Thread (55 messages) 55 messages, 6 authors, 2015-12-02
STALE3864d

[PATCH v4 08/21] KVM: ARM64: Add reset and access handlers for PMXEVTYPER register

From: Christopher Covington <hidden>
Date: 2015-11-02 20:54:12
Also in: kvm, kvmarm

Hi Shannon,

On 10/30/2015 02:21 AM, Shannon Zhao wrote:
quoted hunk ↗ jump to hunk
From: Shannon Zhao <redacted>

Since the reset value of PMXEVTYPER is UNKNOWN, use reset_unknown or
reset_unknown_cp15 for its reset handler. Add access handler which
emulates writing and reading PMXEVTYPER register. When writing to
PMXEVTYPER, call kvm_pmu_set_counter_event_type to create a perf_event
for the selected event type.

Signed-off-by: Shannon Zhao <redacted>
---
 arch/arm64/kvm/sys_regs.c | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index cb82b15..4e606ea 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -491,6 +491,17 @@ static bool access_pmu_regs(struct kvm_vcpu *vcpu,
 
 	if (p->is_write) {
 		switch (r->reg) {
+		case PMXEVTYPER_EL0: {
+			val = vcpu_sys_reg(vcpu, PMSELR_EL0);
+			kvm_pmu_set_counter_event_type(vcpu,
+						       *vcpu_reg(vcpu, p->Rt),
+						       val);
+			vcpu_sys_reg(vcpu, PMXEVTYPER_EL0) =
+							 *vcpu_reg(vcpu, p->Rt);
Why does PMXEVTYPER get set directly? It seems like it could have an accessor
that redirected to PMEVTYPER<n>.
+			vcpu_sys_reg(vcpu, PMEVTYPER0_EL0 + val) =
+							 *vcpu_reg(vcpu, p->Rt);
I tried to look around briefly but couldn't find counter number range checking
in the PMSELR handler or here. Should there be some here and in PMXEVCNTR?

Thanks,
Christopher Covington

-- 
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
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