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[54.240.197.234]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4a1cca43012sm17041055e9.3.2026.10.16.02.46.10 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 16 Oct 2026 02:46:12 -0700 (PDT) From: Fred Griffoul To: Paolo Bonzini , Sean Christopherson , Marc Zyngier , Oliver Upton , Catalin Marinas , Andrew Morton , David Hildenbrand , Alexander Viro , Christian Brauner , Jan Kara , Jason Gunthorpe , Kevin Tian , Joerg Roedel , Will Deacon , Robin Murphy , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , Jonathan Corbet , Shuah Khan , Shuah Khan Cc: David Woodhouse , Ackerley Tng , "Aneesh Kumar K . V" , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Steffen Eiden , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [RFC PATCH v2 07/11] iommufd: Use large IOMMU pages for provider mappings Date: Fri, 16 Oct 2026 09:46:10 +0000 Message-ID: <20261016094610.57849-1-griffoul@gmail.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261016001448.GC14213@ziepe.ca> References: <20261014093733.90312-1-griffoul@gmail.com> <20261014093733.90312-8-griffoul@gmail.com> <20261016001448.GC14213@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Stat-Signature: 5gwje8bkcoijcxkk67fab4tdp4faf1d5 X-Rspam-User: X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 7C9AC140002 X-HE-Tag: 1792143974-744888 X-HE-Meta: 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 2G5xzhfz 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Oct 15, 2026 at 09:14:48PM -0300, Jason Gunthorpe wrote: > You are going to need to go into generic_pt and implement cut and a > more suitable unmap to make this stuff work properly. We can't over > unmap on conversions. Agreed. I'll drop this patch from v3 for now. Just to check I understand what you have in mind: a cut operation in generic_pt that splits a large entry in place into smaller ones, so that the revoke unmaps exactly its range, and iommufd uses large pages only on domains that support it? > Also please don't write commit messages with AI. WTF is this even > trying to say? The subject is "use large pages" and this text says > "map each page with its own call" Sorry about that. It goes away with the patch, and I'll check and rewrite the other commit messages for v3. Fred