On Thu, Jan 17, 2013 at 11:20:43AM +0800, Xiao Guangrong wrote: > On 01/17/2013 03:07 AM, Marcelo Tosatti wrote: > > On Fri, Jan 11, 2013 at 06:25:18PM +0900, Takuya Yoshikawa wrote: > >> Patches 1 to 3 are trivial. > >> > >> Patch 4 is the main cause of the increased lines, but I think the new > >> code makes it easier to understand why each condition in > >> __kvm_set_memory_region() is there. > >> > >> If you don't agree with patch 4, please consider taking the rest of the > >> series at this time. > >> > >> Takuya Yoshikawa (4): > >> KVM: set_memory_region: Don't jump to out_free unnecessarily > >> KVM: set_memory_region: Don't check for overlaps unless we create or > >> move a slot > >> KVM: set_memory_region: Remove unnecessary variable memslot > >> KVM: set_memory_region: Identify the requested change explicitly > >> > >> virt/kvm/kvm_main.c | 94 > >> ++++++++++++++++++++++++++++++++------------------- > >> 1 files changed, 59 insertions(+), 35 deletions(-) > >> > >> -- > >> 1.7.5.4 > > > > Reviewed-by: Marcelo Tosatti <mtosa...@redhat.com> > > > > BTW, while at it, its probably worthwhile to restrict flags > > modifications: change from flags = 0 to flags = read-only is > > incomplete. Xiao, should it be allowed only during creation? > > Will Readonly memory be used for VM-mem-sharing in the future? > I remember you mentioned about mem-sharing things before. ;)
It can. > Actually, It is safe on KVM MMU because all the gfns in the slot > can become readonly after calling __kvm_set_memory_region. It is > unsafe on IOMMU, what need to be fixed is unmapping gfns on IOMMU > when the flag is changed. Kvm.git next does not clear spte W bit on 0 -> readonly flags change. -- 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