From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Parav Pandit Subject: RE: [PATCH 1/5] Add virtio Admin Virtqueue specification Date: Tue, 18 Jan 2022 08:23:57 +0000 Message-ID: References: <20220113145103.26894-1-mgurtovoy@nvidia.com> <20220113145103.26894-2-mgurtovoy@nvidia.com> <20220113124137-mutt-send-email-mst@kernel.org> <4946a0fe-70f0-43cc-6730-f8ab0f3d8687@nvidia.com> <20220117160951-mutt-send-email-mst@kernel.org> <20220118011334-mutt-send-email-mst@kernel.org> <20220118030205-mutt-send-email-mst@kernel.org> In-Reply-To: <20220118030205-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable To: "Michael S. Tsirkin" Cc: Max Gurtovoy , "cohuck@redhat.com" , "virtio-dev@lists.oasis-open.org" , "jasowang@redhat.com" , Shahaf Shuler , Oren Duer , "stefanha@redhat.com" List-ID: > From: Michael S. Tsirkin > Sent: Tuesday, January 18, 2022 1:36 PM [..] > > > > > You can map it to a queue, yes. But something static and read > > > > > only such as list of commands maps well to config space. And > > > > > it's not controlling one device from another, so does not really > > > > > seem to belong in > > > the admin queue. > > > > > > > > > Aq serves the writing device config too in patch-5 in this patchset= . > > > > > > List of available admin commands does not need to be written. > > > > > It is not written into the aq commands. > > It is part of the feature bit VIRTIO_F_ADMIN_PCI_VIRT_MANAGER indicatin= g > a given functionality supported or not in patch-5. >=20 >=20 > Btw I don't see what does "VIRT_MANAGER" mean here. "manager" is just a > generic thing that means nothing, and VIRT just repeats VIRTIO. >=20 VIRT doesn't repeat VIRTIO. VIRT indicates PCI virtual functions. Manager is generic thing to manage. Below is the snippet from patch-5.=20 + \item[VIRTIO_F_ADMIN_PCI_VIRT_MANAGER (44)] This feature indicates =20 + that the device can manage PCI related capabilities for its managed=20 + PCI VF devices and supports VIRTIO_ADMIN_PCI_VIRT_MGMT_ATTR_IDENTIFY, + VIRTIO_ADMIN_PCI_VIRT_PROPERTY_SET and=20 + VIRTIO_ADMIN_PCI_VIRT_PROPERTY_GET + admin commands. This feature can be supported only by PCI devices. + >=20 > > And structure like, virtio_admin_pci_virt_mgmt_attr_identify_result can > potentially grow and storing those fields on on-chip resource is less eff= icient. > > Hence, they are shared via AQ. >=20 > The issue is this: VIRTIO_F_ADMIN_PCI_VIRT_MANAGER seems to mean there > are pci related admin commands. OK I guess.=20 Right. > However you then say this same > feature bit implies generic functionality like list of supported commands= . > Confusing. > Not sure where I mentioned generic functionality. This feature bit implies pci virtualization related functionality by means = of above listed commands.