anierin/msm-5.15
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

KVM: arm64: PMU: Restore the guest's EL0 event counting after migration

Browse Source 
commit f9ea835e99bc8d049bf2a3ec8fa5a7cb4fcade23 upstream.

Currently, with VHE, KVM enables the EL0 event counting for the
guest on vcpu_load() or KVM enables it as a part of the PMU
register emulation process, when needed.  However, in the migration
case (with VHE), the same handling is lacking, as vPMU register
values that were restored by userspace haven't been propagated yet
(the PMU events haven't been created) at the vcpu load-time on the
first KVM_RUN (kvm_vcpu_pmu_restore_guest() called from vcpu_load()
on the first KVM_RUN won't do anything as events_{guest,host} of
kvm_pmu_events are still zero).

So, with VHE, enable the guest's EL0 event counting on the first
KVM_RUN (after the migration) when needed.  More specifically,
have kvm_pmu_handle_pmcr() call kvm_vcpu_pmu_restore_guest()
so that kvm_pmu_handle_pmcr() on the first KVM_RUN can take
care of it.

Fixes: d0c94c4979 ("KVM: arm64: Restore PMU configuration on first run")
Cc: stable@vger.kernel.org
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Link: https://lore.kernel.org/r/20230329023944.2488484-1-reijiw@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Reiji Watanabe
2023-03-28 19:39:44 -07:00
committed by Greg Kroah-Hartman
parent c7acce3a0e
commit 1bb4a52c3c
2 changed files with 1 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
arch/arm64/kvm/pmu-emul.c
View File

@@ -554,6 +554,7 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val)
__vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= BIT(i);
}
}
kvm_vcpu_pmu_restore_guest(vcpu);
}
/**

1
arch/arm64/kvm/sys_regs.c
View File

@@ -702,7 +702,6 @@ static bool access_pmcr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
val |= ARMV8_PMU_PMCR_LC;
__vcpu_sys_reg(vcpu, PMCR_EL0) = val;
kvm_pmu_handle_pmcr(vcpu, val);
kvm_vcpu_pmu_restore_guest(vcpu);
} else {
/* PMCR.P & PMCR.C are RAZ */
val = __vcpu_sys_reg(vcpu, PMCR_EL0)