lkml.org 
[lkml]   [2006]   [Jul]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH 16/33] Add support for Xen to entry.S.
Chris Wright wrote:
> * Rusty Russell (rusty@rustcorp.com.au) wrote:
>
>> On Tue, 2006-07-18 at 00:00 -0700, Chris Wright wrote:
>>
>>> plain text document attachment (i386-entry.S)
>>> - change cli/sti
>>> - change test for user mode return to work for kernel mode in ring1
>>> - check hypervisor saved event mask on return from exception
>>> - add entry points for the hypervisor upcall handlers
>>> - avoid math emulation check when running on Xen
>>> - add nmi handler for running on Xen
>>>
>>> Signed-off-by: Ian Pratt <ian.pratt@xensource.com>
>>> Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
>>> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
>>> Signed-off-by: Chris Wright <chrisw@sous-sol.org>
>>>
>>> ---
>>> arch/i386/kernel/asm-offsets.c | 26 +++++++
>>> arch/i386/kernel/entry.S | 141 ++++++++++++++++++++++++++++++++++++-----
>>> arch/i386/mach-xen/setup-xen.c | 19 +++++
>>> drivers/xen/core/features.c | 2
>>> 4 files changed, 169 insertions(+), 19 deletions(-)
>>>
>>> diff -r 5cca1805b8a7 arch/i386/kernel/entry.S
>>> --- a/arch/i386/kernel/entry.S Tue Jul 18 02:20:39 2006 -0400
>>> +++ b/arch/i386/kernel/entry.S Tue Jul 18 02:22:56 2006 -0400
>>> @@ -76,8 +76,39 @@ NT_MASK = 0x00004000
>>> NT_MASK = 0x00004000
>>> VM_MASK = 0x00020000
>>>
>>> +#ifndef CONFIG_XEN
>>> +#define DISABLE_INTERRUPTS cli
>>> +#define ENABLE_INTERRUPTS sti
>>> +#else
>>> +#include <xen/interface/xen.h>
>>> +
>>> +EVENT_MASK = 0x2E
>>> +
>>> +/* Offsets into shared_info_t. */
>>> +#define evtchn_upcall_pending /* 0 */
>>> +#define evtchn_upcall_mask 1
>>>
>> Erk... Can we get these into asm-offsets?
>>
>
> Hmm, we put the vcpu shift in, guess we missed that. Thanks for noticing.
>
>
>>> +
>>> +#ifdef CONFIG_SMP
>>> +/* Set %esi to point to the appropriate vcpu structure */
>>> +#define GET_VCPU_INFO movl TI_cpu(%ebp),%esi ; \
>>> + shl $SIZEOF_VCPU_INFO_SHIFT,%esi ; \
>>> + addl HYPERVISOR_shared_info,%esi
>>> +#else
>>> +#define GET_VCPU_INFO movl HYPERVISOR_shared_info,%esi
>>> +#endif
>>> +
>>> +/* The following end up using/clobbering %esi, because of GET_VCPU_INFO */
>>> +#define __DISABLE_INTERRUPTS movb $1,evtchn_upcall_mask(%esi)
>>> +#define DISABLE_INTERRUPTS GET_VCPU_INFO ; \
>>> + __DISABLE_INTERRUPTS
>>> +#define ENABLE_INTERRUPTS GET_VCPU_INFO ; \
>>> + movb $0,evtchn_upcall_mask(%esi)
>>> +#define __TEST_PENDING testb $0xFF,evtchn_upcall_pending(%esi)
>>> +#endif
>>>
>> Actually, is it possible to move these to a header somewhere? In the
>> paravirt_ops patches I used the names CLI and STI (copied from the VMI
>> patches), but didn't allow them to clobber any regs. They're defined in
>> asm-i386/paravirt.h.
>>
>
> Sure, although it's only used here. Got a preference?
>

It might be an idea to use something other than STI, CLI and CPUID,
since the assembler is case-insensitive. We've already had one bug
where CPUID didn't get replaced and the assembler quietly accepted it as-is.

J
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-07-19 01:05    [W:0.084 / U:0.520 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site