From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate001.proxmox.com (gate001.proxmox.com [IPv6:2a0f:8001:1:32::40]) by lore.proxmox.com (Postfix) with ESMTPS id 44A011FF0E5 for ; Wed, 15 Jul 2026 15:01:36 +0200 (CEST) Received: from gate001.proxmox.com (localhost.localdomain [127.0.0.1]) by gate001.proxmox.com (Proxmox) with ESMTP id 680AB21436; Wed, 15 Jul 2026 15:01:35 +0200 (CEST) From: Maximiliano Sandoval To: pve-devel@lists.proxmox.com Subject: [PATCH docs] qm: document potential host cpu type drawback Date: Wed, 15 Jul 2026 15:01:30 +0200 Message-ID: <20260715130131.397579-1-m.sandoval@proxmox.com> X-Mailer: git-send-email 2.47.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1784120473326 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.310 Adjusted score from AWL reputation of From: address DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment (newer systems) RCVD_IN_DNSWL_LOW -0.7 Sender listed at https://www.dnswl.org/, low trust SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Message-ID-Hash: WDGGBPECFM2SK4NDPELIKZ2J6I6GAJMW X-Message-ID-Hash: WDGGBPECFM2SK4NDPELIKZ2J6I6GAJMW X-MailFrom: m.sandoval@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox VE development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Signed-off-by: Maximiliano Sandoval --- Notes: This happened for example on Kernel 7.0.0 where the vmx-mbec is now enabled. qm.adoc | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/qm.adoc b/qm.adoc index 96ba68b..bca5792 100644 --- a/qm.adoc +++ b/qm.adoc @@ -482,6 +482,10 @@ cluster, choose the lowest compatible virtual QEMU CPU type. NOTE: Live migrations between Intel and AMD host CPUs have no guarantee to work. +WARNING: The 'host' CPU type can potentially enable new CPU features for the +guest when the guest is restarted after a system upgrade. This can result in +unexpected consequences. + See also xref:chapter_qm_vcpu_list[List of AMD and Intel CPU Types as Defined in QEMU]. -- 2.47.3