From: Nicolin Chen <nicolinc@nvidia.com>
To: Robin Murphy <robin.murphy@arm.com>
Cc: <jgg@nvidia.com>, <will@kernel.org>, <eric.auger@redhat.com>,
<kevin.tian@intel.com>, <baolu.lu@linux.intel.com>,
<joro@8bytes.org>, <shameerali.kolothum.thodi@huawei.com>,
<jean-philippe@linaro.org>,
<linux-arm-kernel@lists.infradead.org>, <iommu@lists.linux.dev>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1 04/14] iommu/arm-smmu-v3: Add arm_smmu_hw_info
Date: Wed, 15 Mar 2023 17:13:25 -0700 [thread overview]
Message-ID: <ZBJfJUjbAUId68s1@Asurada-Nvidia> (raw)
In-Reply-To: <5cc56149-965a-bb47-f23f-6aa9d0ecce4e@arm.com>
On Fri, Mar 10, 2023 at 03:28:56PM +0000, Robin Murphy wrote:
> External email: Use caution opening links or attachments
>
>
> On 2023-03-10 01:17, Nicolin Chen wrote:
> > Hi Robin,
> >
> > Thanks for the inputs.
> >
> > On Thu, Mar 09, 2023 at 01:03:41PM +0000, Robin Murphy wrote:
> > > External email: Use caution opening links or attachments
> > >
> > >
> > > On 2023-03-09 10:53, Nicolin Chen wrote:
> > > > This is used to forward the host IDR values to the user space, so the
> > > > hypervisor and the guest VM can learn about the underlying hardware's
> > > > capabilities.
> > > >
> > > > Also, set the driver_type to IOMMU_HW_INFO_TYPE_ARM_SMMUV3 to pass the
> > > > corresponding type sanity in the core.
> > > >
> > > > Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> > > > ---
> > > > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 25 +++++++++++++++++++++
> > > > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 2 ++
> > > > include/uapi/linux/iommufd.h | 14 ++++++++++++
> > > > 3 files changed, 41 insertions(+)
> > > >
> > > > diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> > > > index f2425b0f0cd6..c1aac695ae0d 100644
> > > > --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> > > > +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> > > > @@ -2005,6 +2005,29 @@ static bool arm_smmu_capable(struct device *dev, enum iommu_cap cap)
> > > > }
> > > > }
> > > >
> > > > +static void *arm_smmu_hw_info(struct device *dev, u32 *length)
> > > > +{
> > > > + struct arm_smmu_master *master = dev_iommu_priv_get(dev);
> > > > + struct iommu_hw_info_smmuv3 *info;
> > > > + void *base_idr;
> > > > + int i;
> > > > +
> > > > + if (!master || !master->smmu)
> > > > + return ERR_PTR(-ENODEV);
> > > > +
> > > > + info = kzalloc(sizeof(*info), GFP_KERNEL);
> > > > + if (!info)
> > > > + return ERR_PTR(-ENOMEM);
> > > > +
> > > > + base_idr = master->smmu->base + ARM_SMMU_IDR0;
> > > > + for (i = 0; i <= 5; i++)
> > > > + info->idr[i] = readl_relaxed(base_idr + 0x4 * i);
> > >
> > > You need to take firmware overrides etc. into account here. In
> > > particular, features like BTM may need to be hidden to work around
> > > errata either in the system integration or the SMMU itself. It isn't
> > > reasonable to expect every VMM to be aware of every erratum and
> > > workaround, and there may even be workarounds where we need to go out of
> > > our way to prevent guests from trying to use certain features in order
> > > to maintain correctness at S2.
> >
> > We can add a bit of overrides after this for errata, perhaps?
> >
> > I have some trouble with finding the errata docs. Would it be
> > possible for you to direct me to it with a link maybe?
>
> The key Arm term is "Software Developer Errata Notice", or just SDEN.
> Here's the ones for MMU-600 and MMU-700:
>
> https://developer.arm.com/documentation/SDEN-946810/latest/
This page shows "Arm CoreLink MMU-600 System Memory Management
Unit Software Developer Errata Notice" but the downloaded file
is "Arm CoreLink CI-700 Coherent Interconnect" errata notice.
