From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
To: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
LKML <linux-kernel@vger.kernel.org>, KVM <kvm@vger.kernel.org>
Subject: Re: [PATCH 07/10] KVM: introduce readonly_fault_pfn
Date: Fri, 20 Jul 2012 10:56:30 +0800 [thread overview]
Message-ID: <5008C8DE.4000602@linux.vnet.ibm.com> (raw)
In-Reply-To: <5007DE28.2080305@redhat.com>
On 07/19/2012 06:15 PM, Avi Kivity wrote:
> On 07/17/2012 05:44 PM, Xiao Guangrong wrote:
>> Introduce readonly_fault_pfn, in the later patch, it indicates failure
>> when we try to get a writable pfn from the readonly memslot
>>
>> +
>> inline int kvm_is_mmio_pfn(pfn_t pfn)
>> {
>> if (pfn_valid(pfn)) {
>> @@ -949,13 +952,15 @@ EXPORT_SYMBOL_GPL(kvm_disable_largepages);
>>
>> int is_error_page(struct page *page)
>> {
>> - return page == bad_page || page == hwpoison_page || page == fault_page;
>> + return page == bad_page || page == hwpoison_page || page == fault_page
>> + || page == readonly_fault_page;
>
> All those checks are slow, and get_page(fault_page) etc. isn't very
> scalable.
>
> We should move to ERR_PTR() etc. We could use ENOENT, EHWPOISON,
> EFAULT, and EROFS for the above, or maybe there are better matches.
>
Good point. I will do it in the next version, thank you, Avi!
next prev parent reply other threads:[~2012-07-20 2:56 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-17 14:39 [PATCH 00/10 v4] KVM: introduce readonly memslot Xiao Guangrong
2012-07-17 14:40 ` [PATCH 01/10] KVM: fix missing check for memslot flags Xiao Guangrong
2012-07-17 14:41 ` [PATCH 02/10] KVM: hide KVM_MEMSLOT_INVALID from userspace Xiao Guangrong
2012-07-17 14:41 ` [PATCH 03/10] KVM: introduce gfn_to_pfn_memslot_atomic Xiao Guangrong
2012-07-17 14:42 ` [PATCH 04/10] KVM: introduce gfn_to_hva_read/kvm_read_hva/kvm_read_hva_atomic Xiao Guangrong
2012-07-17 14:43 ` [PATCH 05/10] KVM: reorganize hva_to_pfn Xiao Guangrong
2012-07-17 14:43 ` [PATCH 06/10] KVM: use 'writable' as a hint to map writable pfn Xiao Guangrong
2012-07-17 14:44 ` [PATCH 07/10] KVM: introduce readonly_fault_pfn Xiao Guangrong
2012-07-19 10:15 ` Avi Kivity
2012-07-20 2:56 ` Xiao Guangrong [this message]
2012-07-17 14:45 ` [PATCH 08/10] KVM: introduce readonly_bad_hva Xiao Guangrong
2012-07-19 10:16 ` Avi Kivity
2012-07-20 3:01 ` Xiao Guangrong
2012-07-17 14:45 ` [PATCH 09/10] KVM: introduce readonly memslot Xiao Guangrong
2012-07-17 14:46 ` [PATCH 10/10] KVM: indicate readonly access fault Xiao Guangrong
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