[PATCH v5 13/24] KVM: arm64: Writethrough trapped PMOVS register

[Colton Lewis]

Because PMOVS remains trapped, it needs to be written through when
partitioned to affect PMU hardware when expected.

Signed-off-by: Colton Lewis <coltonlewis at google.com>
---
 arch/arm64/include/asm/arm_pmuv3.h | 10 ++++++++++
 arch/arm64/kvm/sys_regs.c          | 17 ++++++++++++++++-
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/arm_pmuv3.h b/arch/arm64/include/asm/arm_pmuv3.h
index 60600f04b5902..3e25c0313263c 100644
--- a/arch/arm64/include/asm/arm_pmuv3.h
+++ b/arch/arm64/include/asm/arm_pmuv3.h
@@ -140,6 +140,16 @@ static inline u64 read_pmicfiltr(void)
 	return read_sysreg_s(SYS_PMICFILTR_EL0);
 }
 
+static inline void write_pmovsset(u64 val)
+{
+	write_sysreg(val, pmovsset_el0);
+}
+
+static inline u64 read_pmovsset(void)
+{
+	return read_sysreg(pmovsset_el0);
+}
+
 static inline void write_pmovsclr(u64 val)
 {
 	write_sysreg(val, pmovsclr_el0);
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 2e6d907fa8af2..bee892db9ca8b 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1307,6 +1307,19 @@ static bool access_pminten(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 	return true;
 }
 
+static void writethrough_pmovs(struct kvm_vcpu *vcpu, struct sys_reg_params *p, bool set)
+{
+	u64 mask = kvm_pmu_accessible_counter_mask(vcpu);
+
+	if (set) {
+		__vcpu_rmw_sys_reg(vcpu, PMOVSSET_EL0, |=, (p->regval & mask));
+		write_pmovsset(p->regval & mask);
+	} else {
+		__vcpu_rmw_sys_reg(vcpu, PMOVSSET_EL0, &=, ~(p->regval & mask));
+		write_pmovsclr(p->regval & mask);
+	}
+}
+
 static bool access_pmovs(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 			 const struct sys_reg_desc *r)
 {
@@ -1315,7 +1328,9 @@ static bool access_pmovs(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 	if (pmu_access_el0_disabled(vcpu))
 		return false;
 
-	if (p->is_write) {
+	if (kvm_vcpu_pmu_is_partitioned(vcpu) && p->is_write) {
+		writethrough_pmovs(vcpu, p, r->CRm & 0x2);
+	} else if (p->is_write) {
 		if (r->CRm & 0x2)
 			/* accessing PMOVSSET_EL0 */
 			__vcpu_rmw_sys_reg(vcpu, PMOVSSET_EL0, |=, (p->regval & mask));
-- 
2.52.0.239.gd5f0c6e74e-goog