From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <pve-devel-bounces@lists.proxmox.com> Received: from firstgate.proxmox.com (firstgate.proxmox.com [IPv6:2a01:7e0:0:424::9]) by lore.proxmox.com (Postfix) with ESMTPS id 2F21F1FF168 for <inbox@lore.proxmox.com>; Tue, 18 Feb 2025 13:39:40 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 92551B8F0; Tue, 18 Feb 2025 13:39:35 +0100 (CET) Message-ID: <753aa95e-77c3-4df4-9217-2c736703b747@proxmox.com> Date: Tue, 18 Feb 2025 13:39:02 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Proxmox VE development discussion <pve-devel@lists.proxmox.com>, Fiona Ebner <f.ebner@proxmox.com> References: <20250217150444.142182-1-f.ebner@proxmox.com> Content-Language: en-US From: Friedrich Weber <f.weber@proxmox.com> In-Reply-To: <20250217150444.142182-1-f.ebner@proxmox.com> X-SPAM-LEVEL: Spam detection results: 0 AWL 0.002 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: Re: [pve-devel] [PATCH qemu-server/manager/docs 0/3] close #5291: support disabling KSM for specific VMs X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion <pve-devel.lists.proxmox.com> List-Unsubscribe: <https://lists.proxmox.com/cgi-bin/mailman/options/pve-devel>, <mailto:pve-devel-request@lists.proxmox.com?subject=unsubscribe> List-Archive: <http://lists.proxmox.com/pipermail/pve-devel/> List-Post: <mailto:pve-devel@lists.proxmox.com> List-Help: <mailto:pve-devel-request@lists.proxmox.com?subject=help> List-Subscribe: <https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel>, <mailto:pve-devel-request@lists.proxmox.com?subject=subscribe> Reply-To: Proxmox VE development discussion <pve-devel@lists.proxmox.com> Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: pve-devel-bounces@lists.proxmox.com Sender: "pve-devel" <pve-devel-bounces@lists.proxmox.com> On 17/02/2025 16:04, Fiona Ebner wrote: > KSM exposes a guest's virtual memory to side-channel attacks. Add a VM > configuration option to disable KSM for specific VMs that need to be > protected against such attacks. This makes it possible to still > benefit from KSM for other processes on the host rather than needing > to turn of KSM completely. As I had a KSM test setup available, I quickly tested this: - created 4 VMs that, together, exceed 80% host RAM usage - on one VM, set `allow-ksm=0` (tested via CLI and GUI) - started VMs, monitored /proc/PID/ksm_stat - only for the VM with `allow-ksm=0`, ksm_rmap_items/ksm_merging_pages in ksm_stat stayed at 0. For all other VMs, both started to grow after a couple of minutes. So consider this: Tested-by: Friedrich Weber <f.weber@proxmox.com> _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel