[PATCH] xen: vcpu_info reinit error after hold/release if VM has multi-cpu

[PATCH] xen: vcpu_info reinit error after hold/release if VM has multi-cpu

[Ouyang Zhaowei (Charles)]

If the VM has multi-cpu the vcpu_info of cpu0 is the member of the structure HYPERVISOR_shared_info,
and the others is not, but after hold/release the VM, the vcpu_info will be reinitialized,
the vcpu_info of all the vcpus will be considered as the member of HYPERVISOR_shared_info.
This will cause the cpu1 and other cpu keep receiving interrupts, and the cpu0 is waiting them to
finish the job.
So we do not reinit the vcpu_info if it's doing hold/release.

Signed-off-by: Charles Ouyang <ouyangzhaowei@huawei.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 c4df9db..832480c 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)) {

Re: [PATCH] xen: vcpu_info reinit error after hold/release if VM has multi-cpu

[Konrad Rzeszutek Wilk]

On Mon, Mar 30, 2015 at 09:33:16PM +0800, Ouyang Zhaowei (Charles) wrote:
> If the VM has multi-cpu the vcpu_info of cpu0 is the member of the structure HYPERVISOR_shared_info,
> and the others is not, but after hold/release the VM, the vcpu_info will be reinitialized,

What is 'hold/release' ? Pause and suspend? or do you mean suspend
was cancelled?

> the vcpu_info of all the vcpus will be considered as the member of HYPERVISOR_shared_info.
> This will cause the cpu1 and other cpu keep receiving interrupts, and the cpu0 is waiting them to
> finish the job.
> So we do not reinit the vcpu_info if it's doing hold/release.

s/"hold/release"/suspend cancelled/ ?

> 
> Signed-off-by: Charles Ouyang <ouyangzhaowei@huawei.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 c4df9db..832480c 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)) {
>