Re: [Qemu-devel] [5318] SYSENTER/SYSEXIT IA-32e implementation (Alexander Graf).

[Alexander Graf <agraf@suse.de>]

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Anthony Liguori wrote:
> Andrzej Zaborowski wrote:
>> Revision: 5318
>>           http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=5318
>> Author:   balrog
>> Date:     2008-09-25 18:16:18 +0000 (Thu, 25 Sep 2008)
>>
>> Log Message:
>> -----------
>> SYSENTER/SYSEXIT IA-32e implementation (Alexander Graf).
>>
>> On Intel CPUs, sysenter and sysexit are valid in 64-bit mode. This patch
>> makes both 64-bit aware and enables them for Intel CPUs.
>> Add cpu save/load for 64-bit wide sysenter variables.
>>
>> Signed-off-by: Alexander Graf <agraf@suse.de>
>>   
>
> This change broke save/restore.  It was already broken when this 
> commit happened so it really just further broke it :-)
>
>> Modified: trunk/target-i386/cpu.h
>> ===================================================================
>> --- trunk/target-i386/cpu.h    2008-09-25 18:11:30 UTC (rev 5317)
>> +++ trunk/target-i386/cpu.h    2008-09-25 18:16:18 UTC (rev 5318)
>> @@ -549,8 +549,8 @@
>>  
>>      /* sysenter registers */
>>      uint32_t sysenter_cs;
>>   
>
> is a u32
>
>> -    uint32_t sysenter_esp;
>> -    uint32_t sysenter_eip;
>> +    target_ulong sysenter_esp;
>> +    target_ulong sysenter_eip;
>>      uint64_t efer;
>>      uint64_t star;
>>   
>
> But is being saved as a target_ulong.
>
>> -    qemu_put_be32s(f, &env->sysenter_cs);
>> -    qemu_put_be32s(f, &env->sysenter_esp);
>> -    qemu_put_be32s(f, &env->sysenter_eip);
>> +    qemu_put_betls(f, &env->sysenter_cs);
>> +    qemu_put_betls(f, &env->sysenter_esp);
>> +    qemu_put_betls(f, &env->sysenter_eip);
>>  
>>      qemu_put_betls(f, &env->cr[0]);
>>      qemu_put_betls(f, &env->cr[2]);
>> @@ -169,7 +169,7 @@
>
> And loaded as a u32.
>
>>  
>>      qemu_get_be32s(f, &env->sysenter_cs);
>> -    qemu_get_be32s(f, &env->sysenter_esp);
>> -    qemu_get_be32s(f, &env->sysenter_eip);
>> +    if (version_id >= 7) {
>> +        qemu_get_betls(f, &env->sysenter_esp);
>> +        qemu_get_betls(f, &env->sysenter_eip);
>> +    } else {
>> +        qemu_get_be32s(f, &env->sysenter_esp);
>> +        qemu_get_be32s(f, &env->sysenter_eip);
>> +    }
>>  
>
> When making changes to target-i386, please make sure to test both qemu 
> and qemu-system-x86_64.  In this case, the code would have worked with 
> qemu but it doesn't work with qemu-system-x86_64.

Ouch, thanks for the catch. Please  double-check and apply :-).

Alex

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Index: target-i386/machine.c
===================================================================
--- target-i386/machine.c	(revision 5350)
+++ target-i386/machine.c	(working copy)
@@ -88,7 +88,7 @@
     cpu_put_seg(f, &env->gdt);
     cpu_put_seg(f, &env->idt);
 
-    qemu_put_betls(f, &env->sysenter_cs);
+    qemu_put_be32s(f, &env->sysenter_cs);
     qemu_put_betls(f, &env->sysenter_esp);
     qemu_put_betls(f, &env->sysenter_eip);