And I don't quite understand what it's about.
> https://developer.arm.com/documentation/SDEN-1786925/latest/
Yea, this one I got an "MMU-700 System Memory Management Unit"
SMMU errata file that I can read and understand.
> Note that until now it has been extremely fortunate that in pretty much
> every case Linux either hasn't supported the affected feature at all, or
> has happened to avoid meeting the conditions. Once we do introduce
> nesting support that all goes out the window (and I'll have to think
> more when reviewing new errata in future...)
>
> I've been putting off revisiting all the existing errata to figure out
> what we'd need to do until new nesting patches appeared, so I'll try to
> get to that soon now. I think in many cases it's likely to be best to
> just disallowing nesting entirely on affected implementations.
Do we have already a list of "affected implementations"? Or,
we would need to make such a list now? In a latter case, can
these affected implementations be detected from their IRD0-5
registers, so that we can simply do something in hw_info()?
Thanks
Nic
next prev parent reply other threads:[~2023-03-16 0:13 UTC|newest]
Thread overview: 165+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-09 10:53 [PATCH v1 00/14] Add Nested Translation Support for SMMUv3 Nicolin Chen
2023-03-09 10:53 ` [PATCH v1 01/14] iommu: Add iommu_get_unmanaged_domain helper Nicolin Chen
2023-03-09 12:51 ` Robin Murphy
2023-03-09 14:19 ` Jason Gunthorpe
2023-03-09 19:04 ` Robin Murphy
2023-03-10 0:23 ` Jason Gunthorpe
2023-03-10 8:41 ` Eric Auger
2023-03-10 15:55 ` Jason Gunthorpe
2023-03-16 1:21 ` Nicolin Chen
2023-03-16 18:42 ` Robin Murphy
2023-03-16 20:01 ` Nicolin Chen
2023-03-20 12:51 ` Jason Gunthorpe
2023-03-10 10:14 ` Eric Auger
2023-03-10 15:33 ` Jason Gunthorpe
2023-03-10 15:44 ` Shameerali Kolothum Thodi
2023-03-10 15:56 ` Jason Gunthorpe
2023-03-10 16:07 ` Shameerali Kolothum Thodi
2023-03-10 16:21 ` Jason Gunthorpe
2023-03-10 16:30 ` Shameerali Kolothum Thodi
2023-03-10 17:03 ` Jason Gunthorpe
2023-03-22 16:07 ` Eric Auger
2023-03-22 17:02 ` Jason Gunthorpe
2023-03-22 17:41 ` Eric Auger
2023-03-22 18:07 ` Jason Gunthorpe
2023-03-16 19:51 ` Nicolin Chen
2023-03-16 19:56 ` Shameerali Kolothum Thodi
2023-03-22 15:44 ` Eric Auger
2023-03-09 10:53 ` [PATCH v1 02/14] iommufd: Add nesting related data structures for ARM SMMUv3 Nicolin Chen
2023-03-09 13:42 ` Jean-Philippe Brucker
2023-03-09 14:48 ` Jason Gunthorpe
2023-03-09 18:26 ` Jean-Philippe Brucker
2023-03-09 21:01 ` Jason Gunthorpe
2023-03-10 12:16 ` Jean-Philippe Brucker
2023-03-10 14:52 ` Robin Murphy
