Re: [PATCH] target/i386: seg_helper: Correct segement selector nullification in the RET/IRET helper

[Bin Meng]

On Thu, Oct 22, 2020 at 6:16 PM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> From: Bin Meng <bin.meng@windriver.com>
>
> Per the SDM, when returning to outer privilege level, for segment
> registers (ES, FS, GS, and DS) if the check fails, the segment
> selector becomes null, but QEMU clears the base/limit/flags as well
> as nullifying the segment selector, which should be a spec violation.
>
> Real hardware seems to be compliant with the spec, at least on one
> Coffee Lake board I tested.
>
> Signed-off-by: Bin Meng <bin.meng@windriver.com>
> ---
>
>  target/i386/seg_helper.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>

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