Message-ID: <d5ff098a-731c-f336-efd4-b7405c5e776e@redhat.com>
Date:   Tue, 7 Feb 2023 17:17:46 +0100
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Subject: Re: [PATCH V2 4/8] kvm: x86/mmu: Set mmu->sync_page as NULL for
 direct paging
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To:     Lai Jiangshan <jiangshanlai@gmail.com>,
        linux-kernel@vger.kernel.org
Cc:     Sean Christopherson <seanjc@google.com>,
        Lai Jiangshan <jiangshan.ljs@antgroup.com>,
        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>, kvm@vger.kernel.org
References: <20230207155735.2845-1-jiangshanlai@gmail.com>
 <20230207155735.2845-5-jiangshanlai@gmail.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
In-Reply-To: <20230207155735.2845-5-jiangshanlai@gmail.com>
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On 2/7/23 16:57, Lai Jiangshan wrote:
> From: Lai Jiangshan<jiangshan.ljs@antgroup.com>
> 
> mmu->sync_page for direct paging is never called.
> 
> And both mmu->sync_page and mm->invlpg only make sense in shadowpaging.
> Setting mmu->sync_page as NULL for direct paging makes it consistent
> with mm->invlpg which is set NULL for the case.
> 
> Signed-off-by: Lai Jiangshan<jiangshan.ljs@antgroup.com>

I'd rather have a WARN_ON_ONCE in kvm_sync_page(), otherwise looks good.

Paolo