[PATCH 4/8] arm64: KVM: pmu: Inject UNDEF exception on illegal register access
From: Marc Zyngier <hidden>
Date: 2017-02-22 11:47:24
Also in:
kvm, kvmarm
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
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 <redacted> --- 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