kernel/linux.git/include/linux/hyperv.h, branch linux-7.1.y

mshv: Add conditional VMBus dependency

2026-05-27T22:11:05+00:00

When the VMBus driver is not part of the kernel (CONFIG_HYPERV_VMBUS=n), the MSHV root driver fails to link: ERROR: modpost: "hv_vmbus_exists" [drivers/hv/mshv_root.ko] undefined! Fix this while meeting these requirements: * It must be possible to include the MSHV root driver without the VMBus driver. In such case, the MSHV root driver can be built-in to the kernel image, or it can be built as a separate module. * If both the MSHV root driver and the VMBus driver are present, the MSHV root driver and VMBus driver can both be built-in, or they can both be separate modules. Or the MSHV root driver can be a module while the VMBus driver can be built-in, but the reverse is disallowed. Regardless of the build choices, the VMBus driver must be loaded before the MSHV driver in order for the SynIC to be managed properly (see comments in the MSHV SynIC code). The fix has two parts: * Add a Kconfig entry for MSHV_ROOT to depend on HYPERV_VMBUS if HYPERV_VMBUS is present. The entry disallows MSHV_ROOT being built-in when HYPERV_VMBUS is a module, but without requiring that HYPERV_VMBUS be built. * Add a stub implementation of hv_vmbus_exists() for when the VMBus driver is not present so that the MSHV root driver has no module dependency on VMBus. When the VMBus driver *is* present, the module dependency ensures that the VMBus driver loads first when both are built as modules. Existing code ensures that the VMBus driver loads first if it is built-in. The VMBus driver uses subsys_initcall(), which is initcall level 4. The MSHV root driver uses module_init(), which becomes device_init() when built-in, and device_init() is initcall level 6. Reported-by: Arnd Bergmann Closes: https://lore.kernel.org/all/20260520074044.923728-1-arnd@kernel.org/ Signed-off-by: Michael Kelley Acked-by: Arnd Bergmann Reviewed-by: Jork Loeser Reviewed-by: Hardik Garg Signed-off-by: Wei Liu

Drivers: hv: vmbus: Provide option to skip VMBus unload on panic

2026-05-13T22:29:32+00:00

Currently, VMBus code initiates a VMBus unload in the panic path so that if a kdump kernel is loaded, it can start fresh in setting up its own VMBus connection. However, a driver for the VMBus virtual frame buffer may need to flush dirty portions of the frame buffer back to the Hyper-V host so that panic information is visible in the graphics console. To support such flushing, provide exported functions for the frame buffer driver to specify that the VMBus unload should not be done by the VMBus driver, and to initiate the VMBus unload itself. Together these allow a frame buffer driver to delay the VMBus unload until after it has completed the flush. Ideally, the VMBus driver could use its own panic-path callback to do the unload after all frame buffer drivers have finished. But DRM frame buffer drivers use the kmsg dump callback, and there are no callbacks after that in the panic path. Hence this somewhat messy approach to properly sequencing the frame buffer flush and the VMBus unload. Fixes: 3671f3777758 ("drm/hyperv: Add support for drm_panic") Signed-off-by: Michael Kelley Reviewed-by: Long Li Signed-off-by: Wei Liu

Merge tag 'hyperv-next-signed-20260421' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

2026-04-22T16:50:46+00:00

Pull Hyper-V updates from Wei Liu: - Fix cross-compilation for hv tools (Aditya Garg) - Fix vmemmap_shift exceeding MAX_FOLIO_ORDER in mshv_vtl (Naman Jain) - Limit channel interrupt scan to relid high water mark (Michael Kelley) - Export hv_vmbus_exists() and use it in pci-hyperv (Dexuan Cui) - Fix cleanup and shutdown issues for MSHV (Jork Loeser) - Introduce more tracing support for MSHV (Stanislav Kinsburskii) * tag 'hyperv-next-signed-20260421' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Skip LP/VP creation on kexec x86/hyperv: move stimer cleanup to hv_machine_shutdown() Drivers: hv: vmbus: fix hyperv_cpuhp_online variable shadowing mshv: Add tracepoint for GPA intercept handling mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER tools: hv: Fix cross-compilation Drivers: hv: vmbus: Export hv_vmbus_exists() and use it in pci-hyperv mshv: Introduce tracing support Drivers: hv: vmbus: Limit channel interrupt scan to relid high water mark

