From: Paolo Bonzini <pbonzini@redhat.com>
To: Mohammed Gamal <m.gamal005@gmail.com>
Cc: avi@redhat.com, mtosatti@redhat.com, kvm@vger.kernel.org
Subject: Re: [PATCH] x86 emulator: Add IRET instruction
Date: Wed, 28 Jul 2010 15:30:10 +0200 [thread overview]
Message-ID: <4C5030E2.8050202@redhat.com> (raw)
In-Reply-To: <1280309920-13539-1-git-send-email-m.gamal005@gmail.com>
On 07/28/2010 11:38 AM, Mohammed Gamal wrote:
> + unsigned long mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_TF |
> + EFLG_IF | EFLG_DF | EFLG_OF | EFLG_IOPL | EFLG_NT | EFLG_RF |
> + EFLG_AC | EFLG_ID | (1 << 1); /* Last one is the reserved bit */
> + unsigned long vm86_mask = EFLG_VM | EFLG_VIF | EFLG_VIP;
> ...
> + if (c->op_bytes == 4)
> + ctxt->eflags = ((temp_eflags & mask) | (ctxt->eflags & vm86_mask));
> + else if (c->op_bytes == 2) {
> + ctxt->eflags &= ~0xffff;
> + ctxt->eflags |= temp_eflags;
> + }
I think that's still not it. You can set reserved bits for c->op_bytes
== 2, and you can clear bit 1 for both 16- and 32-bit IRET.
IOW you need something like this:
mask = ...; /* without (1 << 1); */
ctxt_mask = (1 << 1) | EFLG_VM | EFLG_VIF | EFLG_VIP;
if (c->op_bytes == 2) {
mask &= 0xffff;
ctxt_mask |= ~0xffff;
}
ctxt->eflags = (temp_eflags & mask) | (ctxt->eflags & ctxt_mask);
Paolo
next prev parent reply other threads:[~2010-07-28 13:30 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-28 9:38 [PATCH] x86 emulator: Add IRET instruction Mohammed Gamal
2010-07-28 10:30 ` Avi Kivity
2010-07-28 13:30 ` Paolo Bonzini [this message]
2010-07-28 13:49 ` Paolo Bonzini
2010-07-28 17:15 ` Marcelo Tosatti
-- strict thread matches above, loose matches on Subject: below --
2010-07-27 23:06 Mohammed Gamal
2010-07-28 4:20 ` Avi Kivity
2010-07-25 19:20 Mohammed Gamal
2010-07-25 23:59 ` Paolo Bonzini
2010-07-26 0:07 ` Mohammed Gamal
2010-07-26 3:09 ` Wei Yongjun
2010-07-26 8:47 ` Paolo Bonzini
2010-07-26 9:00 ` Avi Kivity
2010-07-26 9:31 ` Paolo Bonzini
2010-07-26 9:32 ` Paolo Bonzini
2010-07-26 11:38 ` Avi Kivity
2010-07-25 19:18 Mohammed Gamal
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