[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH 1/9] x86/hypercall: Move some of the hvm hypercall infrastructure into hypercall.h



Hi Jan,

On 02/08/16 14:28, Jan Beulich wrote:
On 02.08.16 at 15:14, <andrew.cooper3@xxxxxxxxxx> wrote:
On 02/08/16 13:50, Jan Beulich wrote:
On 18.07.16 at 11:51, <andrew.cooper3@xxxxxxxxxx> wrote:
--- a/xen/include/asm-x86/hypercall.h
+++ b/xen/include/asm-x86/hypercall.h
@@ -5,9 +5,21 @@
 #ifndef __ASM_X86_HYPERCALL_H__
 #define __ASM_X86_HYPERCALL_H__

+#include <xen/types.h>
 #include <public/physdev.h>
+#include <public/event_channel.h>
Why?

You snipped the commit message, which justifies why.  This header file
cannot currently be included in isolation, and I need it to be.

Ah, that sentence there also relates to this addition.

 #include <public/arch-x86/xen-mca.h> /* for do_mca */
-#include <xen/types.h>
+
+typedef unsigned long hypercall_fn_t(
+    unsigned long, unsigned long, unsigned long,
+    unsigned long, unsigned long, unsigned long);
Wouldn't this better go into xen/hypercall.h?

It is architecture specific.

ARM's version is

typedef register_t (*arm_hypercall_fn_t)(
    register_t, register_t, register_t, register_t, register_t);

Which is bogus - they're lucky we so far don't have any 6-argument
hypercalls. Or the other way around - we could limit hypercalls to
just five arguments (for now) on x86 too, allowing things to get
unified. Anyway - that probably goes too far right now, so feel free
to add my ack to the patch.

I am not sure why you think we are lucky on ARM. The hypercall has been defined on ARM to support up to 5 arguments (public/arch-arm.h):

"A hypercall can take up to 5 arguments. These are passed in
registers, the first argument in x0/r0 (for arm64/arm32 guests
respectively irrespective of whether the underlying hypervisor is
32- or 64-bit), the second argument in x1/r1, the third in x2/r2,
the forth in x3/r3 and the fifth in x4/r4."

So the prototype matches the ABI.

Regards,

--
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.