Re: [Qemu-devel] [PATCHv2 0/4] Set eflags prior to segments; fix cpl in SMM

[Andreas Färber]

Am 30.04.2014 10:37, schrieb Paolo Bonzini:
> Il 29/04/2014 22:37, Kevin O'Connor ha scritto:
>> This patch series is an update to the patch I sent at:
>>
>> https://lists.gnu.org/archive/html/qemu-devel/2014-04/msg04028.html
>>
>> The goal of the patch series is to fix the SMM handler so that it runs
>> with the proper cpl.  I've broken the series up based on the feedback
>> from Paolo.
>>
>> As with the previous patch, this series moves cr0 and eflags changes
>> above cpu_x86_load_seg_cache() calls as cpu_x86_load_seg_cache()
>> inspects those flags.  I didn't move the eflags setting in
>> helper_ret_protected() because I don't think I can easily move the
>> eflags logic (it's not clear to me that it is safe to change eflags
>> prior to exception checks) and helper_ret_protected() doesn't change
>> any eflags bits that cpu_x86_load_seg_cache() cares about.
>>
>> That said, continuing to have cpu_x86_load_seg_cache() depend on cr0
>> and eflags is painful.  I do wonder if it would be better to calculate
>> hflags lazily to eliminate these ordering issues.
> 
> Reviewed-by: Paolo Bonzini <address@hidden>
> 
> Richard, Andreas, who is going to take this? 

Not my comfort zone.

> I can do it too since I
> plan to put my soft-reset target-i386/ patches in uq/master after they
> are reviewed.
> 
>> Kevin O'Connor (4):
>>   Set eflags prior to calling svm_load_seg_cache() in svm_helper.c.
>>   Set eflags and cr0 prior to calling cpu_x86_load_seg_cache() in
>>     smm_helper.c.
>>   Set eflags prior to calling cpu_x86_load_seg_cache() in seg_helper.c.
>>   The x86 CPL is stored in CS.selector - auto update hflags accordingly.

Please update the subjects to have "target-i386: " and drop the trailing
dot when either of you queues them.

Thanks,
Andreas

>>
>>  bsd-user/main.c          |  2 --
>>  linux-user/main.c        |  2 --
>>  target-i386/cpu.h        | 25 +++++++++++------------
>>  target-i386/seg_helper.c | 53
>> +++++++++++++++++-------------------------------
>>  target-i386/smm_helper.c | 34 +++++++++++++++----------------
>>  target-i386/svm_helper.c | 11 ++--------
>>  6 files changed, 50 insertions(+), 77 deletions(-)

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