Re: [PATCH v2] KVM: x86/mmu: Check every prev_roots in __kvm_mmu_free_obsolete_roots()

[Paolo Bonzini]

On 6/7/22 02:59, shaoqin.huang@xxxxxxxxx wrote:
> From: Shaoqin Huang <shaoqin.huang@xxxxxxxxx>
>
> When freeing obsolete previous roots, check prev_roots as intended, not
> the current root.
>
> Signed-off-by: Shaoqin Huang <shaoqin.huang@xxxxxxxxx>
> Fixes: 527d5cd7eece ("KVM: x86/mmu: Zap only obsolete roots if a root shadow page is zapped")
> ---
> Changes in v2:
>    - Make the commit message more clearer.
>    - Fixed the missing idx.
>
>   arch/x86/kvm/mmu/mmu.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index f4653688fa6d..e826ee9138fa 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -5179,7 +5179,7 @@ static void __kvm_mmu_free_obsolete_roots(struct kvm *kvm, struct kvm_mmu *mmu)
>   		roots_to_free |= KVM_MMU_ROOT_CURRENT;
>   
>   	for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) {
> -		if (is_obsolete_root(kvm, mmu->root.hpa))
> +		if (is_obsolete_root(kvm, mmu->prev_roots[i].hpa))
>   			roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i);
>   	}
>   

Queued, thanks.

Paolo