diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index fd22ef4162..9d8a8982f9 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -276,6 +276,42 @@ static void kvm_cpu_set_multi_ext_cfg(Object *obj, Visitor *v,
     kvm_cpu_cfg_set(cpu, multi_ext_cfg, value);
 }
 
+static KVMCPUConfig kvm_cbom_blocksize = {
+    .name = "cbom_blocksize",
+    .offset = CPUCFG(cbom_blocksize),
+    .kvm_reg_id = KVM_REG_RISCV_CONFIG_REG(zicbom_block_size)
+};
+
+static KVMCPUConfig kvm_cboz_blocksize = {
+    .name = "cboz_blocksize",
+    .offset = CPUCFG(cboz_blocksize),
+    .kvm_reg_id = KVM_REG_RISCV_CONFIG_REG(zicboz_block_size)
+};
+
+static void kvm_cpu_set_cbomz_blksize(Object *obj, Visitor *v,
+                                      const char *name,
+                                      void *opaque, Error **errp)
+{
+    KVMCPUConfig *cbomz_cfg = opaque;
+    RISCVCPU *cpu = RISCV_CPU(obj);
+    uint16_t value, *host_val;
+
+    if (!visit_type_uint16(v, name, &value, errp)) {
+        return;
+    }
+
+    host_val = kvmconfig_get_cfg_addr(cpu, cbomz_cfg);
+
+    if (value != *host_val) {
+        error_report("Unable to set %s to a different value than "
+                     "the host (%u)",
+                     cbomz_cfg->name, *host_val);
+        exit(EXIT_FAILURE);
+    }
+
+    cbomz_cfg->user_set = true;
+}
+
 static void kvm_riscv_update_cpu_cfg_isa_ext(RISCVCPU *cpu, CPUState *cs)
 {
     CPURISCVState *env = &cpu->env;
@@ -329,6 +365,14 @@ static void kvm_riscv_add_cpu_user_properties(Object *cpu_obj)
                             kvm_cpu_set_multi_ext_cfg,
                             NULL, multi_cfg);
     }
+
+    object_property_add(cpu_obj, "cbom_blocksize", "uint16",
+                        NULL, kvm_cpu_set_cbomz_blksize,
+                        NULL, &kvm_cbom_blocksize);
+
+    object_property_add(cpu_obj, "cboz_blocksize", "uint16",
+                        NULL, kvm_cpu_set_cbomz_blksize,
+                        NULL, &kvm_cboz_blocksize);
 }
 
 static int kvm_riscv_get_regs_core(CPUState *cs)
@@ -644,6 +688,24 @@ static void kvm_riscv_init_misa_ext_mask(RISCVCPU *cpu,
     env->misa_ext = env->misa_ext_mask;
 }
 
+static void kvm_riscv_read_cbomz_blksize(RISCVCPU *cpu, KVMScratchCPU *kvmcpu,
+                                         KVMCPUConfig *cbomz_cfg)
+{
+    CPURISCVState *env = &cpu->env;
+    struct kvm_one_reg reg;
+    int ret;
+
+    reg.id = kvm_riscv_reg_id(env, KVM_REG_RISCV_CONFIG,
+                              cbomz_cfg->kvm_reg_id);
+    reg.addr = (uint64_t)kvmconfig_get_cfg_addr(cpu, cbomz_cfg);
+    ret = ioctl(kvmcpu->cpufd, KVM_GET_ONE_REG, &reg);
+    if (ret != 0) {
+        error_report("Unable to read KVM reg %s, error %d",
+                     cbomz_cfg->name, ret);
+        exit(EXIT_FAILURE);
+    }
+}
+
 static void kvm_riscv_init_multiext_cfg(RISCVCPU *cpu, KVMScratchCPU *kvmcpu)
 {
     CPURISCVState *env = &cpu->env;
@@ -675,6 +737,14 @@ static void kvm_riscv_init_multiext_cfg(RISCVCPU *cpu, KVMScratchCPU *kvmcpu)
 
         kvm_cpu_cfg_set(cpu, multi_ext_cfg, val);
     }
+
+    if (cpu->cfg.ext_icbom) {
+        kvm_riscv_read_cbomz_blksize(cpu, kvmcpu, &kvm_cbom_blocksize);
+    }
+
+    if (cpu->cfg.ext_icboz) {
+        kvm_riscv_read_cbomz_blksize(cpu, kvmcpu, &kvm_cboz_blocksize);
+    }
 }
 
 void kvm_riscv_init_user_properties(Object *cpu_obj)