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 523379501E for ; Tue, 17 Jan 2023 11:55:50 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 3A996A985 for ; Tue, 17 Jan 2023 11:55:50 +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 ; Tue, 17 Jan 2023 11:55:48 +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 8ED11448BE for ; Tue, 17 Jan 2023 11:55:48 +0100 (CET) Message-ID: Date: Tue, 17 Jan 2023 11:55:47 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 To: Wolfgang Bumiller Cc: Proxmox VE development discussion References: <20221125140857.121622-1-m.frank@proxmox.com> <20221125140857.121622-5-m.frank@proxmox.com> <20230113100929.ug2oivbml5tuizst@fwblub> <2585bfbd-2d44-5bef-1a0f-ca9e7e84b653@proxmox.com> <20230116100033.drlnujc5kpnhmltw@casey.proxmox.com> Content-Language: en-US From: Markus Frank In-Reply-To: <20230116100033.drlnujc5kpnhmltw@casey.proxmox.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-SPAM-LEVEL: Spam detection results: 0 AWL 0.013 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 -0.097 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: Tue, 17 Jan 2023 10:55:50 -0000 On 1/16/23 11:00, Wolfgang Bumiller wrote: > On Fri, Jan 13, 2023 at 02:31:36PM +0100, Markus Frank wrote: >> >> >> 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 ;) > > Can you define "better"? > My main concern is that if we don't give users the option to choose, the > only data point we have is yours ;-) > If we explicitly mention that you can use one on the other in the docs, > people can try it themselves and maybe we'll see some feedback on the > forums etc. > > However, I'm fine with a patch for only the intel version for now as we > can always add an option later. > >> 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)` > > For that I'd say, try to add the AMDVI-PCI device manually to an > explicitly chosen slot. We need to avoid automatically added devices > like the plague, because moving them later can break live snapshots (and > windows). > I manually added a AMDVI-PCI device with a explicitly chosen slot but amd-iommu still adds an extra AMDVI-PCI device. I do not see any way to prevent this or to change the address of the additionally added AMDVI-PCI device (from amd-iommu). I think amd-iommu is very impractical if we cannot set this slot manually. >> >> I cannot find any good documentation for amd_iommu but it also seems like >> it has less features. > > Less, or just not configurable? ;-) > I mean, if it works it works ;-) > >> >> $ 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)