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charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260807-gmem-inplace-conversion-v10-13-2fc18ee6d3ba@google.com> References: <20260807-gmem-inplace-conversion-v10-0-2fc18ee6d3ba@google.com> In-Reply-To: <20260807-gmem-inplace-conversion-v10-0-2fc18ee6d3ba@google.com> To: aik@amd.com, andrew.jones@linux.dev, binbin.wu@linux.intel.com, brauner@kernel.org, chao.p.peng@linux.intel.com, david@kernel.org, jmattson@google.com, jthoughton@google.com, michael.roth@amd.com, oupton@kernel.org, pankaj.gupta@amd.com, qperret@google.com, rick.p.edgecombe@intel.com, rientjes@google.com, shivankg@amd.com, steven.price@arm.com, tabba@google.com, willy@infradead.org, wyihan@google.com, yan.y.zhao@intel.com, forkloop@google.com, pratyush@kernel.org, suzuki.poulose@arm.com, aneesh.kumar@kernel.org, liam@infradead.org, Paolo Bonzini , Sean Christopherson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , Shuah Khan , Vishal Annapurve , Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Baoquan He , Jason Gunthorpe , John Hubbard , Peter Xu , tarunsahu@google.com, Jason Gunthorpe , Vlastimil Babka , Baoquan He Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, Ackerley Tng X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1786139565; l=1860; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=klJ2px6Wqls0hGacJ6oWy+P1esd5PU6yM+WgWOJIUsI=; b=0vcu/MCQmdtGPWXOU8t4S5wJStaSMSvivJsV/Xl5Og7DLO+sy8ItmzZsKMw2S/tvGBDd0R6fn kv9xs7ln6iLBrXgNjDz8oyAG22n3GxyCUR0wMu/iTJCQy9zQht3v4sP X-Developer-Key: i=ackerleytng@google.com; a=ed25519; pk=sAZDYXdm6Iz8FHitpHeFlCMXwabodTm7p8/3/8xUxuU= X-Endpoint-Received: by B4 Relay for ackerleytng@google.com/20260225 with auth_id=649 X-Original-From: Ackerley Tng Reply-To: ackerleytng@google.com X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 9A5871C000A X-Stat-Signature: djhjqbherryt8rui6rkgicx4u7shk6ye X-HE-Tag: 1786139574-569214 X-HE-Meta: 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 8a0f3d/h XYDg2hfNr9CCkCw27tCukWGYVk+Da7aMTtYEELBQTMyO7rueqZWE9nYMKEeoZmPH/6ZOjvuZf0L7pRksTA+IYWxi/rZiUcBSmKIJk9pbyWGL0333T+NOuVu7gVIdAeLh9Rd/yw3X+OdXkuTaSSIUmPv/yzg95xXIqG7EEkCgtLfwDHC0qlTU4ifOrU7Z1NmuBXAB+y9yo20TBFHi76CaJ3MqqPHeJB0JMmnkD8ERyi8xQA5uoZYV7gVVBggX5ogPyrKUf+Eskvmm/0LIU0RCEaQRIFjq47fqBlPkgPQ/7GHYMpAIf8+wVxQZkqdYgiNAclegAczmpyZ6Xcr0Tshi5WkbKU5Lg6k7VH7s5bu1d6nlUxSOf9buenxuQBh7FxPMHLgCBW6KnRrYjnpWk1bmHAbgZRaGo5eZri8sa9/yS3svFm/T6dwItrBNwex8fNV8o/4yS0PDE4aFSqR/EY/ct857xE37IbGUgcz6+97/KO8xUrdDvflqPia0iAzu9EYKv9OhdF7asPXzNTh0uhH3EjxLgrWqvlYIEFchYDiZDgmrqJ5/X0mZhAE+pPg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Ackerley Tng Provide function to check that a range has given attributes. Optimize setting memory attributes by returning early if all pages in the requested range already has the requested attributes. Reviewed-by: Fuad Tabba Tested-by: Shivank Garg Signed-off-by: Ackerley Tng --- virt/kvm/guest_memfd.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index c9874bd85c5d8..896699afcad9d 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -95,6 +95,24 @@ static bool kvm_gmem_is_shared_mem(struct inode *inode, pgoff_t index) return !kvm_gmem_is_private_mem(inode, index); } +static bool kvm_gmem_range_has_attributes(struct inode *inode, + pgoff_t index, size_t nr_pages, + u64 attributes) +{ + struct maple_tree *mt = &GMEM_I(inode)->attributes; + pgoff_t end = index + nr_pages - 1; + void *entry; + + lockdep_assert(mt_lock_is_held(mt)); + + mt_for_each(mt, entry, index, end) { + if (kvm_gmem_get_attributes(inode, entry) != attributes) + return false; + } + + return true; +} + /* * Returns a locked folio on success. The caller is responsible for * setting the up-to-date flag before the memory is mapped into the guest. @@ -605,12 +623,15 @@ static int __kvm_gmem_set_attributes(struct inode *inode, pgoff_t start, pgoff_t end = start + nr_pages; struct maple_tree *mt; struct ma_state mas; - int r; + int r = 0; mt = &gi->attributes; filemap_invalidate_lock(mapping); + if (kvm_gmem_range_has_attributes(inode, start, nr_pages, attrs)) + goto out; + mas_init(&mas, mt, start); r = kvm_gmem_mas_preallocate(&mas, attrs, start, nr_pages); if (r) { -- 2.55.0.654.g21b8a5bc05-goog