Re: [PATCH RFC v7 01/64] KVM: Fix memslot boundary condition for large page

[Jarkko Sakkinen]

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?

> 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;
> +
>  		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