diff --git a/hw/spapr.c b/hw/spapr.c
index fecfa4a..26333ac 100644
--- a/hw/spapr.c
+++ b/hw/spapr.c
@@ -186,8 +186,6 @@ static void *spapr_create_fdt_skel(const char *cpu_model,
                            0xffffffff, 0xffffffff};
         uint32_t tbfreq = kvm_enabled() ? kvmppc_get_tbfreq() : TIMEBASE_FREQ;
         uint32_t cpufreq = kvm_enabled() ? kvmppc_get_clockfreq() : 1000000000;
-        uint32_t vmx = kvm_enabled() ? kvmppc_get_vmx() : 0;
-        uint32_t dfp = kvm_enabled() ? kvmppc_get_dfp() : 0;
 
         if ((index % smt) != 0) {
             continue;
@@ -239,15 +237,17 @@ static void *spapr_create_fdt_skel(const char *cpu_model,
          *   0 / no property == no vector extensions
          *   1               == VMX / Altivec available
          *   2               == VSX available */
-        if (vmx) {
+        if (env->insns_flags & PPC_ALTIVEC) {
+            uint32_t vmx = (env->insns_flags2 & PPC2_VSX) ? 2 : 1;
+
             _FDT((fdt_property_cell(fdt, "ibm,vmx", vmx)));
         }
 
         /* Advertise DFP (Decimal Floating Point) if available
          *   0 / no property == no DFP
          *   1               == DFP available */
-        if (dfp) {
-            _FDT((fdt_property_cell(fdt, "ibm,dfp", dfp)));
+        if (env->insns_flags2 & PPC2_DFP) {
+            _FDT((fdt_property_cell(fdt, "ibm,dfp", 1)));
         }
 
         _FDT((fdt_end_node(fdt)));
diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
index 8e5c85c..d177bd4 100644
--- a/target-ppc/cpu.h
+++ b/target-ppc/cpu.h
@@ -858,6 +858,22 @@ enum {
 /* The whole PowerPC CPU context */
 #define NB_MMU_MODES 3
 
+struct ppc_def_t {
+    const char *name;
+    uint32_t pvr;
+    uint32_t svr;
+    uint64_t insns_flags;
+    uint64_t insns_flags2;
+    uint64_t msr_mask;
+    powerpc_mmu_t   mmu_model;
+    powerpc_excp_t  excp_model;
+    powerpc_input_t bus_model;
+    uint32_t flags;
+    int bfd_mach;
+    void (*init_proc)(CPUPPCState *env);
+    int  (*check_pow)(CPUPPCState *env);
+};
+
 struct CPUPPCState {
     /* First are the most commonly used resources
      * during translated code execution
@@ -1844,6 +1860,10 @@ enum {
 
     /* BookE 2.06 PowerPC specification                                      */
     PPC2_BOOKE206      = 0x0000000000000001ULL,
+    /* VSX (extensions to Altivec / VMX)                                     */
+    PPC2_VSX           = 0x0000000000000002ULL,
+    /* Decimal Floating Point (DFP)                                          */
+    PPC2_DFP           = 0x0000000000000004ULL,
 };
 
 /*****************************************************************************/
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index 430558b..3d12c5c 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -887,14 +887,35 @@ static inline uint32_t mfpvr(void)
     return pvr;
 }
 
+static void alter_insns(uint64_t *word, uint64_t flags, bool on)
+{
+    if (on) {
+        *word |= flags;
+    } else {
+        *word &= ~flags;
+    }
+}
+
 const ppc_def_t *kvmppc_host_cpu_def(void)
 {
     uint32_t host_pvr = mfpvr();
     const ppc_def_t *base_spec;
+    ppc_def_t *spec;
+    uint32_t vmx = kvmppc_get_vmx();
+    uint32_t dfp = kvmppc_get_dfp();
 
     base_spec = ppc_find_by_pvr(host_pvr);
 
-    return base_spec;
+    spec = g_malloc0(sizeof(*spec));
+    memcpy(spec, base_spec, sizeof(*spec));
+
+    /* Now fix up the spec with information we can query from the host */
+
+    alter_insns(&spec->insns_flags, PPC_ALTIVEC, vmx > 0);
+    alter_insns(&spec->insns_flags2, PPC2_VSX, vmx > 1);
+    alter_insns(&spec->insns_flags2, PPC2_DFP, dfp);
+
+    return spec;
 }
 
 bool kvm_arch_stop_on_emulation_error(CPUState *env)
diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
index 7de097d..c954192 100644
--- a/target-ppc/translate_init.c
+++ b/target-ppc/translate_init.c
@@ -34,22 +34,6 @@
 #define TODO_USER_ONLY 1
 #endif
 
-struct ppc_def_t {
-    const char *name;
-    uint32_t pvr;
-    uint32_t svr;
-    uint64_t insns_flags;
-    uint64_t insns_flags2;
-    uint64_t msr_mask;
-    powerpc_mmu_t   mmu_model;
-    powerpc_excp_t  excp_model;
-    powerpc_input_t bus_model;
-    uint32_t flags;
-    int bfd_mach;
-    void (*init_proc)(CPUPPCState *env);
-    int  (*check_pow)(CPUPPCState *env);
-};
-
 /* For user-mode emulation, we don't emulate any IRQ controller */
 #if defined(CONFIG_USER_ONLY)
 #define PPC_IRQ_INIT_FN(name)                                                 \
@@ -6535,6 +6519,8 @@ static void init_proc_970MP (CPUPPCState *env)
                               PPC_64B | PPC_ALTIVEC |                         \
                               PPC_SEGMENT_64B | PPC_SLBI |                    \
                               PPC_POPCNTB | PPC_POPCNTWD)
+/* FIXME: Should also have PPC2_VSX and PPC2_DFP, but we don't
+ * implement those in TCG yet */
 #define POWERPC_INSNS2_POWER7 (PPC_NONE)
 #define POWERPC_MSRM_POWER7   (0x800000000204FF36ULL)
 #define POWERPC_MMU_POWER7    (POWERPC_MMU_2_06)
