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 4332F9493D for ; Fri, 13 Jan 2023 14:32:09 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 54C2A5CA2 for ; Fri, 13 Jan 2023 14:31:38 +0100 (CET) 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 ; Fri, 13 Jan 2023 14:31:37 +0100 (CET) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 425B141B5E for ; Fri, 13 Jan 2023 14:31:37 +0100 (CET) Message-ID: <2585bfbd-2d44-5bef-1a0f-ca9e7e84b653@proxmox.com> Date: Fri, 13 Jan 2023 14:31:36 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 From: Markus Frank To: Wolfgang Bumiller References: <20221125140857.121622-1-m.frank@proxmox.com> <20221125140857.121622-5-m.frank@proxmox.com> <20230113100929.ug2oivbml5tuizst@fwblub> Content-Language: en-US Cc: Proxmox VE development discussion In-Reply-To: <20230113100929.ug2oivbml5tuizst@fwblub> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-SPAM-LEVEL: Spam detection results: 0 AWL -0.035 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 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 Subject: Re: [pve-devel] [PATCH docs v4 4/5] added vIOMMU documentation 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: Fri, 13 Jan 2023 13:32:09 -0000 On 1/13/23 11:09, Wolfgang Bumiller wrote: > On Fri, Nov 25, 2022 at 03:08:56PM +0100, Markus Frank wrote: >> Signed-off-by: Markus Frank >> --- >> qm-pci-passthrough.adoc | 25 +++++++++++++++++++++++++ >> 1 file changed, 25 insertions(+) >> >> diff --git a/qm-pci-passthrough.adoc b/qm-pci-passthrough.adoc >> index fa6ba35..7ed4d49 100644 >> --- a/qm-pci-passthrough.adoc >> +++ b/qm-pci-passthrough.adoc >> @@ -389,6 +389,31 @@ Example configuration with an `Intel GVT-g vGPU` (`Intel Skylake 6700k`): >> With this set, {pve} automatically creates such a device on VM start, and >> cleans it up again when the VM stops. >> >> +[[qm_pci_viommu]] >> +vIOMMU >> +~~~~~~ >> + >> +vIOMMU enables the option to passthrough pci devices to Level-2 VMs >> +in Level-1 VMs via Nested Virtualisation. >> + >> +Host-Requirement: Set `intel_iommu=on` or `amd_iommu=on` depending on your >> +CPU. > > And by "CPU" you mean kernel command line? ;-) Host-Requirement: Add `intel_iommu=on` or `amd_iommu=on` depending on your CPU to your kernel command line. like this? > >> + >> +VM-Requirement: For both Intel and AMD CPUs you will have to set >> +`intel_iommu=on` as a Linux boot parameter in the vIOMMU-enabled-VM, because >> +Qemu implements the Intel variant. > > ^ As mentioned, there does appear to be an amd_iommu device in the qemu > code, so would the amd variant work? > > In my reply to the code patch I mentioned checking the host arch. But if > you say we can use intel_iommu on AMD as well, I'd say, if both work, > give the user a choice, otherwise we can of course just stick to the one > that works ;-) intel_iommu works better on my AMD CPU than amd_iommu ;) Moreover it adds an extra AMDVI-PCI device that is using the first pci address. `kvm: -device VGA,id=vga,bus=pcie.0,addr=0x1: PCI: slot 1 function 0 not available for VGA, in use by AMDVI-PCI,id=(null)` I cannot find any good documentation for amd_iommu but it also seems like it has less features. $ qemu-system-x86_64 -device 'amd-iommu,help' amd-iommu options: device-iotlb= - (default: false) intremap= - on/off/auto (default: "auto") pt= - (default: true) $ qemu-system-x86_64 -device 'intel-iommu,help' intel-iommu options: aw-bits= - (default: 39) caching-mode= - (default: false) device-iotlb= - (default: false) dma-drain= - (default: true) dma-translation= - (default: true) eim= - on/off/auto (default: "auto") intremap= - on/off/auto (default: "auto") pt= - (default: true) snoop-control= - (default: false) version= - (default: 0) x-buggy-eim= - (default: false) x-pasid-mode= - (default: false) x-scalable-mode= - (default: false)