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From: Will Deacon <will.deacon@arm.com>
To: Marc Zyngier <marc.zyngier@arm.com>
Cc: "kvmarm@lists.cs.columbia.edu" <kvmarm@lists.cs.columbia.edu>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
	"linux@arm.linux.org.uk" <linux@arm.linux.org.uk>,
	"christoffer.dall@linaro.org" <christoffer.dall@linaro.org>,
	"stable@vger.kernel.org" <stable@vger.kernel.org>
Subject: Re: [PATCH] KVM: arm64: add workaround for Cortex-A57 erratum #852523
Date: Mon, 14 Sep 2015 18:01:11 +0100	[thread overview]
Message-ID: <20150914170111.GH23878@arm.com> (raw)
In-Reply-To: <55F6EBD4.30809@arm.com>

On Mon, Sep 14, 2015 at 04:46:28PM +0100, Marc Zyngier wrote:
> On 14/09/15 16:06, Will Deacon wrote:
> > When restoring the system register state for an AArch32 guest at EL2,
> > writes to DACR32_EL2 may not be correctly synchronised by Cortex-A57,
> > which can lead to the guest effectively running with junk in the DACR
> > and running into unexpected domain faults.
> > 
> > This patch works around the issue by re-ordering our restoration of the
> > AArch32 register aliases so that they happen before the AArch64 system
> > registers. Ensuring that the registers are restored in this order
> > guarantees that they will be correctly synchronised by the core.
> > 
> > Cc: <stable@vger.kernel.org>
> > Cc: Marc Zyngier <marc.zyngier@arm.com>
> > Signed-off-by: Will Deacon <will.deacon@arm.com>
> 
> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
> 
> I'll queue that together with the next batch of fixes.

Great, thanks Marc.

Will

WARNING: multiple messages have this Message-ID (diff)
From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] KVM: arm64: add workaround for Cortex-A57 erratum #852523
Date: Mon, 14 Sep 2015 18:01:11 +0100	[thread overview]
Message-ID: <20150914170111.GH23878@arm.com> (raw)
In-Reply-To: <55F6EBD4.30809@arm.com>

On Mon, Sep 14, 2015 at 04:46:28PM +0100, Marc Zyngier wrote:
> On 14/09/15 16:06, Will Deacon wrote:
> > When restoring the system register state for an AArch32 guest at EL2,
> > writes to DACR32_EL2 may not be correctly synchronised by Cortex-A57,
> > which can lead to the guest effectively running with junk in the DACR
> > and running into unexpected domain faults.
> > 
> > This patch works around the issue by re-ordering our restoration of the
> > AArch32 register aliases so that they happen before the AArch64 system
> > registers. Ensuring that the registers are restored in this order
> > guarantees that they will be correctly synchronised by the core.
> > 
> > Cc: <stable@vger.kernel.org>
> > Cc: Marc Zyngier <marc.zyngier@arm.com>
> > Signed-off-by: Will Deacon <will.deacon@arm.com>
> 
> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
> 
> I'll queue that together with the next batch of fixes.

Great, thanks Marc.

Will

  parent reply	other threads:[~2015-09-14 17:01 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-14 15:06 [PATCH] KVM: arm64: add workaround for Cortex-A57 erratum #852523 Will Deacon
2015-09-14 15:06 ` Will Deacon
2015-09-14 15:06 ` Will Deacon
2015-09-14 15:36 ` Ian Campbell
2015-09-14 15:58   ` Will Deacon
2015-09-14 23:08     ` Julien Grall
2015-09-15  8:40       ` Ian Campbell
2015-09-14 15:46 ` Marc Zyngier
2015-09-14 15:46   ` Marc Zyngier
2015-09-14 17:01   ` Will Deacon
2015-09-14 17:01   ` Will Deacon [this message]
2015-09-14 17:01     ` Will Deacon
2015-09-15 19:00   ` Christoffer Dall
2015-09-15 19:00     ` Christoffer Dall
2015-09-15 19:00   ` Christoffer Dall
2015-09-14 15:46 ` Marc Zyngier
  -- strict thread matches above, loose matches on Subject: below --
2015-09-14 15:06 Will Deacon

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