On 06/12/16 13:25, Jan Beulich wrote:
> Both need to raise #GP(0) when in VM86 mode with IOPL < 3.
>
> Additionally PUSHF is documented to clear VM and RF from the value
> placed onto the stack.
>
> Signed-off-by: Jan Beulich <jbeul...@suse.com>
>
> --- a/xen/arch/x86/x86_emulate/x86_emulate.c
> +++ b/xen/arch/x86/x86_emulate/x86_emulate.c
> @@ -3121,13 +3121,20 @@ x86_emulate(
> }
>
> case 0x9c: /* pushf */
> - src.val = _regs.eflags;
> + generate_exception_if((_regs.eflags & EFLG_VM) &&
> + (_regs.eflags & EFLG_IOPL) != EFLG_IOPL,
How about "MASK_EXTR(_regs.eflags, EFLG_IOPL) != 3"
This would be rather clear to read, as the two EFLG_IOPL have two
different purposes in the line as presented.
Otherwise, Reviewed-by: Andrew Cooper <andrew.coop...@citrix.com>
> + EXC_GP, 0);
> + src.val = _regs.eflags & ~(EFLG_VM | EFLG_RF);
> goto push;
>
> case 0x9d: /* popf */ {
> uint32_t mask = EFLG_VIP | EFLG_VIF | EFLG_VM;
> +
> if ( !mode_ring0() )
> {
> + generate_exception_if((_regs.eflags & EFLG_VM) &&
> + (_regs.eflags & EFLG_IOPL) != EFLG_IOPL,
> + EXC_GP, 0);
> mask |= EFLG_IOPL;
> if ( !mode_iopl() )
> mask |= EFLG_IF;
>
>
>
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