From: Xiao Guangrong Date: Wed, 19 Jun 2013 09:09:23 +0000 (+0800) Subject: KVM: MMU: document fast page fault X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2d49c47f350b939b395cd2d1abaa8c3bb6c54326;p=linux-beck.git 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 --- 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