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

[Anthony Liguori <anthony@codemonkey.ws>]

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.

Regards,

Anthony Liguori