linux-kernel - Re: [patch 21/32] NTB/msi: Convert to msi_on_each

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: <0eab4c0e-c672-1138-2d95-3c9bee9ecdb1@intel.com>
Date:   Wed, 1 Dec 2021 15:53:46 -0700
From:   Dave Jiang <dave.jiang@...el.com>
To:     Thomas Gleixner <tglx@...utronix.de>,
        Jason Gunthorpe <jgg@...dia.com>
Cc:     Logan Gunthorpe <logang@...tatee.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Bjorn Helgaas <helgaas@...nel.org>,
        Marc Zygnier <maz@...nel.org>,
        Alex Williamson <alex.williamson@...hat.com>,
        Kevin Tian <kevin.tian@...el.com>,
        Megha Dey <megha.dey@...el.com>,
        Ashok Raj <ashok.raj@...el.com>, linux-pci@...r.kernel.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jon Mason <jdmason@...zu.us>, Allen Hubbe <allenbh@...il.com>,
        linux-ntb@...glegroups.com, linux-s390@...r.kernel.org,
        Heiko Carstens <hca@...ux.ibm.com>,
        Christian Borntraeger <borntraeger@...ibm.com>, x86@...nel.org,
        Joerg Roedel <jroedel@...e.de>,
        iommu@...ts.linux-foundation.org
Subject: Re: [patch 21/32] NTB/msi: Convert to msi_on_each_desc()


On 12/1/2021 3:03 PM, Thomas Gleixner wrote:
> On Wed, Dec 01 2021 at 14:49, Dave Jiang wrote:
>> On 12/1/2021 2:44 PM, Thomas Gleixner wrote:
>>> How that is backed on the host does not really matter. You can expose
>>> MSI-X to the guest with a INTx backing as well.
>>>
>>> I'm still failing to see the connection between the 9 MSIX vectors and
>>> the 2048 IMS vectors which I assume that this is the limitation of the
>>> physical device, right?
>> I think I was confused with what you were asking and was thinking you
>> are saying why can't we just have MSIX on guest backed by the MSIX on
>> the physical device and thought there would not be enough vectors to
>> service the many guests. I think I understand what your position is now
>> with the clarification above.
> This still depends on how this overall discussion about representation
> of all of this stuff is resolved.
>
>>> What needs a subdevice to expose?
> Can you answer that too please?

Sorry. So initial version of the IDXD sub-device is represented with a 
single queue. It needs a command irq (emulated) and a completion irq 
that is backed by a device vector (currently IMS).


>
> Thanks,
>
>          tglx