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-rw-r--r--arch/riscv/kvm/vcpu_sbi.c421
1 files changed, 421 insertions, 0 deletions
diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c
new file mode 100644
index 0000000000..9cd97091c7
--- /dev/null
+++ b/arch/riscv/kvm/vcpu_sbi.c
@@ -0,0 +1,421 @@
+// 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>
+
+#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
+
+#ifndef CONFIG_RISCV_PMU_SBI
+static const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_pmu = {
+ .extid_start = -1UL,
+ .extid_end = -1UL,
+ .handler = NULL,
+};
+#endif
+
+struct kvm_riscv_sbi_extension_entry {
+ enum KVM_RISCV_SBI_EXT_ID ext_idx;
+ const struct kvm_vcpu_sbi_extension *ext_ptr;
+};
+
+static const struct kvm_riscv_sbi_extension_entry sbi_ext[] = {
+ {
+ .ext_idx = KVM_RISCV_SBI_EXT_V01,
+ .ext_ptr = &vcpu_sbi_ext_v01,
+ },
+ {
+ .ext_idx = KVM_RISCV_SBI_EXT_MAX, /* Can't be disabled */
+ .ext_ptr = &vcpu_sbi_ext_base,
+ },
+ {
+ .ext_idx = KVM_RISCV_SBI_EXT_TIME,
+ .ext_ptr = &vcpu_sbi_ext_time,
+ },
+ {
+ .ext_idx = KVM_RISCV_SBI_EXT_IPI,
+ .ext_ptr = &vcpu_sbi_ext_ipi,
+ },
+ {
+ .ext_idx = KVM_RISCV_SBI_EXT_RFENCE,
+ .ext_ptr = &vcpu_sbi_ext_rfence,
+ },
+ {
+ .ext_idx = KVM_RISCV_SBI_EXT_SRST,
+ .ext_ptr = &vcpu_sbi_ext_srst,
+ },
+ {
+ .ext_idx = KVM_RISCV_SBI_EXT_HSM,
+ .ext_ptr = &vcpu_sbi_ext_hsm,
+ },
+ {
+ .ext_idx = KVM_RISCV_SBI_EXT_PMU,
+ .ext_ptr = &vcpu_sbi_ext_pmu,
+ },
+ {
+ .ext_idx = KVM_RISCV_SBI_EXT_EXPERIMENTAL,
+ .ext_ptr = &vcpu_sbi_ext_experimental,
+ },
+ {
+ .ext_idx = KVM_RISCV_SBI_EXT_VENDOR,
+ .ext_ptr = &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;
+}
+
+static int riscv_vcpu_set_sbi_ext_single(struct kvm_vcpu *vcpu,
+ unsigned long reg_num,
+ unsigned long reg_val)
+{
+ unsigned long i;
+ const struct kvm_riscv_sbi_extension_entry *sext = NULL;
+ struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context;
+
+ if (reg_num >= KVM_RISCV_SBI_EXT_MAX)
+ return -ENOENT;
+
+ if (reg_val != 1 && reg_val != 0)
+ return -EINVAL;
+
+ for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) {
+ if (sbi_ext[i].ext_idx == reg_num) {
+ sext = &sbi_ext[i];
+ break;
+ }
+ }
+ if (!sext)
+ return -ENOENT;
+
+ /*
+ * We can't set the extension status to available here, since it may
+ * have a probe() function which needs to confirm availability first,
+ * but it may be too early to call that here. We can set the status to
+ * unavailable, though.
+ */
+ if (!reg_val)
+ scontext->ext_status[sext->ext_idx] =
+ KVM_RISCV_SBI_EXT_UNAVAILABLE;
+
+ return 0;
+}
+
+static int riscv_vcpu_get_sbi_ext_single(struct kvm_vcpu *vcpu,
+ unsigned long reg_num,
+ unsigned long *reg_val)
+{
+ unsigned long i;
+ const struct kvm_riscv_sbi_extension_entry *sext = NULL;
+ struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context;
+
+ if (reg_num >= KVM_RISCV_SBI_EXT_MAX)
+ return -ENOENT;
+
+ for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) {
+ if (sbi_ext[i].ext_idx == reg_num) {
+ sext = &sbi_ext[i];
+ break;
+ }
+ }
+ if (!sext)
+ return -ENOENT;
+
+ /*
+ * If the extension status is still uninitialized, then we should probe
+ * to determine if it's available, but it may be too early to do that
+ * here. The best we can do is report that the extension has not been
+ * disabled, i.e. we return 1 when the extension is available and also
+ * when it only may be available.
