Subject: [PATCH 5/5] KVM: arm64: Upgrade PMU support to ARMv8.4

From: Marc Zyngier <[email-masked]>
Date: Sun, 16 Feb 2020 18:53:24 +0000

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 <[email-masked]>
---
 arch/arm64/include/asm/sysreg.h | 2 ++
 arch/arm64/kvm/sys_regs.c       | 9 ++++++---
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index b91570ff9db1..16d91ed51d06 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -312,6 +312,8 @@
 #define SYS_PMINTENSET_EL1		sys_reg(3, 0, 9, 14, 1)
 #define SYS_PMINTENCLR_EL1		sys_reg(3, 0, 9, 14, 2)
 
+#define SYS_PMMIR_EL1			sys_reg(3, 0, 9, 14, 6)
+
 #define SYS_MAIR_EL1			sys_reg(3, 0, 10, 2, 0)
 #define SYS_AMAIR_EL1			sys_reg(3, 0, 10, 3, 0)
 
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 43087b50a211..4eee61fb94be 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1097,9 +1097,11 @@ 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 PMU to ARMv8.1 */
-		val &= ~FEATURE(ID_AA64DFR0_PMUVER);
-		val |= FIELD_PREP(FEATURE(ID_AA64DFR0_PMUVER), 4);
+		/* Limit PMU to ARMv8.4 */
+		if (FIELD_GET(FEATURE(ID_AA64DFR0_PMUVER), val) > 5) {
+			val &= ~FEATURE(ID_AA64DFR0_PMUVER);
+			val |= FIELD_PREP(FEATURE(ID_AA64DFR0_PMUVER), 5);
+		}
 		break;
 	}
 
@@ -1524,6 +1526,7 @@ 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, NULL, 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 },
-- 
2.20.1

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