From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.14]) (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 D2DC0334C04; Thu, 5 Feb 2026 07:23:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770276227; cv=none; b=QESX9Gs4wQm0n+jSf9nBu0BfImtexKF7Rh7rc2fVlYJ9pgU6dNQ/Gp7miFIN3lvXH7HDeUudRnP8qY0UaRSPQ1gNjsmiw93HzIjtLr6mLfIX5YfK0mQZDaPDjzPudYr/IHwRkZ16wIwjYjjUVcPh/KkxP6INlTyB0pMVUxTbqSo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770276227; c=relaxed/simple; bh=FgmZNaT1AJdOs3lof3+rnMI62Gul05tMmOYxnVyfbkM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GP424HfNlp/tDTUgBHk19t/qxLuNZWZthNvecfytWPYxaFNTjtR6sbPbLR67K+MRMuzOqfqv64CALZmOz8Ro7yGDEVs9gsphsTrTib0I7yH+yPWBNYS6nt3nOCxl1JVF5a0HbsIFxMs7bfkkJN3tbvtAtKCP84DYxO35jFxCabU= 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=agCF42zA; arc=none smtp.client-ip=198.175.65.14 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="agCF42zA" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1770276227; x=1801812227; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=FgmZNaT1AJdOs3lof3+rnMI62Gul05tMmOYxnVyfbkM=; b=agCF42zAxuBVhVQS8q2VvWYrlrkCT2ODu1cM10v8ui1sFGAjRUkxbNR6 rnhFQaTT0mrhYPT59/WMkhR14DuNtxVGgHKLHtP5Eaqr1oZm/XZtyM/J1 6NsyzpV6WhKKCPxbEW1Fgx399k2t0kP1ebX+BOPEwpoFTKi3dSWr+xSQ7 dlx3QdbplY4XPr8nBhlISDcxVt/BohwMEwIQwYdeD9FuBGUZeqghZgdBs zFnBjM7BjGxUtFHHglP/nr0xGUKM68xtGKao1KBE08j68SxhMnw6UrH3u zS6Frw3kKkKjm73pEQVOTdp/Q4LhAJLLxhz+7ZGcJTRL7nOvUBYyNFm1W g==; X-CSE-ConnectionGUID: n81A8imZTBikNvPrxWRJ7Q== X-CSE-MsgGUID: ToEhKqrwTDWDAOks9art2Q== X-IronPort-AV: E=McAfee;i="6800,10657,11691"; a="75322708" X-IronPort-AV: E=Sophos;i="6.21,274,1763452800"; d="scan'208";a="75322708" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Feb 2026 23:23:44 -0800 X-CSE-ConnectionGUID: w4M3nSSLQ/mBj1j0Il6KlQ== X-CSE-MsgGUID: NkzCqGaoSdu69QFLY8HZpA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,274,1763452800"; d="scan'208";a="214913923" Received: from yilunxu-optiplex-7050.sh.intel.com (HELO localhost) ([10.239.159.165]) by fmviesa005.fm.intel.com with ESMTP; 04 Feb 2026 23:23:21 -0800 Date: Thu, 5 Feb 2026 15:04:48 +0800 From: Xu Yilun To: Jason Gunthorpe Cc: Sean Christopherson , Ackerley Tng , Alexey Kardashevskiy , cgroups@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, x86@kernel.org, akpm@linux-foundation.org, binbin.wu@linux.intel.com, bp@alien8.de, brauner@kernel.org, chao.p.peng@intel.com, chenhuacai@kernel.org, corbet@lwn.net, dave.hansen@intel.com, dave.hansen@linux.intel.com, david@redhat.com, dmatlack@google.com, erdemaktas@google.com, fan.du@intel.com, fvdl@google.com, haibo1.xu@intel.com, hannes@cmpxchg.org, hch@infradead.org, hpa@zytor.com, hughd@google.com, ira.weiny@intel.com, isaku.yamahata@intel.com, jack@suse.cz, james.morse@arm.com, jarkko@kernel.org, jgowans@amazon.com, jhubbard@nvidia.com, jroedel@suse.de, jthoughton@google.com, jun.miao@intel.com, kai.huang@intel.com, keirf@google.com, kent.overstreet@linux.dev, liam.merwick@oracle.com, maciej.wieczor-retman@intel.com, mail@maciej.szmigiero.name, maobibo@loongson.cn, mathieu.desnoyers@efficios.com, maz@kernel.org, mhiramat@kernel.org, mhocko@kernel.org, mic@digikod.net, michael.roth@amd.com, mingo@redhat.com, mlevitsk@redhat.com, mpe@ellerman.id.au, muchun.song@linux.dev, nikunj@amd.com, nsaenz@amazon.es, oliver.upton@linux.dev, palmer@dabbelt.com, pankaj.gupta@amd.com, paul.walmsley@sifive.com, pbonzini@redhat.com, peterx@redhat.com, pgonda@google.com, prsampat@amd.com, pvorel@suse.cz, qperret@google.com, richard.weiyang@gmail.com, rick.p.edgecombe@intel.com, rientjes@google.com, rostedt@goodmis.org, roypat@amazon.co.uk, rppt@kernel.org, shakeel.butt@linux.dev, shuah@kernel.org, steven.price@arm.com, steven.sistare@oracle.com, suzuki.poulose@arm.com, tabba@google.com, tglx@linutronix.de, thomas.lendacky@amd.com, vannapurve@google.com, vbabka@suse.cz, viro@zeniv.linux.org.uk, vkuznets@redhat.com, wei.w.wang@intel.com, will@kernel.org, willy@infradead.org, wyihan@google.com, xiaoyao.li@intel.com, yan.y.zhao@intel.com, yilun.xu@intel.com, yuzenghui@huawei.com, zhiquan1.li@intel.com Subject: Re: [RFC PATCH v1 05/37] KVM: guest_memfd: Wire up kvm_get_memory_attributes() to per-gmem attributes Message-ID: References: <071a3c6603809186e914fe5fed939edee4e11988.1760731772.git.ackerleytng@google.com> <07836b1d-d0d8-40f2-8f7b-7805beca31d0@amd.com> <20260129003753.GZ1641016@ziepe.ca> <20260203181618.GY2328995@ziepe.ca> <20260204124715.GA2328995@ziepe.ca> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260204124715.GA2328995@ziepe.ca> On Wed, Feb 04, 2026 at 08:47:15AM -0400, Jason Gunthorpe wrote: > On Wed, Feb 04, 2026 at 12:43:16PM +0800, Xu Yilun wrote: > > > Which means we need VFIO to know what they are, and hopefully it is > > > just static based on the TDISP reports.. > > > > I don't think VMM need to check TDISP report. The only special thing is > > the MSI-X mixed pages which can be figured out by standard PCI > > discovery. > > Either that or follow along with the guests's choices on > shared/private. > > We can't let VFIO mmap a private MMIO page, so it has to know which > pages are private at any moment, and it can't guess. No we could only let VFIO mmap MMIO pages that need emulation (like this MSI-X mixed page). MMIOs in such page cannot be assigned to guest so no way to convert to private. We don't allow VFIO mmap all asigned MMIO pages, no matter they will be private or shared. They are assigned to guest, so host don't touch them. Does that make sense? > > Jason