From: Avi Kivity <avi@redhat.com>
To: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
LKML <linux-kernel@vger.kernel.org>, KVM <kvm@vger.kernel.org>
Subject: Re: [PATCH 7/7] KVM: MMU: cache guest page number to guest frame number
Date: Tue, 22 Feb 2011 16:32:25 +0200 [thread overview]
Message-ID: <4D63C8F9.1020708@redhat.com> (raw)
In-Reply-To: <4D6370E8.6080008@cn.fujitsu.com>
On 02/22/2011 10:16 AM, Xiao Guangrong wrote:
> Cache guest page number to guest frame number to avoid walk guest page table
> frequently, the 'vtlb' idea is from Xen.
>
> Note:
> we can't use vtlb in ept guests since the guest tlb invalid operation is not
> intercept(reload CR3, invlpg), also can't used in L2 nnpt guest for the same
> reason, but we can used it to cache L1's npt page table.
>
I'm not so hot about introducing a new mechanism strictly for older
hosts... EPT exists in three generations of Intel processors now (Sandy
Bridge, Westmere, and Nehalem), and NPT is significantly older.
I'd rather make the guest page table walk faster. I believe that things
like get_user() can be significantly faster than copy_from_user() on
older hosts, and a four-level page table walk shouldn't be that slow.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2011-02-22 14:32 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-22 8:08 [PATCH 0/7] KVM: optimize memslots searching and cache GPN to GFN Xiao Guangrong
2011-02-22 8:09 ` [PATCH 1/7] KVM: cleanup memslot_id function Xiao Guangrong
2011-02-22 8:10 ` [PATCH 2/7] KVM: introduce KVM_MEM_SLOTS_NUM macro Xiao Guangrong
2011-02-22 8:11 ` [PATCH 1/3] KVM: introduce memslots_updated function Xiao Guangrong
2011-02-22 8:12 ` [PATCH 4/7] KVM: sort memslots and use binary search to search the right slot Xiao Guangrong
2011-02-22 14:25 ` Avi Kivity
2011-02-22 14:54 ` Alex Williamson
2011-02-22 18:54 ` [RFC PATCH 0/3] Weight-balanced binary tree + KVM growable memory slots using wbtree Alex Williamson
2011-02-22 18:55 ` [RFC PATCH 1/3] Weight-balanced tree Alex Williamson
2011-02-23 13:09 ` Avi Kivity
2011-02-23 17:02 ` Alex Williamson
2011-02-23 17:08 ` Avi Kivity
2011-02-23 20:19 ` Alex Williamson
2011-02-24 23:04 ` Andrew Morton
2011-02-22 18:55 ` [RFC PATCH 2/3] kvm: Allow memory slot array to grow on demand Alex Williamson
2011-02-24 10:39 ` Avi Kivity
2011-02-24 18:08 ` Alex Williamson
2011-02-27 9:44 ` Avi Kivity
2011-02-22 18:55 ` [RFC PATCH 3/3] kvm: Use weight-balanced tree for memory slot management Alex Williamson
2011-02-22 18:59 ` [RFC PATCH 0/3] Weight-balanced binary tree + KVM growable memory slots using wbtree Alex Williamson
2011-02-23 1:56 ` Alex Williamson
2011-02-23 13:12 ` Avi Kivity
2011-02-23 18:06 ` Alex Williamson
2011-02-23 19:28 ` Alex Williamson
2011-02-24 10:06 ` Avi Kivity
2011-02-24 17:35 ` Alex Williamson
2011-02-27 9:54 ` Avi Kivity
2011-02-28 23:04 ` Alex Williamson
2011-03-01 15:03 ` Avi Kivity
2011-03-01 18:20 ` Alex Williamson
2011-03-02 13:31 ` Avi Kivity
2011-03-01 19:47 ` Marcelo Tosatti
2011-03-02 13:34 ` Avi Kivity
2011-02-24 10:04 ` Avi Kivity
2011-02-23 1:30 ` [PATCH 4/7] KVM: sort memslots and use binary search to search the right slot Xiao Guangrong
2011-02-22 8:13 ` [PATCH 5/7] KVM: cache the last used slot Xiao Guangrong
2011-02-22 14:26 ` Avi Kivity
2011-02-22 8:15 ` [PATCH 6/7] KVM: cleanup traversal used slots Xiao Guangrong
2011-02-22 8:16 ` [PATCH 7/7] KVM: MMU: cache guest page number to guest frame number Xiao Guangrong
2011-02-22 14:32 ` Avi Kivity [this message]
2011-02-23 1:38 ` Xiao Guangrong
2011-02-23 9:28 ` Avi Kivity
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