[PATCH v3 7/9] KVM: riscv: selftests: Add guest helper to get vcpu id

[Haibo Xu <haibo1.xu@xxxxxxxxx>]

Add guest_get_vcpuid() helper to simplify accessing to per-cpu
private data. The sscratch CSR was used to store the vcpu id.

Signed-off-by: Haibo Xu <haibo1.xu@xxxxxxxxx>
Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
---
 tools/testing/selftests/kvm/include/aarch64/processor.h | 4 ----
 tools/testing/selftests/kvm/include/kvm_util_base.h     | 2 ++
 tools/testing/selftests/kvm/lib/riscv/processor.c       | 8 ++++++++
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
index 69e7b08d3f99..f41fcd63624f 100644
--- a/tools/testing/selftests/kvm/include/aarch64/processor.h
+++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
@@ -219,8 +219,4 @@ void smccc_smc(uint32_t function_id, uint64_t arg0, uint64_t arg1,
 	       uint64_t arg2, uint64_t arg3, uint64_t arg4, uint64_t arg5,
 	       uint64_t arg6, struct arm_smccc_res *res);
 
-
-
-uint32_t guest_get_vcpuid(void);
-
 #endif /* SELFTEST_KVM_PROCESSOR_H */
diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index 135ae2eb5249..666438113d22 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -939,4 +939,6 @@ struct ex_regs;
 typedef void(*exception_handler_fn)(struct ex_regs *);
 void vm_install_exception_handler(struct kvm_vm *vm, int vector, exception_handler_fn handler);
 
+uint32_t guest_get_vcpuid(void);
+
 #endif /* SELFTEST_KVM_UTIL_BASE_H */
diff --git a/tools/testing/selftests/kvm/lib/riscv/processor.c b/tools/testing/selftests/kvm/lib/riscv/processor.c
index efd9ac4b0198..39a1e9902dec 100644
--- a/tools/testing/selftests/kvm/lib/riscv/processor.c
+++ b/tools/testing/selftests/kvm/lib/riscv/processor.c
@@ -316,6 +316,9 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id,
 	vcpu_set_reg(vcpu, RISCV_CORE_REG(regs.sp), stack_vaddr + stack_size);
 	vcpu_set_reg(vcpu, RISCV_CORE_REG(regs.pc), (unsigned long)guest_code);
 
+	/* Setup sscratch for guest_get_vcpuid() */
+	vcpu_set_reg(vcpu, RISCV_CSR_REG(sscratch), vcpu_id);
+
 	/* Setup default exception vector of guest */
 	vcpu_set_reg(vcpu, RISCV_CSR_REG(stvec), (unsigned long)guest_unexp_trap);
 
@@ -436,3 +439,8 @@ void vm_install_interrupt_handler(struct kvm_vm *vm, exception_handler_fn handle
 
 	handlers->exception_handlers[1][0] = handler;
 }
+
+uint32_t guest_get_vcpuid(void)
+{
+	return csr_read(CSR_SSCRATCH);
+}
-- 
2.34.1