From: Gleb Natapov <gleb@redhat.com>
To: Kevin Wolf <kwolf@redhat.com>
Cc: Avi Kivity <avi@redhat.com>,
kvm@vger.kernel.org, joerg.roedel@amd.com,
yoshikawa.takuya@oss.ntt.co.jp, mtosatti@redhat.com
Subject: Re: [PATCH v2 3/3] KVM: x86 emulator: Allow PM/VM86 switch during task switch
Date: Tue, 31 Jan 2012 11:37:46 +0200 [thread overview]
Message-ID: <20120131093746.GJ23536@redhat.com> (raw)
In-Reply-To: <4F26B68E.3030100@redhat.com>
On Mon, Jan 30, 2012 at 04:26:06PM +0100, Kevin Wolf wrote:
> >> Would that be enough or would we have to avoid clearing it in all other
> >> places as well? Where would it be initialised if it's not enough?
> >
> > Maybe vmx_vcpu_reset().
>
> Do all CPL changes go through set_cr0/segment/rflags/cpl? I guess yes,
> so initialising on reset and keeping it valid all the time should be
> possible indeed.
>
CPL can be changed while guest is running. SVM saves it for us in cpl
field. VMX does not, so we either will have to update cpl on each exit
(cpl = cs & 3) or somehow mark it not up-to-date and recalculate on
access. Can VMX exit while cpl != cs & 3 or can this happen only during
emulation? If it can we cannot know real cpl after exit.
--
Gleb.
next prev parent reply other threads:[~2012-01-31 9:37 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-27 19:23 [PATCH v2 0/3] Fix task switches into/out of VM86 Kevin Wolf
2012-01-27 19:23 ` [PATCH v2 1/3] KVM: x86 emulator: Fix task switch privilege checks Kevin Wolf
2012-01-30 10:39 ` Avi Kivity
2012-01-30 11:12 ` Kevin Wolf
2012-01-27 19:23 ` [PATCH v2 2/3] KVM: x86 emulator: VM86 segments must have DPL 3 Kevin Wolf
2012-01-27 19:23 ` [PATCH v2 3/3] KVM: x86 emulator: Allow PM/VM86 switch during task switch Kevin Wolf
2012-01-30 10:24 ` Avi Kivity
2012-01-30 10:56 ` Gleb Natapov
2012-01-30 12:02 ` Avi Kivity
2012-01-30 12:04 ` Gleb Natapov
2012-01-30 13:24 ` Avi Kivity
2012-01-30 11:05 ` Kevin Wolf
2012-01-30 11:09 ` Gleb Natapov
2012-01-30 13:23 ` Avi Kivity
2012-01-30 14:01 ` Kevin Wolf
2012-01-30 14:32 ` Avi Kivity
2012-01-30 15:26 ` Kevin Wolf
2012-01-30 15:44 ` Avi Kivity
2012-01-30 15:55 ` Takuya Yoshikawa
2012-01-31 9:37 ` Gleb Natapov [this message]
2012-01-31 10:26 ` Avi Kivity
2012-01-27 19:52 ` [PATCH v2 0/3] Fix task switches into/out of VM86 Gleb Natapov
2012-01-30 8:48 ` Kevin Wolf
2012-01-30 8:55 ` Gleb Natapov
2012-01-30 10:22 ` Gleb Natapov
2012-01-30 10:35 ` Kevin Wolf
2012-01-30 10:45 ` Avi Kivity
2012-01-30 10:50 ` Gleb Natapov
2012-01-30 11:59 ` Avi Kivity
2012-01-30 12:16 ` Gleb Natapov
2012-01-30 13:27 ` Avi Kivity
2012-01-30 12:31 ` Gleb Natapov
2012-01-30 13:28 ` Avi Kivity
2012-01-30 13:29 ` Gleb Natapov
2012-01-30 13:39 ` Avi Kivity
2012-01-30 10:47 ` Gleb Natapov
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