RISC-V: KVM: Make SBI uapi consistent with ISA uapi

When an SBI extension cannot be enabled, that's a distinct state vs.
enabled and disabled. Modify enum kvm_riscv_sbi_ext_status to
accommodate it, which allows KVM userspace to tell the difference
in state too, as the SBI extension register will disappear when it
cannot be enabled, i.e. accesses to it return ENOENT. get-reg-list is
updated as well to only add SBI extension registers to the list which
may be enabled. Returning ENOENT for SBI extension registers which
cannot be enabled makes them consistent with ISA extension registers.
Any SBI extensions which were enabled by default are still enabled by
default, if they can be enabled at all.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Anup Patel <anup@brainfault.org>

1 files changed, 6 insertions, 4 deletions

diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h
index 6a453f7f8b56..bffda0ac59b6 100644
--- a/arch/riscv/include/asm/kvm_vcpu_sbi.h
+++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h
@@ -15,9 +15,10 @@
 #define KVM_SBI_VERSION_MINOR 0
 
 enum kvm_riscv_sbi_ext_status {
-	KVM_RISCV_SBI_EXT_UNINITIALIZED,
-	KVM_RISCV_SBI_EXT_AVAILABLE,
-	KVM_RISCV_SBI_EXT_UNAVAILABLE,
+	KVM_RISCV_SBI_EXT_STATUS_UNINITIALIZED,
+	KVM_RISCV_SBI_EXT_STATUS_UNAVAILABLE,
+	KVM_RISCV_SBI_EXT_STATUS_ENABLED,
+	KVM_RISCV_SBI_EXT_STATUS_DISABLED,
 };
 
 struct kvm_vcpu_sbi_context {
@@ -36,7 +37,7 @@ struct kvm_vcpu_sbi_extension {
 	unsigned long extid_start;
 	unsigned long extid_end;
 
-	bool default_unavail;
+	bool default_disabled;
 
 	/**
 	 * SBI extension handler. It can be defined for a given extension or group of
@@ -61,6 +62,7 @@ int kvm_riscv_vcpu_get_reg_sbi_ext(struct kvm_vcpu *vcpu,
 				   const struct kvm_one_reg *reg);
 const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(
 				struct kvm_vcpu *vcpu, unsigned long extid);
+bool riscv_vcpu_supports_sbi_ext(struct kvm_vcpu *vcpu, int idx);
 int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run);
 void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu);