On 08/23/2011 03:59 AM, Marcelo Tosatti wrote: >> + if (!vcpu->arch.mmu.direct_map && !mmu_is_nested(vcpu)) >> + gpa = kvm_mmu_gva_to_gpa_write(vcpu, cr2, NULL); > > Why write? >
Since the fault is caused by page table written, and the 'gpa' can be written after instruction is retied. >> + kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); >> + >> + /* >> + * The shadow pages have been zapped, then we call the page >> + * fault path to change the mapping to writable. >> + */ >> + vcpu->arch.mmu.page_fault(vcpu, cr2, PFERR_WRITE_MASK, true); > > I don't see why is this necessary. Just allowing the instruction to > proceed should be enough? > It used to avoid later VM-exit, since we will retry the instruction but the mapped is still read-only. So we can it to let the mapping become writable to avoid page fault again. -- 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
