From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sean Christopherson <sean.j.christopherson@intel.com>
Date: Tue, 22 Oct 2019 15:28:27 +0000
Subject: Re: [PATCH v2 14/15] KVM: Terminate memslot walks via used_slots
Message-Id: <20191022152827.GC2343@linux.intel.com>
List-Id: <kvm-ppc.vger.kernel.org>
References: <20191022003537.13013-1-sean.j.christopherson@intel.com>
 <20191022003537.13013-15-sean.j.christopherson@intel.com>
 <642f73ee-9425-0149-f4f4-f56be9ae5713@redhat.com>
In-Reply-To: <642f73ee-9425-0149-f4f4-f56be9ae5713@redhat.com>
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: James Hogan <jhogan@kernel.org>, Paul Mackerras <paulus@ozlabs.org>, Christian Borntraeger <borntraeger@de.ibm.com>, Janosch Frank <frankja@linux.ibm.com>, Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>, Marc Zyngier <maz@kernel.org>, David Hildenbrand <david@redhat.com>, Cornelia Huck <cohuck@redhat.com>, Vitaly Kuznetsov <vkuznets@redhat.com>, Wanpeng Li <wanpengli@tencent.com>, Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>, James Morse <james.morse@arm.com>, Julien Thierry <julien.thierry.kdev@gmail.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org

On Tue, Oct 22, 2019 at 04:04:18PM +0200, Paolo Bonzini wrote:
> On 22/10/19 02:35, Sean Christopherson wrote:
> > +static inline int kvm_shift_memslots_forward(struct kvm_memslots *slots,
> > +					     struct kvm_memory_slot *new)
> > +{
> > +	struct kvm_memory_slot *mslots = slots->memslots;
> > +	int i;
> > +
> > +	if (WARN_ON_ONCE(slots->id_to_index[new->id] = -1) ||
> > +	    WARN_ON_ONCE(!slots->used_slots))
> > +		return -1;
> > +
> > +	for (i = slots->id_to_index[new->id]; i < slots->used_slots - 1; i++) {
> > +		if (new->base_gfn > mslots[i + 1].base_gfn)
> > +			break;
> > +
> > +		WARN_ON_ONCE(new->base_gfn = mslots[i + 1].base_gfn);
> > +
> > +		/* Shift the next memslot forward one and update its index. */
> > +		mslots[i] = mslots[i + 1];
> > +		slots->id_to_index[mslots[i].id] = i;
> > +	}
> > +	return i;
> > +}
> > +
> > +static inline int kvm_shift_memslots_back(struct kvm_memslots *slots,
> > +					  struct kvm_memory_slot *new,
> > +					  int start)
> 
> This new implementation of the insertion sort loses the comments that
> were there in the old one.  Please keep them as function comments.

I assume you're talking about this blurb in particular?

	 * The ">=" is needed when creating a slot with base_gfn = 0,
	 * so that it moves before all those with base_gfn = npages = 0.