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Wed, 17 Sep 2025 05:36:03 -0700 (PDT) Received: from ziepe.ca ([130.41.10.202]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-4b7af2426a3sm34649061cf.37.2025.09.17.05.36.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Sep 2025 05:36:02 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1uyrOD-00000005jqq-480E; Wed, 17 Sep 2025 09:36:01 -0300 Date: Wed, 17 Sep 2025 09:36:01 -0300 From: Jason Gunthorpe To: Mostafa Saleh Cc: Will Deacon , linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, robin.murphy@arm.com, jean-philippe@linaro.org, qperret@google.com, tabba@google.com, mark.rutland@arm.com, praan@google.com Subject: Re: [PATCH v4 22/28] iommu/arm-smmu-v3-kvm: Emulate CMDQ for host Message-ID: <20250917123601.GA1326709@ziepe.ca> References: <20250819215156.2494305-1-smostafa@google.com> <20250819215156.2494305-23-smostafa@google.com> <20250915163858.GK882933@ziepe.ca> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Sep 16, 2025 at 03:19:02PM +0000, Mostafa Saleh wrote: > I think the fix for the problem Will mentioned is to just use CMOs > before accessing the host structures, so that should be simple. > If it turns to be more complicated, I am happy to drop the support > for non-coherent devices from this series and we can add it later. I feel like it is easier/better to fix the driver to use cachable memory than to add CMOs to the pkvm side.. This way it will help qemu/etc as well. Jason