[PATCH 10/17] KVM: arm64: Writethrough trapped PMEVTYPER register

[Colton Lewis <coltonlewis@google.com>]

With FGT in place, the remaining trapped registers need to be written
through to the underlying physical registers as well as the virtual
ones. Failing to do this means delaying when guest writes take effect.

Signed-off-by: Colton Lewis <coltonlewis@google.com>
---
 arch/arm64/kvm/sys_regs.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index d368eeb4f88e..afd06400429a 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -18,6 +18,7 @@
 #include <linux/printk.h>
 #include <linux/uaccess.h>
 #include <linux/irqchip/arm-gic-v3.h>
+#include <linux/perf/arm_pmu.h>
 #include <linux/perf/arm_pmuv3.h>
 
 #include <asm/arm_pmuv3.h>
@@ -942,7 +943,11 @@ static bool pmu_counter_idx_valid(struct kvm_vcpu *vcpu, u64 idx)
 {
 	u64 pmcr, val;
 
-	pmcr = kvm_vcpu_read_pmcr(vcpu);
+	if (kvm_vcpu_pmu_is_partitioned(vcpu))
+		pmcr = read_pmcr();
+	else
+		pmcr = kvm_vcpu_read_pmcr(vcpu);
+
 	val = FIELD_GET(ARMV8_PMU_PMCR_N, pmcr);
 	if (idx >= val && idx != ARMV8_PMU_CYCLE_IDX) {
 		kvm_inject_undefined(vcpu);
@@ -1037,6 +1042,22 @@ static bool access_pmu_evcntr(struct kvm_vcpu *vcpu,
 	return true;
 }
 
+static void writethrough_pmevtyper(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
+				   u64 reg, u64 idx)
+{
+	u64 evmask = kvm_pmu_evtyper_mask(vcpu->kvm);
+	u64 val = p->regval & evmask;
+
+	__vcpu_sys_reg(vcpu, reg) = val;
+
+	if (idx == ARMV8_PMU_CYCLE_IDX)
+		write_pmccfiltr(val);
+	else if (idx == ARMV8_PMU_INSTR_IDX)
+		write_pmicfiltr(val);
+	else
+		write_pmevtypern(idx, val);
+}
+
 static bool access_pmu_evtyper(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 			       const struct sys_reg_desc *r)
 {
@@ -1063,7 +1084,9 @@ static bool access_pmu_evtyper(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 	if (!pmu_counter_idx_valid(vcpu, idx))
 		return false;
 
-	if (p->is_write) {
+	if (kvm_vcpu_pmu_is_partitioned(vcpu) && p->is_write) {
+		writethrough_pmevtyper(vcpu, p, reg, idx);
+	} else if (p->is_write) {
 		kvm_pmu_set_counter_event_type(vcpu, p->regval, idx);
 		kvm_vcpu_pmu_restore_guest(vcpu);
 	} else {
-- 
2.49.0.1204.g71687c7c1d-goog