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10 daysDrivers: hv: Use nested hypercall for post message and signal eventNuno Das Neves
When running nested, these hypercalls must be sent to the L0 hypervisor or VMBus will fail. Remove hv_do_nested_hypercall() and hv_do_fast_nested_hypercall8() altogether and open-code these cases, since there are only 2 and all they do is add the nested bit. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1752261532-7225-2-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1752261532-7225-2-git-send-email-nunodasneves@linux.microsoft.com>
2025-07-09Drivers: hv: Fix warnings for missing export.h header inclusionNaman Jain
Fix below warning in Hyper-V drivers that comes when kernel is compiled with W=1 option. Include export.h in driver files to fix it. * warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com> Link: https://lore.kernel.org/r/20250611100459.92900-2-namjain@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250611100459.92900-2-namjain@linux.microsoft.com>
2025-07-09Drivers: hv: Fix the check for HYPERVISOR_CALLBACK_VECTORNaman Jain
__is_defined(HYPERVISOR_CALLBACK_VECTOR) would return 1, only if HYPERVISOR_CALLBACK_VECTOR macro is defined as 1. However its value is 0xf3 and this leads to __is_defined() returning 0. The expectation was to just check whether this MACRO is defined or not and get 1 if it's defined. Replace __is_defined with #ifdef blocks instead to fix it. Fixes: 1dc5df133b98 ("Drivers: hv: vmbus: Get the IRQ number from DeviceTree") Cc: stable@kernel.org Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Reviewed-by: Roman Kisel <romank@linux.microsoft.com> Link: https://lore.kernel.org/r/20250707084322.1763-1-namjain@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250707084322.1763-1-namjain@linux.microsoft.com>
2025-07-09Drivers: hv: Select CONFIG_SYSFB only if EFI is enabledMichael Kelley
Commit 96959283a58d ("Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests") selects CONFIG_SYSFB for Hyper-V guests so that screen_info is available to the VMBus driver to get the location of the framebuffer in Generation 2 VMs. However, if CONFIG_HYPERV is enabled but CONFIG_EFI is not, a kernel link error results in ARM64 builds because screen_info is provided by the EFI firmware interface. While configuring an ARM64 Hyper-V guest without EFI isn't useful since EFI is required to boot, the configuration is still possible and the link error should be prevented. Fix this by making the selection of CONFIG_SYSFB conditional on CONFIG_EFI being defined. For Generation 1 VMs on x86/x64, which don't use EFI, the additional condition is OK because such VMs get the framebuffer information via a mechanism that doesn't use screen_info. Fixes: 96959283a58d ("Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests") Reported-by: Arnd Bergmann <arnd@arndb.de> Closes: https://lore.kernel.org/linux-hyperv/20250610091810.2638058-1-arnd@kernel.org/ Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202506080820.1wmkQufc-lkp@intel.com/ Signed-off-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/stable/20250613230059.380483-1-mhklinux%40outlook.com Reviewed-by: Roman Kisel <romank@linux.microsoft.com> Link: https://lore.kernel.org/r/20250613230059.380483-1-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250613230059.380483-1-mhklinux@outlook.com>
2025-06-03Merge tag 'hyperv-next-signed-20250602' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux 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 ...
2025-05-29Merge tag 'driver-core-6.16-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core Pull driver core updates from Greg KH: "Here are the driver core / kernfs changes for 6.16-rc1. Not a huge number of changes this development cycle, here's the summary of what is included in here: - kernfs locking tweaks, pushing some global locks down into a per-fs image lock - rust driver core and pci device bindings added for new features. - sysfs const work for bin_attributes. The final churn of switching away from and removing the transitional struct members, "read_new", "write_new" and "bin_attrs_new" will come after the merge window to avoid unnecesary merge conflicts. - auxbus device creation helpers added - fauxbus fix for creating sysfs files after the probe completed properly - other tiny updates for driver core things. All of these have been in linux-next for over a week with no reported issues" * tag 'driver-core-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: kernfs: Relax constraint in draining guard Documentation: embargoed-hardware-issues.rst: Remove myself drivers: hv: fix up const issue with vmbus_chan_bin_attrs firmware_loader: use SHA-256 library API instead of crypto_shash API docs: debugfs: do not recommend debugfs_remove_recursive PM: wakeup: Do not expose 4 device wakeup source APIs kernfs: switch global kernfs_rename_lock to per-fs lock kernfs: switch global kernfs_idr_lock to per-fs lock driver core: auxiliary bus: Fix IS_ERR() vs NULL mixup in __devm_auxiliary_device_create() sysfs: constify attribute_group::bin_attrs sysfs: constify bin_attribute argument of bin_attribute::read/write() software node: Correct a OOB check in software_node_get_reference_args() devres: simplify devm_kstrdup() using devm_kmemdup() platform: replace magic number with macro PLATFORM_DEVID_NONE component: do not try to unbind unbound components driver core: auxiliary bus: add device creation helpers driver core: faux: Add sysfs groups after probing
2025-05-23Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guestsMichael Kelley
