user/sven/linux.git/include/linux/hyperv.h, branch v4.20.5

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

2018-12-03T07:01:01Z

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

vmbus: split ring buffer allocation from open

2018-09-25T18:33:24Z

The UIO driver needs the ring buffer to be persistent(reused) across open/close. Split the allocation and setup of ring buffer out of vmbus_open. For normal usage vmbus_open/vmbus_close there are no changes; only impacts uio_hv_generic which needs to keep ring buffer memory and reuse when application restarts. Signed-off-by: Stephen Hemminger Signed-off-by: Greg Kroah-Hartman

vmbus: keep pointer to ring buffer page

2018-09-25T18:33:24Z

Avoid going from struct page to virt address (and back) by just keeping pointer to the allocated pages instead of virt address. Signed-off-by: Stephen Hemminger Signed-off-by: Greg Kroah-Hartman

vmbus: pass channel to hv_process_channel_removal

2018-09-25T18:33:24Z

Rather than passing relid and then looking up the channel. Pass the channel directly, since caller already knows it. Signed-off-by: Stephen Hemminger Signed-off-by: Greg Kroah-Hartman

vmbus: add driver_override support

2018-09-12T07:46:46Z

Add support for overriding the default driver for a VMBus device in the same way that it can be done for PCI devices. This patch adds the /sys/bus/vmbus/devices/.../driver_override file and the logic for matching. This is used by driverctl tool to do driver override. https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitlab.com%2Fdriverctl%2Fdriverctl&data=02%7C01%7Ckys%40microsoft.com%7C42e803feb2c544ef6ea908d5fd538878%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636693457619960040&sdata=kEyYHRIjNZCk%2B37moCSqbrZL426YccNQrsWpENcrZdw%3D&reserved=0 Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Reset the channel callback in vmbus_onoffer_rescind()

2018-08-02T08:20:59Z

Before setting channel->rescind in vmbus_rescind_cleanup(), we should make sure the channel callback won't run any more, otherwise a high-level driver like pci_hyperv, which may be infinitely waiting for the host VSP's response and notices the channel has been rescinded, can't safely give up: e.g., in hv_pci_protocol_negotiation() -> wait_for_response(), it's unsafe to exit from wait_for_response() and proceed with the on-stack variable "comp_pkt" popped. The issue was originally spotted by Michael Kelley . In vmbus_close_internal(), the patch also minimizes the range protected by disabling/enabling channel->callback_event: we don't really need that for the whole function. Signed-off-by: Dexuan Cui Reviewed-by: Michael Kelley Cc: stable@vger.kernel.org Cc: K. Y. Srinivasan Cc: Stephen Hemminger Cc: Michael Kelley Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Add comments on ring buffer signaling

2018-07-03T11:02:28Z

Add comments describing intricacies of Hyper-V ring buffer signaling code. This information is not in Hyper-V public documents, so include here to capture the knowledge for future coders. There are no code changes in this commit. Signed-off-by: Michael Kelley Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2018-06-10T20:01:12Z

Pull SCSI updates from James Bottomley: "This is mostly updates to the usual drivers: ufs, qedf, mpt3sas, lpfc, xfcp, hisi_sas, cxlflash, qla2xxx. In the absence of Nic, we're also taking target updates which are mostly minor except for the tcmu refactor. The only real core change to worry about is the removal of high page bouncing (in sas, storvsc and iscsi). This has been well tested and no problems have shown up so far" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (268 commits) scsi: lpfc: update driver version to 12.0.0.4 scsi: lpfc: Fix port initialization failure. scsi: lpfc: Fix 16gb hbas failing cq create. scsi: lpfc: Fix crash in blk_mq layer when executing modprobe -r lpfc scsi: lpfc: correct oversubscription of nvme io requests for an adapter scsi: lpfc: Fix MDS diagnostics failure (Rx < Tx) scsi: hisi_sas: Mark PHY as in reset for nexus reset scsi: hisi_sas: Fix return value when get_free_slot() failed scsi: hisi_sas: Terminate STP reject quickly for v2 hw scsi: hisi_sas: Add v2 hw force PHY function for internal ATA command scsi: hisi_sas: Include TMF elements in struct hisi_sas_slot scsi: hisi_sas: Try wait commands before before controller reset scsi: hisi_sas: Init disks after controller reset scsi: hisi_sas: Create a scsi_host_template per HW module scsi: hisi_sas: Reset disks when discovered scsi: hisi_sas: Add LED feature for v3 hw scsi: hisi_sas: Change common allocation mode of device id scsi: hisi_sas: change slot index allocation mode scsi: hisi_sas: Introduce hisi_sas_phy_set_linkrate() scsi: hisi_sas: fix a typo in hisi_sas_task_prep() ...

Drivers: hv: vmbus: enable VMBus protocol version 5.0

2018-05-14T14:06:48Z

With VMBus protocol 5.0, we're able to better support new features, e.g. running two or more VMBus drivers simultaneously in a single VM -- note: we can't simply load the current VMBus driver twice, instead, a secondary VMBus driver must be implemented. This patch adds the support for the new VMBus protocol, which is available on new Windows hosts, by: 1) We still use SINT2 for compatibility; 2) We must use Connection ID 4 for the Initiate Contact Message, and for subsequent messages, we must use the Message Connection ID field in the host-returned VersionResponse Message. Notes for developers of the secondary VMBus driver: 1) Must use VMBus protocol 5.0 as well; 2) Must use a different SINT number that is not in use. 3) Must use Connection ID 4 for the Initiate Contact Message, and for subsequent messages, must use the Message Connection ID field in the host-returned VersionResponse Message. 4) It's possible that the primary VMBus driver using protocol version 4.0 can work with a secondary VMBus driver using protocol version 5.0, but it's recommended that both should use 5.0 for new Hyper-V features in the future. Signed-off-by: Dexuan Cui Cc: Stephen Hemminger Cc: K. Y. Srinivasan Cc: Michael Kelley Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

scsi: vmbus: Add function to report available ring buffer to write in total ring size percentage

2018-04-18T23:32:51Z

Netvsc has a function to calculate how much ring buffer in percentage is available to write. This function is also useful for storvsc and other vmbus devices. Define a similar function in vmbus to be used by other vmbus devices. Signed-off-by: Long Li Acked-by: David S. Miller Signed-off-by: Martin K. Petersen