[PATCH 4/8] arm64: KVM: pmu: Inject UNDEF exception on illegal register access
Marc Zyngier
marc.zyngier at arm.com
Wed Feb 22 03:47:24 PST 2017
Both pmu_*_el0_disabled() and pmu_counter_idx_valid() perform checks
on the calidity of an access, but only return a boolean indicating
if the access is valid or not.
Let's allow these functions to also inject an UNDEF exception if
the access was illegal. This is where we start flagging a pending
exception.
Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
---
arch/arm64/kvm/sys_regs.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 0ebf27f40f98..eec543906e21 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -460,11 +460,20 @@ static void reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
vcpu_sys_reg(vcpu, PMCR_EL0) = val;
}
+static void pend_undef(struct kvm_vcpu *vcpu)
+{
+ kvm_inject_undefined(vcpu);
+ vcpu->arch.sys_reg->exception_pending = true;
+}
+
static bool check_disabled(struct kvm_vcpu *vcpu, u64 flags)
{
u64 reg = vcpu_sys_reg(vcpu, PMUSERENR_EL0);
bool cond = (reg & flags) || vcpu_mode_priv(vcpu);
+ if (!cond)
+ pend_undef(vcpu);
+
return !cond;
}
@@ -564,8 +573,10 @@ static bool pmu_counter_idx_valid(struct kvm_vcpu *vcpu, u64 idx)
pmcr = vcpu_sys_reg(vcpu, PMCR_EL0);
val = (pmcr >> ARMV8_PMU_PMCR_N_SHIFT) & ARMV8_PMU_PMCR_N_MASK;
- if (idx >= val && idx != ARMV8_PMU_CYCLE_IDX)
+ if (idx >= val && idx != ARMV8_PMU_CYCLE_IDX) {
+ pend_undef(vcpu);
return false;
+ }
return true;
}
--
2.11.0
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