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X-CSE-ConnectionGUID: Zyh0JOAOTs+hazu4ogJkeA== X-CSE-MsgGUID: lydUQ7lxS3qyKwgwyZ56Uw== X-IronPort-AV: E=McAfee;i="6800,10657,11886"; a="99671159" X-IronPort-AV: E=Sophos;i="6.25,243,1779174000"; d="scan'208";a="99671159" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by orvoesa104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Aug 2026 09:14:03 -0700 X-CSE-ConnectionGUID: 1Z8oyHIvRaCdZRwP1LfjXw== X-CSE-MsgGUID: /mJMl5yPRFOgp7AaoGyB2Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,243,1779174000"; d="scan'208";a="265538212" Received: from xiaoyaol-hp-g830.ccr.corp.intel.com (HELO [10.124.240.119]) ([10.124.240.119]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Aug 2026 09:13:50 -0700 Message-ID: <7eba513d-cdae-4832-abac-038dcdd88517@intel.com> Date: Wed, 26 Aug 2026 00:13:47 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v10 09/41] KVM: guest_memfd: Filter both shared and private when invalidating To: Sean Christopherson , Ackerley Tng Cc: Suzuki K Poulose , "David Hildenbrand (Arm)" , aik@amd.com, andrew.jones@linux.dev, binbin.wu@linux.intel.com, brauner@kernel.org, chao.p.peng@linux.intel.com, 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, aneesh.kumar@kernel.org, liam@infradead.org, Paolo Bonzini , 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, Vlastimil Babka , 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 References: <20260807-gmem-inplace-conversion-v10-0-2fc18ee6d3ba@google.com> <20260807-gmem-inplace-conversion-v10-9-2fc18ee6d3ba@google.com> <13ca60c6-e154-4397-8092-09f861e90fe0@kernel.org> Content-Language: en-US From: Xiaoyao Li In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: 9j85fy334ff73hxce9gisjqfktis7czt X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 4463E8000A X-Rspam-User: X-HE-Tag: 1787674445-190804 X-HE-Meta: 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 cL6Va2m2 PgCYX1RSq6CbTBJrzniuUZbdRzUk7qnV3EBAAQXuDjEAbUwuPo45reI7a/PHI/LOcc7k5U+CDWNxqAfpxA1Vre087bC8fWmTL1R28YtmrOxm4MijywjZpYrwHfTGyfZ7gTkY3c6Jssv1SYB/q4ZUB63KZ/VU9lpaKjmTxaEs5X+TIwUbPvOUG+sZvG1hDBDZLxGwSesHoCTBH412R1efO9hX90AtT6xdK4hrj0dFfl4fg6GDHwsUUZ1iN3w== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 8/20/2026 9:32 AM, Sean Christopherson wrote: > And vice versa, a PUNCH_HOLE on a SHARED gmem (if userspace is > using an INIT_SHARED gmem for the shared branch of a memslot) could invalidate the > PRIVATE mappings (of a different gmem instance). I'm wondering now how this could happen. the requirement for PUNCH_HOLE on gmem to trigger mapping invalidation is the gmem is bound with the memslot. But how can a memslot bound with two gmem instances?