From: Song Gao <gaosong@loongson.cn>
Date: Thu, 9 Apr 2026 10:56:37 +0000 (+0800)
Subject: KVM: LoongArch: selftests: Add cpucfg read/write helpers
X-Git-Url: http://git.ipfire.org/index.cgi?a=commitdiff_plain;h=fa19ea9a7bdb97575e05d72305a4c40a3a631357;p=thirdparty%2Fkernel%2Flinux.git

KVM: LoongArch: selftests: Add cpucfg read/write helpers

Add helper macros and functions to read and write CPU configuration
registers (cpucfg) from the guest and from the VMM. This interface is
required in upcoming selftests for querying and setting CPU features,
such as PMU capabilities.

Signed-off-by: Song Gao <gaosong@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
---

diff --git a/tools/testing/selftests/kvm/include/loongarch/processor.h b/tools/testing/selftests/kvm/include/loongarch/processor.h
index 76840ddda57d1..6c1e59484485f 100644
--- a/tools/testing/selftests/kvm/include/loongarch/processor.h
+++ b/tools/testing/selftests/kvm/include/loongarch/processor.h
@@ -128,6 +128,17 @@
 #define  CSR_TLBREHI_PS_SHIFT		0
 #define  CSR_TLBREHI_PS			(0x3fUL << CSR_TLBREHI_PS_SHIFT)
 
+#define read_cpucfg(reg)			\
+({						\
+	register unsigned long __v;		\
+	__asm__ __volatile__(			\
+		"cpucfg %0, %1\n\t"		\
+		: "=r" (__v)			\
+		: "r" (reg)			\
+		: "memory");			\
+	 __v;					\
+})
+
 #define csr_read(csr)				\
 ({						\
 	register unsigned long __v;		\
diff --git a/tools/testing/selftests/kvm/lib/loongarch/processor.c b/tools/testing/selftests/kvm/lib/loongarch/processor.c
index 17aa55a2047a0..0ad4544517e95 100644
--- a/tools/testing/selftests/kvm/lib/loongarch/processor.c
+++ b/tools/testing/selftests/kvm/lib/loongarch/processor.c
@@ -251,6 +251,14 @@ static void loongarch_set_reg(struct kvm_vcpu *vcpu, uint64_t id, uint64_t val)
 	__vcpu_set_reg(vcpu, id, val);
 }
 
+static void loongarch_set_cpucfg(struct kvm_vcpu *vcpu, uint64_t id, uint64_t val)
+{
+	uint64_t cfgid;
+
+	cfgid = KVM_REG_LOONGARCH_CPUCFG | KVM_REG_SIZE_U64 | 8 * id;
+	__vcpu_set_reg(vcpu, cfgid, val);
+}
+
 static void loongarch_get_csr(struct kvm_vcpu *vcpu, uint64_t id, void *addr)
 {
 	uint64_t csrid;