SBI v0.2 base extension defined to allow backward compatibility and
probing of future extensions. This is also the only mandatory SBI
extension that must be implemented by SBI implementors.
Signed-off-by: Atish Patra <atish.patra at wdc.com>
---
arch/riscv/include/asm/kvm_vcpu_sbi.h | 2 +
arch/riscv/include/asm/sbi.h | 8 +++
arch/riscv/kvm/Makefile | 1 +
arch/riscv/kvm/vcpu_sbi.c | 3 +-
arch/riscv/kvm/vcpu_sbi_base.c | 73 +++++++++++++++++++++++++++
5 files changed, 86 insertions(+), 1 deletion(-)
create mode 100644 arch/riscv/kvm/vcpu_sbi_base.c
diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h
index 704151969ceb..76e4e17a3e00 100644
--- a/arch/riscv/include/asm/kvm_vcpu_sbi.h
+++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h
@@ -9,6 +9,8 @@
#ifndef __RISCV_KVM_VCPU_SBI_H__
#define __RISCV_KVM_VCPU_SBI_H__
+#define KVM_SBI_IMPID 3
+
#define KVM_SBI_VERSION_MAJOR 0
#define KVM_SBI_VERSION_MINOR 2
diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 289621da4a2a..20e049857e98 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -28,6 +28,14 @@ enum sbi_ext_id {
SBI_EXT_RFENCE = 0x52464E43,
SBI_EXT_HSM = 0x48534D,
SBI_EXT_SRST = 0x53525354,
+
+ /* Experimentals extensions must lie within this range */
+ SBI_EXT_EXPERIMENTAL_START = 0x0800000,
+ SBI_EXT_EXPERIMENTAL_END = 0x08FFFFFF,
+
+ /* Vendor extensions must lie within this range */
+ SBI_EXT_VENDOR_START = 0x09000000,
+ SBI_EXT_VENDOR_END = 0x09FFFFFF,
};
enum sbi_ext_base_fid {
diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile
index 53cbecc44c4c..aaf02efafc0f 100644
--- a/arch/riscv/kvm/Makefile
+++ b/arch/riscv/kvm/Makefile
@@ -23,4 +23,5 @@ kvm-y += vcpu_exit.o
kvm-y += vcpu_switch.o
kvm-y += vcpu_sbi.o
kvm-$(CONFIG_RISCV_SBI_V01) += vcpu_sbi_legacy.o
+kvm-y += vcpu_sbi_base.o
kvm-y += vcpu_timer.o
diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c
index e51de3e4526a..5533ffc25ed0 100644
--- a/arch/riscv/kvm/vcpu_sbi.c
+++ b/arch/riscv/kvm/vcpu_sbi.c
@@ -39,9 +39,10 @@ static const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_legacy = {
.handler = NULL,
};
#endif
-
+extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_base;
static const struct kvm_vcpu_sbi_extension *sbi_ext[] = {
&vcpu_sbi_ext_legacy,
+ &vcpu_sbi_ext_base,
};
void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run)
diff --git a/arch/riscv/kvm/vcpu_sbi_base.c b/arch/riscv/kvm/vcpu_sbi_base.c
new file mode 100644
index 000000000000..1aeda3e10e7c
--- /dev/null
+++ b/arch/riscv/kvm/vcpu_sbi_base.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ * Atish Patra <atish.patra at wdc.com>
+ */
+
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/kvm_host.h>
+#include <asm/csr.h>
+#include <asm/sbi.h>
+#include <asm/kvm_vcpu_timer.h>
+#include <asm/kvm_vcpu_sbi.h>
+
+static int kvm_sbi_ext_base_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
+ unsigned long *out_val,
+ struct kvm_cpu_trap *trap, bool *exit)
+{
+ int ret = 0;
+ struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
+ struct sbiret ecall_ret;
+
+ if (!cp)
+ return -EINVAL;
+
+ switch (cp->a6) {
+ case SBI_EXT_BASE_GET_SPEC_VERSION:
+ *out_val = (KVM_SBI_VERSION_MAJOR <<
+ SBI_SPEC_VERSION_MAJOR_SHIFT) |
+ KVM_SBI_VERSION_MINOR;
+ break;
+ case SBI_EXT_BASE_GET_IMP_ID:
+ *out_val = KVM_SBI_IMPID;
+ break;
+ case SBI_EXT_BASE_GET_IMP_VERSION:
+ *out_val = 0;
+ break;
+ case SBI_EXT_BASE_PROBE_EXT:
+ *out_val = kvm_vcpu_sbi_find_ext(cp->a0) ? 1 : 0;
+ if ((!*out_val) &&
+ ((cp->a0 >= SBI_EXT_EXPERIMENTAL_START &&
+ cp->a0 <= SBI_EXT_EXPERIMENTAL_END) ||
+ ((cp->a0 >= SBI_EXT_VENDOR_START &&
+ cp->a0 <= SBI_EXT_VENDOR_END)))) {
+ /* For experimental/vendor extensions forward to the userspace*/
+ kvm_riscv_vcpu_sbi_forward(vcpu, run);
+ *exit = true;
+ }
+ break;
+ case SBI_EXT_BASE_GET_MVENDORID:
+ case SBI_EXT_BASE_GET_MARCHID:
+ case SBI_EXT_BASE_GET_MIMPID:
+ ecall_ret = sbi_ecall(SBI_EXT_BASE, cp->a6, 0, 0, 0, 0, 0, 0);
+ if (!ecall_ret.error)
+ *out_val = ecall_ret.value;
+ /*TODO: We are unnecessarily converting the error twice */
+ ret = sbi_err_map_linux_errno(ecall_ret.error);
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ break;
+ }
+
+ return ret;
+}
+
+const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_base = {
+ .extid_start = SBI_EXT_BASE,
+ .extid_end = SBI_EXT_BASE,
+ .handler = kvm_sbi_ext_base_handler,
+};
--
2.31.1