From: Avi Kivity <avi@redhat.com>
To: Anthony Liguori <aliguori@us.ibm.com>
Cc: kvm@vger.kernel.org, Gleb Natapov <gleb@redhat.com>
Subject: Re: [PATCH] When switching to a vm8086 task, load segments as 16-bit (v2)
Date: Wed, 12 Aug 2009 15:11:35 +0300 [thread overview]
Message-ID: <4A82B177.9030607@redhat.com> (raw)
In-Reply-To: <1250024279-6307-1-git-send-email-aliguori@us.ibm.com>
On 08/11/2009 11:57 PM, Anthony Liguori wrote:
> According to 16.2.5 in the SDM, eflags.vm in the tss is consulted before loading
> and new segments. If eflags.vm == 1, then the segments are treated as 16-bit
> segments. The LDTR and TR are not normally available in vm86 mode so if they
> happen to somehow get loaded, they need to be treated as 32-bit segments.
>
> This fixes an invalid vmentry failure in a custom OS that was happening after
> a task switch into vm8086 mode. Since the segments were being mistakenly
> treated as 32-bit, we loaded garbage state.
>
I'm getting a Vista x64 installer failure on reboot with this. One
possibility is that ->get_rflags() is returning the mangled flags state
(we add vm86 for real mode), which confuses the new code.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2009-08-12 12:11 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-11 20:57 [PATCH] When switching to a vm8086 task, load segments as 16-bit (v2) Anthony Liguori
2009-08-12 7:47 ` Avi Kivity
2009-08-12 12:11 ` Avi Kivity [this message]
2009-08-12 12:36 ` Avi Kivity
2009-08-12 13:15 ` Anthony Liguori
2009-08-12 13:40 ` Avi Kivity
2009-08-12 13:50 ` Anthony Liguori
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