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[34.140.183.197]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4a1cca30aa5sm33064205e9.2.2026.10.20.02.02.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Oct 2026 02:02:08 -0700 (PDT) Date: Tue, 20 Oct 2026 10:02:00 +0100 From: Vincent Donnefort To: Snehal Koukuntla Cc: Marc Zyngier , Oliver Upton , Catalin Marinas , Will Deacon , Sudeep Holla , Fuad Tabba , Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Mark Rutland , Sebastian Ene , Mostafa Saleh , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v2 2/2] KVM: arm64: Support FFA_MEM_RECLAIM2 in host handler Message-ID: References: <20261016082341.4030770-1-snehalreddy@google.com> <20261016082341.4030770-3-snehalreddy@google.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261016082341.4030770-3-snehalreddy@google.com> On Fri, Oct 16, 2026 at 08:23:41AM +0000, Snehal Koukuntla wrote: > FF-A v1.3 ALP5 (DEN0140 rev J) adds the FFA_MEM_RECLAIM2 interface, > allowing an Owner to reclaim a subset of pages from a shared or lent > memory region by populating constituent memory region descriptors in > its TX buffer along with a starting descriptor byte offset and initial > page index. Upon completion, the Relayer returns the number of 4K pages > reclaimed in x3. > > Support FFA_MEM_RECLAIM2 in the host FF-A proxy handler. Validate the > register arguments, copy the constituent descriptors from the host TX > buffer into the hypervisor's TX buffer, and check the descriptor bounds, > the total page count and the initial page index on that copy before > forwarding the call to the SPMD. On success, unshare the reclaimed page > ranges from the host stage-2 page tables. > > Link: https://support.arm.com/documentation/den0140/j > Signed-off-by: Snehal Koukuntla Reviewed-by: Vincent Donnefort > --- > Changes in v2: > - Rename FFA_FN64_MEM_RECLAIM2 to FFA_MEM_RECLAIM2 > - Check that the sum of pg_cnt across all constituent descriptors > matches total_pages, guarding against overflow (Vincent) > - Simplify the flags and offset alignment checks (Vincent) > > arch/arm64/kvm/hyp/nvhe/ffa.c | 126 ++++++++++++++++++++++++++++++++++ > 1 file changed, 126 insertions(+) > [...]