The Hyper-V host provides guest VMs with a range of MMIO addresses that guest VMBus drivers can use. The VMBus driver in Linux manages that MMIO space, and allocates portions to drivers upon request. As part of managing that MMIO space in a Generation 2 VM, the VMBus driver must reserve the portion of the MMIO space that Hyper-V has designated for the synthetic frame buffer, and not allocate this space to VMBus drivers other than graphics framebuffer drivers. The synthetic frame buffer MMIO area is described by the screen_info data structure that is passed to the Linux kernel at boot time, so the VMBus driver must access screen_info for Generation 2 VMs. (In Generation 1 VMs, the framebuffer MMIO space is communicated to the guest via a PCI pseudo-device, and access to screen_info is not needed.) In commit a07b50d80ab6 ("hyperv: avoid dependency on screen_info") the VMBus driver's access to screen_info is restricted to when CONFIG_SYSFB is enabled. CONFIG_SYSFB is typically enabled in kernels built for Hyper-V by virtue of having at least one of CONFIG_FB_EFI, CONFIG_FB_VESA, or CONFIG_SYSFB_SIMPLEFB enabled, so the restriction doesn't usually affect anything. But it's valid to have none of these enabled, in which case CONFIG_SYSFB is not enabled, and the VMBus driver is unable to properly reserve the framebuffer MMIO space for graphics framebuffer drivers. The framebuffer MMIO space may be assigned to some other VMBus driver, with undefined results. As an example, if a VM is using a PCI pass-thru NVMe controller to host the OS disk, the PCI NVMe controller is probed before any graphics devices, and the NVMe controller is assigned a portion of the framebuffer MMIO space. Hyper-V reports an error to Linux during the probe, and the OS disk fails to get setup. Then Linux fails to boot in the VM. Fix this by having CONFIG_HYPERV always select SYSFB. Then the VMBus driver in a Gen 2 VM can always reserve the MMIO space for the graphics framebuffer driver, and prevent the undefined behavior. But don't select SYSFB when building for HYPERV_VTL_MODE as VTLs other than VTL 0 don't have a framebuffer and aren't subject to the issue. Adding SYSFB in such cases is harmless, but would increase the image size for no purpose. Fixes: a07b50d80ab6 ("hyperv: avoid dependency on screen_info") Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com> Link: https://lore.kernel.org/stable/20250520040143.6964-1-mhklinux%40outlook.com Link: https://lore.kernel.org/r/20250520040143.6964-1-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250520040143.6964-1-mhklinux@outlook.com>
2025-05-23Drivers: hv: vmbus: Add comments about races with "channels" sysfs dirMichael Kelley
The VMBus driver code has some inherent races in the creation of the "channels" sysfs subdirectory and its per-channel numbered subdirectories. These races have not generally been recognized or understood. Add some comments to call them out. No code changes. Signed-off-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250514225508.52629-1-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250514225508.52629-1-mhklinux@outlook.com>
2025-05-23Drivers: hv: Remove hv_alloc/free_* helpersLong Li
There are no users for those functions, remove them. Signed-off-by: Long Li <longli@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1746492997-4599-6-git-send-email-longli@linuxonhyperv.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1746492997-4599-6-git-send-email-longli@linuxonhyperv.com>
2025-05-23Drivers: hv: Use kzalloc for panic page allocationLong Li
To prepare for removal of hv_alloc_* and hv_free* functions, use kzalloc/kfree directly for panic reporting page. Signed-off-by: Long Li <longli@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1746492997-4599-5-git-send-email-longli@linuxonhyperv.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1746492997-4599-5-git-send-email-longli@linuxonhyperv.com>
2025-05-23Drivers: hv: Allocate interrupt and monitor pages aligned to system page ↵Long Li
boundary There are use cases that interrupt and monitor pages are mapped to user-mode through UIO, so they need to be system page aligned. Some Hyper-V allocation APIs introduced earlier broke those requirements. Fix this by using page allocation functions directly for interrupt and monitor pages. Cc: stable@vger.kernel.org Fixes: ca48739e59df ("Drivers: hv: vmbus: Move Hyper-V page allocator to arch neutral code") Signed-off-by: Long Li <longli@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1746492997-4599-2-git-send-email-longli@linuxonhyperv.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1746492997-4599-2-git-send-email-longli@linuxonhyperv.com>
2025-05-23Drivers: hv: vmbus: Introduce hv_get_vmbus_root_device()Roman Kisel
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 <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250428210742.435282-10-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250428210742.435282-10-romank@linux.microsoft.com>
2025-05-23Drivers: hv: vmbus: Get the IRQ number from DeviceTreeRoman Kisel
The VMBus driver uses ACPI for interrupt assignment on arm64 hence it won't function in the VTL mode where only DeviceTree can be used. Update the VMBus driver to discover interrupt configuration from DT. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250428210742.435282-9-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250428210742.435282-9-romank@linux.microsoft.com>
2025-05-23Drivers: hv: Provide arch-neutral implementation of get_vtl()Roman Kisel
To run in the VTL mode, Hyper-V drivers have to know what VTL the system boots in, and the arm64/hyperv code does not have the means to compute that. Refactor the code to hoist the function that detects VTL, make it arch-neutral to be able to employ it to get the VTL on arm64. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Link: https://lore.kernel.org/r/20250428210742.435282-5-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250428210742.435282-5-romank@linux.microsoft.com>
2025-05-23Drivers: hv: Enable VTL mode for arm64Roman Kisel
Kconfig dependencies for arm64 guests on Hyper-V require that be ACPI enabled, and limit VTL mode to x86/x64. To enable VTL mode on arm64 as well, update the dependencies. Since VTL mode requires DeviceTree instead of ACPI, don’t require arm64 guests on Hyper-V to have ACPI unconditionally. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250428210742.435282-4-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250428210742.435282-4-romank@linux.microsoft.com>
2025-05-21drivers: hv: fix up const issue with vmbus_chan_bin_attrsGreg Kroah-Hartman
In commit 9bec944506fa ("sysfs: constify attribute_group::bin_attrs"), the bin_attributes are now required to be const. Due to merge issues, the original commit could not modify this structure (it came in through a different branch.) Fix this up now by setting the variable properly. Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Naman Jain <namjain@linux.microsoft.com> Fixes: 9bec944506fa ("sysfs: constify attribute_group::bin_attrs") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-15Merge tag 'net-6.15-rc7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 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 ...
