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Subject: Re: [PATCH 02/22] kvm: mmu: Introduce tdp_iter
To:     Sean Christopherson <sean.j.christopherson@intel.com>,
        Ben Gardon <bgardon@google.com>
Cc:     linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        Cannon Matthews <cannonmatthews@google.com>,
        Peter Xu <peterx@redhat.com>, Peter Shier <pshier@google.com>,
        Peter Feiner <pfeiner@google.com>,
        Junaid Shahid <junaids@google.com>,
        Jim Mattson <jmattson@google.com>,
        Yulei Zhang <yulei.kernel@gmail.com>,
        Wanpeng Li <kernellwp@gmail.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Xiao Guangrong <xiaoguangrong.eric@gmail.com>
References: <20200925212302.3979661-1-bgardon@google.com>
 <20200925212302.3979661-3-bgardon@google.com>
 <20200930052336.GD29405@linux.intel.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <61d23bc0-771d-9110-6528-3658a55ccba6@redhat.com>
Date:   Wed, 30 Sep 2020 08:24:17 +0200
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On 30/09/20 07:24, Sean Christopherson wrote:
> Maybe use the params, if only to avoid the line wrap?
> 
> 	iter->gfn = goal_gfn - (goal_gfn % KVM_PAGES_PER_HPAGE(root_level));
> 
> Actually, peeking further into the file, this calculation is repeated in both
> try_step_up and try_step_down,  probably worth adding a helper of some form.

Also it's written more concisely as

	iter->gfn = goal_gfn & -KVM_PAGES_PER_HPAGE(iter->level);

> 
> 
> 	bool done;
> 
> 	if (try_step_down(iter))
> 		return;
> 
> 	do {
> 		done = try_step_side(iter);
> 	} while (!done && try_step_up(iter));
> 
> 	iter->valid = done;

I pointed out something similar in my review, my version was

	bool done;

	if (try_step_down(iter))
		return;

	do {
		if (try_step_side(iter))
			return;
	} while (try_step_up(iter));
	iter->valid = false;

Paolo