ppc/spapr_caps: Add SPAPR_CAP_NESTED_KVM_HV

Add the spapr cap SPAPR_CAP_NESTED_KVM_HV to be used to control the
availability of nested kvm-hv to the level 1 (L1) guest.

Assuming a hypervisor with support enabled an L1 guest can be allowed to
use the kvm-hv module (and thus run it's own kvm-hv guests) by setting:
-machine pseries,cap-nested-hv=true
or disabled with:
-machine pseries,cap-nested-hv=false

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

2 files changed, 24 insertions, 0 deletions

diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 30aeafa7de..f81327d6cd 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -91,6 +91,7 @@ static int cap_ppc_pvr_compat;
 static int cap_ppc_safe_cache;
 static int cap_ppc_safe_bounds_check;
 static int cap_ppc_safe_indirect_branch;
+static int cap_ppc_nested_kvm_hv;
 
 static uint32_t debug_inst_opcode;
 
@@ -150,6 +151,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
     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);
     kvmppc_get_cpu_characteristics(s);
+    cap_ppc_nested_kvm_hv = kvm_vm_check_extension(s, KVM_CAP_PPC_NESTED_HV);
     /*
      * Note: setting it to false because there is not such capability
      * in KVM at this moment.
@@ -2422,6 +2424,16 @@ int kvmppc_get_cap_safe_indirect_branch(void)
     return cap_ppc_safe_indirect_branch;
 }
 
+bool kvmppc_has_cap_nested_kvm_hv(void)
+{
+    return !!cap_ppc_nested_kvm_hv;
+}
+
+int kvmppc_set_cap_nested_kvm_hv(int enable)
+{
+    return kvm_vm_enable_cap(kvm_state, KVM_CAP_PPC_NESTED_HV, 0, enable);
+}
+
 bool kvmppc_has_cap_spapr_vfio(void)
 {
     return cap_spapr_vfio;
diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
index f696c6e498..bdfaa4e70a 100644
--- a/target/ppc/kvm_ppc.h
+++ b/target/ppc/kvm_ppc.h
@@ -62,6 +62,8 @@ bool kvmppc_has_cap_mmu_hash_v3(void);
 int kvmppc_get_cap_safe_cache(void);
 int kvmppc_get_cap_safe_bounds_check(void);
 int kvmppc_get_cap_safe_indirect_branch(void);
+bool kvmppc_has_cap_nested_kvm_hv(void);
+int kvmppc_set_cap_nested_kvm_hv(int enable);
 int kvmppc_enable_hwrng(void);
 int kvmppc_put_books_sregs(PowerPCCPU *cpu);
 PowerPCCPUClass *kvm_ppc_get_host_cpu_class(void);
@@ -320,6 +322,16 @@ static inline int kvmppc_get_cap_safe_indirect_branch(void)
     return 0;
 }
 
+static inline bool kvmppc_has_cap_nested_kvm_hv(void)
+{
+    return false;
+}
+
+static inline int kvmppc_set_cap_nested_kvm_hv(int enable)
+{
+    return -1;
+}
+
 static inline int kvmppc_enable_hwrng(void)
 {
     return -1;