path: root/Documentation
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authorXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>2013-06-19 17:09:23 +0800
committerGleb Natapov <gleb@redhat.com>2013-06-27 14:20:46 +0300
commit2d49c47f350b939b395cd2d1abaa8c3bb6c54326 (patch)
tree15619136c7a2c5e80c205590fa829b23cfa238b6 /Documentation
parent67652ed34390b19ede6f847d23d8c68e2c819b50 (diff)
KVM: MMU: document fast page fault
Document fast page fault to Documentation/virtual/kvm/mmu.txt Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation')
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/mmu.txt b/Documentation/virtual/kvm/mmu.txt
index 0aa8e0e34119..42193f206602 100644
--- a/Documentation/virtual/kvm/mmu.txt
+++ b/Documentation/virtual/kvm/mmu.txt
@@ -277,6 +277,9 @@ Handling a page fault is performed as follows:
- walk shadow page table
- cache the information to vcpu->arch.mmio_gva, vcpu->arch.access and
vcpu->arch.mmio_gfn, and call the emulator
+ - If both P bit and R/W bit of error code are set, this could possibly
+ be handled as a "fast page fault" (fixed without taking the MMU lock). See
+ the description in Documentation/virtual/kvm/locking.txt.
- if needed, walk the guest page tables to determine the guest translation
(gva->gpa or ngpa->gpa)
- if permissions are insufficient, reflect the fault back to the guest