kernel/git/stable/linux.git/drivers/net/hyperv/netvsc.c, branch master

hv_netvsc: Remove GPADL teardown special case for old Hyper-V hosts

2026-08-24T00:35:42+00:00

With the overall removal of Linux support for running on Hyper-V hosts earlier than WS2016 and Windows 10, the special case handling of GPADL teardown is no longer necessary. Remove it. Signed-off-by: Michael Kelley Signed-off-by: Wei Liu

hv_netvsc: Allocate send/receive buffers using vmbus_alloc_buffer()

2026-08-24T00:33:25+00:00

On CoCo VMs without confidential VMBus, the netvsc send and receive buffers must be made host-visible by decrypting them. These buffers are vmalloc'ed, but set_memory_decrypted()/encrypted() do not work on vmalloc'ed memory. This use case is (so far) unique to netvsc, so solve it locally rather than changing the set_memory() or allocation APIs. Use vmbus_alloc_buffer() to allocate the send and receive buffers, which will make them host-visible. Store the list of memory chunks in the netvsc_device struct so they can be individually freed later. Use vmbus_establish_gpadl_caller_decrypted() so there is no attempt to decrypt the virtual address. Appropriately free the buffers with vmbus_free_buffer(). Because vunmap() and set_memory_encrypted() must run in process context, replace the rcu_head/call_rcu() pair used to defer free_netvsc_device() with rcu_work/queue_rcu_work(). This also fixes a small race condition where the buffers may be accessed while being re-encrypted by moving the re-encryption after the RCU grace period. Signed-off-by: Kameron Carr Reviewed-by: Michael Kelley Signed-off-by: Wei Liu

hv_netvsc: use kmap_local_page in netvsc_copy_to_send_buf

2026-06-09T11:16:30+00:00

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

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

net: hv_netvsc: fix loss of early receive events from host during channel open.

2025-08-27T01:15:19+00:00

The hv_netvsc driver currently enables NAPI after opening the primary and subchannels. This ordering creates a race: if the Hyper-V host places data in the host -> guest ring buffer and signals the channel before napi_enable() has been called, the channel callback will run but napi_schedule_prep() will return false. As a result, the NAPI poller never gets scheduled, the data in the ring buffer is not consumed, and the receive queue may remain permanently stuck until another interrupt happens to arrive. Fix this by enabling NAPI and registering it with the RX/TX queues before vmbus channel is opened. This guarantees that any early host signal after open will correctly trigger NAPI scheduling and the ring buffer will be drained. Fixes: 76bb5db5c749d ("netvsc: fix use after free on module removal") Signed-off-by: Dipayaan Roy Link: https://patch.msgid.link/20250825115627.GA32189@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net Signed-off-by: Jakub Kicinski

hv_netvsc: Remove rmsg_pgcnt

2025-05-15T02:45:24+00:00

init_page_array() now always creates a single page buffer array entry for the rndis message, even if the rndis message crosses a page boundary. As such, the number of page buffer array entries used for the rndis message must no longer be tracked -- it is always just 1. Remove the rmsg_pgcnt field and use "1" where the value is needed. Cc: # 6.1.x Signed-off-by: Michael Kelley Link: https://patch.msgid.link/20250513000604.1396-5-mhklinux@outlook.com Signed-off-by: Jakub Kicinski

hv_netvsc: Use vmbus_sendpacket_mpb_desc() to send VMBus messages

2025-05-15T02:45:23+00:00

netvsc currently uses vmbus_sendpacket_pagebuffer() to send VMBus messages. This function creates a series of GPA ranges, each of which contains a single PFN. However, if the rndis header in the VMBus message crosses a page boundary, the netvsc protocol with the host requires that both PFNs for the rndis header must be in a single "GPA range" data structure, which isn't possible with vmbus_sendpacket_pagebuffer(). As the first step in fixing this, add a new function netvsc_build_mpb_array() to build a VMBus message with multiple GPA ranges, each of which may contain multiple PFNs. Use vmbus_sendpacket_mpb_desc() to send this VMBus message to the host. There's no functional change since higher levels of netvsc don't maintain or propagate knowledge of contiguous PFNs. Based on its input, netvsc_build_mpb_array() still produces a separate GPA range for each PFN and the behavior is the same as with vmbus_sendpacket_pagebuffer(). But the groundwork is laid for a subsequent patch to provide the necessary grouping. Cc: # 6.1.x Signed-off-by: Michael Kelley Link: https://patch.msgid.link/20250513000604.1396-3-mhklinux@outlook.com Signed-off-by: Jakub Kicinski

hv_netvsc: Replace one-element array with flexible array member

2025-01-18T03:07:48+00:00

Replace the deprecated one-element array with a modern flexible array member in the struct nvsp_1_message_send_receive_buffer_complete. Use struct_size_t(,,1) instead of sizeof() to maintain the same size. Compile-tested only. Link: https://github.com/KSPP/linux/issues/79 Signed-off-by: Thorsten Blum Tested-by: Roman Kisel Reviewed-by: Roman Kisel Link: https://patch.msgid.link/20250116211932.139564-2-thorsten.blum@linux.dev Signed-off-by: Jakub Kicinski

hv_netvsc: Link queues to NAPIs

2024-10-06T15:24:06+00:00

Use netif_queue_set_napi to link queues to NAPI instances so that they can be queried with netlink. Shradha Gupta tested the patch and reported that the results are as expected: $ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \ --dump queue-get --json='{"ifindex": 2}' [{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'rx'}, {'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'rx'}, {'id': 2, 'ifindex': 2, 'napi-id': 8195, 'type': 'rx'}, {'id': 3, 'ifindex': 2, 'napi-id': 8196, 'type': 'rx'}, {'id': 4, 'ifindex': 2, 'napi-id': 8197, 'type': 'rx'}, {'id': 5, 'ifindex': 2, 'napi-id': 8198, 'type': 'rx'}, {'id': 6, 'ifindex': 2, 'napi-id': 8199, 'type': 'rx'}, {'id': 7, 'ifindex': 2, 'napi-id': 8200, 'type': 'rx'}, {'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'tx'}, {'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'tx'}, {'id': 2, 'ifindex': 2, 'napi-id': 8195, 'type': 'tx'}, {'id': 3, 'ifindex': 2, 'napi-id': 8196, 'type': 'tx'}, {'id': 4, 'ifindex': 2, 'napi-id': 8197, 'type': 'tx'}, {'id': 5, 'ifindex': 2, 'napi-id': 8198, 'type': 'tx'}, {'id': 6, 'ifindex': 2, 'napi-id': 8199, 'type': 'tx'}, {'id': 7, 'ifindex': 2, 'napi-id': 8200, 'type': 'tx'}] Signed-off-by: Joe Damato Reviewed-by: Haiyang Zhang Tested-by: Shradha Gupta Signed-off-by: David S. Miller