From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id B3C1F9053A for ; Thu, 1 Sep 2022 08:26:00 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id A8852233AC for ; Thu, 1 Sep 2022 08:26:00 +0200 (CEST) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [94.136.29.106]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS for ; Thu, 1 Sep 2022 08:25:58 +0200 (CEST) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id AE8E44339F for ; Thu, 1 Sep 2022 08:25:58 +0200 (CEST) Message-ID: <26cef061-6d28-1d8b-b7a7-5810054ff023@proxmox.com> Date: Thu, 1 Sep 2022 08:25:50 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.13.0 Content-Language: en-US To: pve-devel@lists.proxmox.com References: <20220831132803.5596-1-f.ebner@proxmox.com> From: Fiona Ebner In-Reply-To: <20220831132803.5596-1-f.ebner@proxmox.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-SPAM-LEVEL: Spam detection results: 0 AWL -0.079 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment KAM_LOTSOFHASH 0.25 Emails with lots of hash-like gibberish NICE_REPLY_A -0.001 Looks like a legit reply (A) SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record T_SCC_BODY_TEXT_LINE -0.01 - URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [proxmox.com, launchpad.net] Subject: Re: [pve-devel] [RFC kernel] revert problematic TSC multiplier commit X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 01 Sep 2022 06:26:00 -0000 Am 31.08.22 um 15:28 schrieb Fiona Ebner: > which might be responsible for several issues reported in the > community forum[0][1]. > > In my case, loading a VM snapshot that originally was taken on > a CPU from a different vendor often caused problems in other VMs(!). > In particular, it often led to RCU stalls (with similar messages as in > [1]) or slowdowns, and sometimes clock jumps far into the future (like > in [0]). With this revert applied, everything seems to run smoothly > even after loading the "bad" snapshot 10 times. > > [0] https://forum.proxmox.com/threads/112756/ > [1] https://forum.proxmox.com/threads/111494/ > > Signed-off-by: Fiona Ebner > --- > > Needed to build with an ABI bump, AFAICT because of the removed > KVM_X86_OP(write_tsc_multiplier), but it's even an ABI break I guess? > If this is not ok, we can either > A) try to revert while keeping the ABI intact > B) try to backport d1021a1bc47668aa715b7f2121086c9598bffcbf instead Sorry, that's the hash in git://git.launchpad.net/~ubuntu-kernel-test/ubuntu/+source/linux/+git/mainline-crack Upstream it's 11d39e8cc43e1c6737af19ca9372e590061b5ad2 > > That's the one reason it's RFC. The other is that I haven't had much > time to look at the actual code yet. > > ...dd-vendor-callbacks-for-writing-the-.patch | 247 ++++++++++++++++++ > 1 file changed, 247 insertions(+) > create mode 100644 patches/kernel/0032-Revert-KVM-X86-Add-vendor-callbacks-for-writing-the-.patch > > diff --git a/patches/kernel/0032-Revert-KVM-X86-Add-vendor-callbacks-for-writing-the-.patch b/patches/kernel/0032-Revert-KVM-X86-Add-vendor-callbacks-for-writing-the-.patch > new file mode 100644 > index 0000000..d2f7796 > --- /dev/null > +++ b/patches/kernel/0032-Revert-KVM-X86-Add-vendor-callbacks-for-writing-the-.patch > @@ -0,0 +1,247 @@ > +From 0747f18be1da2033a20c2a355678b9c278ce4603 Mon Sep 17 00:00:00 2001 > +From: Fiona Ebner > +Date: Wed, 31 Aug 2022 13:49:55 +0200 > +Subject: [PATCH] Revert "KVM: X86: Add vendor callbacks for writing the TSC > + multiplier" > + > +This reverts commit 1ab9287add5e265352d18517551abf6d01d004fd until commit > +d1021a1bc47668aa715b7f2121086c9598bffcbf which fixes it can be cleanly Same here > +applied. > + > +Signed-off-by: Fiona Ebner