[Qemu-devel] [PATCH v4 5/5] ppc: spapr: Enable FWNMI capability

[Aravinda Prasad]

Enable the KVM capability KVM_CAP_PPC_FWNMI so that
the KVM causes guest exit with NMI as exit reason
when it encounters a machine check exception on the
address belonging to a guest. Without this capability
enabled, KVM redirects machine check exceptions to
guest's 0x200 vector.

Signed-off-by: Aravinda Prasad <aravi...@linux.vnet.ibm.com>
---
 hw/ppc/spapr_rtas.c |   17 +++++++++++++++++
 target/ppc/kvm.c    |    2 ++
 2 files changed, 19 insertions(+)

diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
index 2f3c47b..c2a361a 100644
--- a/hw/ppc/spapr_rtas.c
+++ b/hw/ppc/spapr_rtas.c
@@ -47,6 +47,8 @@
 #include "trace.h"
 #include "hw/ppc/fdt.h"
 
+extern int cap_fwnmi;
+
 static void rtas_display_character(PowerPCCPU *cpu, sPAPRMachineState *spapr,
                                    uint32_t token, uint32_t nargs,
                                    target_ulong args,
@@ -354,7 +356,22 @@ static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
                                   target_ulong args,
                                   uint32_t nret, target_ulong rets)
 {
+    int ret;
+    CPUState *cs = CPU(cpu);
+
+    if (!cap_fwnmi) {
+        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
+        return;
+    }
+
     spapr->guest_machine_check_addr = rtas_ld(args, 1);
+
+    ret = kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_FWNMI, 0);
+    if (ret < 0) {
+        rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
+        return;
+    }
+
     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
 }
 
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index e9ea45f..7d37dba 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -90,6 +90,7 @@ static int cap_htm;             /* Hardware transactional 
memory support */
 static int cap_mmu_radix;
 static int cap_mmu_hash_v3;
 static int cap_resize_hpt;
+int cap_fwnmi;
 
 static uint32_t debug_inst_opcode;
 
@@ -147,6 +148,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
     cap_mmu_radix = kvm_vm_check_extension(s, KVM_CAP_PPC_MMU_RADIX);
     cap_mmu_hash_v3 = kvm_vm_check_extension(s, KVM_CAP_PPC_MMU_HASH_V3);
     cap_resize_hpt = kvm_vm_check_extension(s, KVM_CAP_SPAPR_RESIZE_HPT);
+    cap_fwnmi = kvm_check_extension(s, KVM_CAP_PPC_FWNMI);
 
     if (!cap_interrupt_level) {
         fprintf(stderr, "KVM: Couldn't find level irq capability. Expect the "