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Message-ID: <97789f9e-a33e-bb8d-d5b1-9be31232b64a@redhat.com>
Date:   Tue, 7 Jun 2022 17:14:47 +0200
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Subject: Re: [PATCH v2] KVM: x86/mmu: Check every prev_roots in
 __kvm_mmu_free_obsolete_roots()
Content-Language: en-US
To:     shaoqin.huang@intel.com
Cc:     Sean Christopherson <seanjc@google.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>, Ben Gardon <bgardon@google.com>,
        kvm@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20220607005905.2933378-1-shaoqin.huang@intel.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
In-Reply-To: <20220607005905.2933378-1-shaoqin.huang@intel.com>
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On 6/7/22 02:59, shaoqin.huang@intel.com wrote:
> From: Shaoqin Huang <shaoqin.huang@intel.com>
> 
> When freeing obsolete previous roots, check prev_roots as intended, not
> the current root.
> 
> Signed-off-by: Shaoqin Huang <shaoqin.huang@intel.com>
> 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