On 2015.5.5 17:09, David Vrabel wrote:
> 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
Sure, please let me know if there is anything not clear enough.
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 <ouyangzhao...@huawei.com>
>> Reviewed-by: Boris Ostrovsky <boris.ostrov...@oracle.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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