Cover Letter Detail
Show a cover letter.
GET /api/covers/2226027/?format=api
{ "id": 2226027, "url": "http://patchwork.ozlabs.org/api/covers/2226027/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linux-pci/cover/20260422023239.1171963-1-mrathor@linux.microsoft.com/", "project": { "id": 28, "url": "http://patchwork.ozlabs.org/api/projects/28/?format=api", "name": "Linux PCI development", "link_name": "linux-pci", "list_id": "linux-pci.vger.kernel.org", "list_email": "linux-pci@vger.kernel.org", "web_url": null, "scm_url": null, "webscm_url": null, "list_archive_url": "", "list_archive_url_format": "", "commit_url_format": "" }, "msgid": "<20260422023239.1171963-1-mrathor@linux.microsoft.com>", "list_archive_url": null, "date": "2026-04-22T02:32:26", "name": "[V1,00/13] PCI passthru on Hyper-V (Part I)", "submitter": { "id": 91512, "url": "http://patchwork.ozlabs.org/api/people/91512/?format=api", "name": "Mukesh R", "email": "mrathor@linux.microsoft.com" }, "mbox": "http://patchwork.ozlabs.org/project/linux-pci/cover/20260422023239.1171963-1-mrathor@linux.microsoft.com/mbox/", "series": [ { "id": 500915, "url": "http://patchwork.ozlabs.org/api/series/500915/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linux-pci/list/?series=500915", "date": "2026-04-22T02:32:26", "name": "PCI passthru on Hyper-V (Part I)", "version": 1, "mbox": "http://patchwork.ozlabs.org/series/500915/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/covers/2226027/comments/", "headers": { "Return-Path": "\n <linux-pci+bounces-52895-incoming=patchwork.ozlabs.org@vger.kernel.org>", "X-Original-To": [ "incoming@patchwork.ozlabs.org", "linux-pci@vger.kernel.org" ], "Delivered-To": "patchwork-incoming@legolas.ozlabs.org", "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=linux.microsoft.com header.i=@linux.microsoft.com\n header.a=rsa-sha256 header.s=default header.b=lUQ+NBFU;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c04:e001:36c::12fc:5321; helo=tor.lore.kernel.org;\n envelope-from=linux-pci+bounces-52895-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)", "smtp.subspace.kernel.org;\n\tdkim=pass (1024-bit key) header.d=linux.microsoft.com\n header.i=@linux.microsoft.com header.b=\"lUQ+NBFU\"", "smtp.subspace.kernel.org;\n arc=none smtp.client-ip=13.77.154.182", "smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.microsoft.com", "smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=linux.microsoft.com" ], "Received": [ "from tor.lore.kernel.org (tor.lore.kernel.org\n [IPv6:2600:3c04:e001:36c::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4g0jxz5CH9z1yD5\n\tfor <incoming@patchwork.ozlabs.org>; Wed, 22 Apr 2026 12:35:35 +1000 (AEST)", "from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby tor.lore.kernel.org (Postfix) with ESMTP id F1E5B306B504\n\tfor <incoming@patchwork.ozlabs.org>; Wed, 22 Apr 2026 02:33:46 +0000 (UTC)", "from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 02EB838237E;\n\tWed, 22 Apr 2026 02:33:45 +0000 (UTC)", "from linux.microsoft.com (linux.microsoft.com [13.77.154.182])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 1611E3806D9;\n\tWed, 22 Apr 2026 02:33:32 +0000 (UTC)", "from mrdev.corp.microsoft.com\n (192-184-212-33.fiber.dynamic.sonic.net [192.184.212.33])\n\tby linux.microsoft.com (Postfix) with ESMTPSA id AB52020B6F01;\n\tTue, 21 Apr 2026 19:33:28 -0700 (PDT)" ], "ARC-Seal": "i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1776825220; cv=none;\n