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[80.230.85.71]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-490bc3d663csm466704125e9.11.2026.06.08.13.02.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 08 Jun 2026 13:02:47 -0700 (PDT) Date: Mon, 8 Jun 2026 16:02:42 -0400 From: "Michael S. Tsirkin" To: Matthew Wilcox Cc: linux-kernel@vger.kernel.org, "David Hildenbrand (Arm)" , Jason Wang , Xuan Zhuo , Eugenio =?iso-8859-1?Q?P=E9rez?= , Muchun Song , Oscar Salvador , Andrew Morton , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Hugh Dickins , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Christoph Lameter , David Rientjes , Roman Gushchin , Harry Yoo , Axel Rasmussen , Yuanchu Xie , Wei Xu , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , virtualization@lists.linux.dev, linux-mm@kvack.org, Andrea Arcangeli Subject: Re: [PATCH v10 00/37] mm/virtio: skip redundant zeroing of host-zeroed pages Message-ID: <20260608155918-mutt-send-email-mst@kernel.org> References: Precedence: bulk X-Mailing-List: linux-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: On Mon, Jun 08, 2026 at 03:21:25PM +0100, Matthew Wilcox wrote: > On Mon, Jun 08, 2026 at 04:33:46AM -0400, Michael S. Tsirkin wrote: > > Further, on architectures with aliasing caches, upstream with init_on_alloc > > Further to what? Did you leave out some paragraphs here? > > As far as I can tell, this patch series decides to trust that the > hypervisor has zeroed pages that it allocates to the guest. But > as far as I can tell, the trend is towards less trust in the hypervisor > from the guest, not more. AKA confidential computing. I'm not a visionary, no idea about trends, but yes these are used more than in the past (not hard given it used to be 0% of the market in the past). Page reporting already leaks some info like free page addresses, so it's for trusted hypervisors. Anyway: Subject: [PATCH v10 35/37] virtio_balloon: disable reporting zeroed optimization for confidential guests makes sure guests that do not trust hypervisors are not affected. -- MST