From: Paolo Bonzini <pbonzini@redhat.com>
To: Paul Mackerras <paulus@ozlabs.org>,
kvm@vger.kernel.org, kvm-ppc@vger.kernel.org
Cc: Alexander Graf <agraf@suse.de>, David Gibson <dgibson@redhat.com>
Subject: Re: [PATCH] KVM: PPC: Book3S HV: Sanitize special-purpose register values on guest exit
Date: Mon, 07 Mar 2016 14:07:03 +0000 [thread overview]
Message-ID: <56DD8B07.8050903@redhat.com> (raw)
In-Reply-To: <20160307111230.GC32019@fergus.ozlabs.ibm.com>
On 07/03/2016 12:12, Paul Mackerras wrote:
> Thomas Huth discovered that a guest could cause a hard hang of a
> host CPU by setting the Instruction Authority Mask Register (IAMR)
> to a suitable value. It turns out that this is because when the
> code was added to context-switch the new special-purpose registers
> (SPRs) that were added in POWER8, we forgot to add code to ensure
> that they were restored to a sane value on guest exit.
>
> This adds code to set the those registers where a bad value could
> compromise the execution of the host kernel to a suitable neutral
> value on guest exit.
>
> Cc: stable@vger.kernel.org # v3.14+
> Fixes: b73117c49364
> Reported-by: Thomas Huth <thuth@redhat.com>
> Signed-off-by: Paul Mackerras <paulus@samba.org>
> ---
> Paolo, since this fixes a bug where a guest can cause a hard hang
> of a host CPU, I'd like it to go in 4.5 if possible.
Sure.
Paolo
WARNING: multiple messages have this Message-ID (diff)
From: Paolo Bonzini <pbonzini@redhat.com>
To: Paul Mackerras <paulus@ozlabs.org>,
kvm@vger.kernel.org, kvm-ppc@vger.kernel.org
Cc: Alexander Graf <agraf@suse.de>, David Gibson <dgibson@redhat.com>
Subject: Re: [PATCH] KVM: PPC: Book3S HV: Sanitize special-purpose register values on guest exit
Date: Mon, 7 Mar 2016 15:07:03 +0100 [thread overview]
Message-ID: <56DD8B07.8050903@redhat.com> (raw)
In-Reply-To: <20160307111230.GC32019@fergus.ozlabs.ibm.com>
On 07/03/2016 12:12, Paul Mackerras wrote:
> Thomas Huth discovered that a guest could cause a hard hang of a
> host CPU by setting the Instruction Authority Mask Register (IAMR)
> to a suitable value. It turns out that this is because when the
> code was added to context-switch the new special-purpose registers
> (SPRs) that were added in POWER8, we forgot to add code to ensure
> that they were restored to a sane value on guest exit.
>
> This adds code to set the those registers where a bad value could
> compromise the execution of the host kernel to a suitable neutral
> value on guest exit.
>
> Cc: stable@vger.kernel.org # v3.14+
> Fixes: b73117c49364
> Reported-by: Thomas Huth <thuth@redhat.com>
> Signed-off-by: Paul Mackerras <paulus@samba.org>
> ---
> Paolo, since this fixes a bug where a guest can cause a hard hang
> of a host CPU, I'd like it to go in 4.5 if possible.
Sure.
Paolo
next prev parent reply other threads:[~2016-03-07 14:07 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-07 11:12 [PATCH] KVM: PPC: Book3S HV: Sanitize special-purpose register values on guest exit Paul Mackerras
2016-03-07 11:12 ` Paul Mackerras
2016-03-07 14:07 ` Paolo Bonzini [this message]
2016-03-07 14:07 ` Paolo Bonzini
2016-03-08 2:31 ` David Gibson
2016-03-08 2:31 ` David Gibson
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