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Tsirkin" Cc: linux-kernel@vger.kernel.org, Jason Wang , Xuan Zhuo , =?UTF-8?Q?Eugenio_P=C3=A9rez?= , Adam Litke , Rusty Russell , virtualization@lists.linux.dev, Andrew Morton , linux-mm@kvack.org References: <2f0d0de033f3005d3b985883be3e5cf37b3f6c42.1783278596.git.mst@redhat.com> <13794c5e-375a-4fc5-84b4-a637d077f8a0@kernel.org> <20260706042207-mutt-send-email-mst@kernel.org> <6b8e4ad3-6909-4d0a-89a4-104a5ad9fe79@kernel.org> <20260706044122-mutt-send-email-mst@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <20260706044122-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: EE6CB120003 X-Stat-Signature: yq87eqaifq5f5a7kjgbwkeu8qgb9fknf X-HE-Tag: 1783328258-391080 X-HE-Meta: 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 Fgt5gMH6 aET7ORmciaW+G/hiefuSQ7xqIhGcpMi2Ymh0mEZcy9DOdRwi2Dm/T40H8C2ALcn/NrMJgYaR8f874euCU3Nre6U5MfsUsQFTiQdxfdITPrV78B4kmP0g+855w1evOZh+MOtPrJupZymwnoJ2MjKWFA3SI3hgR1AxSSVCU9SeQR1EO9eRFixvyJI3/m2zqOYy54J6h7SiMA/CAIb7SvdHYM9GYebTXUp8UyD8FzOHWEmy8e5nP1voFRPr82alDl4wEOGYt7ydTM6qs8BnShrsfMAeEHSbA7k0u+bKSbNZo7JuXGlmxJsZUbQpbWw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 7/6/26 10:43, Michael S. Tsirkin wrote: > On Mon, Jul 06, 2026 at 10:38:18AM +0200, David Hildenbrand (Arm) wrote: >>> >>> Yes. >>> >>> >>> Why not? >> >> I was wondering whether the spec would state something about that. > > Sorry I do not get the question. Virtio API expects > callers to serialize calls for each VQ. So this just prevents the work > from running and accessing the VQ while probe calls add_buf/kick. > I'll add a comment explaining that. > But it has nothing to do with the spec. The device is clearly not properly initialized yet. Yet, we expect that we get a stats_request() callback that would try to queue_work(). And IIUC, the stats_request() will be directly issued by the device. In QEMU, that would mean that balloon_stats_poll_cb() runs, which would do a if (s->stats_vq_elem == NULL) { ... return } virtqueue_push(s->svq, s->stats_vq_elem, 0); virtio_notify(vdev, s->svq); That's why I'm confused :) -- Cheers, David