Re: [PATCH] xen: vcpu_info reinit error after 'xl save -c' & 'xl restore' on PVOPS VM which has multi-cpu

From: Boris Ostrovsky
Date: Sat Apr 25 2015 - 19:32:28 EST

On 04/24/2015 05:30 AM, Ouyang Zhaowei (Charles) wrote:
If a PVOPS 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 'xl save -c/restore' 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 when PVOPS vm is doing 'xl save -c/restore'.

Signed-off-by: Charles Ouyang <ouyangzhaowei@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)
int cpu;
- xen_hvm_init_shared_info();
+ if (!suspend_cancelled)
+ xen_hvm_init_shared_info();
if (xen_feature(XENFEAT_hvm_safe_pvclock)) {

Do we need to call other routines if suspend is canceled?

Also, if suspend is canceled then we don't do xen_irq_resume() if that's what you meant by "vcpu_info will be reinitialized". Were you referring some other re-initialization?

(The patch itself looks like the right thing to do though).

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