[PATCH] RISC-V: KVM: Fix HSM hart status error propagation

[Tan Chi]

kvm_sbi_hsm_vcpu_get_status() returns SBI_ERR_INVALID_PARAM when
the requested hart does not exist. However, the HART_STATUS case
returns from the SBI handler without storing this error in
retdata->err_val.

As a result, a guest querying the status of a non-existent hart
observes SBI_SUCCESS instead of SBI_ERR_INVALID_PARAM.

Use the common SBI error handling path for HART_STATUS after
saving a valid hart state in retdata->out_val. This preserves
the returned error when kvm_sbi_hsm_vcpu_get_status() fails.

Fixes: bae0dfd74e01 ("RISC-V: KVM: Modify SBI extension handler to return SBI error code")
Cc: stable@xxxxxxxxxxxxxxx
Assisted-by: LLM
Signed-off-by: Tan Chi <tanchi25@xxxxxxxxxxxxxxxx>
---
 arch/riscv/kvm/vcpu_sbi_hsm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/kvm/vcpu_sbi_hsm.c b/arch/riscv/kvm/vcpu_sbi_hsm.c
index f26207f84bab..06a15629c26b 100644
--- a/arch/riscv/kvm/vcpu_sbi_hsm.c
+++ b/arch/riscv/kvm/vcpu_sbi_hsm.c
@@ -95,9 +95,9 @@ static int kvm_sbi_ext_hsm_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
 		ret = kvm_sbi_hsm_vcpu_get_status(vcpu);
 		if (ret >= 0) {
 			retdata->out_val = ret;
-			retdata->err_val = 0;
+			ret = 0;
 		}
-		return 0;
+		break;
 	case SBI_EXT_HSM_HART_SUSPEND:
 		switch (lower_32_bits(cp->a0)) {
 		case SBI_HSM_SUSPEND_RET_DEFAULT:

base-commit: df2908090cda368b01ff43709f51890076c56157
-- 
2.53.0