2025-05-14Drivers: hv: vmbus: Remove vmbus_sendpacket_pagebuffer()Michael Kelley
With the netvsc driver changed to use vmbus_sendpacket_mpb_desc() instead of vmbus_sendpacket_pagebuffer(), the latter has no remaining callers. Remove it. Cc: <stable@vger.kernel.org> # 6.1.x Signed-off-by: Michael Kelley <mhklinux@outlook.com> Link: https://patch.msgid.link/20250513000604.1396-6-mhklinux@outlook.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-14Drivers: hv: Allow vmbus_sendpacket_mpb_desc() to create multiple rangesMichael Kelley
vmbus_sendpacket_mpb_desc() is currently used only by the storvsc driver and is hardcoded to create a single GPA range. To allow it to also be used by the netvsc driver to create multiple GPA ranges, no longer hardcode as having a single GPA range. Allow the calling driver to specify the rangecount in the supplied descriptor. Update the storvsc driver to reflect this new approach. Cc: <stable@vger.kernel.org> # 6.1.x Signed-off-by: Michael Kelley <mhklinux@outlook.com> Link: https://patch.msgid.link/20250513000604.1396-2-mhklinux@outlook.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-10Merge tag 'char-misc-6.15-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc/IIO driver fixes from Greg KH: "Here are a bunch of small driver fixes (mostly all IIO) for 6.15-rc6. Included in here are: - loads of tiny IIO driver fixes for reported issues - hyperv driver fix for a much-reported and worked on sysfs ring buffer creation bug All of these have been in linux-next for over a week (the IIO ones for many weeks now), with no reported issues" * tag 'char-misc-6.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (30 commits) Drivers: hv: Make the sysfs node size for the ring buffer dynamic uio_hv_generic: Fix sysfs creation path for ring buffer iio: adis16201: Correct inclinometer channel resolution iio: adc: ad7606: fix serial register access iio: pressure: mprls0025pa: use aligned_s64 for timestamp iio: imu: adis16550: align buffers for timestamp staging: iio: adc: ad7816: Correct conditional logic for store mode iio: adc: ad7266: Fix potential timestamp alignment issue. iio: adc: ad7768-1: Fix insufficient alignment of timestamp. iio: adc: dln2: Use aligned_s64 for timestamp iio: accel: adxl355: Make timestamp 64-bit aligned using aligned_s64 iio: temp: maxim-thermocouple: Fix potential lack of DMA safe buffer. iio: chemical: pms7003: use aligned_s64 for timestamp iio: chemical: sps30: use aligned_s64 for timestamp iio: imu: inv_mpu6050: align buffer for timestamp iio: imu: st_lsm6dsx: Fix wakeup source leaks on device unbind iio: adc: qcom-spmi-iadc: Fix wakeup source leaks on device unbind iio: accel: fxls8962af: Fix wakeup source leaks on device unbind iio: adc: ad7380: fix event threshold shift iio: hid-sensor-prox: Fix incorrect OFFSET calculation ...
2025-05-02Drivers: hv: Make the sysfs node size for the ring buffer dynamicNaman Jain
The ring buffer size varies across VMBus channels. The size of sysfs node for the ring buffer is currently hardcoded to 4 MB. Userspace clients either use fstat() or hardcode this size for doing mmap(). To address this, make the sysfs node size dynamic to reflect the actual ring buffer size for each channel. This will ensure that fstat() on ring sysfs node always returns the correct size of ring buffer. Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Link: https://lore.kernel.org/r/20250502074811.2022-3-namjain@linux.microsoft.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-02uio_hv_generic: Fix sysfs creation path for ring bufferNaman Jain
On regular bootup, devices get registered to VMBus first, so when uio_hv_generic driver for a particular device type is probed, the device is already initialized and added, so sysfs creation in hv_uio_probe() works fine. However, when the device is removed and brought back, the channel gets rescinded and the device again gets registered to VMBus. However this time, the uio_hv_generic driver is already registered to probe for that device and in this case sysfs creation is tried before the device's kobject gets initialized completely. Fix this by moving the core logic of sysfs creation of ring buffer, from uio_hv_generic to HyperV's VMBus driver, where the rest of the sysfs attributes for the channels are defined. While doing that, make use of attribute groups and macros, instead of creating sysfs directly, to ensure better error handling and code flow. Problematic path: vmbus_process_offer (A new offer comes for the VMBus device) vmbus_add_channel_work vmbus_device_register |-> device_register | |... | |-> hv_uio_probe | |... | |-> sysfs_create_bin_file (leads to a warning as | the primary channel's kobject, which is used to | create the sysfs file, is not yet initialized) |-> kset_create_and_add |-> vmbus_add_channel_kobj (initialization of the primary channel's kobject happens later) Above code flow is sequential and the warning is always reproducible in this path. Fixes: 9ab877a6ccf8 ("uio_hv_generic: make ring buffer attribute for primary channel") Cc: stable@kernel.org Suggested-by: Saurabh Sengar <ssengar@linux.microsoft.com> Suggested-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Link: https://lore.kernel.org/r/20250502074811.2022-2-namjain@linux.microsoft.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25Drivers: hv: Fix bad ref to hv_synic_eventring_tail when CPU goes offlineMichael Kelley
When a CPU goes offline, hv_common_cpu_die() frees the hv_synic_eventring_tail memory for the CPU. But in a normal VM (i.e., not running in the root partition) the per-CPU memory has not been allocated, resulting in a bad memory reference and oops when computing the argument to kfree(). Fix this by freeing the memory only when running in the root partition. Fixes: 04df7ac39943 ("Drivers: hv: Introduce per-cpu event ring tail") Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Link: https://lore.kernel.org/r/20250421163134.2024-1-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250421163134.2024-1-mhklinux@outlook.com>
2025-04-07Drivers: hv: Fix bad pointer dereference in hv_get_partition_idNuno Das Neves
'output' is already a pointer to the output argument, it should be passed directly to hv_do_hypercall() without the '&' operator. Fixes: e96204e5e96e ("hyperv: Move hv_current_partition_id to arch-generic code") Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1743528737-20310-1-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1743528737-20310-1-git-send-email-nunodasneves@linux.microsoft.com>
2025-04-01Merge tag 'mm-stable-2025-03-30-16-52' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - The series "Enable strict percpu address space checks" from Uros Bizjak uses x86 named address space qualifiers to provide compile-time checking of percpu area accesses. This has caused a small amount of fallout - two or three issues were reported. In all cases the calling code was found to be incorrect. - The series "Some cleanup for memcg" from Chen Ridong implements some relatively monir cleanups for the memcontrol code. - The series "mm: fixes for device-exclusive entries (hmm)" from David Hildenbrand fixes a boatload of issues which David found then using device-exclusive PTE entries when THP is enabled. More work is needed, but this makes thins better - our own HMM selftests now succeed. - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed remove the z3fold and zbud implementations. They have been deprecated for half a year and nobody has complained. - The series "mm: further simplify VMA merge operation" from Lorenzo Stoakes implements numerous simplifications in this area. No runtime effects are anticipated. - The series "mm/madvise: remove redundant mmap_lock operations from process_madvise()" from SeongJae Park rationalizes the locking in the madvise() implementation. Performance gains of 20-25% were observed in one MADV_DONTNEED microbenchmark. - The series "Tiny cleanup and improvements about SWAP code" from Baoquan He contains a number of touchups to issues which Baoquan noticed when working on the swap code. - The series "mm: kmemleak: Usability improvements" from Catalin Marinas implements a couple of improvements to the kmemleak user-visible output. - The series "mm/damon/paddr: fix large folios access and schemes handling" from Usama Arif provides a couple of fixes for DAMON's handling of large folios. - The series "mm/damon/core: fix wrong and/or useless damos_walk() behaviors" from SeongJae Park fixes a few issues with the accuracy of kdamond's walking of DAMON regions. - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo Stoakes changes the interaction between framebuffer deferred-io and core MM. No functional changes are anticipated - this is preparatory work for the future removal of page structure fields. - The series "mm/damon: add support for hugepage_size DAMOS filter" from Usama Arif adds a DAMOS filter which permits the filtering by huge page sizes. - The series "mm: permit guard regions for file-backed/shmem mappings" from Lorenzo Stoakes extends the guard region feature from its present "anon mappings only" state. The feature now covers shmem and file-backed mappings. - The series "mm: batched unmap lazyfree large folios during reclamation" from Barry Song cleans up and speeds up the unmapping for pte-mapped large folios. - The series "reimplement per-vma lock as a refcount" from Suren Baghdasaryan puts the vm_lock back into the vma. Our reasons for pulling it out were largely bogus and that change made the code more messy. This patchset provides small (0-10%) improvements on one microbenchmark. - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and improves" from SeongJae Park does some maintenance work on the DAMON docs. - The series "hugetlb/CMA improvements for large systems" from Frank van der Linden addresses a pile of issues which have been observed when using CMA on large machines. - The series "mm/damon: introduce DAMOS filter type for unmapped pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the page's mapped/unmapped status. - The series "zsmalloc/zram: there be preemption" from Sergey Senozhatsky teaches zram to run its compression and decompression operations preemptibly. - The series "selftests/mm: Some cleanups from trying to run them" from Brendan Jackman fixes a pile of unrelated issues which Brendan encountered while runnimg our selftests. - The series "fs/proc/task_mmu: add guard region bit to pagemap" from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to determine whether a particular page is a guard page. - The series "mm, swap: remove swap slot cache" from Kairui Song removes the swap slot cache from the allocation path - it simply wasn't being effective. - The series "mm: cleanups for device-exclusive entries (hmm)" from David Hildenbrand implements a number of unrelated cleanups in this code. - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual implements a number of preparatoty cleanups to the GENERIC_PTDUMP Kconfig logic. - The series "mm/damon: auto-tune aggregation interval" from SeongJae Park implements a feedback-driven automatic tuning feature for DAMON's aggregation interval tuning. - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in powerpc, sparc and x86 lazy MMU implementations. Ryan did this in preparation for implementing lazy mmu mode for arm64 to optimize vmalloc. - The series "mm/page_alloc: Some clarifications for migratetype fallback" from Brendan Jackman reworks some commentary to make the code easier to follow. - The series "page_counter cleanup and size reduction" from Shakeel Butt cleans up the page_counter code and fixes a size increase which we accidentally added late last year. - The series "Add a command line option that enables control of how many threads should be used to allocate huge pages" from Thomas Prescher does that. It allows the careful operator to significantly reduce boot time by tuning the parallalization of huge page initialization. - The series "Fix calculations in trace_balance_dirty_pages() for cgwb" from Tang Yizhou fixes the tracing output from the dirty page balancing code. - The series "mm/damon: make allow filters after reject filters useful and intuitive" from SeongJae Park improves the handling of allow and reject filters. Behaviour is made more consistent and the documention is updated accordingly. - The series "Switch zswap to object read/write APIs" from Yosry Ahmed updates zswap to the new object read/write APIs and thus permits the removal of some legacy code from zpool and zsmalloc. - The series "Some trivial cleanups for shmem" from Baolin Wang does as it claims. - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from Alistair Popple regularizes the weird ZONE_DEVICE page refcount handling in DAX, permittig the removal of a number of special-case checks. - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a preparatoty refactoring and cleanup of the mremap() code. - The series "mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in which we determine whether a large folio is known to be mapped exclusively into a single MM. - The series "mm/damon: add sysfs dirs for managing DAMOS filters based on handling layers" from SeongJae Park adds a couple of new sysfs directories to ease the management of DAMON/DAMOS filters. - The series "arch, mm: reduce code duplication in mem_init()" from Mike Rapoport consolidates many per-arch implementations of mem_init() into code generic code, where that is practical. - The series "mm/damon/sysfs: commit parameters online via damon_call()" from SeongJae Park continues the cleaning up of sysfs access to DAMON internal data. - The series "mm: page_ext: Introduce new iteration API" from Luiz Capitulino reworks the page_ext initialization to fix a boot-time crash which was observed with an unusual combination of compile and cmdline options. - The series "Buddy allocator like (or non-uniform) folio split" from Zi Yan reworks the code to split a folio into smaller folios. The main benefit is lessened memory consumption: fewer post-split folios are generated. - The series "Minimize xa_node allocation during xarry split" from Zi Yan reduces the number of xarray xa_nodes which are generated during an xarray split. - The series "drivers/base/memory: Two cleanups" from Gavin Shan performs some maintenance work on the drivers/base/memory code. - The series "Add tracepoints for lowmem reserves, watermarks and totalreserve_pages" from Martin Liu adds some more tracepoints to the page allocator code. - The series "mm/madvise: cleanup requests validations and classifications" from SeongJae Park cleans up some warts which SeongJae observed during his earlier madvise work. - The series "mm/hwpoison: Fix regressions in memory failure handling" from Shuai Xue addresses two quite serious regressions which Shuai has observed in the memory-failure implementation. - The series "mm: reliable huge page allocator" from Johannes Weiner makes huge page allocations cheaper and more reliable by reducing fragmentation. - The series "Minor memcg cleanups & prep for memdescs" from Matthew Wilcox is preparatory work for the future implementation of memdescs. - The series "track memory used by balloon drivers" from Nico Pache introduces a way to track memory used by our various balloon drivers. - The series "mm/damon: introduce DAMOS filter type for active pages" from Nhat Pham permits users to filter for active/inactive pages, separately for file and anon pages. - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia separates the proactive reclaim statistics from the direct reclaim statistics. - The series "mm/vmscan: don't try to reclaim hwpoison folio" from Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim code. * tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits) mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex() x86/mm: restore early initialization of high_memory for 32-bits mm/vmscan: don't try to reclaim hwpoison folio mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper cgroup: docs: add pswpin and pswpout items in cgroup v2 doc mm: vmscan: split proactive reclaim statistics from direct reclaim statistics selftests/mm: speed up split_huge_page_test selftests/mm: uffd-unit-tests support for hugepages > 2M docs/mm/damon/design: document active DAMOS filter type mm/damon: implement a new DAMOS filter type for active pages fs/dax: don't disassociate zero page entries MM documentation: add "Unaccepted" meminfo entry selftests/mm: add commentary about 9pfs bugs fork: use __vmalloc_node() for stack allocation docs/mm: Physical Memory: Populate the "Zones" section xen: balloon: update the NR_BALLOON_PAGES state hv_balloon: update the NR_BALLOON_PAGES state balloon_compaction: update the NR_BALLOON_PAGES state meminfo: add a per node counter for balloon drivers mm: remove references to folio in __memcg_kmem_uncharge_page() ...
2025-03-25Merge tag 'hyperv-next-signed-20250324' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - Add support for running as the root partition in Hyper-V (Microsoft Hypervisor) by exposing /dev/mshv (Nuno and various people) - Add support for CPU offlining in Hyper-V (Hamza Mahfooz) - Misc fixes and cleanups (Roman Kisel, Tianyu Lan, Wei Liu, Michael Kelley, Thorsten Blum) * tag 'hyperv-next-signed-20250324' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (24 commits) x86/hyperv: fix an indentation issue in mshyperv.h x86/hyperv: Add comments about hv_vpset and var size hypercall input args Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs hyperv: Add definitions for root partition driver to hv headers x86: hyperv: Add mshv_handler() irq handler and setup function Drivers: hv: Introduce per-cpu event ring tail Drivers: hv: Export some functions for use by root partition module acpi: numa: Export node_to_pxm() hyperv: Introduce hv_recommend_using_aeoi() arm64/hyperv: Add some missing functions to arm64 x86/mshyperv: Add support for extended Hyper-V features hyperv: Log hypercall status codes as strings x86/hyperv: Fix check of return value from snp_set_vmsa() x86/hyperv: Add VTL mode callback for restarting the system x86/hyperv: Add VTL mode emergency restart callback hyperv: Remove unused union and structs hyperv: Add CONFIG_MSHV_ROOT to gate root partition support hyperv: Change hv_root_partition into a function hyperv: Convert hypercall statuses to linux error codes drivers/hv: add CPU offlining support ...
2025-03-21hv_balloon: update the NR_BALLOON_PAGES stateNico Pache
Update the NR_BALLOON_PAGES counter when pages are added to or removed from the Hyper-V balloon. Link: https://lkml.kernel.org/r/20250314213757.244258-4-npache@redhat.com Signed-off-by: Nico Pache <npache@redhat.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Cc: Alexander Atanasov <alexander.atanasov@virtuozzo.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: David Hildenbrand <david@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Juegren Gross <jgross@suse.com> Cc: Kanchana P Sridhar <kanchana.p.sridhar@intel.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-21Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMsNuno Das Neves
Provide a set of IOCTLs for creating and managing child partitions when running as root partition on Hyper-V. The new driver is enabled via CONFIG_MSHV_ROOT. A brief overview of the interface: MSHV_CREATE_PARTITION is the entry point, returning a file descriptor representing a child partition. IOCTLs on this fd can be used to map memory, create VPs, etc. Creating a VP returns another file descriptor representing that VP which in turn has another set of corresponding IOCTLs for running the VP, getting/setting state, etc. MSHV_ROOT_HVCALL is a generic "passthrough" hypercall IOCTL which can be used for a number of partition or VP hypercalls. This is for hypercalls that do not affect any state in the kernel driver, such as getting and setting VP registers and partition properties, translating addresses, etc. It is "passthrough" because the binary input and output for the hypercall is only interpreted by the VMM - the kernel driver does nothing but insert the VP and partition id where necessary (which are always in the same place), and execute the hypercall. Co-developed-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com> Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com> Co-developed-by: Jinank Jain <jinankjain@microsoft.com> Signed-off-by: Jinank Jain <jinankjain@microsoft.com> Co-developed-by: Mukesh Rathor <mrathor@linux.microsoft.com> Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com> Co-developed-by: Muminul Islam <muislam@microsoft.com> Signed-off-by: Muminul Islam <muislam@microsoft.com> Co-developed-by: Praveen K Paladugu <prapal@linux.microsoft.com> Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com> Co-developed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Co-developed-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Roman Kisel <romank@linux.microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-11-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-11-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20x86: hyperv: Add mshv_handler() irq handler and setup functionNuno Das Neves
