[V6] x86/vm_event: Added support for VM_EVENT_REASON_INTERRUPT

Commit Message

Razvan Cojocaru Dec. 14, 2016, 9:14 a.m. UTC

On 12/14/2016 11:04 AM, Jan Beulich wrote:
>>>> On 13.12.16 at 15:50, <[e-mail]> wrote:
>> Added support for a new event type, VM_EVENT_REASON_INTERRUPT,
>> which is now fired in a one-shot manner when enabled via the new
>> VM_EVENT_FLAG_GET_NEXT_INTERRUPT vm_event response flag.
>> The patch also fixes the behaviour of the xc_hvm_inject_trap()
>> hypercall, which would lead to non-architectural interrupts
>> overwriting pending (specifically reinjected) architectural ones.
>>
>> Signed-off-by: Razvan Cojocaru <[e-mail]>
>> Acked-by: Tamas K Lengyel <[e-mail]>
>> Acked-by: Jan Beulich <[e-mail]>
>> Acked-by: Kevin Tian <[e-mail]>
>> Acked-by: Suravee Suthikulpanit <[e-mail]>
>> Acked-by: Julien Grall <[e-mail]>
>>
>> ---
>> Changes since V5:
>>  - Rebased on master and re-tested.
> 
> I have to admit that I find this rather annoying: The patch still
> didn't apply cleanly (perhaps because you indeed did what is
> written above, instead of re-basing onto staging, albeit otoh I
> don't see how you would then have run into the build issue you
> reported), which again I took the time to fix up, just to find that
> again things don't build (for ARM at least).

I first tried it on staging, and I found the build failure I've
reported. I could have just run 'make' in the xen/ subdirectory, but
decided instead to make sure that everything still runs properly by
rebasing on master instead, which did build, and actually do a few
introspection test runs with Xen 4.9.

So I was simply being thorough, and working with the master branch is
the recommended in the official Xen patching guide:
https://wiki.xenproject.org/wiki/Submitting_Xen_Project_Patches

Sorry about the ARM build, I will check it out. I've assumed that since
this is the only ARM change in the patch, it couldn't possibly cause any
issues:

 #endif /* __ASM_ARM_VM_EVENT_H__ */

I'll rebase the patch on staging, check out the ARM build, and send V7.


Thanks,
Razvan

Patch

diff --git a/xen/include/asm-arm/vm_event.h b/xen/include/asm-arm/vm_event.h
index 66f2474..ab9c8cb 100644
--- a/xen/include/asm-arm/vm_event.h
+++ b/xen/include/asm-arm/vm_event.h
@@ -52,4 +52,10 @@  void vm_event_emulate_check(struct vcpu *v,
vm_event_response_t *rsp)
     /* Not supported on ARM. */
 }

+static inline
+void vm_event_monitor_next_interrupt(struct vcpu *v)
+{
+    /* Not supported on ARM. */
+}
+