[PATCH 3/5] RISC-V: KVM: Support lazy enabling of siselect and aia bits

[Atish Patra]

Smstateen extension controls the SISELECT and SIPH/SIEH register
through hstateen.AIA bit (58). Add lazy enabling support for those
bits.

Signed-off-by: Atish Patra <atishp at rivosinc.com>
---
 arch/riscv/include/asm/kvm_aia.h | 13 ++++++++++++-
 arch/riscv/kvm/aia.c             | 34 ++++++++++++++++++++++++++++++++++
 arch/riscv/kvm/vcpu_insn.c       |  3 +++
 3 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/kvm_aia.h b/arch/riscv/include/asm/kvm_aia.h
index 760a1aef09f7..9e39b0e15169 100644
--- a/arch/riscv/include/asm/kvm_aia.h
+++ b/arch/riscv/include/asm/kvm_aia.h
@@ -142,12 +142,23 @@ int kvm_riscv_vcpu_aia_rmw_topei(struct kvm_vcpu *vcpu,
 				 unsigned long *val,
 				 unsigned long new_val,
 				 unsigned long wr_mask);
+int kvm_riscv_vcpu_aia_hstateen_enable(struct kvm_vcpu *vcpu,
+				       unsigned int csr_num, unsigned long *val,
+				       unsigned long new_val, unsigned long wr_mask);
+int kvm_riscv_vcpu_aia_rmw_isel(struct kvm_vcpu *vcpu, unsigned int csr_num, unsigned long *val,
+				unsigned long new_val, unsigned long wr_mask);
 int kvm_riscv_vcpu_aia_rmw_ireg(struct kvm_vcpu *vcpu, unsigned int csr_num,
 				unsigned long *val, unsigned long new_val,
 				unsigned long wr_mask);
 #define KVM_RISCV_VCPU_AIA_CSR_FUNCS \
 { .base = CSR_SIREG,      .count = 1, .func = kvm_riscv_vcpu_aia_rmw_ireg }, \
-{ .base = CSR_STOPEI,     .count = 1, .func = kvm_riscv_vcpu_aia_rmw_topei },
+{ .base = CSR_SISELECT,   .count = 1, .func = kvm_riscv_vcpu_aia_rmw_isel }, \
+{ .base = CSR_STOPEI,     .count = 1, .func = kvm_riscv_vcpu_aia_rmw_topei }, \
+{ .base = CSR_STOPI,      .count = 1, .func = kvm_riscv_vcpu_aia_hstateen_enable }, \
+
+#define KVM_RISCV_VCPU_AIA_CSR_32BIT_FUNCS \
+{ .base = CSR_SIPH,	  .count = 1, .func = kvm_riscv_vcpu_aia_hstateen_enable }, \
+{ .base = CSR_SIEH,	  .count = 1, .func = kvm_riscv_vcpu_aia_hstateen_enable }, \
 
 int kvm_riscv_vcpu_aia_update(struct kvm_vcpu *vcpu);
 void kvm_riscv_vcpu_aia_reset(struct kvm_vcpu *vcpu);
diff --git a/arch/riscv/kvm/aia.c b/arch/riscv/kvm/aia.c
index 1e0d2217ade7..3dfabf51a4d2 100644
--- a/arch/riscv/kvm/aia.c
+++ b/arch/riscv/kvm/aia.c
@@ -235,6 +235,40 @@ int kvm_riscv_vcpu_aia_set_csr(struct kvm_vcpu *vcpu,
 	return 0;
 }
 
+int kvm_riscv_vcpu_aia_hstateen_enable(struct kvm_vcpu *vcpu,
+				       unsigned int csr_num,
+				       unsigned long *val,
+				       unsigned long new_val,
+				       unsigned long wr_mask)
+{
+	/* If AIA not available then redirect trap */
+	if (!kvm_riscv_aia_available())
+		return KVM_INSN_ILLEGAL_TRAP;
+
+	/* If AIA not initialized then forward to user space */
+	if (!kvm_riscv_aia_initialized(vcpu->kvm))
+		return KVM_INSN_EXIT_TO_USER_SPACE;
+
+	return kvm_riscv_vcpu_hstateen_lazy_enable(vcpu, csr_num, SMSTATEEN0_AIA);
+}
+
+int kvm_riscv_vcpu_aia_rmw_isel(struct kvm_vcpu *vcpu,
+				unsigned int csr_num,
+				unsigned long *val,
+				unsigned long new_val,
+				unsigned long wr_mask)
+{
+	/* If AIA not available then redirect trap */
+	if (!kvm_riscv_aia_available())
+		return KVM_INSN_ILLEGAL_TRAP;
+
+	/* If AIA not initialized then forward to user space */
+	if (!kvm_riscv_aia_initialized(vcpu->kvm))
+		return KVM_INSN_EXIT_TO_USER_SPACE;
+
+	return kvm_riscv_vcpu_hstateen_lazy_enable(vcpu, csr_num, SMSTATEEN0_AIA_ISEL);
+}
+
 int kvm_riscv_vcpu_aia_rmw_topei(struct kvm_vcpu *vcpu,
 				 unsigned int csr_num,
 				 unsigned long *val,
diff --git a/arch/riscv/kvm/vcpu_insn.c b/arch/riscv/kvm/vcpu_insn.c
index 3bc39572b79d..c46907bfe42f 100644
--- a/arch/riscv/kvm/vcpu_insn.c
+++ b/arch/riscv/kvm/vcpu_insn.c
@@ -260,6 +260,9 @@ static const struct csr_func csr_funcs[] = {
 	KVM_RISCV_VCPU_AIA_CSR_FUNCS
 	KVM_RISCV_VCPU_HPMCOUNTER_CSR_FUNCS
 	{ .base = CSR_SEED, .count = 1, .func = seed_csr_rmw },
+#ifdef CONFIG_32BIT
+	KVM_RISCV_VCPU_AIA_CSR_32BIT_FUNCS
+#endif
 };
 
 /**

-- 
2.43.0