Add mshv_handler() to process messages related to managing guest partitions such as intercepts, doorbells, and scheduling messages. In a (non-nested) root partition, the same interrupt vector is shared between the vmbus and mshv_root drivers. Introduce a stub for mshv_handler() and call it in sysvec_hyperv_callback alongside vmbus_handler(). Even though both handlers will be called for every Hyper-V interrupt, the messages for each driver are delivered to different offsets within the SYNIC message page, so they won't step on each other. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-9-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-9-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20Drivers: hv: Introduce per-cpu event ring tailNuno Das Neves
Add a pointer hv_synic_eventring_tail to track the tail pointer for the SynIC event ring buffer for each SINT. This will be used by the mshv driver, but must be tracked independently since the driver module could be removed and re-inserted. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-8-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-8-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20Drivers: hv: Export some functions for use by root partition moduleNuno Das Neves
hv_get_hypervisor_version(), hv_call_deposit_pages(), and hv_call_create_vp(), are all needed in-module with CONFIG_MSHV_ROOT=m. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@microsoft.linux.com> Reviewed-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-7-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-7-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20hyperv: Introduce hv_recommend_using_aeoi()Nuno Das Neves
Factor out the check for enabling auto eoi, to be reused in root partition code. No functional changes. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-5-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-5-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20hyperv: Log hypercall status codes as stringsNuno Das Neves
Introduce hv_status_printk() macros as a convenience to log hypercall errors, formatting them with the status code (HV_STATUS_*) as a raw hex value and also as a string, which saves some time while debugging. Create a table of HV_STATUS_ codes with strings and mapped errnos, and use it for hv_result_to_string() and hv_result_to_errno(). Use the new hv_status_printk()s in hv_proc.c, hyperv-iommu.c, and irqdomain.c hypercalls to aid debugging in the root partition. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-2-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-2-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20hyperv: Add CONFIG_MSHV_ROOT to gate root partition supportNuno Das Neves
CONFIG_MSHV_ROOT allows kernels built to run as a normal Hyper-V guest to exclude the root partition code, which is expected to grow significantly over time. This option is a tristate so future driver code can be built as a (m)odule, allowing faster development iteration cycles. If CONFIG_MSHV_ROOT is disabled, don't compile hv_proc.c, and stub hv_root_partition() to return false unconditionally. This allows the compiler to optimize away root partition code blocks since they will be disabled at compile time. In the case of booting as root partition *without* CONFIG_MSHV_ROOT enabled, print a critical error (the kernel will likely crash). Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1740167795-13296-4-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1740167795-13296-4-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-10Drivers: hv: vmbus: Don't release fb_mmio resource in vmbus_free_mmio()Michael Kelley
The VMBus driver manages the MMIO space it owns via the hyperv_mmio resource tree. Because the synthetic video framebuffer portion of the MMIO space is initially setup by the Hyper-V host for each guest, the VMBus driver does an early reserve of that portion of MMIO space in the hyperv_mmio resource tree. It saves a pointer to that resource in fb_mmio. When a VMBus driver requests MMIO space and passes "true" for the "fb_overlap_ok" argument, the reserved framebuffer space is used if possible. In that case it's not necessary to do another request against the "shadow" hyperv_mmio resource tree because that resource was already requested in the early reserve steps. However, the vmbus_free_mmio() function currently does no special handling for the fb_mmio resource. When a framebuffer device is removed, or the driver is unbound, the current code for vmbus_free_mmio() releases the reserved resource, leaving fb_mmio pointing to memory that has been freed. If the same or another driver is subsequently bound to the device, vmbus_allocate_mmio() checks against fb_mmio, and potentially gets garbage. Furthermore a second unbind operation produces this "nonexistent resource" error because of the unbalanced behavior between vmbus_allocate_mmio() and vmbus_free_mmio(): [ 55.499643] resource: Trying to free nonexistent resource <0x00000000f0000000-0x00000000f07fffff> Fix this by adding logic to vmbus_free_mmio() to recognize when MMIO space in the fb_mmio reserved area would be released, and don't release it. This filtering ensures the fb_mmio resource always exists, and makes vmbus_free_mmio() more parallel with vmbus_allocate_mmio(). Fixes: be000f93e5d7 ("drivers:hv: Track allocations of children of hv_vmbus in private resource tree") Signed-off-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Saurabh Sengar <ssengar@linux.microsoft.com> Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com> Link: https://lore.kernel.org/r/20250310035208.275764-1-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250310035208.275764-1-mhklinux@outlook.com>
2025-02-22hyperv: Change hv_root_partition into a functionNuno Das Neves
Introduce hv_curr_partition_type to store the partition type as an enum. Right now this is limited to guest or root partition, but there will be other kinds in future and the enum is easily extensible. Set up hv_curr_partition_type early in Hyper-V initialization with hv_identify_partition_type(). hv_root_partition() just queries this value, and shouldn't be called before that. Making this check into a function sets the stage for adding a config option to gate the compilation of root partition code. In particular, hv_root_partition() can be stubbed out always be false if root partition support isn't desired. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1740167795-13296-3-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1740167795-13296-3-git-send-email-nunodasneves@linux.microsoft.com>
2025-02-22hyperv: Convert hypercall statuses to linux error codesNuno Das Neves
Return linux-friendly error codes from hypercall helper functions, which allows them to be used more flexibly. Introduce hv_result_to_errno() for this purpose, which also handles the special value U64_MAX returned from hv_do_hypercall(). Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1740167795-13296-2-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1740167795-13296-2-git-send-email-nunodasneves@linux.microsoft.com>
2025-02-13drivers/hv: add CPU offlining supportHamza Mahfooz
