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x86/hyperv: Properly suspend/resume reenlightenment notifications

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Errors during hibernation with reenlightenment notifications enabled were
reported:

 [   51.730435] PM: hibernation entry
 [   51.737435] PM: Syncing filesystems ...
 ...
 [   54.102216] Disabling non-boot CPUs ...
 [   54.106633] smpboot: CPU 1 is now offline
 [   54.110006] unchecked MSR access error: WRMSR to 0x40000106 (tried to
     write 0x47c72780000100ee) at rIP: 0xffffffff90062f24
     native_write_msr+0x4/0x20)
 [   54.110006] Call Trace:
 [   54.110006]  hv_cpu_die+0xd9/0xf0
 ...

Normally, hv_cpu_die() just reassigns reenlightenment notifications to some
other CPU when the CPU receiving them goes offline. Upon hibernation, there
is no other CPU which is still online so cpumask_any_but(cpu_online_mask)
returns >= nr_cpu_ids and using it as hv_vp_index index is incorrect.
Disable the feature when cpumask_any_but() fails.

Also, as we now disable reenlightenment notifications upon hibernation we
need to restore them on resume. Check if hv_reenlightenment_cb was
previously set and restore from hv_resume().

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20200512160153.134467-1-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
This commit is contained in:
Vitaly Kuznetsov 2020-05-12 18:01:53 +02:00 committed by Wei Liu
parent f081bbb3fd
commit 38dce4195f
1 changed files with 17 additions and 2 deletions
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19
arch/x86/hyperv/hv_init.c
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@ -226,10 +226,18 @@ static int hv_cpu_die(unsigned int cpu)
rdmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl));
if (re_ctrl.target_vp == hv_vp_index[cpu]) {
/* Reassign to some other online CPU */
/*
* Reassign reenlightenment notifications to some other online
* CPU or just disable the feature if there are no online CPUs
* left (happens on hibernation).
*/
new_cpu = cpumask_any_but(cpu_online_mask, cpu);
re_ctrl.target_vp = hv_vp_index[new_cpu];
if (new_cpu < nr_cpu_ids)
re_ctrl.target_vp = hv_vp_index[new_cpu];
else
re_ctrl.enabled = 0;
wrmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl));
}
@ -293,6 +301,13 @@ static void hv_resume(void)
hv_hypercall_pg = hv_hypercall_pg_saved;
hv_hypercall_pg_saved = NULL;
/*
* Reenlightenment notifications are disabled by hv_cpu_die(0),
* reenable them here if hv_reenlightenment_cb was previously set.
*/
if (hv_reenlightenment_cb)
set_hv_tscchange_cb(hv_reenlightenment_cb);
}
/* Note: when the ops are called, only CPU0 is online and IRQs are disabled. */