From: Alexander Graf <agraf@suse•de>
To: Avi Kivity <avi@redhat•com>
Cc: linuxppc-dev <linuxppc-dev@lists•ozlabs.org>,
KVM list <kvm@vger•kernel.org>,
kvm-ppc@vger•kernel.org
Subject: Re: [PATCH 0/2] Faster MMU lookups for Book3s v3
Date: Thu, 01 Jul 2010 12:00:37 +0200 [thread overview]
Message-ID: <4C2C6745.8040001@suse.de> (raw)
In-Reply-To: <4C2C547E.7010404@redhat.com>
Avi Kivity wrote:
> On 07/01/2010 11:18 AM, Alexander Graf wrote:
>>
>> How does dirty bitmap flushing work on x86 atm? I loop through all
>> mapped pages and flush the ones that match the range of the region I
>> need to flush. But wouldn't it be a lot more efficient to have an
>> hlist in the memslot and loop through that when I need to flush that
>> memslot?
>>
>
> x86 loops through the reverse-map link list rooted at the memory
> slot. The linked list links all sptes for a single hva.
>
> So, it's like you describe, except it's an array of lists instead of a
> single list. We need per-page rmap lists to be able to remove a
> page's sptes in response to an mmu notifier callback, and to be able
> to write protect a guest page if it's used as a page table.
>
But doesn't that mean that you still need to loop through all the hvas
that you want to invalidate? Wouldn't it speed up dirty bitmap flushing
a lot if we'd just have a simple linked list of all sPTEs belonging to
that memslot?
Alex
next prev parent reply other threads:[~2010-07-01 10:00 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-30 13:18 [PATCH 0/2] Faster MMU lookups for Book3s v3 Alexander Graf
2010-06-30 13:18 ` [PATCH 1/2] KVM: PPC: Add generic hpte management functions Alexander Graf
2010-06-30 13:18 ` [PATCH 2/2] KVM: PPC: Make use of hash based Shadow MMU Alexander Graf
2010-07-01 7:29 ` [PATCH 0/2] Faster MMU lookups for Book3s v3 Avi Kivity
2010-07-01 8:18 ` Alexander Graf
2010-07-01 8:40 ` Avi Kivity
2010-07-01 10:00 ` Alexander Graf [this message]
2010-07-01 11:14 ` Avi Kivity
2010-07-01 12:28 ` Alexander Graf
2010-07-01 12:43 ` Avi Kivity
2010-07-01 12:52 ` Alexander Graf
2010-07-01 13:42 ` Avi Kivity
2010-07-02 2:54 ` Benjamin Herrenschmidt
2010-07-02 2:50 ` Benjamin Herrenschmidt
2010-07-01 15:40 ` Marcelo Tosatti
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