[PATCH 06/18] KVM: ARM64: Add reset and access handlers for PMCEID0_EL0 and PMCEID1_EL0 register

[shannon.zhao at linaro.org]

From: Shannon Zhao <shannon.zhao at linaro.org>

Add reset handler which gets host value of PMCEID0_EL0 or PMCEID1_EL0.
Add access handler which emulates writing and reading PMCEID0_EL0 or
PMCEID1_EL0 register.

Signed-off-by: Shannon Zhao <shannon.zhao at linaro.org>
---
 arch/arm64/kvm/sys_regs.c | 36 ++++++++++++++++++++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 69c8c48..1df9ef3 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -246,6 +246,19 @@ static void reset_pmcr_el0(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
 				       | (ARMV8_PMCR_MASK & 0xdecafbad);
 }
 
+static void reset_pmceid(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
+{
+	u32 pmceid;
+
+	if (r->reg == PMCEID0_EL0) {
+		asm volatile("mrs %0, pmceid0_el0\n" : "=r" (pmceid));
+		vcpu_sys_reg(vcpu, r->reg) = pmceid;
+	} else {
+		asm volatile("mrs %0, pmceid1_el0\n" : "=r" (pmceid));
+		vcpu_sys_reg(vcpu, r->reg) = pmceid;
+	}
+}
+
 /* PMCR_EL0 accessor. Only called as long as MDCR_EL2.TPMCR is set. */
 static bool access_pmcr(struct kvm_vcpu *vcpu,
 			const struct sys_reg_params *p,
@@ -299,6 +312,25 @@ static bool access_pmselr(struct kvm_vcpu *vcpu,
 	return true;
 }
 
+/* PMCEID0_EL0 and PMCEID1_EL0 accessor. */
+static bool access_pmceid(struct kvm_vcpu *vcpu,
+			  const struct sys_reg_params *p,
+			  const struct sys_reg_desc *r)
+{
+	unsigned long val;
+
+	if (p->is_write) {
+		return ignore_write(vcpu, p);
+	} else {
+		if (!p->is_aarch32)
+			val = vcpu_sys_reg(vcpu, r->reg);
+		else
+			val = vcpu_cp15(vcpu, r->reg);
+		*vcpu_reg(vcpu, p->Rt) = val;
+		return true;
+	}
+}
+
 /* Silly macro to expand the DBG{BCR,BVR,WVR,WCR}n_EL1 registers in one go */
 #define DBG_BCR_BVR_WCR_WVR_EL1(n)					\
 	/* DBGBVRn_EL1 */						\
@@ -508,10 +540,10 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	  access_pmselr, reset_unknown, PMSELR_EL0 },
 	/* PMCEID0_EL0 */
 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b110),
-	  trap_raz_wi },
+	  access_pmceid, reset_pmceid, PMCEID0_EL0, },
 	/* PMCEID1_EL0 */
 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b111),
-	  trap_raz_wi },
+	  access_pmceid, reset_pmceid, PMCEID1_EL0, },
 	/* PMCCNTR_EL0 */
 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b000),
 	  trap_raz_wi },
-- 
2.1.0