RISC-V: KVM: Add in-kernel virtualization of AIA IMSIC

We can have AIA IMSIC support for both HS-level and VS-level but
the VS-level IMSICs are optional. We use the VS-level IMSICs for
Guest/VM whenever available otherwise we fallback to software
emulation of AIA IMSIC.

This patch adds in-kernel virtualization of AIA IMSIC.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

arch/riscv/include/asm/kvm_aia.h

@@ -90,44 +90,18 @@ DECLARE_STATIC_KEY_FALSE(kvm_riscv_aia_available);
 
 extern struct kvm_device_ops kvm_riscv_aia_device_ops;
 
-static inline void kvm_riscv_vcpu_aia_imsic_release(struct kvm_vcpu *vcpu)
-{
-}
-
-static inline int kvm_riscv_vcpu_aia_imsic_update(struct kvm_vcpu *vcpu)
-{
-	return 1;
-}
+void kvm_riscv_vcpu_aia_imsic_release(struct kvm_vcpu *vcpu);
+int kvm_riscv_vcpu_aia_imsic_update(struct kvm_vcpu *vcpu);
 
 #define KVM_RISCV_AIA_IMSIC_TOPEI	(ISELECT_MASK + 1)
-static inline int kvm_riscv_vcpu_aia_imsic_rmw(struct kvm_vcpu *vcpu,
-					       unsigned long isel,
-					       unsigned long *val,
-					       unsigned long new_val,
-					       unsigned long wr_mask)
-{
-	return 0;
-}
-
-static inline void kvm_riscv_vcpu_aia_imsic_reset(struct kvm_vcpu *vcpu)
-{
-}
-
-static inline int kvm_riscv_vcpu_aia_imsic_inject(struct kvm_vcpu *vcpu,
-						  u32 guest_index, u32 offset,
-						  u32 iid)
-{
-	return 0;
-}
-
-static inline int kvm_riscv_vcpu_aia_imsic_init(struct kvm_vcpu *vcpu)
-{
-	return 0;
-}
-
-static inline void kvm_riscv_vcpu_aia_imsic_cleanup(struct kvm_vcpu *vcpu)
-{
-}
+int kvm_riscv_vcpu_aia_imsic_rmw(struct kvm_vcpu *vcpu, unsigned long isel,
+				 unsigned long *val, unsigned long new_val,
+				 unsigned long wr_mask);
+void kvm_riscv_vcpu_aia_imsic_reset(struct kvm_vcpu *vcpu);
+int kvm_riscv_vcpu_aia_imsic_inject(struct kvm_vcpu *vcpu,
+				    u32 guest_index, u32 offset, u32 iid);
+int kvm_riscv_vcpu_aia_imsic_init(struct kvm_vcpu *vcpu);
+void kvm_riscv_vcpu_aia_imsic_cleanup(struct kvm_vcpu *vcpu);
 
 int kvm_riscv_aia_aplic_set_attr(struct kvm *kvm, unsigned long type, u32 v);
 int kvm_riscv_aia_aplic_get_attr(struct kvm *kvm, unsigned long type, u32 *v);

arch/riscv/kvm/Makefile

@@ -29,3 +29,4 @@ kvm-$(CONFIG_RISCV_PMU_SBI) += vcpu_pmu.o vcpu_sbi_pmu.o
 kvm-y += aia.o
 kvm-y += aia_device.o
 kvm-y += aia_aplic.o
+kvm-y += aia_imsic.o