diff --git a/arch/riscv/kvm/vcpu_onereg.c b/arch/riscv/kvm/vcpu_onereg.c
index 753f66c8b70a..93115abca3b8 100644
--- a/arch/riscv/kvm/vcpu_onereg.c
+++ b/arch/riscv/kvm/vcpu_onereg.c
@@ -23,7 +23,7 @@
 #define KVM_ISA_EXT_ARR(ext)		\
 [KVM_RISCV_ISA_EXT_##ext] = RISCV_ISA_EXT_##ext
 
-/* Mapping between KVM ISA Extension ID & Host ISA extension ID */
+/* Mapping between KVM ISA Extension ID & guest ISA extension ID */
 static const unsigned long kvm_isa_ext_arr[] = {
 	/* Single letter extensions (alphabetically sorted) */
 	[KVM_RISCV_ISA_EXT_A] = RISCV_ISA_EXT_a,
@@ -35,7 +35,7 @@ static const unsigned long kvm_isa_ext_arr[] = {
 	[KVM_RISCV_ISA_EXT_M] = RISCV_ISA_EXT_m,
 	[KVM_RISCV_ISA_EXT_V] = RISCV_ISA_EXT_v,
 	/* Multi letter extensions (alphabetically sorted) */
-	[KVM_RISCV_ISA_EXT_SMNPM] = RISCV_ISA_EXT_SSNPM,
+	KVM_ISA_EXT_ARR(SMNPM),
 	KVM_ISA_EXT_ARR(SMSTATEEN),
 	KVM_ISA_EXT_ARR(SSAIA),
 	KVM_ISA_EXT_ARR(SSCOFPMF),
@@ -107,6 +107,36 @@ static unsigned long kvm_riscv_vcpu_base2isa_ext(unsigned long base_ext)
 	return KVM_RISCV_ISA_EXT_MAX;
 }
 
+static int kvm_riscv_vcpu_isa_check_host(unsigned long kvm_ext, unsigned long *guest_ext)
+{
+	unsigned long host_ext;
+
+	if (kvm_ext >= KVM_RISCV_ISA_EXT_MAX ||
+	    kvm_ext >= ARRAY_SIZE(kvm_isa_ext_arr))
+		return -ENOENT;
+
+	*guest_ext = kvm_isa_ext_arr[kvm_ext];
+	switch (*guest_ext) {
+	case RISCV_ISA_EXT_SMNPM:
+		/*
+		 * Pointer masking effective in (H)S-mode is provided by the
+		 * Smnpm extension, so that extension is reported to the guest,
+		 * even though the CSR bits for configuring VS-mode pointer
+		 * masking on the host side are part of the Ssnpm extension.
+		 */
+		host_ext = RISCV_ISA_EXT_SSNPM;
+		break;
+	default:
+		host_ext = *guest_ext;
+		break;
+	}
+
+	if (!__riscv_isa_extension_available(NULL, host_ext))
+		return -ENOENT;
+
+	return 0;
+}
+
 static bool kvm_riscv_vcpu_isa_enable_allowed(unsigned long ext)
 {
 	switch (ext) {
@@ -209,13 +239,13 @@ static bool kvm_riscv_vcpu_isa_disable_allowed(unsigned long ext)
 
 void kvm_riscv_vcpu_setup_isa(struct kvm_vcpu *vcpu)
 {
-	unsigned long host_isa, i;
+	unsigned long guest_ext, i;
 
 	for (i = 0; i < ARRAY_SIZE(kvm_isa_ext_arr); i++) {
-		host_isa = kvm_isa_ext_arr[i];
-		if (__riscv_isa_extension_available(NULL, host_isa) &&
-		    kvm_riscv_vcpu_isa_enable_allowed(i))
-			set_bit(host_isa, vcpu->arch.isa);
+		if (kvm_riscv_vcpu_isa_check_host(i, &guest_ext))
+			continue;
+		if (kvm_riscv_vcpu_isa_enable_allowed(i))
+			set_bit(guest_ext, vcpu->arch.isa);
 	}
 }
 