b=DGZkrvtIaGmjlszn2lj7/2Lu1Tdy9YqvUSynddtmQG+OeAABssPDya2OrSizXRnAupLBoY1kv/T5bBSZ2CwciEfENk0sP/Jjp7GkMOb4OUtRc9SQKw/2oVO7CISDnFUFuqXHdK8O8u/YmaTQs90wV20tcV05AbVUoP/q3Q50p8w=", "ARC-Message-Signature": "i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1776825220; c=relaxed/simple;\n\tbh=GmhkLwfa6h6rSszM+OfJhO9L6pKs23/XT/lrbTGZNX8=;\n\th=From:To:Cc:Subject:Date:Message-ID:MIME-Version;\n b=suHVzafvR38GbiJzykcBt+vLW/QJifciO2fdeAFN+Jg/D6mKPKeQncb8vRZqV2/hRkpfsarvbE1Rwa5PqPMk2eXSA+N9lt8gpxK+qzgzKBxbPqPW+HbBNuSLYFcf5rYoumBiHA61rq4S+8a5KAiG9bwKGkGJxqXRrhUwFt8+Uaw=", "ARC-Authentication-Results": "i=1; smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=linux.microsoft.com;\n spf=pass smtp.mailfrom=linux.microsoft.com;\n dkim=pass (1024-bit key) header.d=linux.microsoft.com\n header.i=@linux.microsoft.com header.b=lUQ+NBFU;\n arc=none smtp.client-ip=13.77.154.182", "DKIM-Filter": "OpenDKIM Filter v2.11.0 linux.microsoft.com AB52020B6F01", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com;\n\ts=default; t=1776825209;\n\tbh=O+mpjpLBLfXxNngTSPHR4JXlp5P2eN9Wrs/JOmLiTYs=;\n\th=From:To:Cc:Subject:Date:From;\n\tb=lUQ+NBFUMYhMiCKp5hJ4csDmWh7uDXFoFxm83NvWZ/IwJ9a5RxenB0Yd0zUaoi1pw\n\t 3yv9M2bPsfObV813+Lm1OuK3i4jcBXSJHx2cUn1pSWMy43jtuQH42gb29McJePj3lT\n\t Ej8Q0Cx2NZEoOqbrcfAhwc/jLbsHBVnf65GmjuN0=", "From": "Mukesh R <mrathor@linux.microsoft.com>", "To": "hpa@zytor.com,\n\trobin.murphy@arm.com,\n\trobh@kernel.org,\n\twei.liu@kernel.org,\n\tmrathor@linux.microsoft.com,\n\tmhklinux@outlook.com,\n\tmuislam@microsoft.com,\n\tnamjain@linux.microsoft.com,\n\tmagnuskulke@linux.microsoft.com,\n\tanbelski@linux.microsoft.com,\n\tlinux-kernel@vger.kernel.org,\n\tlinux-hyperv@vger.kernel.org,\n\tiommu@lists.linux.dev,\n\tlinux-pci@vger.kernel.org,\n\tlinux-arch@vger.kernel.org", "Cc": "kys@microsoft.com,\n\thaiyangz@microsoft.com,\n\tdecui@microsoft.com,\n\tlongli@microsoft.com,\n\ttglx@kernel.org,\n\tmingo@redhat.com,\n\tbp@alien8.de,\n\tdave.hansen@linux.intel.com,\n\tx86@kernel.org,\n\tjoro@8bytes.org,\n\twill@kernel.org,\n\tlpieralisi@kernel.org,\n\tkwilczynski@kernel.org,\n\tbhelgaas@google.com,\n\tarnd@arndb.de", "Subject": "[PATCH V1 00/13] PCI passthru on Hyper-V (Part I)", "Date": "Tue, 21 Apr 2026 19:32:26 -0700", "Message-ID": "<20260422023239.1171963-1-mrathor@linux.microsoft.com>", "X-Mailer": "git-send-email 2.51.2.vfs.0.1", "Precedence": "bulk", "X-Mailing-List": "linux-pci@vger.kernel.org", "List-Id": "<linux-pci.vger.kernel.org>", "List-Subscribe": "<mailto:linux-pci+subscribe@vger.kernel.org>", "List-Unsubscribe": "<mailto:linux-pci+unsubscribe@vger.kernel.org>", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit" }, "content": "Implement passthru of PCI devices to unprivileged virtual machines\n(VMs) when Linux is running as a privileged VM on Microsoft Hyper-V\nhypervisor. This support is made to fit within the workings of VFIO\nframework, and any VMM needing to use it must use the VFIO subsystem.\nThis supports both full device passthru and SR-IOV based VFs.\n\nAt a high level, the hypervisor supports traditional mapped iommu domains\nthat use explicit map and unmap hypercalls for mapping and unmapping guest\nRAM into the iommu subsystem. Hyper-V also has a concept of direct attach\ndevices whereby the iommu subsystem simply uses the guest HW page table\n(ept/npt/..). This series adds support for both, and both are made to\nwork with the VFIO subsystem.\n\nWhile this Part I focuses on memory mappings, upcoming Part II\nwill focus on irq bypass along with some minor irq remapping \nupdates.