1. 01 3月, 2010 4 次提交
  2. 10 9月, 2009 2 次提交
  3. 10 6月, 2009 1 次提交
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  5. 20 7月, 2008 1 次提交
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      KVM: MMU: Fix false flooding when a pte points to page table · 1b7fcd32
      Avi Kivity 提交于
      The KVM MMU tries to detect when a speculative pte update is not actually
      used by demand fault, by checking the accessed bit of the shadow pte.  If
      the shadow pte has not been accessed, we deem that page table flooded and
      remove the shadow page table, allowing further pte updates to proceed
      without emulation.
      
      However, if the pte itself points at a page table and only used for write
      operations, the accessed bit will never be set since all access will happen
      through the emulator.
      
      This is exactly what happens with kscand on old (2.4.x) HIGHMEM kernels.
      The kernel points a kmap_atomic() pte at a page table, and then
      proceeds with read-modify-write operations to look at the dirty and accessed
      bits.  We get a false flood trigger on the kmap ptes, which results in the
      mmu spending all its time setting up and tearing down shadows.
      
      Fix by setting the shadow accessed bit on emulated accesses.
      Signed-off-by: NAvi Kivity <avi@qumranet.com>
      1b7fcd32
  6. 04 5月, 2008 2 次提交
  7. 27 4月, 2008 1 次提交
  8. 31 1月, 2008 1 次提交
  9. 30 1月, 2008 2 次提交