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[47.54.130.67]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-8cecd077be8sm204702746d6.40.2026.06.09.07.15.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Jun 2026 07:15:34 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1wWxEs-000000021xL-0mOX; Tue, 09 Jun 2026 11:15:34 -0300 Date: Tue, 9 Jun 2026 11:15:34 -0300 From: Jason Gunthorpe To: "Aneesh Kumar K.V (Arm)" Cc: iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, Robin Murphy , Marek Szyprowski , Will Deacon , Marc Zyngier , Steven Price , Suzuki K Poulose , Catalin Marinas , Jiri Pirko , Mostafa Saleh , Petr Tesarik , Alexey Kardashevskiy , Dan Williams , Xu Yilun , linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , x86@kernel.org, stable@vger.kernel.org, Michael Kelley Subject: Re: [PATCH v6 14/20] dma-direct: return struct page from dma_direct_alloc_from_pool() Message-ID: <20260609141534.GJ2764304@ziepe.ca> References: <20260604083959.1265923-1-aneesh.kumar@kernel.org> <20260604083959.1265923-15-aneesh.kumar@kernel.org> Precedence: bulk X-Mailing-List: linux-coco@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: <20260604083959.1265923-15-aneesh.kumar@kernel.org> On Thu, Jun 04, 2026 at 02:09:53PM +0530, Aneesh Kumar K.V (Arm) wrote: > @@ -270,9 +270,12 @@ void *dma_direct_alloc(struct device *dev, size_t size, > * the atomic pools instead if we aren't allowed block. > */ > if ((remap || (attrs & DMA_ATTR_CC_SHARED)) && > - dma_direct_use_pool(dev, gfp)) > - return dma_direct_alloc_from_pool(dev, size, dma_handle, > - gfp, attrs); > + dma_direct_use_pool(dev, gfp)) { > + page = dma_direct_alloc_from_pool(dev, size, > + dma_handle, &cpu_addr, > + gfp, attrs); > + return page ? cpu_addr : NULL; > + } You should probably put this at the start of the series so it can be backported Reviewed-by: Jason Gunthorpe To Petr's question I think this just shows nobody is really stressing the PCI dma paths on CC VMs today. if (force_dma_unencrypted(dev) && dma_direct_use_pool(dev, gfp)) return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); For instance the places even calling dma_alloc_pages() don't look like things people would use in a CC VM. Jason