Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1165540 > unrolled thread

Re: [PATCH 07/12] x86/virt/guest/xen: Remove use of pgd_list from the Xen guest code

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: [PATCH 07/12] x86/virt/guest/xen: Remove use of pgd_list from  the Xen guest code Ingo Molnar <mingo@kernel.org> - 2015-06-15 22:40 +0200

#1165540 — Re: [PATCH 07/12] x86/virt/guest/xen: Remove use of pgd_list from the Xen guest code

* David Vrabel <david.vrabel@citrix.com> wrote:

> On 15/06/15 10:05, Ian Campbell wrote:
> > On Sat, 2015-06-13 at 11:49 +0200, Ingo Molnar wrote:

> >> xen_mm_pin_all()/unpin_all() are used to implement full guest instance 
> >> suspend/restore. It's a stop-all method that needs to iterate through all 
> >> allocated pgds in the system to fix them up for Xen's use.
> >>
> >> This code uses pgd_list, probably because it was an easy interface.
> >>
> >> But we want to remove the pgd_list, so convert the code over to walk all 
> >> tasks in the system. This is an equivalent method.
> 
> It is not equivalent because pgd_alloc() now populates entries in pgds that are 
> not visible to xen_mm_pin_all() (note how the original code adds the pgd to the 
> pgd_list in pgd_ctor() before calling pgd_prepopulate_pmd()).  These newly 
> allocated page tables won't be correctly converted on suspend/resume and the new 
> process will die after resume.

So how should the Xen logic be fixed for the new scheme? I can't say I can see 
through the paravirt complexity here.

Thanks,

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [standalone]

Back to top | Article view | linux.kernel

csiph-web