From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D8FD0344DAA; Tue, 25 Aug 2026 16:14:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787674447; cv=none; b=NDOHSq7W0PZA756QkiHSyek8SB7AckT1IxMgvV9JVyNTef+9mhhrlZR5KVw0hKBJy15vgNzU9Bu5laxGRpLpsEzsHbSOwz439Z4CSjN+i5q63tDGWI5wEFMjmRbCS8EZ/pdCFaRNqaEQFqUE2TcfCvXu97C97zDHJoD4TRcqJ1c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787674447; c=relaxed/simple; bh=TMHDnAbv6B5815V9xDG8AMy+EDrsmT6X7HPtL1sNbf0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=WuF3c9f41jSODrtNftk+NS02c8zJJZ8hIZ4ebOMeEdH0lu38IHdXMR9pca8vuERU31BOhaSpPy6AwMrlVwjMkef4hxXdycaWBe+1grcvhhGVYZXRWkYfk+gyGUZZMatQHPi/vvBaZuI4ZQcIbCuBGlDUCDd/ItaWIgGDE7ahxiY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=MXEqTnb2; arc=none smtp.client-ip=198.175.65.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="MXEqTnb2" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1787674446; x=1819210446; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=TMHDnAbv6B5815V9xDG8AMy+EDrsmT6X7HPtL1sNbf0=; b=MXEqTnb25UP0Vsg45Y8pbLsp5svKOlxSQQu0HY2yabieYGxLqbohJgD9 LN8zlNGBh8yJ6Ar5/ELkgxPWovsi9MXFyLPS9/c5sjibo46gM3Z8RDGfD 12elSThHtjdrwlRnvy7Aj7e3p787mWv2SpJep8jtZvC2nWY0pgFxpOyJV tGInAh7wFOD/L875D/WttvZsFpeZzCiIylMojYBrXU+SFl/cT4iGpYiDP LVV9PvE14bsIptTrzq2E7TEJCptlxuwG8wlKKsa/vl9irwqnLY7eJzi5t 7c34cuqaSeAvlhjhuCSGrdHwEseQs2s1RWXhfBjuLyssK4AUjDcnGz+p4 Q==; X-CSE-ConnectionGUID: f7+4kvrjRP6i3TsV3vnnog== X-CSE-MsgGUID: RGwmHVhkSK6ZCWdah35jPg== X-IronPort-AV: E=McAfee;i="6800,10657,11886"; a="99671148" X-IronPort-AV: E=Sophos;i="6.25,243,1779174000"; d="scan'208";a="99671148" 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 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 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?