Currently, it is tedious to offline CPUs in a Hyper-V VM since CPUs may have VMBus channels attached to them that a user would have to manually rebind elsewhere. So, as made mention of in commit d570aec0f2154 ("Drivers: hv: vmbus: Synchronize init_vp_index() vs. CPU hotplug"), rebind channels associated with CPUs that a user is trying to offline to a new "randomly" selected CPU. Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Michael Kelley <mhklinux@outlook.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250117203309.192072-3-hamzamahfooz@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250117203309.192072-3-hamzamahfooz@linux.microsoft.com>
2025-02-13drivers/hv: introduce vmbus_channel_set_cpu()Hamza Mahfooz
The core functionality in target_cpu_store() is also needed in a subsequent patch for automatically changing the CPU when taking a CPU offline. As such, factor out the body of target_cpu_store() into new function vmbus_channel_set_cpu() that can also be used elsewhere. No functional change is intended. Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Michael Kelley <mhklinux@outlook.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250117203309.192072-2-hamzamahfooz@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250117203309.192072-2-hamzamahfooz@linux.microsoft.com>
2025-02-13hyperv: Move arch/x86/hyperv/hv_proc.c to drivers/hvNuno Das Neves
These helpers are not specific to x86_64 and will be needed by common code. Remove some unnecessary #includes. Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Link: https://lore.kernel.org/r/1738955002-20821-3-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1738955002-20821-3-git-send-email-nunodasneves@linux.microsoft.com>
2025-02-13hyperv: Move hv_current_partition_id to arch-generic codeNuno Das Neves
Move hv_current_partition_id and hv_get_partition_id() to hv_common.c, and call hv_get_partition_id() on arm64 in hyperv_init(). These aren't specific to x86_64 and will be needed by common code. Set hv_current_partition_id to HV_PARTITION_ID_SELF by default. Rename struct hv_get_partition_id to hv_output_get_partition_id, to make it distinct from the function hv_get_partition_id(), and match the original Hyper-V struct name. Remove the BUG()s. Failing to get the id need not crash the machine. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1738955002-20821-2-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1738955002-20821-2-git-send-email-nunodasneves@linux.microsoft.com>
2025-01-28treewide: const qualify ctl_tables where applicableJoel Granados
Add the const qualifier to all the ctl_tables in the tree except for watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls, loadpin_sysctl_table and the ones calling register_net_sysctl (./net, drivers/inifiniband dirs). These are special cases as they use a registration function with a non-const qualified ctl_table argument or modify the arrays before passing them on to the registration function. Constifying ctl_table structs will prevent the modification of proc_handler function pointers as the arrays would reside in .rodata. This is made possible after commit 78eb4ea25cd5 ("sysctl: treewide: constify the ctl_table argument of proc_handlers") constified all the proc_handlers. Created this by running an spatch followed by a sed command: Spatch: virtual patch @ depends on !(file in "net") disable optional_qualifier @ identifier table_name != { watchdog_hardlockup_sysctl, iwcm_ctl_table, ucma_ctl_table, memory_allocation_profiling_sysctls, loadpin_sysctl_table }; @@ + const struct ctl_table table_name [] = { ... }; sed: sed --in-place \ -e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \ kernel/utsname_sysctl.c Reviewed-by: Song Liu <song@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> # for kernel/trace/ Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> # SCSI Reviewed-by: Darrick J. Wong <djwong@kernel.org> # xfs Acked-by: Jani Nikula <jani.nikula@intel.com> Acked-by: Corey Minyard <cminyard@mvista.com> Acked-by: Wei Liu <wei.liu@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Bill O'Donnell <bodonnel@redhat.com> Acked-by: Baoquan He <bhe@redhat.com> Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com> Acked-by: Anna Schumaker <anna.schumaker@oracle.com> Signed-off-by: Joel Granados <joel.granados@kernel.org>
2025-01-10hyperv: Enable the hypercall output page for the VTL modeRoman Kisel
Due to the hypercall page not being allocated in the VTL mode, the code resorts to using a part of the input page. Allocate the hypercall output page in the VTL mode thus enabling it to use it for output and share code with dom0. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Link: https://lore.kernel.org/r/20250108222138.1623703-4-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250108222138.1623703-4-romank@linux.microsoft.com>
2025-01-10hv_balloon: Fallback to generic_online_page() for non-HV hot added memJacob Pan
The Hyper-V balloon driver installs a custom callback for handling page onlining operations performed by the memory hotplug subsystem. This custom callback is global, and overrides the default callback (generic_online_page) that Linux otherwise uses. The custom callback properly handles memory that is hot-added by the balloon driver as part of a Hyper-V hot-add region. But memory can also be hot-added directly by a device driver for a vPCI device, particularly GPUs. In such a case, the custom callback installed by the balloon driver runs, but won't find the page in its hot-add region list and doesn't online it, which could cause driver initialization failures. Fix this by having the balloon custom callback run generic_online_page() when the page isn't part of a Hyper-V hot-add region, thereby doing the default Linux behavior. This allows device driver hot-adds to work properly. Similar cases are handled the same way in the virtio-mem driver. Suggested-by: Vikram Sethi <vsethi@nvidia.com> Tested-by: Michael Frohlich <mfrohlich@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Jacob Pan <jacob.pan@linux.microsoft.com> Link: https://lore.kernel.org/r/20250107180918.1053933-1-jacob.pan@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250107180918.1053933-1-jacob.pan@linux.microsoft.com>
2025-01-10Drivers: hv: vmbus: Log on missing offers if anyJohn Starks
When resuming from hibernation, log any channels that were present before hibernation but now are gone. In general, the boot-time devices configured for a resuming VM should be the same as the devices in the VM at the time of hibernation. It's uncommon for the configuration to have been changed such that offers are missing. Changing the configuration violates the rules for hibernation anyway. The cleanup of missing channels is not straight-forward and dependent on individual device driver functionality and implementation, so it can be added in future with separate changes. Signed-off-by: John Starks <jostarks@microsoft.com> Co-developed-by: Naman Jain <namjain@linux.microsoft.com> Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250102130712.1661-3-namjain@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250102130712.1661-3-namjain@linux.microsoft.com>
