linux-kernel - Re: [RESEND PATCH] xen: vcpu_info would be reset to wrong place on canceled suspend on PVOPS VM which has multi-cpu

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Date:	Tue, 5 May 2015 10:09:54 +0100
From:	David Vrabel <david.vrabel@...rix.com>
To:	"Ouyang Zhaowei (Charles)" <ouyangzhaowei@...wei.com>,
	Boris Ostrovsky <boris.ostrovsky@...cle.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
CC:	<linux-kernel@...r.kernel.org>,
	Dingweiping <weiping.ding@...wei.com>,
	Yanqiangjun <yanqiangjun@...wei.com>, <jinjian@...wei.com>
Subject: Re: [RESEND PATCH] xen: vcpu_info would be reset to wrong place on
 canceled suspend on PVOPS VM which has multi-cpu

On 04/05/15 03:56, Ouyang Zhaowei (Charles) wrote:
> The hypervisor continues assuming that vcpu_info is stored in per-cpu data which was set up by xen_vcpu_setup(),
> while on canceled suspend, the call to xen_hvm_init_shared_info() will now make the guest think that vcpu_info
> is in the shared page, so we do not call xen_hvm_init_shared_info() on suspend canceled.

I don't understand what the impact of this fix is.  Can you include this
in the commit message?

David

> Signed-off-by: Charles Ouyang <ouyangzhaowei@...wei.com>
> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@...cle.com>
> ---
>  arch/x86/xen/suspend.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c
> index d949769..b2bed45 100644
> --- a/arch/x86/xen/suspend.c
> +++ b/arch/x86/xen/suspend.c
> @@ -32,7 +32,8 @@ static void xen_hvm_post_suspend(int suspend_cancelled)
>  {
>  #ifdef CONFIG_XEN_PVHVM
>         int cpu;
> -       xen_hvm_init_shared_info();
> +       if (!suspend_cancelled)
> +               xen_hvm_init_shared_info();
>         xen_callback_vector();
>         xen_unplug_emulated_devices();
>         if (xen_feature(XENFEAT_hvm_safe_pvclock)) {
> 

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