[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH RESEND 0/3][4.16?] VT-d: misc (regression) fixes
- To: "xen-devel@xxxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxxx>
- From: Jan Beulich <jbeulich@xxxxxxxx>
- Date: Fri, 12 Nov 2021 11:31:21 +0100
- 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=HnuP7QcwIlJAt4A1Wfn2ZyD3e0l7FRzYFgO5D4oczZg=; b=ArWrr1B/kejWUbWfJomU3xdP9GUSGJVFpkx2l+0iRCEbyz+7CllponfpqoAwx4DNMilW0ywjHETc4NM11DEGBjnNxblS3qUTo94bMp2VWVYjVYX76klsvgBtXB49QEz3p69UNjkiH6wmhCkp4+pW9pjCtAIEcjAgYSHyHK/UJ+vdHtElpUY+xq0n06Cv2ZN8n1hzqOJwD7PHDIK3q80i3STXZrrZdme3AR4N4kA0KKmNeaXJ6cItCV7ahr+Ilxvm7GT5hqYpLqGs0NrWYsNyRr9b0dWasme3Xbz/bCPLMuLIF6LnfF0zEKJmucu6f06PyNQujX31pELEWG0wS4HfHg==
- Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=AtWx1GpO6woXWc3EcVcqHyUMXrxRpnzMOTo8VqwR5Wj/982iEmEBH6G5RHdOn1Xk1WscgkNO9sizV7LNB+p6mK8ct+QzGHPrCJHFu1B+KH15q3WcYpTN2e+vz6/T9cLMygXR6sFSKv5COBeIX8vm6I1tXifSmXAyTPT/eFYj0iVe4z/8Oqi22NB53GRpmxSkRcwcA+B+IdwWfnfMMoFK2VchgPOi5WVaiIHVZAqWWSWhnJekf6OoE1fVgITHFeQb1hp9BeFFKun6YgXrP52CDFlP2B+cX3usSGIAGhpWfrR8iNAYF47Ifta09LqMllwdGJ/dxebwN7ca1EyoXyT0FQ==
- Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=suse.com;
- Cc: Kevin Tian <kevin.tian@xxxxxxxxx>, Paul Durrant <paul@xxxxxxx>, Ian Jackson <iwj@xxxxxxxxxxxxxx>
- Delivery-date: Fri, 12 Nov 2021 10:31:42 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
(re-sending upon Ian's request with his address adjusted, including
Kevin's R-b at this occasion)
1: per-domain IOMMU bitmap needs to have dynamic size
2: fix reduced page table levels support when sharing tables
3: don't needlessly engage the untrusted-MSI workaround
As to 4.16 considerations: Only patch 1 addresses a regression
introduced after 4.15, the others are older. Patch 3 additionally
only addresses an inefficiency; the code we have is correct from
a functional pov.
As to patch 1: Without the earlier change, systems with more than 32
IOMMUs simply would fail to enable use of the IOMMUs altogether. Now
systems with more than 64 IOMMUs would observe memory corruption
(with unclear knock-on effects). Whether systems with this many IOMMUs
actually exist I can't tell; I know of ones with 40, which isn't all
that far away from 64.
Jan
|
