From: Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
To: Frank Blaschka
<blaschka-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
Cc: linux-s390-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
sebott-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
schwidefsky-tA70FqPdS9bQT0dZR+AlfA@public.gmane.org,
gerald.schaefer-tA70FqPdS9bQT0dZR+AlfA@public.gmane.org
Subject: Re: [PATCH linux-next] iommu: add iommu for s390 platform
Date: Wed, 22 Oct 2014 16:17:29 +0200 [thread overview]
Message-ID: <20141022141728.GG10074@8bytes.org> (raw)
In-Reply-To: <1413892645-37657-1-git-send-email-blaschka-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
Hi Frank,
On Tue, Oct 21, 2014 at 01:57:25PM +0200, Frank Blaschka wrote:
> Add a basic iommu for the s390 platform. The code is pretty simple
> since on s390 each PCI device has its own virtual io address space
> starting at the same vio address.
Are there any limitations on IOVA address space for the devices or can
be really any system physical address mapped starting from 0 to 2^64?
> For this a domain could hold only one pci device.
This bothers me, as it is not compatible with the IOMMU-API. I looked a
little bit into how the mappings are created, and it seems there is a
per-device dma_table.
Is there any reason a dma_table can't be per IOMMU domain and assigned
to multiple devices at the same time?
Otherwise the code looks quite simple and straight forward.
Joerg
WARNING: multiple messages have this Message-ID (diff)
From: Joerg Roedel <joro@8bytes.org>
To: Frank Blaschka <blaschka@linux.vnet.ibm.com>
Cc: schwidefsky@de.ibm.com, linux-kernel@vger.kernel.org,
linux-s390@vger.kernel.org, iommu@lists.linux-foundation.org,
sebott@linux.vnet.ibm.com, gerald.schaefer@de.ibm.com
Subject: Re: [PATCH linux-next] iommu: add iommu for s390 platform
Date: Wed, 22 Oct 2014 16:17:29 +0200 [thread overview]
Message-ID: <20141022141728.GG10074@8bytes.org> (raw)
In-Reply-To: <1413892645-37657-1-git-send-email-blaschka@linux.vnet.ibm.com>
Hi Frank,
On Tue, Oct 21, 2014 at 01:57:25PM +0200, Frank Blaschka wrote:
> Add a basic iommu for the s390 platform. The code is pretty simple
> since on s390 each PCI device has its own virtual io address space
> starting at the same vio address.
Are there any limitations on IOVA address space for the devices or can
be really any system physical address mapped starting from 0 to 2^64?
> For this a domain could hold only one pci device.
This bothers me, as it is not compatible with the IOMMU-API. I looked a
little bit into how the mappings are created, and it seems there is a
per-device dma_table.
Is there any reason a dma_table can't be per IOMMU domain and assigned
to multiple devices at the same time?
Otherwise the code looks quite simple and straight forward.
Joerg
next prev parent reply other threads:[~2014-10-22 14:17 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-21 11:57 [PATCH linux-next] iommu: add iommu for s390 platform Frank Blaschka
[not found] ` <1413892645-37657-1-git-send-email-blaschka-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2014-10-22 14:17 ` Joerg Roedel [this message]
2014-10-22 14:17 ` Joerg Roedel
2014-10-22 15:43 ` Frank Blaschka
[not found] ` <20141022154320.GA42442-++28Fms/gMmXI4yAdoq52KN5r0PSdgG1zG2AekJRRhI@public.gmane.org>
2014-10-23 12:41 ` Joerg Roedel
2014-10-23 12:41 ` Joerg Roedel
[not found] ` <20141023124115.GB10053-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
2014-10-23 14:04 ` Frank Blaschka
2014-10-23 14:04 ` Frank Blaschka
[not found] ` <20141023140437.GA31009-++28Fms/gMmXI4yAdoq52KN5r0PSdgG1zG2AekJRRhI@public.gmane.org>
2014-10-24 23:33 ` Joerg Roedel
2014-10-24 23:33 ` Joerg Roedel
2014-10-27 14:32 ` Gerald Schaefer
2014-10-27 16:25 ` Joerg Roedel
2014-10-27 16:25 ` Joerg Roedel
[not found] ` <20141027162502.GB6202-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
2014-10-27 17:02 ` Gerald Schaefer
2014-10-27 17:02 ` Gerald Schaefer
2014-10-27 17:58 ` Joerg Roedel
2014-10-27 17:58 ` Joerg Roedel
[not found] ` <20141027175835.GC6202-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
2014-10-27 18:18 ` Gerald Schaefer
2014-10-27 18:18 ` Gerald Schaefer
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