2025-01-10Drivers: hv: vmbus: Wait for boot-time offers during boot and resumeNaman Jain
Channel offers are requested during VMBus initialization and resume from hibernation. Add support to wait for all boot-time channel offers to be delivered and processed before returning from vmbus_request_offers. This is in analogy to a PCI bus not returning from probe until it has scanned all devices on the bus. Without this, user mode can race with VMBus initialization and miss channel offers. User mode has no way to work around this other than sleeping for a while, since there is no way to know when VMBus has finished processing boot-time offers. With this added functionality, remove earlier logic which keeps track of count of offered channels post resume from hibernation. Once all offers delivered message is received, no further boot-time offers are going to be received. Consequently, logic to prevent suspend from happening after previous resume had missing offers, is also removed. Co-developed-by: John Starks <jostarks@microsoft.com> Signed-off-by: John Starks <jostarks@microsoft.com> Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250102130712.1661-2-namjain@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250102130712.1661-2-namjain@linux.microsoft.com>
2025-01-10Drivers: hv: Don't assume cpu_possible_mask is denseMichael Kelley
Current code allocates the hv_vp_index array with size num_possible_cpus(). This code assumes cpu_possible_mask is dense, which is not true in the general case per [1]. If cpu_possible_mask is sparse, the array might be indexed by a value beyond the size of the array. However, the configurations that Hyper-V provides to guest VMs on x86 and ARM64 hardware, in combination with how architecture specific code assigns Linux CPU numbers, *does* always produce a dense cpu_possible_mask. So the dense assumption is not currently causing failures. But for robustness against future changes in how cpu_possible_mask is populated, update the code to no longer assume dense. The correct approach is to allocate and initialize the array using size "nr_cpu_ids". While this leaves unused array entries corresponding to holes in cpu_possible_mask, the holes are assumed to be minimal and hence the amount of memory wasted by unused entries is minimal. Using nr_cpu_ids also reduces initialization time, in that the loop to initialize the array currently rescans cpu_possible_mask on each iteration. This is n-squared in the number of CPUs, which could be significant for large CPU counts. [1] https://lore.kernel.org/lkml/SN6PR02MB4157210CC36B2593F8572E5ED4692@SN6PR02MB4157.namprd02.prod.outlook.com/ Signed-off-by: Michael Kelley <mhklinux@outlook.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20241003035333.49261-3-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20241003035333.49261-3-mhklinux@outlook.com>
2025-01-10hyperv: Switch from hyperv-tlfs.h to hyperv/hvhdk.hNuno Das Neves
Switch to using hvhdk.h everywhere in the kernel. This header includes all the new Hyper-V headers in include/hyperv, which form a superset of the definitions found in hyperv-tlfs.h. This makes it easier to add new Hyper-V interfaces without being restricted to those in the TLFS doc (reflected in hyperv-tlfs.h). To be more consistent with the original Hyper-V code, the names of some definitions are changed slightly. Update those where needed. Update comments in mshyperv.h files to point to include/hyperv for adding new definitions. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Link: https://lore.kernel.org/r/1732577084-2122-5-git-send-email-nunodasneves@linux.microsoft.com Link: https://lore.kernel.org/r/20250108222138.1623703-3-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2024-12-09Drivers: hv: util: Avoid accessing a ringbuffer not initialized yetMichael Kelley
If the KVP (or VSS) daemon starts before the VMBus channel's ringbuffer is fully initialized, we can hit the panic below: hv_utils: Registering HyperV Utility Driver hv_vmbus: registering driver hv_utils ... BUG: kernel NULL pointer dereference, address: 0000000000000000 CPU: 44 UID: 0 PID: 2552 Comm: hv_kvp_daemon Tainted: G E 6.11.0-rc3+ #1 RIP: 0010:hv_pkt_iter_first+0x12/0xd0 Call Trace: ... vmbus_recvpacket hv_kvp_onchannelcallback vmbus_on_event tasklet_action_common tasklet_action handle_softirqs irq_exit_rcu sysvec_hyperv_stimer0 </IRQ> <TASK> asm_sysvec_hyperv_stimer0 ... kvp_register_done hvt_op_read vfs_read ksys_read __x64_sys_read This can happen because the KVP/VSS channel callback can be invoked even before the channel is fully opened: 1) as soon as hv_kvp_init() -> hvutil_transport_init() creates /dev/vmbus/hv_kvp, the kvp daemon can open the device file immediately and register itself to the driver by writing a message KVP_OP_REGISTER1 to the file (which is handled by kvp_on_msg() ->kvp_handle_handshake()) and reading the file for the driver's response, which is handled by hvt_op_read(), which calls hvt->on_read(), i.e. kvp_register_done(). 2) the problem with kvp_register_done() is that it can cause the channel callback to be called even before the channel is fully opened, and when the channel callback is starting to run, util_probe()-> vmbus_open() may have not initialized the ringbuffer yet, so the callback can hit the panic of NULL pointer dereference. To reproduce the panic consistently, we can add a "ssleep(10)" for KVP in __vmbus_open(), just before the first hv_ringbuffer_init(), and then we unload and reload the driver hv_utils, and run the daemon manually within the 10 seconds. Fix the panic by reordering the steps in util_probe() so the char dev entry used by the KVP or VSS daemon is not created until after vmbus_open() has completed. This reordering prevents the race condition from happening. Reported-by: Dexuan Cui <decui@microsoft.com> Fixes: e0fa3e5e7df6 ("Drivers: hv: utils: fix a race on userspace daemons registration") Cc: stable@vger.kernel.org Signed-off-by: Michael Kelley <mhklinux@outlook.com> Acked-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20241106154247.2271-3-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20241106154247.2271-3-mhklinux@outlook.com>
2024-12-09Drivers: hv: util: Don't force error code to ENODEV in util_probe()Michael Kelley
If the util_init function call in util_probe() returns an error code, util_probe() always return ENODEV, and the error code from the util_init function is lost. The error message output in the caller, vmbus_probe(), doesn't show the real error code. Fix this by just returning the error code from the util_init function. There doesn't seem to be a reason to force ENODEV, as other errors such as ENOMEM can already be returned from util_probe(). And the code in call_driver_probe() implies that ENODEV should mean that a matching driver wasn't found, which is not the case here. Suggested-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Michael Kelley <mhklinux@outlook.com> Acked-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20241106154247.2271-2-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20241106154247.2271-2-mhklinux@outlook.com>
generated by cgit (git 2.34.1) at 2025-07-25 17:53:25 +0000