On Fri, Jan 25, 2013 at 11:28:40AM +0800, Xiao Guangrong wrote: > On 01/25/2013 09:17 AM, Takuya Yoshikawa wrote: > > On Thu, 24 Jan 2013 15:03:57 -0700 > > Alex Williamson <alex.williamson@xxxxxxxxxx> wrote: > > > >> A couple patches to make KVM IOMMU support honor read-only mappings. > >> This causes an un-map, re-map when the read-only flag changes and > >> makes use of it when setting IOMMU attributes. Thanks, > > > > Looks good to me. > > > > I think I can naturally update my patch after this gets merged. > > > > Please wait. > > The commit c972f3b1 changed the write-protect behaviour - it does > wirte-protection only when dirty flag is set. > [ I did not see this commit when we discussed the problem before. ] > > Further more, i notice that write-protect is not enough, when do sync > shadow page: > > FNAME(sync_page): > > host_writable = sp->spt[i] & SPTE_HOST_WRITEABLE; > > set_spte(vcpu, &sp->spt[i], pte_access, > PT_PAGE_TABLE_LEVEL, gfn, > spte_to_pfn(sp->spt[i]), true, false, > host_writable); > > It sets spte based on the old value that means the readonly flag check > is missed. We need to call kvm_arch_flush_shadow_all under this case. Why not just disallow changing memory region KVM_MEM_READONLY flag without deleting the region? -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
