Re: [PATCH v2] KVM: x86: enable dirty log gradually in small chunks

From: Peter Xu <peterx@redhat.com>
To: Jay Zhou <jianjay.zhou@huawei.com>
Cc: kvm@vger.kernel.org, pbonzini@redhat.com,
	wangxinxin.wang@huawei.com, weidong.huang@huawei.com,
	sean.j.christopherson@intel.com, liu.jinsong@huawei.com
Subject: Re: [PATCH v2] KVM: x86: enable dirty log gradually in small chunks
Date: Thu, 20 Feb 2020 14:28:09 -0500	[thread overview]
Message-ID: <20200220192809.GA15253@xz-x1> (raw)
In-Reply-To: <20200220042828.27464-1-jianjay.zhou@huawei.com>

On Thu, Feb 20, 2020 at 12:28:28PM +0800, Jay Zhou wrote:
> @@ -5865,8 +5865,12 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
>  	bool flush;
>  
>  	spin_lock(&kvm->mmu_lock);
> -	flush = slot_handle_all_level(kvm, memslot, slot_rmap_write_protect,
> -				      false);
> +	if (kvm->manual_dirty_log_protect & KVM_DIRTY_LOG_INITIALLY_SET)
> +		flush = slot_handle_large_level(kvm, memslot,
> +						slot_rmap_write_protect, false);
> +	else
> +		flush = slot_handle_all_level(kvm, memslot,
> +						slot_rmap_write_protect, false);

Another extra comment:

I think we should still keep the old behavior for KVM_MEM_READONLY (in
kvm_mmu_slot_apply_flags())) for this...  Say, instead of doing this,
maybe we want kvm_mmu_slot_remove_write_access() to take a new
parameter to decide to which level we do the wr-protect.

Thanks,

>  	spin_unlock(&kvm->mmu_lock);
>  
>  	/*

-- 
Peter Xu