From 2d49c47f350b939b395cd2d1abaa8c3bb6c54326 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Wed, 19 Jun 2013 17:09:23 +0800 Subject: [PATCH] KVM: MMU: document fast page fault Document fast page fault to Documentation/virtual/kvm/mmu.txt Signed-off-by: Xiao Guangrong Signed-off-by: Paolo Bonzini --- Documentation/virtual/kvm/mmu.txt | 3 +++ 1 file changed, 3 insertions(+) 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 -- 2.11.0