diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 69ddc4bb2348..f006662c5c98 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -557,14 +557,16 @@ static void spapr_populate_cpu_dt(CPUState *cs, void *fdt, int offset,
                           segs, sizeof(segs))));
     }
 
-    /* Advertise VMX/VSX (vector extensions) if available
-     *   0 / no property == no vector extensions
+    /* Advertise VSX (vector extensions) if available
      *   1               == VMX / Altivec available
-     *   2               == VSX available */
-    if (env->insns_flags & PPC_ALTIVEC) {
-        uint32_t vmx = (env->insns_flags2 & PPC2_VSX) ? 2 : 1;
-
-        _FDT((fdt_setprop_cell(fdt, offset, "ibm,vmx", vmx)));
+     *   2               == VSX available
+     *
+     * Only CPUs for which we create core types in spapr_cpu_core.c
+     * are possible, and all of those have VMX */
+    if (spapr_has_cap(spapr, SPAPR_CAP_VSX)) {
+        _FDT((fdt_setprop_cell(fdt, offset, "ibm,vmx", 2)));
+    } else {
+        _FDT((fdt_setprop_cell(fdt, offset, "ibm,vmx", 1)));
     }
 
     /* Advertise DFP (Decimal Floating Point) if available
@@ -3678,7 +3680,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
      */
     mc->numa_mem_align_shift = 28;
 
-    smc->default_caps = spapr_caps(0);
+    smc->default_caps = spapr_caps(SPAPR_CAP_VSX);
     spapr_caps_add_properties(smc, &error_abort);
 }
 
@@ -3760,7 +3762,7 @@ static void spapr_machine_2_11_class_options(MachineClass *mc)
     sPAPRMachineClass *smc = SPAPR_MACHINE_CLASS(mc);
 
     spapr_machine_2_12_class_options(mc);
-    smc->default_caps = spapr_caps(SPAPR_CAP_HTM);
+    smc->default_caps = spapr_caps(SPAPR_CAP_HTM | SPAPR_CAP_VSX);
     SET_MACHINE_COMPAT(mc, SPAPR_COMPAT_2_11);
 }
 
diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
index cad40fe49af5..7c855c67ad40 100644
--- a/hw/ppc/spapr_caps.c
+++ b/hw/ppc/spapr_caps.c
@@ -57,6 +57,19 @@ static void cap_htm_allow(sPAPRMachineState *spapr, Error **errp)
     }
 }
 
+static void cap_vsx_allow(sPAPRMachineState *spapr, Error **errp)
+{
+    PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
+    CPUPPCState *env = &cpu->env;
+
+    /* Allowable CPUs in spapr_cpu_core.c should already have gotten
+     * rid of anything that doesn't do VMX */
+    g_assert(env->insns_flags & PPC_ALTIVEC);
+    if (!(env->insns_flags2 & PPC2_VSX)) {
+        error_setg(errp, "VSX support not available, try cap-vsx=off");
+    }
+}
+
 static sPAPRCapabilityInfo capability_table[] = {
     {
         .name = "htm",
@@ -65,6 +78,13 @@ static sPAPRCapabilityInfo capability_table[] = {
         .allow = cap_htm_allow,
         /* TODO: add cap_htm_disallow */
     },
+    {
+        .name = "vsx",
+        .description = "Allow Vector Scalar Extensions (VSX)",
+        .flag = SPAPR_CAP_VSX,
+        .allow = cap_vsx_allow,
+        /* TODO: add cap_vsx_disallow */
+    },
 };
 
 static sPAPRCapabilities default_caps_with_cpu(sPAPRMachineState *spapr,
@@ -81,6 +101,11 @@ static sPAPRCapabilities default_caps_with_cpu(sPAPRMachineState *spapr,
         caps.mask &= ~SPAPR_CAP_HTM;
     }
 
+    if (!ppc_check_compat(cpu, CPU_POWERPC_LOGICAL_2_06,
+                          0, spapr->max_compat_pvr)) {
+        caps.mask &= ~SPAPR_CAP_VSX;
+    }
+
     return caps;
 }
 
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 985948b6221f..7765f3439d9b 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -59,6 +59,9 @@ typedef enum {
 /* Hardware Transactional Memory */
 #define SPAPR_CAP_HTM               0x0000000000000001ULL
 
+/* Vector Scalar Extensions */
+#define SPAPR_CAP_VSX               0x0000000000000002ULL
+
 typedef struct sPAPRCapabilities sPAPRCapabilities;
 struct sPAPRCapabilities {
     uint64_t mask;