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Tsirkin" Cc: =?UTF-8?Q?Philippe_Mathieu-Daud=C3=A9?= , Marcel Apfelbaum , Alex Williamson , =?UTF-8?Q?C=C3=A9dric_Le_Goater?= , Paolo Bonzini , =?UTF-8?Q?Daniel_P=2E_Berrang=C3=A9?= , Eduardo Habkost , Sriram Yagnaraman , Jason Wang , Keith Busch , Klaus Jensen , qemu-devel@nongnu.org, qemu-block@nongnu.org References: <20240212-reuse-v3-0-8017b689ce7f@daynix.com> <20240212-reuse-v3-6-8017b689ce7f@daynix.com> <20240213060116-mutt-send-email-mst@kernel.org> From: Akihiko Odaki In-Reply-To: <20240213060116-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: none client-ip=2607:f8b0:4864:20::62e; envelope-from=akihiko.odaki@daynix.com; helo=mail-pl1-x62e.google.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_NONE=0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 2024/02/13 20:01, Michael S. Tsirkin wrote: > On Mon, Feb 12, 2024 at 07:20:34PM +0900, Akihiko Odaki wrote: >> Disable SR-IOV VF devices by reusing code to power down PCI devices >> instead of removing them when the guest requests to disable VFs. This >> allows to realize devices and report VF realization errors at PF >> realization time. >> >> Signed-off-by: Akihiko Odaki > > It is simpler for sure, but I am worried that all of these > unused VFs will consume lots of resources even if never > enabled. Thoughts? My rationale behind this change is that the resources should be allocated when the PF is realized to ensure the resources are available when the guest requests to enable VFs. When it is necessary to allocate resources dynamically, the conventional hotplug mechanism should be used instead since the SR-IOV interface is not designed to report resource allocation errors.