[Libvir] PATCH: support Xen 3.0.5
Richard W.M. Jones
rjones at redhat.com
Thu Apr 12 09:02:45 UTC 2007
A Man Without A Country Daniel P. Berrange wrote:
> I've been doing some testing with current xen-unstable (ie what will very
> shortly be 3.0.5) and came across a whole bunch of things which needed
> fixing - some expected, others not expected. The attached patch addresses
> the following issues:
As a general question about policy, are we going to support every rev of
the HV interface? If Xen change the interface again before 3.0.5 will
we support this "pre-3.0.5" and the final interface?
> - Many of the hypercalls have their structs changed so that int64_t
> or 'foo *' members are always 64-bit aligned even on 32-bit platforms.
> This is part of the work to allow 32-bit Dom0/DomU to work on 64-bit
> hypervisor.
>
> For the int64_t types I had to annotate with __attribute__((aligned(8))).
> This did not work for pointer data types, so I for those I had to do
> a more complex hack with
>
> union {
> foo *v;
> int64_t pad __attribute__((aligned(8)))
> }
What is the problem here? I did some tests and it seems to work just fine:
/* Test alignment of pointers.
* Richard Jones <rjones~at~redhat~dot~com>
*/
#include <stdio.h>
#undef offsetof
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
struct s {
char c;
//int v;
//int v __attribute__((aligned(16)));
int *v __attribute__((aligned(16)));
//struct s *v __attribute__((aligned(16)));
};
int
main ()
{
printf ("offset = %d\n", offsetof (struct s, v));
return 0;
}
$ gcc -Wall -Werror align.c -o align
$ ./align
offset = 16
$ arch
i686
$ gcc --version
gcc (GCC) 3.3.5 (Debian 1:3.3.5-13)
Copyright (C) 2003 Free Software Foundation, Inc. [etc]
> - The unified Xen driver broke the GetVCPUs method - it was mistakenly
> checking for return value == 0, instead of > 0. Trivial fix.
Ooops.
> I've tested all this on a 32-bit Dom0 running on 32-bit HV, and 64-bit HV,
> but not tested a 64-bit Dom0 on 64-bit HV. I'm pretty sure it'll work,but
> if anyone is runnning 64-on-64 please test this patch.
I don't have 3.0.5 to test here, but I can possibly test this on Monday.
In the meantime I eyeballed the patch and from what I can tell it
seems fine.
Rich.
--
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