iommu.lists.linux-foundation.org archive mirror
 help / color / mirror / Atom feed
From: Jean-Philippe Brucker <jean-philippe@linaro.org>
To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
Cc: "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"kevin.tian@intel.com" <kevin.tian@intel.com>,
	"will@kernel.org" <will@kernel.org>,
	"fenghua.yu@intel.com" <fenghua.yu@intel.com>,
	"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
	"felix.kuehling@amd.com" <felix.kuehling@amd.com>,
	"hch@infradead.org" <hch@infradead.org>,
	"jgg@ziepe.ca" <jgg@ziepe.ca>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
	"zhangfei.gao@linaro.org" <zhangfei.gao@linaro.org>,
	"robin.murphy@arm.com" <robin.murphy@arm.com>,
	"christian.koenig@amd.com" <christian.koenig@amd.com>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v7 21/24] iommu/arm-smmu-v3: Add stall support for platform devices
Date: Wed, 3 Jun 2020 09:38:51 +0200	[thread overview]
Message-ID: <20200603073851.GA3198@myrica> (raw)
In-Reply-To: <c165fe41230f49baba991f1a416a4739@huawei.com>

On Tue, Jun 02, 2020 at 12:12:30PM +0000, Shameerali Kolothum Thodi wrote:
> > > > > > +		if (ssid_valid)
> > > > > > +			flt->prm.flags |=
> > > > IOMMU_FAULT_PAGE_REQUEST_PASID_VALID;
> > > > >
> > > > > Do we need to set this for STALL mode only support? I had an issue
> > > > > with this being set on a vSVA POC based on our D06 zip
> > > > > device(which is a "fake " pci dev that supports STALL mode but no
> > > > > PRI). The issue is, CMDQ_OP_RESUME doesn't have any ssid or SSV
> > > > > params and works on sid
> > > > and stag only.
> > > >
> > > > I don't understand the problem, arm_smmu_page_response() doesn't set
> > > > SSID or SSV when sending a CMDQ_OP_RESUME. Could you detail the flow
> > > > of a stall event and RESUME command in your prototype?  Are you
> > > > getting issues with the host driver or the guest driver?
> > >
> > > The issue is on the host side iommu_page_response(). The flow is
> > > something like below.
> > >
> > > Stall: Host:-
> > >
> > > arm_smmu_handle_evt()
> > >   iommu_report_device_fault()
> > >     vfio_pci_iommu_dev_fault_handler()
> > >
> > > Stall: Qemu:-
> > >
> > > vfio_dma_fault_notifier_handler()
> > >   inject_faults()
> > >     smmuv3_inject_faults()
> > >
> > > Stall: Guest:-
> > >
> > > arm_smmu_handle_evt()
> > >   iommu_report_device_fault()
> > >     iommu_queue_iopf
> > >   ...
> > >   iopf_handle_group()
> > >     iopf_handle_single()
> > >       handle_mm_fault()
> > >         iopf_complete()
> > >            iommu_page_response()
> > >              arm_smmu_page_response()
> > >                arm_smmu_cmdq_issue_cmd(CMDQ_OP_RESUME)
> > >
> > > Resume: Qemu:-
> > >
> > > smmuv3_cmdq_consume(SMMU_CMD_RESUME)
> > >   smmuv3_notify_page_resp()
> > >     vfio:ioctl(page_response)  --> struct iommu_page_response is filled
> > >                              with only version, grpid and code.
> > >
> > > Resume: Host:-
> > >   ioctl(page_response)
> > >     iommu_page_response()  --> fails as the pending req has PASID_VALID
> > flag
> > >                              set and it checks for a match.
> > 
> > I believe the fix needs to be here. It's also wrong for PRI since not all PCIe
> > endpoint require a PASID in the page response. Could you try the attached
> > patch?
> 
> Going through the patch, yes, that will definitely fix the issue. But isn't it better if
> the request itself indicate whether it expects a response msg with a valid pasid or
> not? The response msg can come from userspace as well(vSVA) and if for some reason
> doesn't set it for a req that expects pasid then it should be an error, right? In the temp
> fix I had, I introduced another flag to indicate the endpoint has PRI support or not and
> used that to verify the pasid requirement. But for the PRI case you mentioned 
> above, not sure it is easy to get that information or not. May be I am complicating things
> here :)

No you're right, we shouldn't send back malformed responses to the SMMU. I
suppose we can store a flag "PASID required" in the fault and check that
against the response. If we have to discard the guest's response, then we
can either fake a response (abort the stall) right away, or wait for the
response timeout to kick, which will do the same.

