linux-kernel - Re: [PATCH v4 3/3] iommu: Drop sw_msi from iommu

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 for Android: free password hash cracker in your pocket

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

Message-ID: <Z+G67avxHQt5L+62@nvidia.com>
Date: Mon, 24 Mar 2025 17:05:01 -0300
From: Jason Gunthorpe <jgg@...dia.com>
To: Nathan Chancellor <nathan@...nel.org>
Cc: Nicolin Chen <nicolinc@...dia.com>, kevin.tian@...el.com,
	robin.murphy@....com, joro@...tes.org, will@...nel.org,
	iommu@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 3/3] iommu: Drop sw_msi from iommu_domain

On Mon, Mar 24, 2025 at 10:07:43AM -0700, Nathan Chancellor wrote:

> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 0f4cc15ded1c..2b81166350ae 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -3661,7 +3661,6 @@ int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr)
>  			ret = iommufd_sw_msi(group->domain, desc, msi_addr);
>  			break;
>  		default:
> -			ret = -EOPNOTSUPP;
>  			break;
>  		}
>  	}

Can we explain why this scenario has a 0 cookie_type?

Actually.. Is it just an identity domain? Nicolin did you test this on
your arm system with a device using identity (iommu=pt kernel param)?
I would expect identity to end up with a 0 cookie because we never
setup dma-iommu.c code on it.

Should we be testing for identity to return 0 instead?

Jason