[PATCH v4 5/8] RISC-V: KVM: Handle software-check exits for VCPU

[Inochi Amaoto <inochiama@gmail.com>]

The extension Zicfiss/Zicfilp introduces a software-check exception
to the privilege architecture. Delegate this exception to VS mode
when vCPU enable Zicfiss/Zicfilp so the CFI violations in VU/VS could
be reported.

Assisted-by: YuanSheng:claude-4.7-opus
Co-developed-by: Quan Zhou <zhouquan@iscas.ac.cn>
Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn>
Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
---
 arch/riscv/include/asm/csr.h | 1 +
 arch/riscv/kvm/vcpu_exit.c   | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index 31b8988f4488..224af9facf1f 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -117,6 +117,7 @@
 #define EXC_INST_PAGE_FAULT	12
 #define EXC_LOAD_PAGE_FAULT	13
 #define EXC_STORE_PAGE_FAULT	15
+#define EXC_SOFTWARE_CHECK		18
 #define EXC_INST_GUEST_PAGE_FAULT	20
 #define EXC_LOAD_GUEST_PAGE_FAULT	21
 #define EXC_VIRTUAL_INST_FAULT		22
diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c
index 0bb0c51e3c89..12eebeabdf14 100644
--- a/arch/riscv/kvm/vcpu_exit.c
+++ b/arch/riscv/kvm/vcpu_exit.c
@@ -243,6 +243,10 @@ int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
 		run->exit_reason = KVM_EXIT_DEBUG;
 		ret = 0;
 		break;
+	case EXC_SOFTWARE_CHECK:
+		if (vcpu->arch.cfg.henvcfg & (ENVCFG_LPE | ENVCFG_SSE))
+			ret = vcpu_redirect(vcpu, trap);
+		break;
 	default:
 		break;
 	}
-- 
2.55.0