@@ -597,18 +627,15 @@ static int riscv_vcpu_get_isa_ext_single(struct kvm_vcpu *vcpu,
 					 unsigned long reg_num,
 					 unsigned long *reg_val)
 {
-	unsigned long host_isa_ext;
-
-	if (reg_num >= KVM_RISCV_ISA_EXT_MAX ||
-	    reg_num >= ARRAY_SIZE(kvm_isa_ext_arr))
-		return -ENOENT;
+	unsigned long guest_ext;
+	int ret;
 
-	host_isa_ext = kvm_isa_ext_arr[reg_num];
-	if (!__riscv_isa_extension_available(NULL, host_isa_ext))
-		return -ENOENT;
+	ret = kvm_riscv_vcpu_isa_check_host(reg_num, &guest_ext);
+	if (ret)
+		return ret;
 
 	*reg_val = 0;
-	if (__riscv_isa_extension_available(vcpu->arch.isa, host_isa_ext))
+	if (__riscv_isa_extension_available(vcpu->arch.isa, guest_ext))
 		*reg_val = 1; /* Mark the given extension as available */
 
 	return 0;
@@ -618,17 +645,14 @@ static int riscv_vcpu_set_isa_ext_single(struct kvm_vcpu *vcpu,
 					 unsigned long reg_num,
 					 unsigned long reg_val)
 {
-	unsigned long host_isa_ext;
-
-	if (reg_num >= KVM_RISCV_ISA_EXT_MAX ||
-	    reg_num >= ARRAY_SIZE(kvm_isa_ext_arr))
-		return -ENOENT;
+	unsigned long guest_ext;
+	int ret;
 
-	host_isa_ext = kvm_isa_ext_arr[reg_num];
-	if (!__riscv_isa_extension_available(NULL, host_isa_ext))
-		return -ENOENT;
+	ret = kvm_riscv_vcpu_isa_check_host(reg_num, &guest_ext);
+	if (ret)
+		return ret;
 
-	if (reg_val == test_bit(host_isa_ext, vcpu->arch.isa))
+	if (reg_val == test_bit(guest_ext, vcpu->arch.isa))
 		return 0;
 
 	if (!vcpu->arch.ran_atleast_once) {
@@ -638,10 +662,10 @@ static int riscv_vcpu_set_isa_ext_single(struct kvm_vcpu *vcpu,
 		 */
 		if (reg_val == 1 &&
 		    kvm_riscv_vcpu_isa_enable_allowed(reg_num))
-			set_bit(host_isa_ext, vcpu->arch.isa);
+			set_bit(guest_ext, vcpu->arch.isa);
 		else if (!reg_val &&
 			 kvm_riscv_vcpu_isa_disable_allowed(reg_num))
-			clear_bit(host_isa_ext, vcpu->arch.isa);
+			clear_bit(guest_ext, vcpu->arch.isa);
 		else
 			return -EINVAL;
 		kvm_riscv_vcpu_fp_reset(vcpu);
@@ -999,16 +1023,15 @@ static int copy_fp_d_reg_indices(const struct kvm_vcpu *vcpu,
 static int copy_isa_ext_reg_indices(const struct kvm_vcpu *vcpu,
 				u64 __user *uindices)
 {
+	unsigned long guest_ext;
 	unsigned int n = 0;
-	unsigned long isa_ext;
 
 	for (int i = 0; i < KVM_RISCV_ISA_EXT_MAX; i++) {
 		u64 size = IS_ENABLED(CONFIG_32BIT) ?
 			   KVM_REG_SIZE_U32 : KVM_REG_SIZE_U64;
 		u64 reg = KVM_REG_RISCV | size | KVM_REG_RISCV_ISA_EXT | i;
 
-		isa_ext = kvm_isa_ext_arr[i];
-		if (!__riscv_isa_extension_available(NULL, isa_ext))
+		if (kvm_riscv_vcpu_isa_check_host(i, &guest_ext))
 			continue;
 
 		if (uindices) {