[PATCH 6/6] KVM: arm64: Upgrade PMU support to ARMv8.4

Marc Zyngier
2021-01-14T10:58:15Z

Upgrading the PMU code from ARMv8.1 to ARMv8.4 turns out to be
pretty easy. All that is required is support for PMMIR_EL1, which
is read-only, and for which returning 0 is a valid option.

Let's just do that and adjust what we return to the guest.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/sys_regs.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 8f79ec1fffa7..2f4ecbd2abfb 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1051,10 +1051,10 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
/* Limit debug to ARMv8.0 */
val &= ~FEATURE(ID_AA64DFR0_DEBUGVER);
val |= FIELD_PREP(FEATURE(ID_AA64DFR0_DEBUGVER), 6);
- /* Limit guests to PMUv3 for ARMv8.1 */
+ /* Limit guests to PMUv3 for ARMv8.4 */
val = cpuid_feature_cap_perfmon_field(val,
ID_AA64DFR0_PMUVER_SHIFT,
- kvm_vcpu_has_pmu(vcpu) ? ID_AA64DFR0_PMUVER_8_1 : 0);
+ kvm_vcpu_has_pmu(vcpu) ? ID_AA64DFR0_PMUVER_8_4 : 0);
break;
case SYS_ID_DFR0_EL1:
/* Limit guests to PMUv3 for ARMv8.1 */
@@ -1496,6 +1496,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {

{ SYS_DESC(SYS_PMINTENSET_EL1), access_pminten, reset_unknown, PMINTENSET_EL1 },
{ SYS_DESC(SYS_PMINTENCLR_EL1), access_pminten, reset_unknown, PMINTENSET_EL1 },
+ { SYS_DESC(SYS_PMMIR_EL1), trap_raz_wi },

{ SYS_DESC(SYS_MAIR_EL1), access_vm_reg, reset_unknown, MAIR_EL1 },
{ SYS_DESC(SYS_AMAIR_EL1), access_vm_reg, reset_amair_el1, AMAIR_EL1 },
--
2.29.2