On Fri, May 15, 2009 at 10:22:16AM +0200, Alexander Graf wrote: > A 64bit PTE can have bit7 set to 1 which means "Use this bit for the PAT". > Currently KVM's MMU code treats this bit as reserved, even though it's not. > > As long as we're not required to make use of the PAT bits which is only > required for DMA/MMIO from my understanding, we can safely ignore it. > > Hyper-V uses this bit for kernel PTEs. > > Signed-off-by: Alexander Graf <agraf@xxxxxxx> > --- > arch/x86/kvm/mmu.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index 8fcdae9..cce055a 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -2169,7 +2169,7 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, int level) > context->rsvd_bits_mask[1][1] = exb_bit_rsvd | > rsvd_bits(maxphyaddr, 51) | > rsvd_bits(13, 20); /* large page */ > - context->rsvd_bits_mask[1][0] = ~0ull; > + context->rsvd_bits_mask[1][0] = 0ull; > break; > } > } Just to make sure I understand what this does: if guest sets bit7, will bit7 get set in shadow PTEs as well? -- MST -- 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
