On 5/13/2020 12:01 AM, Vitaly Kuznetsov wrote:
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 <vkuzn...@redhat.com> --- arch/x86/hyperv/hv_init.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index fd51bac11b46..acf76b466db6 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -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. */
Reviewed-by: Tianyu Lan <tianyu....@microsoft.com>
