From: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
To: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Eric Auger <eric.auger@redhat.com>,
"eric.auger.pro@gmail.com" <eric.auger.pro@gmail.com>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"kvmarm@lists.cs.columbia.edu" <kvmarm@lists.cs.columbia.edu>,
"joro@8bytes.org" <joro@8bytes.org>,
"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
"yi.l.liu@linux.intel.com" <yi.l.liu@linux.intel.com>,
Will Deacon <Will.Deacon@arm.com>,
Robin Murphy <Robin.Murphy@arm.com>,
Marc Zyngier <Marc.Zyngier@arm.com>,
"peter.maydell@linaro.org" <peter.maydell@linaro.org>,
"kevin.tian@intel.com" <kevin.tian@intel.com>,
"ashok.raj@intel.com" <ashok.raj@intel.com>,
Christoffer Dall <Christoffer.Dall@a>
Subject: Re: [PATCH v4 03/22] iommu: introduce device fault report API
Date: Thu, 7 Mar 2019 11:42:59 +0000 [thread overview]
Message-ID: <1500594f-d7ea-94f2-01aa-0dc0e08b391b@arm.com> (raw)
In-Reply-To: <20190306154616.648e2523@jacob-builder>
On 06/03/2019 23:46, Jacob Pan wrote:
> On Tue, 5 Mar 2019 15:03:41 +0000
> Jean-Philippe Brucker <jean-philippe.brucker@arm.com> wrote:
>
>> On 18/02/2019 13:54, Eric Auger wrote:
>> [...]> +/**
>> > + * iommu_register_device_fault_handler() - Register a device fault
>> > handler
>> > + * @dev: the device
>> > + * @handler: the fault handler
>> > + * @data: private data passed as argument to the handler
>> > + *
>> > + * When an IOMMU fault event is received, call this handler with
>> > the fault event
>> > + * and data as argument. The handler should return 0 on success.
>> > If the fault is
>> > + * recoverable (IOMMU_FAULT_PAGE_REQ), the handler can also
>> > complete
>> > + * the fault by calling iommu_page_response() with one of the
>> > following
>> > + * response code:
>> > + * - IOMMU_PAGE_RESP_SUCCESS: retry the translation
>> > + * - IOMMU_PAGE_RESP_INVALID: terminate the fault
>> > + * - IOMMU_PAGE_RESP_FAILURE: terminate the fault and stop
>> > reporting
>> > + * page faults if possible.
>>
>> The comment refers to function and values that haven't been defined
>> yet. Either the page_response() patch should come before, or we need
>> to split this patch.
>>
>> Something I missed before: if the handler fails (returns != 0) it
>> should complete the fault by calling iommu_page_response(), if we're
>> not doing it in iommu_report_device_fault(). It should be indicated
>> in this comment. It's safe for the handler to call page_response()
>> since we're not holding fault_param->lock when calling the handler.
>>
> If the page request fault is to be reported to a guest, the report
> function cannot wait for the completion status. As long as the fault is
> injected into the guest, the handler should complete with success. If
> the PRQ report fails, IMHO, the caller of iommu_report_device_fault()
> should send page_response, perhaps after clean up all partial response
> of the group too.
Ok, the caller (IOMMU driver) sending the page_response if
iommu_report_device_fault() fails does make more sense. Agreed on the
partial cleanup as well, we don't keep track of them here, but I need to
add that to the io-pgfault layer. However some cleanup should probably
happen in here...
>> > + /* we only report device fault if there is a handler
>> > registered */
>> > + mutex_lock(&dev->iommu_param->lock);
>> > + if (!dev->iommu_param->fault_param ||
>> > + !dev->iommu_param->fault_param->handler) {
>> > + ret = -EINVAL;
>> > + goto done_unlock;
>> > + }
>> > + fparam = dev->iommu_param->fault_param;
>> > + if (evt->fault.type == IOMMU_FAULT_PAGE_REQ &&
>> > + evt->fault.prm.flags &
>> > IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE) {
>> > + evt_pending = kmemdup(evt, sizeof(struct
>> > iommu_fault_event),
>> > + GFP_KERNEL);
>> > + if (!evt_pending) {
>> > + ret = -ENOMEM;
>> > + goto done_unlock;
>> > + }
>> > + mutex_lock(&fparam->lock);
>> > + list_add_tail(&evt_pending->list, &fparam->faults);
>> > + mutex_unlock(&fparam->lock);
>> > + }
>> > + ret = fparam->handler(evt, fparam->data);
... if ret != 0, removing and freeing the pending event seems more
appropriate here than asking our caller to do it
Thanks,
Jean
>> > +done_unlock:
>> > + mutex_unlock(&dev->iommu_param->lock);
>> > + return ret;
>> > +}
>> > +EXPORT_SYMBOL_GPL(iommu_report_device_fault);
>> [...]