2023-03-10 15:25 ` Jason Gunthorpe
2023-03-10 15:57 ` Robin Murphy
2023-03-10 16:03 ` Jason Gunthorpe
2023-03-17 10:10 ` Tian, Kevin
2023-03-17 10:04 ` Tian, Kevin
2023-03-10 4:50 ` Nicolin Chen
2023-03-10 12:54 ` Jean-Philippe Brucker
2023-03-10 14:00 ` Jason Gunthorpe
2023-03-10 16:06 ` Jason Gunthorpe
2023-03-16 0:59 ` Nicolin Chen
2023-03-09 15:26 ` Shameerali Kolothum Thodi
2023-03-09 15:40 ` Jason Gunthorpe
2023-03-09 15:51 ` Shameerali Kolothum Thodi
2023-03-09 15:59 ` Jason Gunthorpe
2023-03-09 16:07 ` Shameerali Kolothum Thodi
2023-03-10 5:26 ` Nicolin Chen
2023-03-10 5:36 ` Nicolin Chen
2023-03-10 12:55 ` Jason Gunthorpe
2023-03-10 5:18 ` Nicolin Chen
2023-03-10 5:04 ` Nicolin Chen
2023-03-10 11:33 ` Eric Auger
2023-03-10 12:51 ` Jason Gunthorpe
2023-03-17 10:17 ` Tian, Kevin
2023-03-09 10:53 ` [PATCH v1 03/14] iommufd/device: Setup MSI on kernel-managed domains Nicolin Chen
2023-03-10 16:45 ` Eric Auger
2023-03-11 0:17 ` Nicolin Chen
2023-03-09 10:53 ` [PATCH v1 04/14] iommu/arm-smmu-v3: Add arm_smmu_hw_info Nicolin Chen
2023-03-09 13:03 ` Robin Murphy
2023-03-10 1:17 ` Nicolin Chen
2023-03-10 15:28 ` Robin Murphy
2023-03-16 0:13 ` Nicolin Chen [this message]
2023-03-16 15:19 ` Robin Murphy
2023-03-16 20:06 ` Nicolin Chen
2023-04-12 7:47 ` Nicolin Chen
2023-03-09 10:53 ` [PATCH v1 05/14] iommu/arm-smmu-v3: Remove ARM_SMMU_DOMAIN_NESTED Nicolin Chen
2023-03-10 16:39 ` Eric Auger
2023-03-10 17:05 ` Jason Gunthorpe
2023-03-11 0:24 ` Nicolin Chen
2023-03-11 0:23 ` Nicolin Chen
2023-03-09 10:53 ` [PATCH v1 06/14] iommu/arm-smmu-v3: Unset corresponding STE fields when s2_cfg is NULL Nicolin Chen
2023-03-09 13:13 ` Robin Murphy
2023-03-09 18:24 ` Shameerali Kolothum Thodi
2023-03-10 1:54 ` Nicolin Chen
2023-03-09 10:53 ` [PATCH v1 07/14] iommu/arm-smmu-v3: Add STRTAB_STE_0_CFG_NESTED for 2-stage translation Nicolin Chen
2023-03-09 10:53 ` [PATCH v1 08/14] iommu/arm-smmu-v3: Prepare for nested domain support Nicolin Chen
2023-03-10 20:39 ` Robin Murphy
2023-03-11 12:40 ` Nicolin Chen
2023-03-09 10:53 ` [PATCH v1 09/14] iommu/arm-smmu-v3: Implement arm_smmu_get_unmanaged_domain Nicolin Chen
2023-03-09 10:53 ` [PATCH v1 10/14] iommu/arm-smmu-v3: Pass in user_cfg to arm_smmu_domain_finalise Nicolin Chen
2023-03-09 10:53 ` [PATCH v1 11/14] iommu/arm-smmu-v3: Add arm_smmu_domain_alloc_user Nicolin Chen
2023-03-24 15:28 ` Eric Auger
2023-03-24 17:40 ` Nicolin Chen
2023-03-24 17:50 ` Jason Gunthorpe
2023-03-24 18:00 ` Nicolin Chen
2023-03-24 15:33 ` Eric Auger
2023-03-24 17:43 ` Nicolin Chen
2023-03-09 10:53 ` [PATCH v1 12/14] iommu/arm-smmu-v3: Support IOMMU_DOMAIN_NESTED type of allocations Nicolin Chen
2023-03-09 13:20 ` Robin Murphy
2023-03-09 14:28 ` Robin Murphy
2023-03-10 1:34 ` Nicolin Chen
2023-03-24 15:44 ` Eric Auger
2023-03-24 16:30 ` Jason Gunthorpe
2023-03-24 17:50 ` Nicolin Chen
2023-03-24 17:51 ` Jason Gunthorpe
2023-03-24 17:55 ` Nicolin Chen
2023-03-09 10:53 ` [PATCH v1 13/14] iommu/arm-smmu-v3: Add CMDQ_OP_TLBI_NH_VAA and CMDQ_OP_TLBI_NH_ALL Nicolin Chen
2023-03-09 13:44 ` Robin Murphy
2023-03-10 1:19 ` Nicolin Chen
2023-03-09 10:53 ` [PATCH v1 14/14] iommu/arm-smmu-v3: Add arm_smmu_cache_invalidate_user Nicolin Chen
2023-03-09 14:49 ` Robin Murphy
2023-03-09 15:31 ` Jason Gunthorpe
2023-03-10 4:20 ` Nicolin Chen
2023-03-10 16:19 ` Jason Gunthorpe
2023-03-11 11:56 ` Nicolin Chen
2023-03-11 12:53 ` Nicolin Chen
2023-03-20 13:03 ` Jason Gunthorpe
2023-03-20 15:56 ` Nicolin Chen
2023-03-20 16:04 ` Jason Gunthorpe
2023-03-20 16:59 ` Nicolin Chen
2023-03-20 18:45 ` Jason Gunthorpe
2023-03-20 21:22 ` Nicolin Chen
2023-03-20 22:19 ` Jason Gunthorpe
2023-03-22 20:57 ` Nicolin Chen
2023-03-23 12:17 ` Jason Gunthorpe
2023-03-17 9:41 ` Tian, Kevin
2023-03-17 14:24 ` Nicolin Chen
2023-03-20 12:59 ` Jason Gunthorpe
2023-03-20 16:12 ` Nicolin Chen
2023-03-20 18:00 ` Jason Gunthorpe
2023-03-21 8:34 ` Tian, Kevin
2023-03-21 11:48 ` Jason Gunthorpe
2023-03-22 6:42 ` Nicolin Chen
2023-03-22 12:43 ` Jason Gunthorpe
2023-03-22 17:11 ` Nicolin Chen
2023-03-22 17:28 ` Jason Gunthorpe
2023-03-22 19:21 ` Nicolin Chen
2023-03-22 19:41 ` Jason Gunthorpe
2023-03-22 20:43 ` Nicolin Chen
2023-03-23 12:16 ` Jason Gunthorpe
2023-03-23 18:13 ` Nicolin Chen
2023-03-23 18:27 ` Jason Gunthorpe
2023-03-24 9:02 ` Tian, Kevin
2023-03-24 14:57 ` Jason Gunthorpe
2023-03-24 17:35 ` Nicolin Chen
2023-03-28 3:03 ` Tian, Kevin
2023-03-24 8:47 ` Tian, Kevin
2023-03-24 14:44 ` Jason Gunthorpe
2023-03-28 2:48 ` Tian, Kevin
2023-03-28 12:26 ` Jason Gunthorpe
2023-03-31 8:09 ` Tian, Kevin
2023-03-17 9:24 ` Tian, Kevin
2023-03-10 3:51 ` Nicolin Chen
2023-03-10 17:53 ` Robin Murphy
2023-03-10 18:49 ` Jason Gunthorpe
2023-03-11 12:38 ` Nicolin Chen
2023-03-13 13:07 ` Robin Murphy
2023-03-16 0:01 ` Nicolin Chen
2023-03-16 14:58 ` Robin Murphy
2023-03-16 21:09 ` Nicolin Chen
2023-03-20 1:32 ` Nicolin Chen
2023-03-20 13:11 ` Jason Gunthorpe
2023-03-20 15:28 ` Nicolin Chen
2023-03-20 16:01 ` Jason Gunthorpe
2023-03-20 16:35 ` Nicolin Chen
2023-03-20 18:07 ` Jason Gunthorpe
2023-03-20 20:46 ` Nicolin Chen
2023-03-20 22:14 ` Jason Gunthorpe
2023-03-22 5:14 ` Nicolin Chen
2023-03-24 8:55 ` Tian, Kevin
2023-03-17 9:47 ` Tian, Kevin
2023-03-17 14:16 ` Nicolin Chen
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