Thanks,
Jean
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

  reply	other threads:[~2020-06-03  7:39 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-19 17:54 [PATCH v7 00/24] iommu: Shared Virtual Addressing for SMMUv3 Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 01/24] mm: Add a PASID field to mm_struct Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 02/24] iommu/ioasid: Add ioasid references Jean-Philippe Brucker
2020-05-20  2:31   ` Lu Baolu
2020-05-19 17:54 ` [PATCH v7 03/24] iommu/sva: Add PASID helpers Jean-Philippe Brucker
2020-05-20  2:41   ` Lu Baolu
2020-05-19 17:54 ` [PATCH v7 04/24] iommu: Add a page fault handler Jean-Philippe Brucker
2020-05-20  6:42   ` Lu Baolu
2020-11-11 13:57     ` Jean-Philippe Brucker
2020-11-11 23:11       ` Lu Baolu
2020-05-29  9:18   ` Xiang Zheng
2020-11-11 13:57     ` Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 05/24] arm64: mm: Add asid_gen_match() helper Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 06/24] arm64: mm: Pin down ASIDs for sharing mm with devices Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 07/24] iommu/io-pgtable-arm: Move some definitions to a header Jean-Philippe Brucker
2020-05-21 14:16   ` Will Deacon
2020-05-19 17:54 ` [PATCH v7 08/24] iommu/arm-smmu-v3: Manage ASIDs with xarray Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 09/24] arm64: cpufeature: Export symbol read_sanitised_ftr_reg() Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 10/24] iommu/arm-smmu-v3: Share process page tables Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 11/24] iommu/arm-smmu-v3: Seize private ASID Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 12/24] iommu/arm-smmu-v3: Add support for VHE Jean-Philippe Brucker
2020-05-21 14:16   ` Will Deacon
2020-05-19 17:54 ` [PATCH v7 13/24] iommu/arm-smmu-v3: Enable broadcast TLB maintenance Jean-Philippe Brucker
2020-05-21 14:17   ` Will Deacon
2020-05-21 14:38     ` Marc Zyngier
2020-05-22 10:17       ` Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 14/24] iommu/arm-smmu-v3: Add SVA feature checking Jean-Philippe Brucker
2020-05-21 14:17   ` Will Deacon
2020-05-19 17:54 ` [PATCH v7 15/24] iommu/arm-smmu-v3: Add SVA device feature Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 16/24] iommu/arm-smmu-v3: Implement iommu_sva_bind/unbind() Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 17/24] iommu/arm-smmu-v3: Hook up ATC invalidation to mm ops Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 18/24] iommu/arm-smmu-v3: Add support for Hardware Translation Table Update Jean-Philippe Brucker
2020-05-21 11:12   ` Will Deacon
2020-05-27  3:00   ` Xiang Zheng
2020-05-27  8:41     ` Jean-Philippe Brucker
2020-08-28  9:28   ` Zenghui Yu
2020-09-16 14:11     ` Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 19/24] iommu/arm-smmu-v3: Maintain a SID->device structure Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 20/24] dt-bindings: document stall property for IOMMU masters Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 21/24] iommu/arm-smmu-v3: Add stall support for platform devices Jean-Philippe Brucker
2020-06-01 12:42   ` Shameerali Kolothum Thodi
2020-06-02  9:38     ` Jean-Philippe Brucker
2020-06-02 10:31       ` Shameerali Kolothum Thodi
2020-06-02 11:46         ` Jean-Philippe Brucker
2020-06-02 12:12           ` Shameerali Kolothum Thodi
2020-06-03  7:38             ` Jean-Philippe Brucker [this message]
2020-05-19 17:55 ` [PATCH v7 22/24] PCI/ATS: Add PRI stubs Jean-Philippe Brucker
2020-05-19 17:55 ` [PATCH v7 23/24] PCI/ATS: Export PRI functions Jean-Philippe Brucker
2020-05-19 17:55 ` [PATCH v7 24/24] iommu/arm-smmu-v3: Add support for PRI Jean-Philippe Brucker
2020-05-21 10:35 ` [PATCH v7 00/24] iommu: Shared Virtual Addressing for SMMUv3 Will Deacon
2020-05-21 14:17   ` Will Deacon

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=20200603073851.GA3198@myrica \
    --to=jean-philippe@linaro.org \
    --cc=catalin.marinas@arm.com \
    --cc=christian.koenig@amd.com \
    --cc=devicetree@vger.kernel.org \
    --cc=felix.kuehling@amd.com \
    --cc=fenghua.yu@intel.com \
    --cc=hch@infradead.org \
    --cc=iommu@lists.linux-foundation.org \
    --cc=jgg@ziepe.ca \
    --cc=kevin.tian@intel.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=robin.murphy@arm.com \
    --cc=shameerali.kolothum.thodi@huawei.com \
    --cc=will@kernel.org \
    --cc=zhangfei.gao@linaro.org \
    --subject='Re: [PATCH v7 21/24] iommu/arm-smmu-v3: Add stall support for platform devices' \
    /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).