Hi,
On 2020/2/19 12:30, Jerry Snitselaar wrote:
On Wed Feb 19 20, Lu Baolu wrote:
Hi Jerry,
On 2020/2/18 23:45, Jerry Snitselaar wrote:
Hi Joerg and Baolu,
I'm chasing down one last issue. I'm waiting to hear back from them
testing with Joerg's patchset, but I'm guessing this will still pop
up. It looks like right around when the domain switch occurs in
iommu_need_mapping there are some dmar faults (below is from 5.6-rc1
plus earlier fix attempt that moved deferred attach to beginning of
iommu_need_mapping):
[ 12.546920] DMAR: DRHD: handling fault status reg 2
[ 12.546923] DMAR: [DMA Read] Request device [02:00.0] PASID
ffffffff fault addr 791dd000 [fault reason 02] Present bit in context
entry is clear
[ 12.635193] hpsa 0000:02:00.0: Using iommu dma mapping
[ 12.776712] hpsa 0000:02:00.0: DMAR: 32bit DMA uses non-identity
mapping
[ 14.091219] DMAR: [DMA Read] Request device [07:00.0] PASID
ffffffff fault addr 791dd000 [fault reason 02] Present bit in context
entry is clear
[ 14.180842] DMAR: DRHD: handling fault status reg 202
[ 14.180845] DMAR: [DMA Read] Request device [07:00.0] PASID
ffffffff fault addr 791dd000 [fault reason 02] Present bit in context
entry is clear
[ 14.268756] DMAR: DRHD: handling fault status reg 302
[ 15.542551] hpsa 0000:07:00.0: Using iommu dma mapping
[ 15.567256] hpsa 0000:07:00.0: DMAR: 32bit DMA uses non-identity
mapping
It seems to only happen right then, and then things are fine. Happens
during both regular and kdump boot. With the kdump boot the faults
are from the hpilo in the logs I'm looking at, so it doesn't seem to
be tied to a device, or certain rmrr. The faulting address always
seems to be the base address of the rmrr. The dmar tables look sane.
Perhaps like this?
The device was boot with an identity domain (iommu=pt). When loading the
driver for this device, iommu driver finds that it's a 32-bit device and
tries to convert it to DMA domain. The rmrr is still active during the
switch, hence you see dma faults during that time window.
Best regards,
baolu
It looks like it doesn't occur with Joerg's patchset.
Okay. Cool!
Best regards,
baolu
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