ppc/spapr: KVM FWNMI should not be enabled until guest requests it

The KVM FWNMI capability should be enabled with the "ibm,nmi-register"
rtas call. Although MCEs from KVM will be delivered as architected
interrupts to the guest before "ibm,nmi-register" is called, KVM has
different behaviour depending on whether the guest has enabled FWNMI
(it attempts to do more recovery on behalf of a non-FWNMI guest).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20200325142906.221248-2-npiggin@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 7 insertions, 0 deletions

diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 597f72be1b..03d0667e8f 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -88,6 +88,7 @@ static int cap_ppc_safe_indirect_branch;
 static int cap_ppc_count_cache_flush_assist;
 static int cap_ppc_nested_kvm_hv;
 static int cap_large_decr;
+static int cap_fwnmi;
 
 static uint32_t debug_inst_opcode;
 
@@ -136,6 +137,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
     kvmppc_get_cpu_characteristics(s);
     cap_ppc_nested_kvm_hv = kvm_vm_check_extension(s, KVM_CAP_PPC_NESTED_HV);
     cap_large_decr = kvmppc_get_dec_bits();
+    cap_fwnmi = kvm_vm_check_extension(s, KVM_CAP_PPC_FWNMI);
     /*
      * Note: setting it to false because there is not such capability
      * in KVM at this moment.
@@ -2064,6 +2066,11 @@ void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
     }
 }
 
+bool kvmppc_get_fwnmi(void)
+{
+    return cap_fwnmi;
+}
+
 int kvmppc_set_fwnmi(void)
 {
     PowerPCCPU *cpu = POWERPC_CPU(first_cpu);