linux-kernel - Re: [PATCH v3 11/23] iommufd/viommu: Add IOMMUFD_CMD_VQUEUE

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: <2356ff85-6651-47d9-90c7-f8cbf43b053b@amd.com>
Date: Thu, 8 May 2025 10:16:51 +0530
From: Vasant Hegde <vasant.hegde@....com>
To: Jason Gunthorpe <jgg@...dia.com>
Cc: Nicolin Chen <nicolinc@...dia.com>, kevin.tian@...el.com, corbet@....net,
 will@...nel.org, bagasdotme@...il.com, robin.murphy@....com,
 joro@...tes.org, thierry.reding@...il.com, vdumpa@...dia.com,
 jonathanh@...dia.com, shuah@...nel.org, jsnitsel@...hat.com,
 nathan@...nel.org, peterz@...radead.org, yi.l.liu@...el.com,
 mshavit@...gle.com, praan@...gle.com, zhangzekun11@...wei.com,
 iommu@...ts.linux.dev, linux-doc@...r.kernel.org,
 linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
 linux-tegra@...r.kernel.org, linux-kselftest@...r.kernel.org,
 patches@...ts.linux.dev, mochs@...dia.com, alok.a.tiwari@...cle.com,
 Suravee Suthikulpanit <suravee.suthikulpanit@....com>
Subject: Re: [PATCH v3 11/23] iommufd/viommu: Add IOMMUFD_CMD_VQUEUE_ALLOC
 ioctl

Jason,

On 5/7/2025 6:01 PM, Jason Gunthorpe wrote:
> On Wed, May 07, 2025 at 01:11:43PM +0530, Vasant Hegde wrote:
>>   -  MMIO Offset 0018h IOMMU Control Register
>>      EventLogEn: Event log enable
>>        * When guest sets this bit, qemu will trap and will send queue_alloc
>>        * When guest disables this bit, qemu will trap and send vqueue_destroy
>>
>>      This part is fine.
> 
> Ok
> 
>>      EventIntEn: Event log interrupt enable
>>        * When guest sets this bit, qemu will trap
>>        * this needs to be communicated to Host so that we can program VF Control
>> BAR and enable the interrupt
> 
> This sounds like modifying the vqueue? Or maybe on the viommu?

IMO its VIOMMU as it informs HW to trigger interrupt or not.


> 
>>   - There is other bit "Completion wait interrupt enable"
>>     This doesn't related to any buffer. Instead if we configure this for
>> completion wait command it will generate interrupt.
> 
> This sounds like a modify on the VIOMMU object?

Again in my view its VIOMMU object as it tells HW what to do when it finishes
completion wait command.

-Vasant