+ */
+ *reg_val = scontext->ext_status[sext->ext_idx] !=
+ KVM_RISCV_SBI_EXT_UNAVAILABLE;
+
+ return 0;
+}
+
+static int riscv_vcpu_set_sbi_ext_multi(struct kvm_vcpu *vcpu,
+ unsigned long reg_num,
+ unsigned long reg_val, bool enable)
+{
+ unsigned long i, ext_id;
+
+ if (reg_num > KVM_REG_RISCV_SBI_MULTI_REG_LAST)
+ return -ENOENT;
+
+ for_each_set_bit(i, &reg_val, BITS_PER_LONG) {
+ ext_id = i + reg_num * BITS_PER_LONG;
+ if (ext_id >= KVM_RISCV_SBI_EXT_MAX)
+ break;
+
+ riscv_vcpu_set_sbi_ext_single(vcpu, ext_id, enable);
+ }
+
+ return 0;
+}
+
+static int riscv_vcpu_get_sbi_ext_multi(struct kvm_vcpu *vcpu,
+ unsigned long reg_num,
+ unsigned long *reg_val)
+{
+ unsigned long i, ext_id, ext_val;
+
+ if (reg_num > KVM_REG_RISCV_SBI_MULTI_REG_LAST)
+ return -ENOENT;
+
+ for (i = 0; i < BITS_PER_LONG; i++) {
+ ext_id = i + reg_num * BITS_PER_LONG;
+ if (ext_id >= KVM_RISCV_SBI_EXT_MAX)
+ break;
+
+ ext_val = 0;
+ riscv_vcpu_get_sbi_ext_single(vcpu, ext_id, &ext_val);
+ if (ext_val)
+ *reg_val |= KVM_REG_RISCV_SBI_MULTI_MASK(ext_id);
+ }
+
+ return 0;
+}
+
+int kvm_riscv_vcpu_set_reg_sbi_ext(struct kvm_vcpu *vcpu,
+ const struct kvm_one_reg *reg)
+{
+ unsigned long __user *uaddr =
+ (unsigned long __user *)(unsigned long)reg->addr;
+ unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
+ KVM_REG_SIZE_MASK |
+ KVM_REG_RISCV_SBI_EXT);
+ unsigned long reg_val, reg_subtype;
+
+ if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
+ return -EINVAL;
+
+ if (vcpu->arch.ran_atleast_once)
+ return -EBUSY;
+
+ reg_subtype = reg_num & KVM_REG_RISCV_SUBTYPE_MASK;
+ reg_num &= ~KVM_REG_RISCV_SUBTYPE_MASK;
+
+ if (copy_from_user(&reg_val, uaddr, KVM_REG_SIZE(reg->id)))
+ return -EFAULT;
+
+ switch (reg_subtype) {
+ case KVM_REG_RISCV_SBI_SINGLE:
+ return riscv_vcpu_set_sbi_ext_single(vcpu, reg_num, reg_val);
+ case KVM_REG_RISCV_SBI_MULTI_EN:
+ return riscv_vcpu_set_sbi_ext_multi(vcpu, reg_num, reg_val, true);
+ case KVM_REG_RISCV_SBI_MULTI_DIS:
+ return riscv_vcpu_set_sbi_ext_multi(vcpu, reg_num, reg_val, false);
+ default:
+ return -ENOENT;
+ }
+
+ return 0;
+}
+
+int kvm_riscv_vcpu_get_reg_sbi_ext(struct kvm_vcpu *vcpu,
+ const struct kvm_one_reg *reg)
+{
+ int rc;
+ unsigned long __user *uaddr =
+ (unsigned long __user *)(unsigned long)reg->addr;
+ unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
+ KVM_REG_SIZE_MASK |
+ KVM_REG_RISCV_SBI_EXT);
+ unsigned long reg_val, reg_subtype;
+
+ if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
+ return -EINVAL;
+
+ reg_subtype = reg_num & KVM_REG_RISCV_SUBTYPE_MASK;
+ reg_num &= ~KVM_REG_RISCV_SUBTYPE_MASK;
+
+ reg_val = 0;
+ switch (reg_subtype) {
+ case KVM_REG_RISCV_SBI_SINGLE:
+ rc = riscv_vcpu_get_sbi_ext_single(vcpu, reg_num, &reg_val);
