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  1. 30 6月, 2009 2 次提交
  3. 29 6月, 2009 26 次提交
  5. 26 6月, 2009 1 次提交
  7. 24 6月, 2009 1 次提交
    • F
      IOMMU Identity Mapping Support (drivers/pci/intel_iommu.c) · 2c2e2c38
      由 Fenghua Yu 提交于 
      Identity mapping for IOMMU defines a single domain to 1:1 map all PCI
devices to all usable memory.

This reduces map/unmap overhead in DMA API's and improve IOMMU
performance. On 10Gb network cards, Netperf shows no performance
degradation compared to non-IOMMU performance.

This method may lose some of DMA remapping benefits like isolation.

The patch sets up identity mapping for all PCI devices to all usable
memory. In the DMA API, there is no overhead to maintain page tables,
invalidate iotlb, flush cache etc.

32 bit DMA devices don't use identity mapping domain, in order to access
memory beyond 4GiB.

When kernel option iommu=pt, pass through is first tried. If pass
through succeeds, IOMMU goes to pass through. If pass through is not
supported in hw or fail for whatever reason, IOMMU goes to identity
mapping.
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
      2c2e2c38
  9. 18 5月, 2009 2 次提交
  11. 11 5月, 2009 5 次提交
    • D
      intel-iommu: PAE memory corruption fix · fd18de50
      由 David Woodhouse 提交于 
      PAGE_MASK is 0xFFFFF000 on i386 -- even with PAE.

So it's not sufficient to ensure that you use phys_addr_t or uint64_t
everywhere you handle physical addresses -- you also have to avoid using
the construct 'addr & PAGE_MASK', because that will strip the high 32
bits of the address.

This patch avoids that problem by using PHYSICAL_PAGE_MASK instead of
PAGE_MASK where appropriate. It leaves '& PAGE_MASK' in a few instances
that don't matter -- where it's being used on the virtual bus addresses
we're dishing out, which are 32-bit anyway.

Since PHYSICAL_PAGE_MASK is not present on other architectures, we have
to define it (to PAGE_MASK) if it's not already defined.

Maybe it would be better just to fix PAGE_MASK for i386/PAE?
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      fd18de50
    • D
      intel-iommu: Tidy up iommu->gcmd handling · c416daa9
      由 David Woodhouse 提交于 
      Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
      c416daa9
    • D
      intel-iommu: Fix tiny theoretical race in write-buffer flush. · 462b60f6
      由 David Woodhouse 提交于 
      In iommu_flush_write_buffer() we read iommu->gcmd before taking the
register_lock, and then we mask in the WBF bit and write it to the
register.

There is a tiny chance that something else could have _changed_
iommu->gcmd before we take the lock, but after we read it. So we could
be undoing that change.

Never actually going to have happened in practice, since nothing else
changes that register at runtime -- aside from the write-buffer flush
it's only ever touched at startup for enabling translation, etc.

But worth fixing anyway.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
      462b60f6
    • D
      intel-iommu: Clean up handling of "caching mode" vs. IOTLB flushing. · 1f0ef2aa
      由 David Woodhouse 提交于 
      As we just did for context cache flushing, clean up the logic around
whether we need to flush the iotlb or just the write-buffer, depending
on caching mode.

Fix the same bug in qi_flush_iotlb() that qi_flush_context() had -- it
isn't supposed to be returning an error; it's supposed to be returning a
flag which triggers a write-buffer flush.

Remove some superfluous conditional write-buffer flushes which could
never have happened because they weren't for non-present-to-present
mapping changes anyway.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
      1f0ef2aa
    • D
      intel-iommu: Clean up handling of "caching mode" vs. context flushing. · 4c25a2c1
      由 David Woodhouse 提交于 
      It really doesn't make a lot of sense to have some of the logic to
handle caching vs. non-caching mode duplicated in qi_flush_context() and
__iommu_flush_context(), while the return value indicates whether the
caller should take other action which depends on the same thing.

Especially since qi_flush_context() thought it was returning something
entirely different anyway.

This patch makes qi_flush_context() and __iommu_flush_context() both
return void, removes the 'non_present_entry_flush' argument and makes
the only call site which _set_ that argument to 1 do the right thing.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
      4c25a2c1
  13. 10 5月, 2009 1 次提交
  15. 01 5月, 2009 1 次提交
  17. 29 4月, 2009 1 次提交
    • F
      Intel IOMMU Pass Through Support · 4ed0d3e6
      由 Fenghua Yu 提交于 
      The patch adds kernel parameter intel_iommu=pt to set up pass through
mode in context mapping entry. This disables DMAR in linux kernel; but
KVM still runs on VT-d and interrupt remapping still works.

In this mode, kernel uses swiotlb for DMA API functions but other VT-d
functionalities are enabled for KVM. KVM always uses multi level
translation page table in VT-d. By default, pass though mode is disabled
in kernel.

This is useful when people don't want to enable VT-d DMAR in kernel but
still want to use KVM and interrupt remapping for reasons like DMAR
performance concern or debug purpose.
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Acked-by: NWeidong Han <weidong@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
      4ed0d3e6