Il 19/06/2013 11:09, Xiao Guangrong ha scritto: > Document it to Documentation/virtual/kvm/mmu.txt > > Signed-off-by: Xiao Guangrong <xiaoguangr...@linux.vnet.ibm.com> > --- > Documentation/virtual/kvm/mmu.txt | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/Documentation/virtual/kvm/mmu.txt > b/Documentation/virtual/kvm/mmu.txt > index 5a6b2e2..4fb442b 100644 > --- a/Documentation/virtual/kvm/mmu.txt > +++ b/Documentation/virtual/kvm/mmu.txt > @@ -270,14 +270,21 @@ This is the most complicated event. The cause of a > page fault can be: > > Handling a page fault is performed as follows: > > + - if the RSV bit of the error code is set, the page fault is caused by guest > + accessing MMIO, walk shadow page table to get the last spte where the mmio > + information is stored and cache the information to vcpu->arch.mmio_gva, > + vcpu->arch.access and vcpu->arch.mmio_gfn then call the emulator to > emulate > + the instruction who will get the benefit from the cached mmio info
+ - if the RSV bit of the error code is set, the page fault is caused by guest + accessing MMIO and cached MMIO information is available. + - 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 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 > - determine the host page > - - if this is an mmio request, there is no host page; call the emulator > - to emulate the instruction instead > + - if this is an mmio request, there is no host page; cache the info to > + vcpu->arch.mmio_gva, vcpu->arch.access and vcpu->arch.mmio_gfn > - walk the shadow page table to find the spte for the translation, > instantiating missing intermediate page tables as necessary > + - If this is an mmio request, cache the mmio info to the spte and set some > + reserved bits on the spte Added "(see callers of kvm_mmu_set_mmio_spte_mask)". Not really related, but just came to my mind: perhaps we can have a section on A/D bits too. Paolo > - try to unsynchronize the page > - if successful, we can let the guest continue and modify the gpte > - emulate the instruction > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