+ break;
+ case KVM_REG_RISCV_SBI_MULTI_EN:
+ case KVM_REG_RISCV_SBI_MULTI_DIS:
+ rc = riscv_vcpu_get_sbi_ext_multi(vcpu, reg_num, &reg_val);
+ if (!rc && reg_subtype == KVM_REG_RISCV_SBI_MULTI_DIS)
+ reg_val = ~reg_val;
+ break;
+ default:
+ rc = -ENOENT;
+ }
+ if (rc)
+ return rc;
+
+ if (copy_to_user(uaddr, &reg_val, KVM_REG_SIZE(reg->id)))
+ return -EFAULT;
+
+ return 0;
+}
+
+const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(
+ struct kvm_vcpu *vcpu, unsigned long extid)
+{
+ struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context;
+ const struct kvm_riscv_sbi_extension_entry *entry;
+ const struct kvm_vcpu_sbi_extension *ext;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) {
+ entry = &sbi_ext[i];
+ ext = entry->ext_ptr;
+
+ if (ext->extid_start <= extid && ext->extid_end >= extid) {
+ if (entry->ext_idx >= KVM_RISCV_SBI_EXT_MAX ||
+ scontext->ext_status[entry->ext_idx] ==
+ KVM_RISCV_SBI_EXT_AVAILABLE)
+ return ext;
+ if (scontext->ext_status[entry->ext_idx] ==
+ KVM_RISCV_SBI_EXT_UNAVAILABLE)
+ return NULL;
+ if (ext->probe && !ext->probe(vcpu)) {
+ scontext->ext_status[entry->ext_idx] =
+ KVM_RISCV_SBI_EXT_UNAVAILABLE;
+ return NULL;
+ }
+
+ scontext->ext_status[entry->ext_idx] =
+ KVM_RISCV_SBI_EXT_AVAILABLE;
+ return ext;
+ }
+ }
+
+ return NULL;
+}
+
+int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+ int ret = 1;
+ bool next_sepc = true;
+ struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
+ const struct kvm_vcpu_sbi_extension *sbi_ext;
+ struct kvm_cpu_trap utrap = {0};
+ struct kvm_vcpu_sbi_return sbi_ret = {
+ .out_val = 0,
+ .err_val = 0,
+ .utrap = &utrap,
+ };
+ bool ext_is_v01 = false;
+
+ sbi_ext = kvm_vcpu_sbi_find_ext(vcpu, 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, &sbi_ret);
+ } else {
+ /* Return error for unsupported SBI calls */
+ cp->a0 = SBI_ERR_NOT_SUPPORTED;
+ goto ecall_done;
+ }
+
+ /*
+ * When the SBI extension returns a Linux error code, it exits the ioctl
+ * loop and forwards the error to userspace.
+ */
+ if (ret < 0) {
+ next_sepc = false;
+ goto ecall_done;
+ }
+
+ /* Handle special error cases i.e trap, exit or userspace forward */
+ if (sbi_ret.utrap->scause) {
+ /* No need to increment sepc or exit ioctl loop */
+ ret = 1;
+ sbi_ret.utrap->sepc = cp->sepc;
+ kvm_riscv_vcpu_trap_redirect(vcpu, sbi_ret.utrap);
+ next_sepc = false;
+ goto ecall_done;
+ }
+
+ /* Exit ioctl loop or Propagate the error code the guest */
+ if (sbi_ret.uexit) {
+ next_sepc = false;
+ ret = 0;
+ } else {
+ cp->a0 = sbi_ret.err_val;
+ ret = 1;
+ }
+ecall_done:
+ if (next_sepc)
+ cp->sepc += 4;
+ /* a1 should only be updated when we continue the ioctl loop */
+ if (!ext_is_v01 && ret == 1)
+ cp->a1 = sbi_ret.out_val;
+
+ return ret;
+}