From: Jason Gunthorpe <jgg@ziepe.ca>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
Robin Murphy <robin.murphy@arm.com>,
Kevin Tian <kevin.tian@intel.com>,
iommu@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] iommu/vt-d: Omit devTLB invalidation requests when TES=0
Date: Wed, 29 Nov 2023 16:10:20 -0400 [thread overview]
Message-ID: <20231129201020.GK1312390@ziepe.ca> (raw)
In-Reply-To: <20231114011036.70142-2-baolu.lu@linux.intel.com>
On Tue, Nov 14, 2023 at 09:10:34AM +0800, Lu Baolu wrote:
> The latest VT-d spec indicates that when remapping hardware is disabled
> (TES=0 in Global Status Register), upstream ATS Invalidation Completion
> requests are treated as UR (Unsupported Request).
>
> Consequently, the spec recommends in section 4.3 Handling of Device-TLB
> Invalidations that software refrain from submitting any Device-TLB
> invalidation requests when address remapping hardware is disabled.
>
> Verify address remapping hardware is enabled prior to submitting Device-
> TLB invalidation requests.
>
> Fixes: 792fb43ce2c9 ("iommu/vt-d: Enable Intel IOMMU scalable mode by default")
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
> drivers/iommu/intel/dmar.c | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
How did you get to the point where flush_dev_iotlb could even be
called if the iommu has somehow been globally disabled?
Shouldn't the attach of the domain compeltely fail if the HW is
disabled?
If the domain is not attached to anything why would flushing happen?
Jason
next prev parent reply other threads:[~2023-11-29 20:10 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-14 1:10 [PATCH 1/1] iommu/vt-d: Support enforce_cache_coherency only for empty domains Lu Baolu
2023-11-14 1:10 ` [PATCH 1/1] iommu/vt-d: Omit devTLB invalidation requests when TES=0 Lu Baolu
2023-11-14 3:14 ` Tian, Kevin
2023-11-14 3:13 ` Baolu Lu
2023-11-14 4:45 ` Tian, Kevin
2023-11-14 4:54 ` Baolu Lu
2023-11-14 5:31 ` Tian, Kevin
2023-11-29 20:10 ` Jason Gunthorpe [this message]
2023-11-30 4:06 ` Baolu Lu
2023-11-30 12:15 ` Jason Gunthorpe
2023-11-14 1:10 ` [PATCH 1/1] iommu/vt-d: Disable PCI ATS in legacy passthrough mode Lu Baolu
2023-11-14 3:14 ` Tian, Kevin
2023-11-16 7:35 ` Baolu Lu
2023-11-16 8:24 ` Tian, Kevin
2023-11-17 1:09 ` Baolu Lu
2023-11-17 2:22 ` Tian, Kevin
2023-11-29 20:13 ` Jason Gunthorpe
2023-11-30 5:44 ` Baolu Lu
2023-11-30 16:18 ` Jason Gunthorpe
2023-11-14 1:10 ` [PATCH 1/1] iommu/vt-d: Make context clearing consistent with context mapping Lu Baolu
2023-11-14 3:20 ` Tian, Kevin
2023-11-14 3:22 ` Baolu Lu
2023-11-14 4:46 ` Tian, Kevin
2023-11-14 3:16 ` [PATCH 1/1] iommu/vt-d: Support enforce_cache_coherency only for empty domains Tian, Kevin
2023-11-29 20:08 ` Jason Gunthorpe
2023-11-30 3:48 ` Baolu Lu
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