|
|
|
|
|
|
|
|
|
|
xen-devel
RE: Hypercall number assignment convension (was Re: [Xen-devel] Re:[PATC
To: |
"Keir Fraser" <Keir.Fraser@xxxxxxxxxxxx> |
Subject: |
RE: Hypercall number assignment convension (was Re: [Xen-devel] Re:[PATCH]: kexec: framework and i386) |
From: |
"Tian, Kevin" <kevin.tian@xxxxxxxxx> |
Date: |
Wed, 26 Apr 2006 15:54:05 +0800 |
Cc: |
xen-devel@xxxxxxxxxxxxxxxxxxx, Akio Takebe <takebe_akio@xxxxxxxxxxxxxx>, Isaku Yamahata <yamahata@xxxxxxxxxxxxx>, Magnus Damm <magnus@xxxxxxxxxxxxx>, Horms <horms@xxxxxxxxxxxx>, Mark Williamson <mark.williamson@xxxxxxxxxxxx> |
Delivery-date: |
Wed, 26 Apr 2006 00:54:44 -0700 |
Envelope-to: |
www-data@xxxxxxxxxxxxxxxxxx |
List-help: |
<mailto:xen-devel-request@lists.xensource.com?subject=help> |
List-id: |
Xen developer discussion <xen-devel.lists.xensource.com> |
List-post: |
<mailto:xen-devel@lists.xensource.com> |
List-subscribe: |
<http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe> |
List-unsubscribe: |
<http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe> |
Sender: |
xen-devel-bounces@xxxxxxxxxxxxxxxxxxx |
Thread-index: |
AcZpBP0DntZ/dy+9Rz2I/Cf+frEvmwAAEU9g |
Thread-topic: |
Hypercall number assignment convension (was Re: [Xen-devel] Re:[PATCH]: kexec: framework and i386) |
>From: Keir Fraser [mailto:Keir.Fraser@xxxxxxxxxxxx]
>Sent: 2006年4月26日 15:38
>
>On 26 Apr 2006, at 03:34, Tian, Kevin wrote:
>
>> I prefer to the first one. However not the current
>> __HYPERVISOR_arch_specific_0, *_1, *_2, ..., how about just call
>> it as __HYPERVISOR_arch_specific_ops which contains another
>> namespace defined by different architecture seperately?
>
>Sometimes you might want a fast hypercall that doesn't have two levels
>of demultiplexing, or where the register/stack parameters are carefully
>crafted and would not fit with an ioctl()-style hypercall (see x86's
>IRET hypercall).
See.
>
>How about reserving 8 or 16 arch-specific hypercalls up front?
>#define __HYPERVISOR_arch_0 32
> ...
>#define __HYPERVISOR_arch_7 39
>
>We could give a bit of breathing space to the non-arch range by
>starting __HYPERVISOR_arch_* at. e.g., 40 or 48?
>
> -- Keir
Then we may need to fill that breathing space with do_ni_hypercall
to ensure no leakage from NR_hypercall check. If that's the case,
how about define the __HYPERVISOR_arch_* at end of 256 spaces,
and fill all unused entries with do_ni_hypercall. By that way, the check
to illegal hypercall (<256) is a bit slower, however it shouldn't matter
for that rare cases.
Thanks,
Kevin
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
|
|
|
|