From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.20]) (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 300CA30ACF2; Tue, 23 Jun 2026 06:49:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.20 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782197346; cv=none; b=CkIBz8SC+4a50qepz1vV+MqBh80oj8dKZ/QGFaHDmHkUHYLIDIEzGP+KyFOXH7KYImvQb+UFSNR5nsrqGopvoHQBvTG69sIN3kgQRwCGZMHD6Tpw06aWPxJBxXJfc83ECfhnu0TdTgM2/eoWm+e4+sjR3N9BVm89x2rXMgoOyZE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782197346; c=relaxed/simple; bh=h8AQJDX3UfNiJ86zepeJMtjP8yPCQGflfnfOwDXysvw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=eTfvdOD/UfQiD7fgQuiCVOMxtTtyKbo2fMNpwx+DU/GZ6u+iJITeufvAQIpamJ91/JUZBIRIsHfo6tvpMv7bbMcUyiAvBV+nPj7W/onnWTAb/JakLo6LXQ1FEvVKhrpJrq90TNMmolq3C4QRFvwzu+QZyjy1Hb419zu1FNLmI74= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=bXK1xsux; arc=none smtp.client-ip=198.175.65.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="bXK1xsux" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1782197344; x=1813733344; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=h8AQJDX3UfNiJ86zepeJMtjP8yPCQGflfnfOwDXysvw=; b=bXK1xsuxNccQ8Ip6aNhtnU6cXJtpMepuLUyp1On0HmupbKsCHCfw1KAy c8kjycCVFLMLfrGqWVpbnXVYBozuVEr5y4vUv9urHvVpdzei7ylN32uNZ t4cT/HQSrzG7DSzKUjyuQPvE0K2GP9RFT8JdXysujXqTd4HBFybRUtIFm xG0B1Fydsw8OSjQTc6ssAurth7UCbnm1xZxpeSbC6TKkxhpQThxQVw+js /5+OeDxIHZ5lSbqzIxT7p20wn3KM2CcCgLDy058hbS/gubvI0ljpnPO7G hGGBgaI/Iz49bd6b4piunb7P+h1OIYn2pghPYqXOTm3e+9pr/An/9asfF Q==; X-CSE-ConnectionGUID: VamQVzpbRgmoOQA8+QBoqQ== X-CSE-MsgGUID: eu4+u/1wQ9ioe4cLA93wEg== X-IronPort-AV: E=McAfee;i="6800,10657,11825"; a="82701955" X-IronPort-AV: E=Sophos;i="6.24,220,1774335600"; d="scan'208";a="82701955" Received: from fmviesa009.fm.intel.com ([10.60.135.149]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jun 2026 23:49:03 -0700 X-CSE-ConnectionGUID: UQ6n62bSSPGTWfszTIj7Fw== X-CSE-MsgGUID: AN4e/MmzQW2EM/WlHV3RkA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.24,220,1774335600"; d="scan'208";a="243076433" Received: from unknown (HELO [10.238.2.81]) ([10.238.2.81]) by fmviesa009-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jun 2026 23:48:50 -0700 Message-ID: <120b6d16-4218-4ba6-824e-54c62dd3d74f@linux.intel.com> Date: Tue, 23 Jun 2026 14:48:47 +0800 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v8 12/46] KVM: guest_memfd: Only prepare folios for private pages To: ackerleytng@google.com Cc: aik@amd.com, andrew.jones@linux.dev, 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 , 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: <20260618-gmem-inplace-conversion-v8-0-9d2959357853@google.com> <20260618-gmem-inplace-conversion-v8-12-9d2959357853@google.com> Content-Language: en-US From: Binbin Wu In-Reply-To: <20260618-gmem-inplace-conversion-v8-12-9d2959357853@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/19/2026 8:31 AM, Ackerley Tng via B4 Relay wrote: > From: Ackerley Tng > > All-shared guest_memfd used to be only supported for non-CoCo VMs where > preparation doesn't apply. INIT_SHARED is about to be supported for CoCo > VMs in a later patch in this series. > > In addition, KVM_SET_MEMORY_ATTRIBUTES2 is about to be supported in > guest_memfd in a later patch in this series. > > This means that the kvm fault handler may now call kvm_gmem_get_pfn() on a > shared folio for a CoCo VM where preparation applies. > > Add a check to make sure that preparation is only performed for private > folios. > > Preparation will be undone on freeing (see kvm_gmem_free_folio()) and on > conversion to shared. > > Suggested-by: Michael Roth > Reviewed-by: Fuad Tabba > Signed-off-by: Ackerley Tng Reviewed-by: Binbin Wu