[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH 4/8] VT-d: refuse to use IOMMU with reserved CAP.ND value


  • To: Roger Pau Monné <roger.pau@xxxxxxxxxx>
  • From: Jan Beulich <jbeulich@xxxxxxxx>
  • Date: Tue, 12 Apr 2022 12:35:54 +0200
  • Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=suse.com; dmarc=pass action=none header.from=suse.com; dkim=pass header.d=suse.com; arc=none
  • Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=f71msdOqqBAgXBkZWxPjrJDYt9BvK8zXaPfKjRtojEo=; b=WN5p7Z0LHzt3h808LntcdLLZ8lzpQNGsnD5Co0OhMH4/xHOBN33LujOqln4HEA+RnsXlomP9GnIfuBaBlpXfTv1Ymnw97UnBbt0ELH6OZQldXQn3D6Xzsxdt58SiviVVqR8p3Citz+3DOKh9YyzSOBVX9kkLKAwLe6BURa6LocVjCxK5IyAGS1QNRvpLuI0O7F0D/vbsxIjmH+9Y57dN+cK8Zj2oL7DztlzBd4dTqMKSW2z3gGOofmk+X/x3kb7gF0PICH0GyhT/mWqhDWZJqFXXk8jveAfwHqGVeZsCHP0+/4nsushO+4sGijR8bhFbiYWBwyUD5hpdB+D3rm5auA==
  • Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=luRPLNHCiL8kgv1vAo/TIqVP/djujOpY+mntta9pcLUnHvKH3x+5mWbU4Lcs1JrAiRuQzpAe0o0cUqwtNaPSjujgKcZ7MLcXwy19tLbNmwB5wX9uLzwAx00WHpx+tCqKyvp9Z5OiQduTkaSjNmQ+8r3/UqVCsj4Ex6m+bOgO4MHPLXHLooog9y+3K2uNfXrhdsNSv5QMO5q9jBpDeTFbbwYx5IAALZ+lldzkmxzNgE6pE29cJ4OeM6OVmPFLPckyTgQz5P5ffavXk6DQ6MN4ek5CHBgGflfAG/sNJcYyHU95VFCo6wRQu3Sd04BBy9jiGDsX2oH5O3n5GCeYKm2x5Q==
  • Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=suse.com;
  • Cc: "xen-devel@xxxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxxx>, Kevin Tian <kevin.tian@xxxxxxxxx>, Paul Durrant <paul@xxxxxxx>
  • Delivery-date: Tue, 12 Apr 2022 10:36:06 +0000
  • List-id: Xen developer discussion <xen-devel.lists.xenproject.org>

On 12.04.2022 11:22, Roger Pau Monné wrote:
> On Mon, Apr 11, 2022 at 11:37:28AM +0200, Jan Beulich wrote:
>> The field taking the value 7 (resulting in 18-bit DIDs when using the
>> calculation in cap_ndoms(), when the DID fields are only 16 bits wide)
>> is reserved. Instead of misbehaving in case we would encounter such an
>> IOMMU, refuse to use it.
>>
>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> 
> Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

Thanks.

> I would maybe prefer to get more specific error message rather than
> "IOMMU: unsupported" and a dump of the iommu registers.

Perhaps, but this extends to other properties being checked as well then,
I would say, and hence may want to be the subject of yet another patch.

Jan




 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.