kernel/linux.git/drivers/hv, branch v5.4.50

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

2020-06-22T07:31:00+00:00

[ 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: Fix Suspend-to-Idle for Generation-2 VM

2020-05-06T06:15:09+00:00

commit 1a06d017fb3f388734ffbe5dedee6f8c3af5f2db upstream. Before the hibernation patchset (e.g. f53335e3289f), in a Generation-2 Linux VM on Hyper-V, the user can run "echo freeze > /sys/power/state" to freeze the system, i.e. Suspend-to-Idle. The user can press the keyboard or move the mouse to wake up the VM. With the hibernation patchset, Linux VM on Hyper-V can hibernate to disk, but Suspend-to-Idle is broken: when the synthetic keyboard/mouse are suspended, there is no way to wake up the VM. Fix the issue by not suspending and resuming the vmbus devices upon Suspend-to-Idle. Fixes: f53335e3289f ("Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernation") Cc: stable@vger.kernel.org Reviewed-by: Michael Kelley Signed-off-by: Dexuan Cui Link: https://lore.kernel.org/r/1586663435-36243-1-git-send-email-decui@microsoft.com Signed-off-by: Wei Liu Signed-off-by: Greg Kroah-Hartman

x86/Hyper-V: Free hv_panic_page when fail to register kmsg dump

2020-04-23T08:36:27+00:00

[ Upstream commit 7f11a2cc10a4ae3a70e2c73361f4a9a33503539b ] If kmsg_dump_register() fails, hv_panic_page will not be used anywhere. So free and reset it. Fixes: 81b18bce48af ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic") Reviewed-by: Michael Kelley Signed-off-by: Tianyu Lan Link: https://lore.kernel.org/r/20200406155331.2105-3-Tianyu.Lan@microsoft.com Signed-off-by: Wei Liu Signed-off-by: Sasha Levin

x86/Hyper-V: Report crash data in die() when panic_on_oops is set

2020-04-23T08:36:24+00:00

commit f3a99e761efa616028b255b4de58e9b5b87c5545 upstream. When oops happens with panic_on_oops unset, the oops thread is killed by die() and system continues to run. In such case, guest should not report crash register data to host since system still runs. Check panic_on_oops and return directly in hyperv_report_panic() when the function is called in the die() and panic_on_oops is unset. Fix it. Fixes: 7ed4325a44ea ("Drivers: hv: vmbus: Make panic reporting to be more useful") Signed-off-by: Tianyu Lan Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20200406155331.2105-7-Tianyu.Lan@microsoft.com Signed-off-by: Wei Liu Signed-off-by: Greg Kroah-Hartman

x86/Hyper-V: Report crash register data when sysctl_record_panic_msg is not set

2020-04-23T08:36:24+00:00

commit 040026df7088c56ccbad28f7042308f67bde63df upstream. When sysctl_record_panic_msg is not set, the panic will not be reported to Hyper-V via hyperv_report_panic_msg(). So the crash should be reported via hyperv_report_panic(). Fixes: 81b18bce48af ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic") Reviewed-by: Michael Kelley Signed-off-by: Tianyu Lan Link: https://lore.kernel.org/r/20200406155331.2105-6-Tianyu.Lan@microsoft.com Signed-off-by: Wei Liu Signed-off-by: Greg Kroah-Hartman

x86/Hyper-V: Trigger crash enlightenment only once during system crash.

2020-04-23T08:36:24+00:00

commit 73f26e526f19afb3a06b76b970a76bcac2cafd05 upstream. When a guest VM panics, Hyper-V should be notified only once via the crash synthetic MSRs. Current Linux code might write these crash MSRs twice during a system panic: 1) hyperv_panic/die_event() calling hyperv_report_panic() 2) hv_kmsg_dump() calling hyperv_report_panic_msg() Fix this by not calling hyperv_report_panic() if a kmsg dump has been successfully registered. The notification will happen later via hyperv_report_panic_msg(). Fixes: 7ed4325a44ea ("Drivers: hv: vmbus: Make panic reporting to be more useful") Reviewed-by: Michael Kelley Signed-off-by: Tianyu Lan Link: https://lore.kernel.org/r/20200406155331.2105-4-Tianyu.Lan@microsoft.com Signed-off-by: Wei Liu Signed-off-by: Greg Kroah-Hartman

