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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240730_045224_183543_20D0C9F3 X-CRM114-Status: GOOD ( 16.84 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 7/27/24 01:51, Sean Christopherson wrote: > arm64 folks, the first two patches are bug fixes, but I have very low > confidence that they are correct and/or desirable. If they are more or > less correct, I can post them separately if that'd make life easier. I > included them here to avoid conflicts, and because I'm pretty sure how > KVM deals with MTE tags vs. dirty logging will impact what APIs KVM needs > to provide to arch code. > > On to the series... The TL;DR is that I would like to get input on two > things: > > 1. Marking folios dirty/accessed only on the intial stage-2 page fault > 2. The new APIs for faulting, prefetching, and doing "lookups" on pfns Wow! Splitting out prefetching makes a lot of sense, as it's the only one with npages > 1 and it doesn't need all the complexity of hva_to_pfn(). I've left a comment on the lookup API, which is probably the only one that can be simplified further. The faulting API looks good as a first iteration. Code-wise, kvm_resolve_pfn() is probably unnecessary at the end of the series but I can see why you had to restrain yourself and declare it done. :) An interesting evolution of the API could be to pass a struct kvm_follow_pfn pointer to {,__}kvm_faultin_pfn() and __gfn_to_page() (the "constructors"); and on the other side to kvm_release_faultin_page() and kvm_release_page_*(). The struct kvm_follow_pfn could be embedded in the (x86) kvm_page_fault and (generic) kvm_host_map structs. But certainly not as part of this already huge work. Paolo