On Wed, Jan 04, 2023 at 12:01:05PM +0000, Jarkko Sakkinen wrote: > On Wed, Dec 14, 2022 at 01:39:53PM -0600, Michael Roth wrote: > > From: Nikunj A Dadhania <nikunj@xxxxxxx> > > > > Aligned end boundary causes a kvm crash, handle the case. > > > > Link: https://lore.kernel.org/kvm/20221202061347.1070246-8-chao.p.peng@xxxxxxxxxxxxxxx/ > > Chao, are you aware of this issue already? Thanks Jarkko adding me. I'm not aware of there is a fix. > > > Signed-off-by: Nikunj A Dadhania <nikunj@xxxxxxx> > > Signed-off-by: Michael Roth <michael.roth@xxxxxxx> > > --- > > arch/x86/kvm/mmu/mmu.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > > index b1953ebc012e..b3ffc61c668c 100644 > > --- a/arch/x86/kvm/mmu/mmu.c > > +++ b/arch/x86/kvm/mmu/mmu.c > > @@ -7159,6 +7159,9 @@ static void kvm_update_lpage_private_shared_mixed(struct kvm *kvm, > > for (gfn = first + pages; gfn < last; gfn += pages) > > linfo_set_mixed(gfn, slot, level, false); > > > > + if (gfn == last) > > + goto out; > > + Nikunj or Michael, could you help me understand in which case it causes a KVM crash? To me, even the end is aligned to huge page boundary, but: last = (end - 1) & mask; so 'last' is the base address for the last effective huage page. Even when gfn == last, it should still a valid page and needs to be updated for mem_attrs, correct? Thanks, Chao > > gfn = last; > > gfn_end = min(last + pages, slot->base_gfn + slot->npages); > > mixed = mem_attrs_mixed(kvm, slot, level, attrs, gfn, gfn_end); > > -- > > 2.25.1 > > > > > BR, Jarkko
