Re: [PATCH 1/2] mm, Make __get_user_pages return -EHWPOISON for HWPOISONpage optionally

From: Avi Kivity
Date: Sun Jan 16 2011 - 10:36:22 EST


On 01/14/2011 03:37 AM, Huang Ying wrote:
On Thu, 2011-01-13 at 18:43 +0800, Avi Kivity wrote:
> On 01/13/2011 10:42 AM, Huang Ying wrote:
> > Make __get_user_pages return -EHWPOISON for HWPOISON page only if
> > FOLL_HWPOISON is specified. With this patch, the interested callers
> > can distinguish HWPOISON page from general FAULT page, while other
> > callers will still get -EFAULT for pages, so the user space interface
> > need not to be changed.
> >
> > get_user_pages_hwpoison is added as a variant of get_user_pages that
> > can return -EHWPOISON for HWPOISON page.
> >
> > This feature is needed by KVM, where UCR MCE should be relayed to
> > guest for HWPOISON page, while instruction emulation and MMIO will be
> > tried for general FAULT page.
> >
> > The idea comes from Andrew Morton.
> >
> > Signed-off-by: Huang Ying<ying.huang@xxxxxxxxx>
> > Cc: Andrew Morton<akpm@xxxxxxxxxxxxxxxxxxxx>
> >
> > +#ifdef CONFIG_MEMORY_FAILURE
> > +int get_user_pages_hwpoison(struct task_struct *tsk, struct mm_struct *mm,
> > + unsigned long start, int nr_pages, int write,
> > + int force, struct page **pages,
> > + struct vm_area_struct **vmas);
> > +#else
>
> Since we'd also like to add get_user_pages_noio(), perhaps adding a
> flags field to get_user_pages() is better.

Or export __get_user_pages()?

That's better, yes.

--
error compiling committee.c: too many arguments to function

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