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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: MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: eZRH8amtfOWN9C5qw9knGiOyihPjGsnOUCVWlNLquxM_1780948969 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: D84F1140006 X-Stat-Signature: gccubxf58x8s994a6s8g6euo7gqm6cfx X-Rspam-User: X-HE-Tag: 1780948972-905486 X-HE-Meta: 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 Z+PedRiN baQ38Onuk14jI1cBQe8JtbTAw8uRClABR/h+Bkp88/tJmmtldgdbqjgMI07Q0CGMDbcldrRt6qxPF801WzOGOK5BFhNn3HJDsR7Ljj1ynQ2nOtz6GCLtupKqc1I+rtRxhjO20rBw6/oC3/hWCe4ezJi/Bgc6d8//zsK6HG7xDlxNl27u7LZHAFVrccIlmUGTWiZjvpDkOxZ7oIdItVVktf8KJX8d6izzayXPD8JzVAtxlqTN2LQukDlg3fxlmQ9nwNUDz3hKH115Egq6fjoIn4UtISCs83rTo9Oxc2YEftHv7tuJ0W3O0I7Wl8uw3vZfVM19xtek1XjX37CuFXcHp5tcrvnmG57QIkqrU+0y5evH5FvfCX6oSyPDL8Q== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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