RISC-V: KVM: Fix error code returned for Ssaia ONE_REG

Return -ENOENT for Ssaia ONE_REG when Ssaia is not enabled
for a VCPU.

This will make Ssaia ONE_REG error codes consistent with
other ONE_REG interfaces of KVM RISC-V.

Fixes: 2a88f38 ("RISC-V: KVM: return ENOENT in *_one_reg() when reg is unknown")
Signed-off-by: Anup Patel <anup.patel@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260120080013.2153519-3-anup.patel@oss.qualcomm.com
Signed-off-by: Anup Patel <anup@brainfault.org>

Author: avpatel

arch/riscv/kvm/aia.c

@@ -185,6 +185,8 @@ int kvm_riscv_vcpu_aia_get_csr(struct kvm_vcpu *vcpu,
 	struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
 	unsigned long regs_max = sizeof(struct kvm_riscv_aia_csr) / sizeof(unsigned long);
 
+	if (!riscv_isa_extension_available(vcpu->arch.isa, SSAIA))
+		return -ENOENT;
 	if (reg_num >= regs_max)
 		return -ENOENT;
 
@@ -204,6 +206,8 @@ int kvm_riscv_vcpu_aia_set_csr(struct kvm_vcpu *vcpu,
 	struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
 	unsigned long regs_max = sizeof(struct kvm_riscv_aia_csr) / sizeof(unsigned long);
 
+	if (!riscv_isa_extension_available(vcpu->arch.isa, SSAIA))
+		return -ENOENT;
 	if (reg_num >= regs_max)
 		return -ENOENT;