LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
To: Robin Murphy <robin.murphy@arm.com>,
	"joro@8bytes.org" <joro@8bytes.org>,
	"alex.williamson@redhat.com" <alex.williamson@redhat.com>
Cc: "yi.l.liu@linux.intel.com" <yi.l.liu@linux.intel.com>,
	"ashok.raj@intel.com" <ashok.raj@intel.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>
Subject: Re: [PATCH 3/4] iommu: Introduce device fault report API
Date: Fri, 31 May 2019 14:37:59 +0100	[thread overview]
Message-ID: <023acfae-5c93-9e20-8355-5cd7410c15e7@arm.com> (raw)
In-Reply-To: <e56244fd-86fd-1fc9-17f7-d00179d586ac@arm.com>

On 23/05/2019 19:56, Robin Murphy wrote:
> On 23/05/2019 19:06, Jean-Philippe Brucker wrote:
>> From: Jacob Pan <jacob.jun.pan@linux.intel.com>
>>
>> Traditionally, device specific faults are detected and handled within
>> their own device drivers. When IOMMU is enabled, faults such as DMA
>> related transactions are detected by IOMMU. There is no generic
>> reporting mechanism to report faults back to the in-kernel device
>> driver or the guest OS in case of assigned devices.
>>
>> This patch introduces a registration API for device specific fault
>> handlers. This differs from the existing iommu_set_fault_handler/
>> report_iommu_fault infrastructures in several ways:
>> - it allows to report more sophisticated fault events (both
>>    unrecoverable faults and page request faults) due to the nature
>>    of the iommu_fault struct
>> - it is device specific and not domain specific.
>>
>> The current iommu_report_device_fault() implementation only handles
>> the "shoot and forget" unrecoverable fault case. Handling of page
>> request faults or stalled faults will come later.
>>
>> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
>> Signed-off-by: Ashok Raj <ashok.raj@intel.com>
>> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>> ---
>>   drivers/iommu/iommu.c | 127 ++++++++++++++++++++++++++++++++++++++++++
>>   include/linux/iommu.h |  29 ++++++++++
>>   2 files changed, 156 insertions(+)
>>
>> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
>> index 67ee6623f9b2..d546f7baa0d4 100644
>> --- a/drivers/iommu/iommu.c
>> +++ b/drivers/iommu/iommu.c
>> @@ -644,6 +644,13 @@ int iommu_group_add_device(struct iommu_group *group, struct device *dev)
>>   		goto err_free_name;
>>   	}
>>   
>> +	dev->iommu_param = kzalloc(sizeof(*dev->iommu_param), GFP_KERNEL);
>> +	if (!dev->iommu_param) {
>> +		ret = -ENOMEM;
>> +		goto err_free_name;
>> +	}
>> +	mutex_init(&dev->iommu_param->lock);
>> +
> 
> Note that this gets a bit tricky when we come to move to move the 
> fwspec/ops/etc. into iommu_param, since that data can have a longer 
> lifespan than the group association. I'd suggest moving this management 
> out to the iommu_{probe,release}_device() level from the start, but 
> maybe we're happy to come back and change things later as necessary.

I'll do that, but iommu_probe_device() might still be too late.
According to of_iommu_configure() there might be cases where
iommu_probe_device() is called after iommu_fwspec_init(). So when moving
everything to iommu_param, we might need to introduce something like
iommu_get_dev_param() which allocates the param if it doesn't exist.

Thanks,
Jean

  parent reply	other threads:[~2019-05-31 13:38 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-23 18:06 [PATCH 0/4] iommu: Add device fault reporting API Jean-Philippe Brucker
2019-05-23 18:06 ` [PATCH 1/4] driver core: Add per device iommu param Jean-Philippe Brucker
2019-05-23 18:06 ` [PATCH 2/4] iommu: Introduce device fault data Jean-Philippe Brucker
2019-05-23 18:43   ` Robin Murphy
2019-05-24 13:49     ` Jacob Pan
2019-05-24 16:14       ` Jean-Philippe Brucker
2019-05-24 17:44         ` Jacob Pan
2019-05-23 18:06 ` [PATCH 3/4] iommu: Introduce device fault report API Jean-Philippe Brucker
2019-05-23 18:56   ` Robin Murphy
2019-05-24 18:00     ` Jacob Pan
2019-05-31 13:37     ` Jean-Philippe Brucker [this message]
2019-05-23 18:06 ` [PATCH 4/4] iommu: Add recoverable fault reporting Jean-Philippe Brucker
2019-05-24 18:14   ` Jacob Pan
2019-05-31 11:05     ` Jean-Philippe Brucker

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=023acfae-5c93-9e20-8355-5cd7410c15e7@arm.com \
    --to=jean-philippe.brucker@arm.com \
    --cc=alex.williamson@redhat.com \
    --cc=ashok.raj@intel.com \
    --cc=iommu@lists.linux-foundation.org \
    --cc=joro@8bytes.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=robin.murphy@arm.com \
    --cc=yi.l.liu@linux.intel.com \
    --subject='Re: [PATCH 3/4] iommu: Introduce device fault report API' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).