kernel/linux.git/drivers/hv, branch linux-4.20.y

vmbus: fix subchannel removal

2019-01-31T07:15:45+00:00

[ Upstream commit b5679cebf780c6f1c2451a73bf1842a4409840e7 ] The changes to split ring allocation from open/close, broke the cleanup of subchannels. This resulted in problems using uio on network devices because the subchannel was left behind when the network device was unbound. The cause was in the disconnect logic which used list splice to move the subchannel list into a local variable. This won't work because the subchannel list is needed later during the process of the rescind messages (relid2channel). The fix is to just leave the subchannel list in place which is what the original code did. The list is cleaned up later when the host rescind is processed. Without the fix, we have a lot of "hang" issues in netvsc when we try to change the NIC's MTU, set the number of channels, etc. Fixes: ae6935ed7d42 ("vmbus: split ring buffer allocation from open") Cc: stable@vger.kernel.org Signed-off-by: Stephen Hemminger Signed-off-by: Dexuan Cui Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Remove the useless API vmbus_get_outgoing_channel()

2019-01-31T07:15:45+00:00

[ Upstream commit 4d3c5c69191f98c7f7e699ff08d2fd96d7070ddb ] Commit d86adf482b84 ("scsi: storvsc: Enable multi-queue support") removed the usage of the API in Jan 2017, and the API is not used since then. netvsc and storvsc have their own algorithms to determine the outgoing channel, so this API is useless. And the API is potentially unsafe, because it reads primary->num_sc without any lock held. This can be risky considering the RESCIND-OFFER message. Let's remove the API. Cc: Long Li Cc: Stephen Hemminger Cc: K. Y. Srinivasan Cc: Haiyang Zhang Signed-off-by: Dexuan Cui Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman Signed-off-by: Dexuan Cui Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Check for ring when getting debug info

2019-01-31T07:15:40+00:00

commit ba50bf1ce9a51fc97db58b96d01306aa70bc3979 upstream. fc96df16a1ce is good and can already fix the "return stack garbage" issue, but let's also improve hv_ringbuffer_get_debuginfo(), which would silently return stack garbage, if people forget to check channel->state or ring_info->ring_buffer, when using the function in the future. Having an error check in the function would eliminate the potential risk. Add a Fixes tag to indicate the patch depdendency. Fixes: fc96df16a1ce ("Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels") Cc: stable@vger.kernel.org Cc: K. Y. Srinivasan Cc: Haiyang Zhang Signed-off-by: Stephen Hemminger Signed-off-by: Dexuan Cui Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

hv_balloon: avoid touching uninitialized struct page during tail onlining

2019-01-31T07:15:39+00:00

commit da8ced360ca8ad72d8f41f5c8fcd5b0e63e1555f upstream. Hyper-V memory hotplug protocol has 2M granularity and in Linux x86 we use 128M. To deal with it we implement partial section onlining by registering custom page onlining callback (hv_online_page()). Later, when more memory arrives we try to online the 'tail' (see hv_bring_pgs_online()). It was found that in some cases this 'tail' onlining causes issues: BUG: Bad page state in process kworker/0:2 pfn:109e3a page:ffffe08344278e80 count:0 mapcount:1 mapping:0000000000000000 index:0x0 flags: 0xfffff80000000() raw: 000fffff80000000 dead000000000100 dead000000000200 0000000000000000 raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 page dumped because: nonzero mapcount ... Workqueue: events hot_add_req [hv_balloon] Call Trace: dump_stack+0x5c/0x80 bad_page.cold.112+0x7f/0xb2 free_pcppages_bulk+0x4b8/0x690 free_unref_page+0x54/0x70 hv_page_online_one+0x5c/0x80 [hv_balloon] hot_add_req.cold.24+0x182/0x835 [hv_balloon] ... Turns out that we now have deferred struct page initialization for memory hotplug so e.g. memory_block_action() in drivers/base/memory.c does pages_correctly_probed() check and in that check it avoids inspecting struct pages and checks sections instead. But in Hyper-V balloon driver we do PageReserved(pfn_to_page()) check and this is now wrong. Switch to checking online_section_nr() instead. Signed-off-by: Vitaly Kuznetsov Cc: stable@kernel.org Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Merge tag 'hyperv-fixes-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux into char-misc-linus

2018-12-14T14:36:56+00:00

Sasha writes: hyperv-fixes-4.20-rc6 * tag 'hyperv-fixes-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels x86, hyperv: remove PCI dependency

Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels

2018-12-13T19:58:27+00:00

Before 98f4c651762c, we returned zeros for unopened channels. With 98f4c651762c, we started to return random on-stack values. We'd better return -EINVAL instead. Fixes: 98f4c651762c ("hv: move ringbuffer bus attributes to dev_groups") Cc: stable@vger.kernel.org Cc: K. Y. Srinivasan Cc: Haiyang Zhang Cc: Stephen Hemminger Signed-off-by: Dexuan Cui Signed-off-by: Sasha Levin

x86, hyperv: remove PCI dependency

2018-12-13T19:55:57+00:00

Need to be able to boot without PCI devices present. Signed-off-by: Sinan Kaya Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Offload the handling of channels to two workqueues

2018-12-03T07:01:01+00:00

vmbus_process_offer() mustn't call channel->sc_creation_callback() directly for sub-channels, because sc_creation_callback() -> vmbus_open() may never get the host's response to the OPEN_CHANNEL message (the host may rescind a channel at any time, e.g. in the case of hot removing a NIC), and vmbus_onoffer_rescind() may not wake up the vmbus_open() as it's blocked due to a non-zero vmbus_connection.offer_in_progress, and finally we have a deadlock. The above is also true for primary channels, if the related device drivers use sync probing mode by default. And, usually the handling of primary channels and sub-channels can depend on each other, so we should offload them to different workqueues to avoid possible deadlock, e.g. in sync-probing mode, NIC1's netvsc_subchan_work() can race with NIC2's netvsc_probe() -> rtnl_lock(), and causes deadlock: the former gets the rtnl_lock and waits for all the sub-channels to appear, but the latter can't get the rtnl_lock and this blocks the handling of sub-channels. The patch can fix the multiple-NIC deadlock described above for v3.x kernels (e.g. RHEL 7.x) which don't support async-probing of devices, and v4.4, v4.9, v4.14 and v4.18 which support async-probing but don't enable async-probing for Hyper-V drivers (yet). The patch can also fix the hang issue in sub-channel's handling described above for all versions of kernels, including v4.19 and v4.20-rc4. So actually the patch should be applied to all the existing kernels, not only the kernels that have 8195b1396ec8. Fixes: 8195b1396ec8 ("hv_netvsc: fix deadlock on hotplug") Cc: stable@vger.kernel.org Cc: Stephen Hemminger Cc: K. Y. Srinivasan Cc: Haiyang Zhang Signed-off-by: Dexuan Cui Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: check the creation_status in vmbus_establish_gpadl()

2018-11-26T19:33:56+00:00

This is a longstanding issue: if the vmbus upper-layer drivers try to consume too many GPADLs, the host may return with an error 0xC0000044 (STATUS_QUOTA_EXCEEDED), but currently we forget to check the creation_status, and hence we can pass an invalid GPADL handle into the OPEN_CHANNEL message, and get an error code 0xc0000225 in open_info->response.open_result.status, and finally we hang in vmbus_open() -> "goto error_free_info" -> vmbus_teardown_gpadl(). With this patch, we can exit gracefully on STATUS_QUOTA_EXCEEDED. Cc: Stephen Hemminger Cc: K. Y. Srinivasan Cc: Haiyang Zhang Cc: stable@vger.kernel.org Signed-off-by: Dexuan Cui Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

Drivers: hv: kvp: Fix the recent regression caused by incorrect clean-up

2018-11-11T17:00:20+00:00

In kvp_send_key(), we do need call process_ib_ipinfo() if message->kvp_hdr.operation is KVP_OP_GET_IP_INFO, because it turns out the userland hv_kvp_daemon needs the info of operation, adapter_id and addr_family. With the incorrect fc62c3b1977d, the host can't get the VM's IP via KVP. And, fc62c3b1977d added a "break;", but actually forgot to initialize the key_size/value in the case of KVP_OP_SET, so the default key_size of 0 is passed to the kvp daemon, and the pool files /var/lib/hyperv/.kvp_pool_* can't be updated. This patch effectively rolls back the previous fc62c3b1977d, and correctly fixes the "this statement may fall through" warnings. This patch is tested on WS 2012 R2 and 2016. Fixes: fc62c3b1977d ("Drivers: hv: kvp: Fix two "this statement may fall through" warnings") Signed-off-by: Dexuan Cui Cc: K. Y. Srinivasan Cc: Stephen Hemminger Signed-off-by: Haiyang Zhang Cc: Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman