kernel.git/drivers/hv/hv.c, branch linux-5.4.y

Drivers: hv: vmbus: Allow cleanup of VMBUS_CONNECT_CPU if disconnected

2020-11-24T12:29:23Z

commit 92e4dc8b05663d6539b1b8375f3b1cf7b204cfe9 upstream. When invoking kexec() on a Linux guest running on a Hyper-V host, the kernel panics. RIP: 0010:cpuhp_issue_call+0x137/0x140 Call Trace: __cpuhp_remove_state_cpuslocked+0x99/0x100 __cpuhp_remove_state+0x1c/0x30 hv_kexec_handler+0x23/0x30 [hv_vmbus] hv_machine_shutdown+0x1e/0x30 machine_shutdown+0x10/0x20 kernel_kexec+0x6d/0x96 __do_sys_reboot+0x1ef/0x230 __x64_sys_reboot+0x1d/0x20 do_syscall_64+0x6b/0x3d8 entry_SYSCALL_64_after_hwframe+0x44/0xa9 This was due to hv_synic_cleanup() callback returning -EBUSY to cpuhp_issue_call() when tearing down the VMBUS_CONNECT_CPU, even if the vmbus_connection.conn_state = DISCONNECTED. hv_synic_cleanup() should succeed in the case where vmbus_connection.conn_state is DISCONNECTED. Fix is to add an extra condition to test for vmbus_connection.conn_state == CONNECTED on the VMBUS_CONNECT_CPU and only return early if true. This way the kexec() path can still shut everything down while preserving the initial behavior of preventing CPU offlining on the VMBUS_CONNECT_CPU while the VM is running. Fixes: 8a857c55420f29 ("Drivers: hv: vmbus: Always handle the VMBus messages on CPU0") Signed-off-by: Chris Co Reviewed-by: Andrea Parri (Microsoft) Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201110190118.15596-1-chrco@linux.microsoft.com Signed-off-by: Wei Liu Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Always handle the VMBus messages on CPU0

2020-06-22T07:31:00Z

[ Upstream commit 8a857c55420f29da4fc131adc22b12d474c48f4c ] A Linux guest have to pick a "connect CPU" to communicate with the Hyper-V host. This CPU can not be taken offline because Hyper-V does not provide a way to change that CPU assignment. Current code sets the connect CPU to whatever CPU ends up running the function vmbus_negotiate_version(), and this will generate problems if that CPU is taken offine. Establish CPU0 as the connect CPU, and add logics to prevents the connect CPU from being taken offline. We could pick some other CPU, and we could pick that "other CPU" dynamically if there was a reason to do so at some point in the future. But for now, #defining the connect CPU to 0 is the most straightforward and least complex solution. While on this, add inline comments explaining "why" offer and rescind messages should not be handled by a same serialized work queue. Suggested-by: Dexuan Cui Signed-off-by: Andrea Parri (Microsoft) Reviewed-by: Vitaly Kuznetsov Link: https://lore.kernel.org/r/20200406001514.19876-2-parri.andrea@gmail.com Reviewed-by: Michael Kelley Signed-off-by: Wei Liu Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Break out synic enable and disable operations

2019-09-06T18:52:44Z

Break out synic enable and disable operations into separate hv_synic_disable_regs() and hv_synic_enable_regs() functions for use by a later patch to support hibernation. There is no functional change except the unnecessary check "if (sctrl.enable != 1) return -EFAULT;" which is removed, because when we're in hv_synic_cleanup(), we're absolutely sure sctrl.enable must be 1. Signed-off-by: Dexuan Cui Reviewed-by: Michael Kelley Signed-off-by: Sasha Levin

clocksource/drivers: Make Hyper-V clocksource ISA agnostic

2019-07-03T09:00:59Z

Hyper-V clock/timer code and data structures are currently mixed in with other code in the ISA independent drivers/hv directory as well as the ISA dependent Hyper-V code under arch/x86. Consolidate this code and data structures into a Hyper-V clocksource driver to better follow the Linux model. In doing so, separate out the ISA dependent portions so the new clocksource driver works for x86 and for the in-process Hyper-V on ARM64 code. To start, move the existing clockevents code to create the new clocksource driver. Update the VMbus driver to call initialization and cleanup routines since the Hyper-V synthetic timers are not independently enumerated in ACPI. No behavior is changed and no new functionality is added. Suggested-by: Marc Zyngier Signed-off-by: Michael Kelley Signed-off-by: Thomas Gleixner Reviewed-by: Vitaly Kuznetsov Cc: "bp@alien8.de" Cc: "will.deacon@arm.com" Cc: "catalin.marinas@arm.com" Cc: "mark.rutland@arm.com" Cc: "linux-arm-kernel@lists.infradead.org" Cc: "gregkh@linuxfoundation.org" Cc: "linux-hyperv@vger.kernel.org" Cc: "olaf@aepfle.de" Cc: "apw@canonical.com" Cc: "jasowang@redhat.com" Cc: "marcelo.cerri@canonical.com" Cc: Sunil Muthuswamy Cc: KY Srinivasan Cc: "sashal@kernel.org" Cc: "vincenzo.frascino@arm.com" Cc: "linux-arch@vger.kernel.org" Cc: "linux-mips@vger.kernel.org" Cc: "linux-kselftest@vger.kernel.org" Cc: "arnd@arndb.de" Cc: "linux@armlinux.org.uk" Cc: "ralf@linux-mips.org" Cc: "paul.burton@mips.com" Cc: "daniel.lezcano@linaro.org" Cc: "salyzyn@android.com" Cc: "pcc@google.com" Cc: "shuah@kernel.org" Cc: "0x7f454c46@gmail.com" <0x7f454c46@gmail.com> Cc: "linux@rasmusvillemoes.dk" Cc: "huw@codeweavers.com" Cc: "sfr@canb.auug.org.au" Cc: "pbonzini@redhat.com" Cc: "rkrcmar@redhat.com" Cc: "kvm@vger.kernel.org" Link: https://lkml.kernel.org/r/1561955054-1838-2-git-send-email-mikelley@microsoft.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 320

