linux-kernel - RE: [RFC PATCH 1/5] nvme-pci: add function nvme_submit_vf_cmd to issue admin commands for VF driver.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <BL0PR11MB3042C010D7673B87C3C3C7B78A1C9@BL0PR11MB3042.namprd11.prod.outlook.com>
Date:   Fri, 9 Dec 2022 18:56:24 +0000
From:   "Dong, Eddie" <eddie.dong@...el.com>
To:     "Tian, Kevin" <kevin.tian@...el.com>,
        Jason Gunthorpe <jgg@...pe.ca>, Christoph Hellwig <hch@....de>
CC:     "Rao, Lei" <lei.rao@...el.com>,
        "kbusch@...nel.org" <kbusch@...nel.org>,
        "axboe@...com" <axboe@...com>, "kch@...dia.com" <kch@...dia.com>,
        "sagi@...mberg.me" <sagi@...mberg.me>,
        "alex.williamson@...hat.com" <alex.williamson@...hat.com>,
        "cohuck@...hat.com" <cohuck@...hat.com>,
        "yishaih@...dia.com" <yishaih@...dia.com>,
        "shameerali.kolothum.thodi@...wei.com" 
        <shameerali.kolothum.thodi@...wei.com>,
        "mjrosato@...ux.ibm.com" <mjrosato@...ux.ibm.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-nvme@...ts.infradead.org" <linux-nvme@...ts.infradead.org>,
        "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "Li, Yadong" <yadong.li@...el.com>,
        "Liu, Yi L" <yi.l.liu@...el.com>,
        "Wilk, Konrad" <konrad.wilk@...cle.com>,
        "stephen@...eticom.com" <stephen@...eticom.com>,
        "Yuan, Hang" <hang.yuan@...el.com>
Subject: RE: [RFC PATCH 1/5] nvme-pci: add function nvme_submit_vf_cmd to
 issue admin commands for VF driver.

> 
> If following the direction having controlling function to explicitly provide
> services then all those doorbells should be deprecated and instead we want
> explicit communications between VF driver and PF driver.

Hardware mechanism of communication (door bell here) can be used to 
support broader scenario when VF driver and PF driver run in 2 different
OS kernels (when the VF is assigned to a VM).

> 
> From userspace driver p.o.v. the VFIO uAPI is kind of a device programming
> interface. Here we just present everything related to the controlled device
> itself (including the state management) via a centralized portal though in the
> kernel there might be linkage out of VFIO to reach the controlling driver. kind
> of a sw doorbell. 😊

Yes.
And sw doorbell is more efficient than hardware doorbell 😊 .