diff options
Diffstat (limited to 'arch/riscv/kvm/vcpu_sbi.c')
| -rw-r--r-- | arch/riscv/kvm/vcpu_sbi.c | 180 |
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; +} |