x86/Hyper-V: Unload vmbus channel in hv panic callback

2020-04-23T08:36:23+00:00

commit 74347a99e73ae00b8385f1209aaea193c670f901 upstream. When kdump is not configured, a Hyper-V VM might still respond to network traffic after a kernel panic when kernel parameter panic=0. The panic CPU goes into an infinite loop with interrupts enabled, and the VMbus driver interrupt handler still works because the VMbus connection is unloaded only in the kdump path. The network responses make the other end of the connection think the VM is still functional even though it has panic'ed, which could affect any failover actions that should be taken. Fix this by unloading the VMbus connection during the panic process. vmbus_initiate_unload() could then be called twice (e.g., by hyperv_panic_event() and hv_crash_handler(), so reset the connection state in vmbus_initiate_unload() to ensure the unload is done only once. Fixes: 81b18bce48af ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic") Reviewed-by: Michael Kelley Signed-off-by: Tianyu Lan Link: https://lore.kernel.org/r/20200406155331.2105-2-Tianyu.Lan@microsoft.com Signed-off-by: Wei Liu Signed-off-by: Greg Kroah-Hartman

hv_balloon: Balloon up according to request page number

2020-02-11T12:35:21+00:00

commit d33c240d47dab4fd15123d9e73fc8810cbc6ed6a upstream. Current code has assumption that balloon request memory size aligns with 2MB. But actually Hyper-V doesn't guarantee such alignment. When balloon driver receives non-aligned balloon request, it produces warning and balloon up more memory than requested in order to keep 2MB alignment. Remove the warning and balloon up memory according to actual requested memory size. Fixes: f6712238471a ("hv: hv_balloon: avoid memory leak on alloc_error of 2MB memory block") Cc: stable@vger.kernel.org Reviewed-by: Vitaly Kuznetsov Signed-off-by: Tianyu Lan Reviewed-by: Michael Kelley Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Fix crash handler reset of Hyper-V synic

2020-01-04T18:18:21+00:00

[ Upstream commit 7a1323b5dfe44a9013a2cc56ef2973034a00bf88 ] The crash handler calls hv_synic_cleanup() to shutdown the Hyper-V synthetic interrupt controller. But if the CPU that calls hv_synic_cleanup() has a VMbus channel interrupt assigned to it (which is likely the case in smaller VM sizes), hv_synic_cleanup() returns an error and the synthetic interrupt controller isn't shutdown. While the lack of being shutdown hasn't caused a known problem, it still should be fixed for highest reliability. So directly call hv_synic_disable_regs() instead of hv_synic_cleanup(), which ensures that the synic is always shutdown. Signed-off-by: Michael Kelley Reviewed-by: Vitaly Kuznetsov Reviewed-by: Dexuan Cui Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Fix harmless building warnings without CONFIG_PM_SLEEP

2019-10-01T18:49:45+00:00

If CONFIG_PM_SLEEP is not set, we can comment out these functions to avoid the below warnings: drivers/hv/vmbus_drv.c:2208:12: warning: ‘vmbus_bus_resume’ defined but not used [-Wunused-function] drivers/hv/vmbus_drv.c:2128:12: warning: ‘vmbus_bus_suspend’ defined but not used [-Wunused-function] drivers/hv/vmbus_drv.c:937:12: warning: ‘vmbus_resume’ defined but not used [-Wunused-function] drivers/hv/vmbus_drv.c:918:12: warning: ‘vmbus_suspend’ defined but not used [-Wunused-function] Fixes: 271b2224d42f ("Drivers: hv: vmbus: Implement suspend/resume for VSC drivers for hibernation") Fixes: f53335e3289f ("Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernation") Reported-by: Arnd Bergmann Signed-off-by: Dexuan Cui Reviewed-by: Michael Kelley Signed-off-by: Sasha Levin