2019-06-05T15:37:05Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 33 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Kate Stewart Reviewed-by: Alexios Zavras Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190530000435.254582722@linutronix.de Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Remove the undesired put_cpu_ptr() in hv_synic_cleanup()

2019-04-13T13:36:35Z

With CONFIG_DEBUG_PREEMPT=y, the put_cpu_ptr() triggers an underflow warning in preempt_count_sub(). Fixes: 37cdd991fac8 ("vmbus: put related per-cpu variable together") Cc: stable@vger.kernel.org Cc: Stephen Hemminger Signed-off-by: Dexuan Cui Reviewed-by: Michael Kelley Signed-off-by: Sasha Levin (Microsoft)

Merge tag 'char-misc-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2018-12-29T04:54:57Z

Pull char/misc driver updates from Greg KH: "Here is the big set of char and misc driver patches for 4.21-rc1. Lots of different types of driver things in here, as this tree seems to be the "collection of various driver subsystems not big enough to have their own git tree" lately. Anyway, some highlights of the changes in here: - binderfs: is it a rule that all driver subsystems will eventually grow to have their own filesystem? Binder now has one to handle the use of it in containerized systems. This was discussed at the Plumbers conference a few months ago and knocked into mergable shape very fast by Christian Brauner. Who also has signed up to be another binder maintainer, showing a distinct lack of good judgement :) - binder updates and fixes - mei driver updates - fpga driver updates and additions - thunderbolt driver updates - soundwire driver updates - extcon driver updates - nvmem driver updates - hyper-v driver updates - coresight driver updates - pvpanic driver additions and reworking for more device support - lp driver updates. Yes really, it's _finally_ moved to the proper parallal port driver model, something I never thought I would see happen. Good stuff. - other tiny driver updates and fixes. All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (116 commits) MAINTAINERS: add another Android binder maintainer intel_th: msu: Fix an off-by-one in attribute store stm class: Add a reference to the SyS-T document stm class: Fix a module refcount leak in policy creation error path char: lp: use new parport device model char: lp: properly count the lp devices char: lp: use first unused lp number while registering char: lp: detach the device when parallel port is removed char: lp: introduce list to save port number bus: qcom: remove duplicated include from qcom-ebi2.c VMCI: Use memdup_user() rather than duplicating its implementation char/rtc: Use of_node_name_eq for node name comparisons misc: mic: fix a DMA pool free failure ptp: fix an IS_ERR() vs NULL check genwqe: Fix size check binder: implement binderfs binder: fix use-after-free due to ksys_close() during fdget() bus: fsl-mc: remove duplicated include files bus: fsl-mc: explicitly define the fsl_mc_command endianness misc: ti-st: make array read_ver_cmd static, shrinks object size ...

x86/hyper-v: move synic/stimer control structures definitions to hyperv-tlfs.h

2018-12-14T16:59:56Z

We implement Hyper-V SynIC and synthetic timers in KVM too so there's some room for code sharing. Signed-off-by: Vitaly Kuznetsov Reviewed-by: Michael Kelley Signed-off-by: Paolo Bonzini

Drivers: hv: vmbus: Get rid of unnecessary state in hv_context

2018-11-11T20:58:26Z

Currently we are replicating state in struct hv_context that is unnecessary - this state can be retrieved from the hypervisor. Furthermore, this is a per-cpu state that is being maintained as a global state in struct hv_context. Get rid of this state in struct hv_context. Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Fix synic per-cpu context initialization

2018-09-12T07:46:46Z

If hv_synic_alloc() errors out, the state of the per-cpu context for some CPUs is unknown since the zero'ing is done as each CPU is iterated over. In such case, hv_synic_cleanup() may try to free memory based on uninitialized values. Fix this by zero'ing the per-cpu context for all CPUs before doing any memory allocations that might fail. Signed-off-by: Michael Kelley Reported-by: Dan Carpenter Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman