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[34.127.9.76]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2b9cae6d123sm33770635ad.84.2026.05.01.15.08.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 01 May 2026 15:08:50 -0700 (PDT) Date: Fri, 1 May 2026 22:08:47 +0000 From: David Matlack To: Samiullah Khawaja Cc: David Woodhouse , Lu Baolu , Joerg Roedel , Will Deacon , Jason Gunthorpe , Robin Murphy , Kevin Tian , Alex Williamson , Shuah Khan , iommu@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Saeed Mahameed , Adithya Jayachandran , Parav Pandit , Leon Romanovsky , William Tu , Pratyush Yadav , Pasha Tatashin , Andrew Morton , Chris Li , Pranjal Shrivastava , Vipin Sharma , YiFei Zhu Subject: Re: [PATCH v2 03/16] iommu: Implement IOMMU domain preservation Message-ID: References: <20260427175633.1978233-1-skhawaja@google.com> <20260427175633.1978233-4-skhawaja@google.com> Precedence: bulk X-Mailing-List: kvm@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: <20260427175633.1978233-4-skhawaja@google.com> On 2026-04-27 05:56 PM, Samiullah Khawaja wrote: > Add IOMMU domain ops that can be implemented by the IOMMU drivers if > they support IOMMU domain preservation across liveupdate. The new IOMMU > domain preserve, unpreserve and restore APIs call these ops to perform > respective live update operations. > > Signed-off-by: Samiullah Khawaja > +static int alloc_object_ser(struct iommu_array_hdr_ser **curr_array_ptr, u64 max_objs) > +{ > + struct iommu_array_hdr_ser *curr_array = *curr_array_ptr; > + struct iommu_array_hdr_ser *next_array; > + There's a trade-off being made in this function to leak deleted array elements instead of trying to reuse them that warrants a comment. > + if (curr_array->nr_objects >= max_objs) { > + next_array = kho_alloc_preserve(PAGE_SIZE); > + if (IS_ERR(next_array)) > + return PTR_ERR(next_array); > + > + curr_array->next_array_phys = virt_to_phys(next_array); > + *curr_array_ptr = next_array; > + curr_array = next_array; > + } > + > + return curr_array->nr_objects++; > +}