[PATCH v2 2/9] arm64: KVM: PMU: Inject UNDEF exception on illegal register access

Marc Zyngier
2017-03-27T16:02:06Z

Both pmu_*_el0_disabled() and pmu_counter_idx_valid() perform checks
on the validity 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.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/kvm/sys_regs.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 7e1d673304d5..d98ce9a52291 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -465,6 +465,9 @@ 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)
+ kvm_inject_undefined(vcpu);
+
return !cond;
}

@@ -564,8 +567,10 @@ 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) {
+ kvm_inject_undefined(vcpu);
return false;
+ }

return true;
}
--
2.11.0