kernel/linux.git/drivers/net/hyperv, branch v5.15.210

hv_netvsc: use kmap_local_page in netvsc_copy_to_send_buf

2026-06-19T11:33:49+00:00

[ Upstream commit 004e9ecfe6c5384f9e0b2f6f6389d42ec22789af ] netvsc_copy_to_send_buf() copies page buffer entries into the VMBus send buffer using phys_to_virt() on the entry PFN. Entries for the RNDIS header and the skb linear data come from kmalloc'd memory and are always in the kernel direct map, but entries for skb fragments reference page cache or user pages, which on 32-bit x86 with CONFIG_HIGHMEM=y can live above the LOWMEM boundary. For such a page phys_to_virt() returns an address outside the direct map and the subsequent memcpy() faults on the transmit softirq path, which is fatal. Map the pages with kmap_local_page() instead, handling two properties of the page buffer entries: - pb[i].pfn is a Hyper-V PFN at HV_HYP_PAGE_SIZE (4K) granularity, not a native PFN. Reconstruct the physical address first and derive the native page from it, so the mapping stays correct where PAGE_SIZE > HV_HYP_PAGE_SIZE (e.g. arm64 with 64K pages). - Since commit 41a6328b2c55 ("hv_netvsc: Preserve contiguous PFN grouping in the page buffer array"), an entry describes a full physically contiguous fragment and pb[i].len can exceed PAGE_SIZE, while kmap_local_page() maps a single page. Copy page by page, splitting at native page boundaries. The copy path only handles packets smaller than the send section size (6144 bytes by default); larger packets take the cp_partial path where only the RNDIS header is copied. So entries here are bounded by the section size and a copy is split at most once on 4K-page systems. On !CONFIG_HIGHMEM configs kmap_local_page() folds to page_address() and no mapping work is added. Fixes: c25aaf814a63 ("hyperv: Enable sendbuf mechanism on the send path") Cc: stable@vger.kernel.org Signed-off-by: Anton Leontev Link: https://patch.msgid.link/20260604165938.32033-1-leontyevantony@gmail.com Signed-off-by: Paolo Abeni [ adapted `phys_to_page(paddr)` to `pfn_to_page(PHYS_PFN(paddr))` ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

hv_netvsc: Fix panic during namespace deletion with VF

2025-08-28T14:24:31+00:00

[ Upstream commit 33caa208dba6fa639e8a92fd0c8320b652e5550c ] The existing code move the VF NIC to new namespace when NETDEV_REGISTER is received on netvsc NIC. During deletion of the namespace, default_device_exit_batch() >> default_device_exit_net() is called. When netvsc NIC is moved back and registered to the default namespace, it automatically brings VF NIC back to the default namespace. This will cause the default_device_exit_net() >> for_each_netdev_safe loop unable to detect the list end, and hit NULL ptr: [ 231.449420] mana 7870:00:00.0 enP30832s1: Moved VF to namespace with: eth0 [ 231.449656] BUG: kernel NULL pointer dereference, address: 0000000000000010 [ 231.450246] #PF: supervisor read access in kernel mode [ 231.450579] #PF: error_code(0x0000) - not-present page [ 231.450916] PGD 17b8a8067 P4D 0 [ 231.451163] Oops: Oops: 0000 [#1] SMP NOPTI [ 231.451450] CPU: 82 UID: 0 PID: 1394 Comm: kworker/u768:1 Not tainted 6.16.0-rc4+ #3 VOLUNTARY [ 231.452042] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 11/21/2024 [ 231.452692] Workqueue: netns cleanup_net [ 231.452947] RIP: 0010:default_device_exit_batch+0x16c/0x3f0 [ 231.453326] Code: c0 0c f5 b3 e8 d5 db fe ff 48 85 c0 74 15 48 c7 c2 f8 fd ca b2 be 10 00 00 00 48 8d 7d c0 e8 7b 77 25 00 49 8b 86 28 01 00 00 <48> 8b 50 10 4c 8b 2a 4c 8d 62 f0 49 83 ed 10 4c 39 e0 0f 84 d6 00 [ 231.454294] RSP: 0018:ff75fc7c9bf9fd00 EFLAGS: 00010246 [ 231.454610] RAX: 0000000000000000 RBX: 0000000000000002 RCX: 61c8864680b583eb [ 231.455094] RDX: ff1fa9f71462d800 RSI: ff75fc7c9bf9fd38 RDI: 0000000030766564 [ 231.455686] RBP: ff75fc7c9bf9fd78 R08: 0000000000000000 R09: 0000000000000000 [ 231.456126] R10: 0000000000000001 R11: 0000000000000004 R12: ff1fa9f70088e340 [ 231.456621] R13: ff1fa9f70088e340 R14: ffffffffb3f50c20 R15: ff1fa9f7103e6340 [ 231.457161] FS: 0000000000000000(0000) GS:ff1faa6783a08000(0000) knlGS:0000000000000000 [ 231.457707] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 231.458031] CR2: 0000000000000010 CR3: 0000000179ab2006 CR4: 0000000000b73ef0 [ 231.458434] Call Trace: [ 231.458600] [ 231.458777] ops_undo_list+0x100/0x220 [ 231.459015] cleanup_net+0x1b8/0x300 [ 231.459285] process_one_work+0x184/0x340 To fix it, move the ns change to a workqueue, and take rtnl_lock to avoid changing the netdev list when default_device_exit_net() is using it. Cc: stable@vger.kernel.org Fixes: 4c262801ea60 ("hv_netvsc: Fix VF namespace also in synthetic NIC NETDEV_REGISTER event") Signed-off-by: Haiyang Zhang Link: https://patch.msgid.link/1754511711-11188-1-git-send-email-haiyangz@linux.microsoft.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

hv_netvsc: Fix VF namespace also in synthetic NIC NETDEV_REGISTER event

2024-11-01T00:52:38+00:00

commit 4c262801ea60c518b5bebc22a09f5b78b3147da2 upstream. The existing code moves VF to the same namespace as the synthetic NIC during netvsc_register_vf(). But, if the synthetic device is moved to a new namespace after the VF registration, the VF won't be moved together. To make the behavior more consistent, add a namespace check for synthetic NIC's NETDEV_REGISTER event (generated during its move), and move the VF if it is not in the same namespace. Cc: stable@vger.kernel.org Fixes: c0a41b887ce6 ("hv_netvsc: move VF to same namespace as netvsc device") Suggested-by: Stephen Hemminger Signed-off-by: Haiyang Zhang Reviewed-by: Simon Horman Link: https://patch.msgid.link/1729275922-17595-1-git-send-email-haiyangz@microsoft.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

hv_netvsc: Register VF in netvsc_probe if NET_DEVICE_REGISTER missed

2024-03-15T14:48:21+00:00

[ Upstream commit 9cae43da9867412f8bd09aee5c8a8dc5e8dc3dc2 ] If hv_netvsc driver is unloaded and reloaded, the NET_DEVICE_REGISTER handler cannot perform VF register successfully as the register call is received before netvsc_probe is finished. This is because we register register_netdevice_notifier() very early( even before vmbus_driver_register()). To fix this, we try to register each such matching VF( if it is visible as a netdevice) at the end of netvsc_probe. Cc: stable@vger.kernel.org Fixes: 85520856466e ("hv_netvsc: Fix race of register_netdevice_notifier and VF register") Suggested-by: Dexuan Cui Signed-off-by: Shradha Gupta Reviewed-by: Haiyang Zhang Reviewed-by: Dexuan Cui Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

hv_netvsc: use netif_is_bond_master() instead of open code

2024-03-15T14:48:21+00:00

[ Upstream commit c60882a4566a0a62dc3a40c85131103aad83dcb3 ] Use netif_is_bond_master() function instead of open code, which is ((event_dev->priv_flags & IFF_BONDING) && (event_dev->flags & IFF_MASTER)). This patch doesn't change logic. Signed-off-by: Juhee Kang Signed-off-by: David S. Miller Stable-dep-of: 9cae43da9867 ("hv_netvsc: Register VF in netvsc_probe if NET_DEVICE_REGISTER missed") Signed-off-by: Sasha Levin

hv_netvsc: Fix race condition between netvsc_probe and netvsc_remove

2024-02-23T07:55:07+00:00

commit e0526ec5360a48ad3ab2e26e802b0532302a7e11 upstream. In commit ac5047671758 ("hv_netvsc: Disable NAPI before closing the VMBus channel"), napi_disable was getting called for all channels, including all subchannels without confirming if they are enabled or not. This caused hv_netvsc getting hung at napi_disable, when netvsc_probe() has finished running but nvdev->subchan_work has not started yet. netvsc_subchan_work() -> rndis_set_subchannel() has not created the sub-channels and because of that netvsc_sc_open() is not running. netvsc_remove() calls cancel_work_sync(&nvdev->subchan_work), for which netvsc_subchan_work did not run. netif_napi_add() sets the bit NAPI_STATE_SCHED because it ensures NAPI cannot be scheduled. Then netvsc_sc_open() -> napi_enable will clear the NAPIF_STATE_SCHED bit, so it can be scheduled. napi_disable() does the opposite. Now during netvsc_device_remove(), when napi_disable is called for those subchannels, napi_disable gets stuck on infinite msleep. This fix addresses this problem by ensuring that napi_disable() is not getting called for non-enabled NAPI struct. But netif_napi_del() is still necessary for these non-enabled NAPI struct for cleanup purpose. Call trace: [ 654.559417] task:modprobe state:D stack: 0 pid: 2321 ppid: 1091 flags:0x00004002 [ 654.568030] Call Trace: [ 654.571221] [ 654.573790] __schedule+0x2d6/0x960 [ 654.577733] schedule+0x69/0xf0 [ 654.581214] schedule_timeout+0x87/0x140 [ 654.585463] ? __bpf_trace_tick_stop+0x20/0x20 [ 654.590291] msleep+0x2d/0x40 [ 654.593625] napi_disable+0x2b/0x80 [ 654.597437] netvsc_device_remove+0x8a/0x1f0 [hv_netvsc] [ 654.603935] rndis_filter_device_remove+0x194/0x1c0 [hv_netvsc] [ 654.611101] ? do_wait_intr+0xb0/0xb0 [ 654.615753] netvsc_remove+0x7c/0x120 [hv_netvsc] [ 654.621675] vmbus_remove+0x27/0x40 [hv_vmbus] Cc: stable@vger.kernel.org Fixes: ac5047671758 ("hv_netvsc: Disable NAPI before closing the VMBus channel") Signed-off-by: Souradeep Chakrabarti Reviewed-by: Dexuan Cui Reviewed-by: Haiyang Zhang Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/1706686551-28510-1-git-send-email-schakrabarti@linux.microsoft.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