Drivers: hv: vmbus: Export hv_vmbus_exists() and use it in pci-hyperv

2026-04-14T04:42:44+00:00

With commit f84b21da3624 ("PCI: hv: Don't load the driver for baremetal root partition"), the bare metal Linux root partition won't use the pci-hyperv driver, but when a Linux VM runs on the Linux root partition, pci-hyperv's module_init function init_hv_pci_drv() can still run, e.g. in the case of CONFIG_PCI_HYPERV=y, even if the VMBus driver is not used in such a VM (i.e. the hv_vmbus driver's init function returns -ENODEV due to vmbus_root_device being NULL). In such a Linux VM, init_hv_pci_drv() runs with a side effect: the 3 hvpci_block_ops callbacks are set to functions that depend on hv_vmbus. Later, when the MLX driver in such a VM invokes the callbacks, e.g. in drivers/net/ethernet/mellanox/mlx5/core/lib/hv.c: mlx5_hv_register_invalidate(), hvpci_block_ops.reg_blk_invalidate() is hv_register_block_invalidate() rather than a NULL function pointer, and hv_register_block_invalidate() assumes that it can find a struct hv_pcibus_device from pdev->bus->sysdata, which is false in such a VM. Consequently, hv_register_block_invalidate() -> get_pcichild_wslot() -> spin_lock_irqsave() may hang since it can be accessing an invalid spinlock pointer. Fix the issue by exporting hv_vmbus_exists() and using it in pci-hyperv: hv_root_partition() is true and hv_nested is false ==> hv_vmbus_exists() is false. hv_root_partition() is true and hv_nested is true ==> hv_vmbus_exists() is true. hv_root_partition() is false ==> hv_vmbus_exists() is true. While at it, rename vmbus_exists() to hv_vmbus_exists() to follow the convention that all public functions have the hv_ prefix; also change the return value's type from int to bool to make the code more readable; also move the two pr_info() calls. Reported-by: Mukesh Rathor Signed-off-by: Dexuan Cui Signed-off-by: Wei Liu

drivers: hv: vmbus: replace deprecated mmap hook with mmap_prepare

2026-04-05T20:53:44+00:00

The f_op->mmap interface is deprecated, so update the vmbus driver to use its successor, mmap_prepare. This updates all callbacks which referenced the function pointer hv_mmap_ring_buffer to instead reference hv_mmap_prepare_ring_buffer, utilising the newly introduced compat_set_desc_from_vma() and __compat_vma_mmap() to be able to implement this change. The UIO HV generic driver is the only user of hv_create_ring_sysfs(), which is the only function which references vmbus_channel->mmap_prepare_ring_buffer which, in turn, is the only external interface to hv_mmap_prepare_ring_buffer. This patch therefore updates this caller to use mmap_prepare instead, which also previously used vm_iomap_memory(), so this change replaces it with its mmap_prepare equivalent, mmap_action_simple_ioremap(). [akpm@linux-foundation.org: restore struct vmbus_channel comment, per Michael Kelley] Link: https://lkml.kernel.org/r/05467cb62267d750e5c770147517d4df0246cda6.1774045440.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) Reviewed-by: Michael Kelley Tested-by: Michael Kelley Acked-by: Vlastimil Babka (SUSE) Cc: Alexander Shishkin Cc: Alexandre Torgue Cc: Al Viro Cc: Arnd Bergmann Cc: Bodo Stroesser Cc: Christian Brauner Cc: Clemens Ladisch Cc: David Hildenbrand Cc: David Howells Cc: Dexuan Cui Cc: Greg Kroah-Hartman Cc: Haiyang Zhang Cc: Jan Kara Cc: Jann Horn Cc: Jonathan Corbet Cc: K. Y. Srinivasan Cc: Liam Howlett Cc: Long Li Cc: Marc Dionne Cc: "Martin K. Petersen" Cc: Maxime Coquelin Cc: Michal Hocko Cc: Mike Rapoport Cc: Miquel Raynal Cc: Pedro Falcato Cc: Richard Weinberger Cc: Ryan Roberts Cc: Suren Baghdasaryan Cc: Vignesh Raghavendra Cc: Wei Liu Signed-off-by: Andrew Morton

Drivers: hv: VMBus protocol version 6.0

2025-11-15T06:18:14+00:00

The confidential VMBus is supported starting from the protocol version 6.0 onwards. Provide the required definitions. No functional changes. Signed-off-by: Roman Kisel Reviewed-by: Alok Tiwari Reviewed-by: Michael Kelley Signed-off-by: Wei Liu

Drivers: hv: Simplify data structures for VMBus channel close message

2025-09-08T22:11:03+00:00

struct vmbus_close_msg is used for sending the VMBus channel close message. It contains a struct vmbus_channel_msginfo, which has a flex array member at the end. The latter's presence in the middle of struct vmbus_close_msg causes warnings when built with -Wflex-array-member-not-at-end. But the struct vmbus_channel_msginfo is unused because the Hyper-V host does not send a response to the channel close message. So remove the struct vmbus_channel_msginfo. Then, since the only remaining field is struct vmbus_channel_close_channel, also remove the containing struct vmbus_close_msg and directly use struct vmbus_channel_close_channel. Besides eliminating unnecessary complexity, these changes resolve the -Wflex-array-member-not-at-end warnings. Signed-off-by: Michael Kelley Reviewed-by: Tianyu Lan Signed-off-by: Wei Liu

Merge tag 'hyperv-next-signed-20250602' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

2025-06-03T15:39:20+00:00

Pull hyperv updates from Wei Liu: - Support for Virtual Trust Level (VTL) on arm64 (Roman Kisel) - Fixes for Hyper-V UIO driver (Long Li) - Fixes for Hyper-V PCI driver (Michael Kelley) - Select CONFIG_SYSFB for Hyper-V guests (Michael Kelley) - Documentation updates for Hyper-V VMBus (Michael Kelley) - Enhance logging for hv_kvp_daemon (Shradha Gupta) * tag 'hyperv-next-signed-20250602' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (23 commits) Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests Drivers: hv: vmbus: Add comments about races with "channels" sysfs dir Documentation: hyperv: Update VMBus doc with new features and info PCI: hv: Remove unnecessary flex array in struct pci_packet Drivers: hv: Remove hv_alloc/free_* helpers Drivers: hv: Use kzalloc for panic page allocation uio_hv_generic: Align ring size to system page uio_hv_generic: Use correct size for interrupt and monitor pages Drivers: hv: Allocate interrupt and monitor pages aligned to system page boundary arch/x86: Provide the CPU number in the wakeup AP callback x86/hyperv: Fix APIC ID and VP index confusion in hv_snp_boot_ap() PCI: hv: Get vPCI MSI IRQ domain from DeviceTree ACPI: irq: Introduce acpi_get_gsi_dispatcher() Drivers: hv: vmbus: Introduce hv_get_vmbus_root_device() Drivers: hv: vmbus: Get the IRQ number from DeviceTree dt-bindings: microsoft,vmbus: Add interrupt and DMA coherence properties arm64, x86: hyperv: Report the VTL the system boots in arm64: hyperv: Initialize the Virtual Trust Level field Drivers: hv: Provide arch-neutral implementation of get_vtl() Drivers: hv: Enable VTL mode for arm64 ...

Drivers: hv: vmbus: Introduce hv_get_vmbus_root_device()

2025-05-23T16:30:55+00:00

The ARM64 PCI code for hyperv needs to know the VMBus root device, and it is private. Provide a function that returns it. Rename it from "hv_dev" as "hv_dev" as a symbol is very overloaded. No functional changes. Signed-off-by: Roman Kisel Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20250428210742.435282-10-romank@linux.microsoft.com Signed-off-by: Wei Liu Message-ID: <20250428210742.435282-10-romank@linux.microsoft.com>

Merge tag 'net-6.15-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2025-05-15T17:40:49+00:00

Pull networking fixes from Jakub Kicinski: "Including fixes from Bluetooth and wireless. A few more fixes for the locking changes trickling in. Nothing too alarming, I suspect those will continue for another release. Other than that things are slowing down nicely. Current release - fix to a fix: - Bluetooth: hci_event: use key encryption size when its known - tools: ynl-gen: allow multi-attr without nested-attributes again Current release - regressions: - locking fixes: - lock lower level devices when updating features - eth: bnxt_en: bring back rtnl_lock() in the bnxt_open() path - devmem: fix panic when Netlink socket closes after module unload Current release - new code bugs: - eth: txgbe: fixes for FW communication on new AML devices Previous releases - always broken: - sched: flush gso_skb list too during ->change(), avoid potential null-deref on reconfig - wifi: mt76: disable NAPI on driver removal - hv_netvsc: fix error 'nvsp_rndis_pkt_complete error status: 2'" * tag 'net-6.15-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (44 commits) net: devmem: fix kernel panic when netlink socket close after module unload tsnep: fix timestamping with a stacked DSA driver net/tls: fix kernel panic when alloc_page failed bnxt_en: bring back rtnl_lock() in the bnxt_open() path mlxsw: spectrum_router: Fix use-after-free when deleting GRE net devices wifi: mac80211: Set n_channels after allocating struct cfg80211_scan_request octeontx2-pf: Do not reallocate all ntuple filters wifi: mt76: mt7925: fix missing hdr_trans_tlv command for broadcast wtbl wifi: mt76: disable napi on driver removal Drivers: hv: vmbus: Remove vmbus_sendpacket_pagebuffer() hv_netvsc: Remove rmsg_pgcnt hv_netvsc: Preserve contiguous PFN grouping in the page buffer array hv_netvsc: Use vmbus_sendpacket_mpb_desc() to send VMBus messages Drivers: hv: Allow vmbus_sendpacket_mpb_desc() to create multiple ranges octeontx2-af: Fix CGX Receive counters net: ethernet: mtk_eth_soc: fix typo for declaration MT7988 ESW capability net: libwx: Fix FW mailbox unknown command net: libwx: Fix FW mailbox reply timeout net: txgbe: Fix to calculate EEPROM checksum for AML devices octeontx2-pf: macsec: Fix incorrect max transmit size in TX secy ...