > is not ready, but then I'll force the iommu clients to use the sketchy > replay path, which seems like a bad idea, according to Robin's feedback. I didn't think that was sketchy, it is part of the boot ordering system to ensure that the iommu driver(s) is probed before the client devices. Half operating a device is definately going to get things into trouble with broken/incomplete domain attachments at least. Jason