hv_netvsc: Calculate correct ring size when PAGE_SIZE is not 4 Kbytes

2024-02-23T07:54:31+00:00

commit 6941f67ad37d5465b75b9ffc498fcf6897a3c00e upstream. Current code in netvsc_drv_init() incorrectly assumes that PAGE_SIZE is 4 Kbytes, which is wrong on ARM64 with 16K or 64K page size. As a result, the default VMBus ring buffer size on ARM64 with 64K page size is 8 Mbytes instead of the expected 512 Kbytes. While this doesn't break anything, a typical VM with 8 vCPUs and 8 netvsc channels wastes 120 Mbytes (8 channels * 2 ring buffers/channel * 7.5 Mbytes/ring buffer). Unfortunately, the module parameter specifying the ring buffer size is in units of 4 Kbyte pages. Ideally, it should be in units that are independent of PAGE_SIZE, but backwards compatibility prevents changing that now. Fix this by having netvsc_drv_init() hardcode 4096 instead of using PAGE_SIZE when calculating the ring buffer size in bytes. Also use the VMBUS_RING_SIZE macro to ensure proper alignment when running with page size larger than 4K. Cc: # 5.15.x Fixes: 7aff79e297ee ("Drivers: hv: Enable Hyper-V code to be built on ARM64") Signed-off-by: Michael Kelley Link: https://lore.kernel.org/r/20240122162028.348885-1-mhklinux@outlook.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

hv_netvsc: rndis_filter needs to select NLS

2023-12-13T17:36:34+00:00

[ Upstream commit 6c89f49964375c904cea33c0247467873f4daf2c ] rndis_filter uses utf8s_to_utf16s() which is provided by setting NLS, so select NLS to fix the build error: ERROR: modpost: "utf8s_to_utf16s" [drivers/net/hyperv/hv_netvsc.ko] undefined! Fixes: 1ce09e899d28 ("hyperv: Add support for setting MAC from within guests") Signed-off-by: Randy Dunlap Cc: Haiyang Zhang Cc: K. Y. Srinivasan Cc: Wei Liu Cc: Dexuan Cui Reviewed-by: Simon Horman Tested-by: Simon Horman # build-tested Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20231130055853.19069-1-rdunlap@infradead.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

hv_netvsc: fix race of netvsc and VF register_netdevice

2023-12-08T07:48:02+00:00

[ Upstream commit d30fb712e52964f2cf9a9c14cf67078394044837 ] The rtnl lock also needs to be held before rndis_filter_device_add() which advertises nvsp_2_vsc_capability / sriov bit, and triggers VF NIC offering and registering. If VF NIC finished register_netdev() earlier it may cause name based config failure. To fix this issue, move the call to rtnl_lock() before rndis_filter_device_add(), so VF will be registered later than netvsc / synthetic NIC, and gets a name numbered (ethX) after netvsc. Cc: stable@vger.kernel.org Fixes: e04e7a7bbd4b ("hv_netvsc: Fix a deadlock by getting rtnl lock earlier in netvsc_probe()") Reported-by: Dexuan Cui Signed-off-by: Haiyang Zhang Reviewed-by: Wojciech Drewek Reviewed-by: Simon Horman Reviewed-by: Dexuan Cui Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

hv_netvsc: Mark VF as slave before exposing it to user-mode

2023-12-03T06:31:24+00:00

commit c807d6cd089d2f4951baa838081ec5ae3e2360f8 upstream. When a VF is being exposed form the kernel, it should be marked as "slave" before exposing to the user-mode. The VF is not usable without netvsc running as master. The user-mode should never see a VF without the "slave" flag. This commit moves the code of setting the slave flag to the time before VF is exposed to user-mode. Cc: stable@vger.kernel.org Fixes: 0c195567a8f6 ("netvsc: transparent VF management") Signed-off-by: Long Li Signed-off-by: Haiyang Zhang Acked-by: Stephen Hemminger Acked-by: Dexuan Cui Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman