From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Avi Kivity <avi@redhat.com>, LKML <linux-kernel@vger.kernel.org>,
KVM <kvm@vger.kernel.org>
Subject: Re: [PATCH 5/9] KVM: MMU: fask check write-protect for direct mmu
Date: Fri, 20 Jul 2012 10:34:28 +0800 [thread overview]
Message-ID: <5008C3B4.1070006@linux.vnet.ibm.com> (raw)
In-Reply-To: <20120720003917.GA8951@amt.cnet>
On 07/20/2012 08:39 AM, Marcelo Tosatti wrote:
> On Tue, Jul 17, 2012 at 09:53:29PM +0800, Xiao Guangrong wrote:
>> If it have no indirect shadow pages we need not protect any gfn,
>> this is always true for direct mmu without nested
>>
>> Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
>
> Xiao,
>
> What is the motivation? Numbers please.
>
mmu_need_write_protect is the common path for both soft-mmu and
hard-mmu, checking indirect_shadow_pages can skip hash-table walking
for the case which is tdp is enabled without nested guest.
I will post the Number after I do the performance test.
> In fact, what case was the original indirect_shadow_pages conditional in
> kvm_mmu_pte_write optimizing again?
>
They are the different paths, mmu_need_write_protect is the real
page fault path, and kvm_mmu_pte_write is caused by mmio emulation.
next prev parent reply other threads:[~2012-07-20 2:34 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-17 13:50 [PATCH 1/9] KVM: x86: remvoe unnecessary mark_page_dirty Xiao Guangrong
2012-07-17 13:51 ` [PATCH 2/9] KVM: x86: simplify read_emulated Xiao Guangrong
2012-07-19 23:58 ` Marcelo Tosatti
2012-07-20 2:17 ` Xiao Guangrong
2012-07-20 10:58 ` Marcelo Tosatti
2012-07-20 13:15 ` Xiao Guangrong
2012-07-20 19:52 ` Marcelo Tosatti
2012-07-23 4:23 ` Xiao Guangrong
2012-07-17 13:52 ` [PATCH 3/9] KVM: x86: introduce set_mmio_exit_info Xiao Guangrong
2012-07-20 0:03 ` Marcelo Tosatti
2012-07-20 2:24 ` Xiao Guangrong
2012-07-17 13:52 ` [PATCH 4/9] KVM: MMU: track the refcount when unmap the page Xiao Guangrong
2012-07-20 0:09 ` Marcelo Tosatti
2012-07-17 13:53 ` [PATCH 5/9] KVM: MMU: fask check write-protect for direct mmu Xiao Guangrong
2012-07-20 0:39 ` Marcelo Tosatti
2012-07-20 2:34 ` Xiao Guangrong [this message]
2012-07-20 11:09 ` Marcelo Tosatti
2012-07-20 13:33 ` Xiao Guangrong
2012-07-20 3:45 ` Xiao Guangrong
2012-07-20 11:45 ` Marcelo Tosatti
2012-07-17 13:54 ` [PATCH 6/9] KVM: using get_fault_pfn to get the fault pfn Xiao Guangrong
2012-07-17 13:54 ` [PATCH 7/9] KVM: mark do not extern bad_pfn Xiao Guangrong
2012-07-17 13:55 ` [PATCH 8/9] KVM: remove is_error_hpa Xiao Guangrong
2012-07-17 13:56 ` [PATCH 9/9] KVM: remove the unused parameter of gfn_to_pfn_memslot Xiao Guangrong
2012-07-20 0:40 ` [PATCH 1/9] KVM: x86: remvoe unnecessary mark_page_dirty Marcelo Tosatti
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