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-rw-r--r--arch/riscv/kvm/vcpu_sbi.c180
1 files changed, 180 insertions, 0 deletions
diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c
new file mode 100644
index 000000000..f96991d23
--- /dev/null
+++ b/arch/riscv/kvm/vcpu_sbi.c
@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ * Atish Patra <atish.patra@wdc.com>
+ */
+
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/kvm_host.h>
+#include <asm/sbi.h>
+#include <asm/kvm_vcpu_sbi.h>
+
+static int kvm_linux_err_map_sbi(int err)
+{
+ switch (err) {
+ case 0:
+ return SBI_SUCCESS;
+ case -EPERM:
+ return SBI_ERR_DENIED;
+ case -EINVAL:
+ return SBI_ERR_INVALID_PARAM;
+ case -EFAULT:
+ return SBI_ERR_INVALID_ADDRESS;
+ case -EOPNOTSUPP:
+ return SBI_ERR_NOT_SUPPORTED;
+ case -EALREADY:
+ return SBI_ERR_ALREADY_AVAILABLE;
+ default:
+ return SBI_ERR_FAILURE;
+ };
+}
+
+#ifndef CONFIG_RISCV_SBI_V01
+static const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_v01 = {
+ .extid_start = -1UL,
+ .extid_end = -1UL,
+ .handler = NULL,
+};
+#endif
+
+static const struct kvm_vcpu_sbi_extension *sbi_ext[] = {
+ &vcpu_sbi_ext_v01,
+ &vcpu_sbi_ext_base,
+ &vcpu_sbi_ext_time,
+ &vcpu_sbi_ext_ipi,
+ &vcpu_sbi_ext_rfence,
+ &vcpu_sbi_ext_srst,
+ &vcpu_sbi_ext_hsm,
+ &vcpu_sbi_ext_experimental,
+ &vcpu_sbi_ext_vendor,
+};
+
+void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+ struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
+
+ vcpu->arch.sbi_context.return_handled = 0;
+ vcpu->stat.ecall_exit_stat++;
+ run->exit_reason = KVM_EXIT_RISCV_SBI;
+ run->riscv_sbi.extension_id = cp->a7;
+ run->riscv_sbi.function_id = cp->a6;
+ run->riscv_sbi.args[0] = cp->a0;
+ run->riscv_sbi.args[1] = cp->a1;
+ run->riscv_sbi.args[2] = cp->a2;
+ run->riscv_sbi.args[3] = cp->a3;
+ run->riscv_sbi.args[4] = cp->a4;
+ run->riscv_sbi.args[5] = cp->a5;
+ run->riscv_sbi.ret[0] = cp->a0;
+ run->riscv_sbi.ret[1] = cp->a1;
+}
+
+void kvm_riscv_vcpu_sbi_system_reset(struct kvm_vcpu *vcpu,
+ struct kvm_run *run,
+ u32 type, u64 reason)
+{
+ unsigned long i;
+ struct kvm_vcpu *tmp;
+
+ kvm_for_each_vcpu(i, tmp, vcpu->kvm)
+ tmp->arch.power_off = true;
+ kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP);
+
+ memset(&run->system_event, 0, sizeof(run->system_event));
+ run->system_event.type = type;
+ run->system_event.ndata = 1;
+ run->system_event.data[0] = reason;
+ run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
+}
+
+int kvm_riscv_vcpu_sbi_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+ struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
+
+ /* Handle SBI return only once */
+ if (vcpu->arch.sbi_context.return_handled)
+ return 0;
+ vcpu->arch.sbi_context.return_handled = 1;
+
+ /* Update return values */
+ cp->a0 = run->riscv_sbi.ret[0];
+ cp->a1 = run->riscv_sbi.ret[1];
+
+ /* Move to next instruction */
+ vcpu->arch.guest_context.sepc += 4;
+
+ return 0;
+}
+
+const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(unsigned long extid)
+{
+ int i = 0;
+
+ for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) {
+ if (sbi_ext[i]->extid_start <= extid &&
+ sbi_ext[i]->extid_end >= extid)
+ return sbi_ext[i];
+ }
+
+ return NULL;
+}
+
+int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+ int ret = 1;
+ bool next_sepc = true;
+ bool userspace_exit = false;
+ struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
+ const struct kvm_vcpu_sbi_extension *sbi_ext;
+ struct kvm_cpu_trap utrap = { 0 };
+ unsigned long out_val = 0;
+ bool ext_is_v01 = false;
+
+ sbi_ext = kvm_vcpu_sbi_find_ext(cp->a7);
+ if (sbi_ext && sbi_ext->handler) {
+#ifdef CONFIG_RISCV_SBI_V01
+ if (cp->a7 >= SBI_EXT_0_1_SET_TIMER &&
+ cp->a7 <= SBI_EXT_0_1_SHUTDOWN)
+ ext_is_v01 = true;
+#endif
+ ret = sbi_ext->handler(vcpu, run, &out_val, &utrap, &userspace_exit);
+ } else {
+ /* Return error for unsupported SBI calls */
+ cp->a0 = SBI_ERR_NOT_SUPPORTED;
+ goto ecall_done;
+ }
+
+ /* Handle special error cases i.e trap, exit or userspace forward */
+ if (utrap.scause) {
+ /* No need to increment sepc or exit ioctl loop */
+ ret = 1;
+ utrap.sepc = cp->sepc;
+ kvm_riscv_vcpu_trap_redirect(vcpu, &utrap);
+ next_sepc = false;
+ goto ecall_done;
+ }
+
+ /* Exit ioctl loop or Propagate the error code the guest */
+ if (userspace_exit) {
+ next_sepc = false;
+ ret = 0;
+ } else {
+ /**
+ * SBI extension handler always returns an Linux error code. Convert
+ * it to the SBI specific error code that can be propagated the SBI
+ * caller.
+ */
+ ret = kvm_linux_err_map_sbi(ret);
+ cp->a0 = ret;
+ ret = 1;
+ }
+ecall_done:
+ if (next_sepc)
+ cp->sepc += 4;
+ if (!ext_is_v01)
+ cp->a1 = out_val;
+
+ return ret;
+}