From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3BDECC433C1 for ; Fri, 19 Mar 2021 20:44:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDE536196A for ; Fri, 19 Mar 2021 20:44:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230219AbhCSUnq (ORCPT ); Fri, 19 Mar 2021 16:43:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:60456 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230092AbhCSUnU (ORCPT ); Fri, 19 Mar 2021 16:43:20 -0400 Received: by mail.kernel.org (Postfix) with ESMTPS id 8457361989 for ; Fri, 19 Mar 2021 20:43:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616186600; bh=mHSpIH9ybVmZsfU9VFMdM5LDTuGMQwxopt5lZ2u2OxE=; h=From:To:Subject:Date:In-Reply-To:References:From; b=JL1Ooc7CStasbZfrfNA6fhKYcEeZdvPzy7JjNe8/bI59n5yrdVykY6Z6e00+ifbLn UM+Plclc98VO7maBhoaO1LxZpIOP42+uwzqYZNh4kbhW2ctlEdGnrEJd6y3WIrVEze RnZhrWL05Sp7JrLmt/me/5WEu0RUdMLlAdhyJDBPbbe8n9eLjI3IOGn+FkXk0gJNoS CQpAcBv0JllwxWHfdMWa+pR7Lz0f/FcO/f3R3AWxnhQB5wq6MHjzLAvueehvlvih6z I13kpn9KcG6ddzhpXXqd7vn4FQNBIkn+8Yr76GXcY9/peuy42WajErOx2FH4oSwzGg c6NdYKq+RIAkw== From: bugzilla-daemon@bugzilla.kernel.org To: kvm@vger.kernel.org Subject: [Bug 201753] AMD-Vi: Unable to write to IOMMU perf counter Date: Fri, 19 Mar 2021 20:43:19 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: AssignedTo virtualization_kvm@kernel-bugs.osdl.org X-Bugzilla-Product: Virtualization X-Bugzilla-Component: kvm X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: david.coe@live.co.uk X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: virtualization_kvm@kernel-bugs.osdl.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org https://bugzilla.kernel.org/show_bug.cgi?id=3D201753 --- Comment #32 from David Coe (david.coe@live.co.uk) --- I'm pretty sure this is because IOMMU (for some Ryzens) unlatches after 5 t= ries on cold boot and 6 tries on warm. Suravee, alas, has set his patch at 5 x 20 msecs just on the 'dither' point! Some time mid-next week I'll lay my sticky hands on a 4700U laptop. I have images re-compiled for Ubuntu's kernel 5.8.0-45 (20.10) and 5.11.0-11 (21.0= 4) patched at 25 x 20 msecs and logged. Ditto with Alex's oh-so-simple patch. If all goes well(!), I'll draw up a nice, comparative table of mine and everybody else's data so we can draw some conclusions. If you scan the Debian/Ubuntu kernel changelog, you'll find a long list of 'cherry-picked' patches for both AMD and Intel for IOMMU. It is very much a work-in-progress still! Best regards and many thanks all for input. David --=20 You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.=