>
> [Jacob Pan]
next prev parent reply other threads:[~2019-03-07 11:42 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-18 13:54 [PATCH v4 00/22] SMMUv3 Nested Stage Setup Eric Auger
2019-02-18 13:54 ` [PATCH v4 01/22] driver core: add per device iommu param Eric Auger
2019-02-18 13:54 ` [PATCH v4 02/22] iommu: introduce device fault data Eric Auger
2019-03-05 14:56 ` Jean-Philippe Brucker
2019-03-06 9:38 ` Auger Eric
2019-03-06 12:08 ` Jean-Philippe Brucker
2019-03-06 11:03 ` Auger Eric
2019-03-06 14:30 ` Auger Eric
2019-03-06 16:07 ` Jean-Philippe Brucker
2019-03-06 17:32 ` Auger Eric
2019-02-18 13:54 ` [PATCH v4 03/22] iommu: introduce device fault report API Eric Auger
2019-03-05 15:03 ` Jean-Philippe Brucker
2019-03-06 23:46 ` Jacob Pan
2019-03-07 11:42 ` Jean-Philippe Brucker [this message]
2019-02-18 13:54 ` [PATCH v4 04/22] iommu: Introduce attach/detach_pasid_table API Eric Auger
2019-03-05 15:23 ` Jean-Philippe Brucker
2019-03-05 18:15 ` Auger Eric
2019-02-18 13:54 ` [PATCH v4 05/22] iommu: Introduce cache_invalidate API Eric Auger
2019-03-05 15:28 ` Jean-Philippe Brucker
2019-03-05 18:14 ` Auger Eric
[not found] ` <0e041735-98e8-1d8c-c866-ad23e6cc1db5-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2019-03-06 21:59 ` Jacob Pan
2019-02-18 13:54 ` [PATCH v4 06/22] iommu: Introduce bind/unbind_guest_msi Eric Auger
2019-02-18 13:54 ` [PATCH v4 07/22] vfio: VFIO_IOMMU_ATTACH/DETACH_PASID_TABLE Eric Auger
2019-02-18 13:54 ` [PATCH v4 08/22] vfio: VFIO_IOMMU_CACHE_INVALIDATE Eric Auger
2019-02-18 13:54 ` [PATCH v4 09/22] vfio: VFIO_IOMMU_BIND/UNBIND_MSI Eric Auger
2019-02-18 13:54 ` [PATCH v4 10/22] iommu/arm-smmu-v3: Link domains and devices Eric Auger
2019-02-18 13:54 ` [PATCH v4 11/22] iommu/arm-smmu-v3: Maintain a SID->device structure Eric Auger
2019-02-18 13:54 ` [PATCH v4 12/22] iommu/smmuv3: Get prepared for nested stage support Eric Auger
2019-02-18 13:54 ` [PATCH v4 13/22] iommu/smmuv3: Implement attach/detach_pasid_table Eric Auger
2019-02-18 13:54 ` [PATCH v4 14/22] iommu/smmuv3: Implement cache_invalidate Eric Auger
2019-02-18 13:54 ` [PATCH v4 15/22] dma-iommu: Implement NESTED_MSI cookie Eric Auger
2019-02-18 13:54 ` [PATCH v4 16/22] iommu/smmuv3: Implement bind/unbind_guest_msi Eric Auger
2019-02-18 13:54 ` [PATCH v4 17/22] iommu/smmuv3: Report non recoverable faults Eric Auger
2019-02-18 13:54 ` [PATCH v4 18/22] vfio-pci: Add a new VFIO_REGION_TYPE_NESTED region type Eric Auger
2019-02-18 13:55 ` [PATCH v4 19/22] vfio-pci: Register an iommu fault handler Eric Auger
2019-02-25 14:22 ` Vincent Stehlé
2019-02-25 17:30 ` Auger Eric
2019-02-18 13:55 ` [PATCH v4 20/22] vfio_pci: Allow to mmap the fault queue Eric Auger
2019-02-18 13:55 ` [PATCH v4 21/22] vfio-pci: Add VFIO_PCI_DMA_FAULT_IRQ_INDEX Eric Auger
2019-02-18 13:55 ` [PATCH v4 22/22] vfio: Document nested stage control Eric Auger
2019-03-05 8:07 ` [PATCH v4 00/22] SMMUv3 Nested Stage Setup Auger Eric
2019-03-05 16:42 ` Auger Eric
2019-06-09 13:44 [PATCH v4 00/22] Shared virtual address IOMMU and VT-d support Jacob Pan
2019-06-09 13:44 ` [PATCH v4 03/22] iommu: Introduce device fault report API Jacob Pan
2019-06-18 15:41 ` Jonathan Cameron
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=1500594f-d7ea-94f2-01aa-0dc0e08b391b@arm.com \
--to=jean-philippe.brucker@arm.com \
--cc=Christoffer.Dall@a \
--cc=Marc.Zyngier@arm.com \
--cc=Robin.Murphy@arm.com \
--cc=Will.Deacon@arm.com \
--cc=alex.williamson@redhat.com \
--cc=ashok.raj@intel.com \
--cc=eric.auger.pro@gmail.com \
--cc=eric.auger@redhat.com \
--cc=iommu@lists.linux-foundation.org \
--cc=jacob.jun.pan@linux.intel.com \
--cc=joro@8bytes.org \
--cc=kevin.tian@intel.com \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=linux-kernel@vger.kernel.org \
--cc=peter.maydell@linaro.org \
--cc=yi.l.liu@linux.intel.com \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
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).