[PATCH v2 4/5] KVM: PPC: Book3S HV: Implement LPCR[AIL]=3 mode for injected interrupts

Nicholas Piggin
2019-09-16T07:31:07Z

kvmppc_inject_interrupt does not implement LPCR[AIL]!=0 modes, which
can result in the guest receiving interrupts as if LPCR[AIL]=0
contrary to the ISA.

In practice, Linux guests cope with this deviation, but it should be
fixed.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kvm/book3s_hv_builtin.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index 47b44d9b5c1f..c73de4e875a5 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c
@@ -792,6 +792,20 @@ static void inject_interrupt(struct kvm_vcpu *vcpu, int vec, u64 srr1_flags)
else
new_msr |= msr & MSR_TS_MASK;

+ /*
+ * LPCR[AIL]=2 deliveries are not supported.
+ *
+ * AIL does not apply to SRESET, MCE, or HMI (which is never
+ * delivered to the guest).
+ */
+ if (vec != BOOK3S_INTERRUPT_SYSTEM_RESET &&
+ vec != BOOK3S_INTERRUPT_MACHINE_CHECK &&
+ (vcpu->arch.vcore->lpcr & LPCR_AIL) = LPCR_AIL_3 &&
+ (msr & (MSR_IR|MSR_DR)) = (MSR_IR|MSR_DR) ) {
+ new_msr |= MSR_IR | MSR_DR;
+ new_pc += 0xC000000000004000ULL;
+ }
+
kvmppc_set_srr0(vcpu, pc);
kvmppc_set_srr1(vcpu, (msr & SRR1_MSR_BITS) | srr1_flags);
kvmppc_set_pc(vcpu, new_pc);
--
2.23.0