\n\nBased on: cd9f2e7d6e5b (origin/hyperv-next)\n\nTesting:\n o Most testing done on hyperv-next:e733a9e28180 using Cloud Hypervisor (51).\n o Limited testing on : cd9f2e7d6e5b\n o Tested with impending Part II irq patches.\n o All tests involved PF passthru of devices using MSIx.\n o Following combinations were tested:\n - L1VH(1): test 1: Mellanox ConnectX-6 Lx passthru\n test 2: NVIDIA Tesla Tesla T4 GPU.\n test 3: Both of above simultaneous passthru\n - Baremetal dom0/root: All of above.\n\n(1) L1VH: this is a semi privileged VM that runs on Windows root on\n Hyper-V, and allows users to create more child VMs.\n\nPending: This to establish a baseline for further enhancements.\n o arm64 : some delta to make this work on arm64 (in progress).\n o device sleep/wakeup.\n o More stress testing \n o CH reports it could not unbind vfio group upon guest shutdown. Need \n to reboot for now.\n o Qemu support (in progress).\n\nChanges in V1:\n o patch 1: Don't tie hyperv-irq.c to CONFIG_HYPERV_IOMMU.\n o patch 4: Redesigned to address security vulnerability found by copilot \n with passing tgid as a parameter. Also, do tgid setting right \n after setting pt_id.\n o patch 5: Remove unused type parameter from mshv_device_ops.device_create\n o patch 7: mshv_partition_ioctl_create_device cleanup on copy_to_user.\n o patch 10: Add export of hv_build_devid_type_pci here to get rid of \n patch 11.\n o patch 12: Move functions to build device ids from patch 11 here for\n the benefit of arm64. Rename file to: hyperv-iommu-root.c.\n o patch 13: removed to be made part of interrupt part II of this support.\n o patch 14: get rid of fast path to reduce review noise.\n o New (last) patch to pin ram regions if device passthru to a VM.\n\nThanks,\n-Mukesh\n\nMukesh R (13):\n iommu/hyperv: rename hyperv-iommu.c to hyperv-irq.c\n x86/hyperv: cosmetic changes in irqdomain.c for readability\n x86/hyperv: add insufficient memory support in irqdomain.c\n mshv: Provide a way to get partition id if running in a VMM process\n mshv: Declarations and definitions for VFIO-MSHV bridge device\n mshv: Implement mshv bridge device for VFIO\n mshv: Add ioctl support for MSHV-VFIO bridge device\n PCI: hv: rename hv_compose_msi_msg to hv_vmbus_compose_msi_msg\n mshv: Import data structs around device passthru from hyperv headers\n PCI: hv: Build device id for a VMBus device, export PCI devid function\n x86/hyperv: Implement hyperv virtual iommu\n mshv: Populate mmio mappings for PCI passthru\n mshv: pin all ram mem regions if partition has device passthru\n\n MAINTAINERS | 3 +-\n arch/x86/hyperv/irqdomain.c | 229 +++--\n arch/x86/include/asm/mshyperv.h | 4 +\n arch/x86/kernel/pci-dma.c | 2 +\n drivers/hv/Makefile | 3 +-\n drivers/hv/mshv_root.h | 26 +\n drivers/hv/mshv_root_main.c | 256 ++++-\n drivers/hv/mshv_vfio.c | 211 ++++\n drivers/iommu/Kconfig | 5 +-\n drivers/iommu/Makefile | 3 +-\n drivers/iommu/hyperv-iommu-root.c | 899 ++++++++++++++++++\n .../iommu/{hyperv-iommu.c => hyperv-irq.c} | 2 +-\n drivers/iommu/irq_remapping.c | 2 +-\n drivers/pci/controller/pci-hyperv.c | 120 ++-\n include/asm-generic/mshyperv.h | 34 +\n include/hyperv/hvgdk_mini.h | 11 +\n include/hyperv/hvhdk_mini.h | 112 +++\n include/linux/hyperv.h | 6 +\n include/uapi/linux/mshv.h | 31 +\n 19 files changed, 1790 insertions(+), 169 deletions(-)\n create mode 100644 drivers/hv/mshv_vfio.c\n create mode 100644 drivers/iommu/hyperv-iommu-root.c\n rename drivers/iommu/{hyperv-iommu.c => hyperv-irq.c} (99%)" }