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

From: Ouyang Zhaowei (Charles)
Date: Thu May 28 2015 - 04:35:29 EST


Hi all,

It's been a long time, I don't know whether this patch is OK or not. Or does it somewhere need to be improved a little bit?

thanks

On 2015.5.6 9:47, Ouyang Zhaowei (Charles) wrote:
> vcpu_info would be reset to wrong place on canceled suspend on PVOPS VM which has multi-cpu
>
> 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 make the guest think that vcpu_info
> is in the shared page. This will cause non-boot cpus keep checking a wrong vcpu_info address and can not handle
> irqs any more after suspend canceled, for example after we do "xl save -c/restore", PVOPS VM can not be resumed
> as the cpus can not finish their irqs.
>
>
> Signed-off-by: Charles Ouyang <ouyangzhaowei@xxxxxxxxxx>
> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
> Reviewed-by: David Vrabel <david.vrabel@xxxxxxxxxx>
> ---
> 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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