Date: Wed, 8 Jul 2015 12:28:46 +0200
From: Robert Richter <robert.richter@caviumnetworks.com>
To: Marc Zyngier <marc.zyngier@arm.com>
CC: Robert Richter <rric@kernel.org>, Thomas Gleixner <tglx@linutronix.de>,
        Jason Cooper <jason@lakedaemon.net>,
        Tirumalesh Chalamarla <tchalamarla@cavium.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 3/4] irqchip, gicv3: Implement Cavium ThunderX erratum
 23154
Message-ID: <20150708102846.GT10428@rric.localhost>
References: <1435673643-31676-1-git-send-email-rric@kernel.org>
 <1435673643-31676-4-git-send-email-rric@kernel.org>
 <559A5BB6.2040509@arm.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <559A5BB6.2040509@arm.com>
User-Agent: Mutt/1.5.23 (2014-03-12)
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Jul 2015 10:28:57.9143 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY1PR0701MB1616
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 1099
Lines: 36

Marc,

On 06.07.15 11:43:02, Marc Zyngier wrote:
> On 30/06/15 15:14, Robert Richter wrote:
> >  static const struct gic_capabilities gicv3_errata[] = {
> >  	{
> > +		.desc	= "GIC: Cavium erratum 23154",
> > +		.id	= 0xa100034c,	/* ThunderX pass 1.x */
> > +		.mask	= 0xffff0fff,
> > +		.init	= gicv3_enable_cavium_thunderx,
> > +	},
> > +	{
> >  	}
> >  };
> >  
> > 
> 
> How does this work when running a guest? Does the virtualized access
> suffer from the same erratum? If that's the case, we need a better
> workaround...

We need to apply the workaround also for guests. So you are right,
evaluating GICD_IIDR does not enable the workaround then as the
register is emulated with ARM as implementer.

We considering MIDR_EL1 as a version check for this errata now. This
should be the host's cpuid when running as a guest, right?

Thanks,

-Robert
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/