arm64: KVM: Add access handler for PMSELR register

Since the reset value of PMSELR_EL0 is UNKNOWN, use reset_unknown for
its reset handler. When reading PMSELR, return the PMSELR.SEL field to
guest.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 5def605b45259796895d56f894ad5a0e8bc5a69b..57a2d8f76c2f6255683100348d42bca67a1c8a15 100644 (file)
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -119,6 +119,7 @@ enum vcpu_sysreg {
 
        /* Performance Monitors Registers */
        PMCR_EL0,       /* Control Register */
+       PMSELR_EL0,     /* Event Counter Selection Register */
 
        /* 32bit specific registers. Keep them at the end of the range */
        DACR32_EL2,     /* Domain Access Control Register */

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index e88ae2d809a5558f51872a3977b052248b0be0d4..b05e20f8a3b963de736a6acfede61b1a51512be9 100644 (file)
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -477,6 +477,22 @@ static bool access_pmcr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
        return true;
 }
 
+static bool access_pmselr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
+                         const struct sys_reg_desc *r)
+{
+       if (!kvm_arm_pmu_v3_ready(vcpu))
+               return trap_raz_wi(vcpu, p, r);
+
+       if (p->is_write)
+               vcpu_sys_reg(vcpu, PMSELR_EL0) = p->regval;
+       else
+               /* return PMSELR.SEL field */
+               p->regval = vcpu_sys_reg(vcpu, PMSELR_EL0)
+                           & ARMV8_PMU_COUNTER_MASK;
+
+       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 */                                               \
@@ -676,7 +692,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
          trap_raz_wi },
        /* PMSELR_EL0 */
        { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b101),
-         trap_raz_wi },
+         access_pmselr, reset_unknown, PMSELR_EL0 },
        /* PMCEID0_EL0 */
        { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b110),
          trap_raz_wi },
@@ -927,7 +943,7 @@ static const struct sys_reg_desc cp15_regs[] = {
        { Op1( 0), CRn( 9), CRm(12), Op2( 1), trap_raz_wi },
        { Op1( 0), CRn( 9), CRm(12), Op2( 2), trap_raz_wi },
        { Op1( 0), CRn( 9), CRm(12), Op2( 3), trap_raz_wi },
-       { Op1( 0), CRn( 9), CRm(12), Op2( 5), trap_raz_wi },
+       { Op1( 0), CRn( 9), CRm(12), Op2( 5), access_pmselr },
        { Op1( 0), CRn( 9), CRm(12), Op2( 6), trap_raz_wi },
        { Op1( 0), CRn( 9), CRm(12), Op2( 7), trap_raz_wi },
        { Op1( 0), CRn( 9), CRm(13), Op2( 0), trap_raz_wi },