1. 10 Jan, 2013 2 commits
    • Xiao Guangrong's avatar
      KVM: MMU: fix infinite fault access retry · 7751babd
      Xiao Guangrong authored
      We have two issues in current code:
      - if target gfn is used as its page table, guest will refault then kvm will use
        small page size to map it. We need two #PF to fix its shadow page table
      
      - sometimes, say a exception is triggered during vm-exit caused by #PF
        (see handle_exception() in vmx.c), we remove all the shadow pages shadowed
        by the target gfn before go into page fault path, it will cause infinite
        loop:
        delete shadow pages shadowed by the gfn -> try to use large page size to map
        the gfn -> retry the access ->...
      
      To fix these, we can adjust page size early if the target gfn is used as page
      table
      Signed-off-by: default avatarXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
      Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
      7751babd
    • Xiao Guangrong's avatar
      KVM: MMU: fix Dirty bit missed if CR0.WP = 0 · c2288505
      Xiao Guangrong authored
      If the write-fault access is from supervisor and CR0.WP is not set on the
      vcpu, kvm will fix it by adjusting pte access - it sets the W bit on pte
      and clears U bit. This is the chance that kvm can change pte access from
      readonly to writable
      
      Unfortunately, the pte access is the access of 'direct' shadow page table,
      means direct sp.role.access = pte_access, then we will create a writable
      spte entry on the readonly shadow page table. It will cause Dirty bit is
      not tracked when two guest ptes point to the same large page. Note, it
      does not have other impact except Dirty bit since cr0.wp is encoded into
      sp.role
      
      It can be fixed by adjusting pte access before establishing shadow page
      table. Also, after that, no mmu specified code exists in the common function
      and drop two parameters in set_spte
      Signed-off-by: default avatarXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
      Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
      c2288505
  2. 09 Jan, 2013 9 commits
  3. 08 Jan, 2013 2 commits
  4. 07 Jan, 2013 9 commits
  5. 02 Jan, 2013 7 commits
  6. 24 Dec, 2012 1 commit
  7. 23 Dec, 2012 9 commits
  8. 18 Dec, 2012 1 commit