> From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> > Sent: Tuesday, May 12, 2020 9:02 AM > To: linux-hyperv@xxxxxxxxxxxxxxx > Cc: Wei Liu <wei.liu@xxxxxxxxxx>; x86@xxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; Michael Kelley > <mikelley@xxxxxxxxxxxxx>; Dexuan Cui <decui@xxxxxxxxxxxxx>; Tianyu Lan > <Tianyu.Lan@xxxxxxxxxxxxx> > Subject: [PATCH] x86/hyperv: Properly suspend/resume reenlightenment > notifications > > 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@xxxxxxxxxx> > --- Looks good to me. Thanks! Reviewed-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
