RISC-V: KVM: Fix the size parameter check in SBI SFENCE calls

[ Upstream commit 6aba0cb ]

As-per the SBI specification, an SBI remote fence operation applies
to the entire address space if either:
1) start_addr and size are both 0
2) size is equal to 2^XLEN-1

>From the above, only #1 is checked by SBI SFENCE calls so fix the
size parameter check in SBI SFENCE calls to cover #2 as well.

Fixes: 13acfec ("RISC-V: KVM: Add remote HFENCE functions based on VCPU requests")
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Link: https://lore.kernel.org/r/20250605061458.196003-2-apatel@ventanamicro.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: avpatel

arch/riscv/kvm/vcpu_sbi_replace.c

@@ -91,14 +91,14 @@ static int kvm_sbi_ext_rfence_handler(struct kvm_vcpu *vcpu, struct kvm_run *run
 		kvm_riscv_fence_i(vcpu->kvm, hbase, hmask);
 		break;
 	case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA:
-		if (cp->a2 == 0 && cp->a3 == 0)
+		if ((cp->a2 == 0 && cp->a3 == 0) || cp->a3 == -1UL)
 			kvm_riscv_hfence_vvma_all(vcpu->kvm, hbase, hmask);
 		else
 			kvm_riscv_hfence_vvma_gva(vcpu->kvm, hbase, hmask,
 						  cp->a2, cp->a3, PAGE_SHIFT);
 		break;
 	case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID:
-		if (cp->a2 == 0 && cp->a3 == 0)
+		if ((cp->a2 == 0 && cp->a3 == 0) || cp->a3 == -1UL)
 			kvm_riscv_hfence_vvma_asid_all(vcpu->kvm,
 						       hbase, hmask, cp->a4);
 		else