Re: [PATCH 1/1] KVM: Fix kernel allocated memory slot

[Sheng Yang <sheng@linux.intel.com>]

On Tuesday 11 November 2008 22:58:25 Hollis Blanchard wrote:
> On Tue, 2008-11-11 at 15:30 +0800, Sheng Yang wrote:
> > Commit 7fd49de9773fdcb7b75e823b21c1c5dc1e218c14 "KVM: ensure that memslot
> > userspace addresses are page-aligned" broke kernel space allocated memory
> > slot, for the userspace_addr is invalid.
> >
> > Signed-off-by: Sheng Yang <sheng@linux.intel.com>
> > ---
> >  virt/kvm/kvm_main.c |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
> >
> > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> > index 0a0a959..4727c08 100644
> > --- a/virt/kvm/kvm_main.c
> > +++ b/virt/kvm/kvm_main.c
> > @@ -715,7 +715,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
> >  		goto out;
> >  	if (mem->guest_phys_addr & (PAGE_SIZE - 1))
> >  		goto out;
> > -	if (mem->userspace_addr & (PAGE_SIZE - 1))
> > +	if (user_alloc && (mem->userspace_addr & (PAGE_SIZE - 1)))
> >  		goto out;
> >  	if (mem->slot >= KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS)
> >  		goto out;
>
> Wow, I didn't realize we still had kernel-allocated guest memory. Why is
> that?
>
> Anyways, the above patch seems fine to me.
> Acked-by: Hollis Blanchard <hollisb@us.ibm.com>

it's for VMX EPT and APIC access page, as well as TSS pages. We are planning 
to change that in the future, but I think it's a quick fix for now.

Thanks.

-- 
regards
Yang, Sheng