RISC-V: KVM: Fix privilege mode setting in kvm_riscv_vcpu_trap_redirect()

The kvm_riscv_vcpu_trap_redirect() should set guest privilege mode
to supervisor mode because guest traps/interrupts are always handled
in virtual supervisor mode.

Fixes: 9f70132651 ("RISC-V: KVM: Handle MMIO exits for VCPU")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

arch/riscv/kvm/vcpu_exit.c

@@ -160,6 +160,9 @@ void kvm_riscv_vcpu_trap_redirect(struct kvm_vcpu *vcpu,
 
 	/* Set Guest PC to Guest exception vector */
 	vcpu->arch.guest_context.sepc = csr_read(CSR_VSTVEC);
+
+	/* Set Guest privilege mode to supervisor */
+	vcpu->arch.guest_context.sstatus |= SR_SPP;
 }
 
 /*