[PATCH 3/6] KVM: arm64: Add handling of AArch32 PCMEID{2, 3} PMUv3 registers

[Marc Zyngier]

Despite advertising support for AArch32 PMUv3p1, we fail to handle
the PMCEID{2,3} registers, which conveniently alias with with the top
bits of PMCEID{0,1}_EL1.

Implement these registers with the usual AA32(HI/LO) aliasing
mechanism.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index ce08d28ab15c..2bea0494b81d 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -685,14 +685,18 @@ static bool access_pmselr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 static bool access_pmceid(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 			  const struct sys_reg_desc *r)
 {
-	u64 pmceid;
+	u64 pmceid, mask, shift;
 
 	BUG_ON(p->is_write);
 
 	if (pmu_access_el0_disabled(vcpu))
 		return false;
 
+	get_access_mask(r, &mask, &shift);
+
 	pmceid = kvm_pmu_get_pmceid(vcpu, (p->Op2 & 1));
+	pmceid &= mask;
+	pmceid >>= shift;
 
 	p->regval = pmceid;
 
@@ -1895,8 +1899,8 @@ static const struct sys_reg_desc cp15_regs[] = {
 	{ Op1( 0), CRn( 9), CRm(12), Op2( 3), access_pmovs },
 	{ Op1( 0), CRn( 9), CRm(12), Op2( 4), access_pmswinc },
 	{ Op1( 0), CRn( 9), CRm(12), Op2( 5), access_pmselr },
-	{ Op1( 0), CRn( 9), CRm(12), Op2( 6), access_pmceid },
-	{ Op1( 0), CRn( 9), CRm(12), Op2( 7), access_pmceid },
+	{ AA32(LO), Op1( 0), CRn( 9), CRm(12), Op2( 6), access_pmceid },
+	{ AA32(LO), Op1( 0), CRn( 9), CRm(12), Op2( 7), access_pmceid },
 	{ Op1( 0), CRn( 9), CRm(13), Op2( 0), access_pmu_evcntr },
 	{ Op1( 0), CRn( 9), CRm(13), Op2( 1), access_pmu_evtyper },
 	{ Op1( 0), CRn( 9), CRm(13), Op2( 2), access_pmu_evcntr },
@@ -1904,6 +1908,8 @@ static const struct sys_reg_desc cp15_regs[] = {
 	{ Op1( 0), CRn( 9), CRm(14), Op2( 1), access_pminten },
 	{ Op1( 0), CRn( 9), CRm(14), Op2( 2), access_pminten },
 	{ Op1( 0), CRn( 9), CRm(14), Op2( 3), access_pmovs },
+	{ AA32(HI), Op1( 0), CRn( 9), CRm(14), Op2( 4), access_pmceid },
+	{ AA32(HI), Op1( 0), CRn( 9), CRm(14), Op2( 5), access_pmceid },
 
 	/* PRRR/MAIR0 */
 	{ AA32(LO), Op1( 0), CRn(10), CRm( 2), Op2( 0), access_vm_reg, NULL, MAIR_EL1 },
-- 
2.29.2