[RFC v2 05/14] arm/sdei: add support to handle SDEI requests from guest

[Heyi Guo]

Add support for all interfaces defined in ARM SDEI 1.0 spec.

http://infocenter.arm.com/help/topic/com.arm.doc.den0054a/ARM_DEN0054A_Software_Delegated_Exception_Interface.pdf

The exit reason KVM_EXIT_HYPERCALL is used to indicate it is an
HVC/SMC forward, and the structure kvm_run->hypercall is used to pass
arguments and return values between KVM and qemu:
Input:
  nr: the immediate value of SMC/HVC calls; not really used today.
  args[6]: x0..x5 (This is not fully conform with SMCCC which requires
           x6 as argument as well, but we can use GET_ONE_REG ioctl
           for such rare case).
Return:
  args[0..3]: x0..x3 as defined in SMCCC. We rely on KVM to extract
              args[0..3] and write them to x0..x3 when hypercall exit
              returns.

Signed-off-by: Heyi Guo <address@hidden>
Signed-off-by: Jingyi Wang <address@hidden>
Cc: Peter Maydell <address@hidden>
Cc: Dave Martin <address@hidden>
Cc: Marc Zyngier <address@hidden>
Cc: Mark Rutland <address@hidden>
Cc: James Morse <address@hidden>
---
 target/arm/sdei.c | 982 ++++++++++++++++++++++++++++++++++++++++++++++
 target/arm/sdei.h |  34 ++
 2 files changed, 1016 insertions(+)
 create mode 100644 target/arm/sdei.h

diff --git a/target/arm/sdei.c b/target/arm/sdei.c
index 931e46923a..0c0212bfa8 100644
--- a/target/arm/sdei.c
+++ b/target/arm/sdei.c
@@ -29,6 +29,7 @@
 #include "sysemu/sysemu.h"
 #include "sysemu/reset.h"
 #include "qemu/error-report.h"
+#include "sdei.h"
 #include "sdei_int.h"
 #include "internals.h"
 #include "hw/boards.h"
@@ -42,6 +43,9 @@
 #define TYPE_ARM_SDEI "arm_sdei"
 #define QEMU_SDEI(obj) OBJECT_CHECK(QemuSDEState, (obj), TYPE_ARM_SDEI)
 
+#define SMCCC_RETURN_REG_COUNT 4
+#define PSTATE_M_EL_SHIFT      2
+
 static QemuSDEState *sde_state;
 
 static void qemu_sde_prop_init(QemuSDEState *s)
@@ -84,6 +88,16 @@ static void qemu_sde_cpu_init(QemuSDEState *s)
     }
 }
 
+static inline QemuSDECpu *get_sde_cpu(QemuSDEState *s, CPUState *cs)
+{
+    if (cs->cpu_index >= s->sdei_max_cpus) {
+        error_report("BUG: cpu index %d >= max_cpus %d",
+                     cs->cpu_index, s->sdei_max_cpus);
+        return NULL;
+    }
+    return &s->sde_cpus[cs->cpu_index];
+}
+
 static bool is_valid_event_number(int32_t event)
 {
     int32_t slot_id;
@@ -122,6 +136,974 @@ static QemuSDEProp *get_sde_prop_no_lock(QemuSDEState *s, 
int32_t event)
     return &s->sde_props_state[SDEI_EVENT_TO_SLOT(event)];
 }
 
+static QemuSDEProp *get_sde_prop(QemuSDEState *s, int32_t event)
+{
+    QemuSDEProp *sde_props = s->sde_props_state;
+
+    if (!is_valid_event_number(event)) {
+        return NULL;
+    }
+
+    event = SDEI_EVENT_TO_SLOT(event);
+
+    qemu_mutex_lock(&sde_props[event].lock);
+    if (sde_props[event].event_id < 0) {
+        qemu_mutex_unlock(&sde_props[event].lock);
+        return NULL;
+    }
+    return &sde_props[event];
+}
+
+static void put_sde_prop(QemuSDEProp *prop)
+{
+    qemu_mutex_unlock(&prop->lock);
+}
+
+static void sde_slot_lock(QemuSDE *sde, CPUState *cs)
+{
+    qemu_mutex_lock(&sde->lock);
+}
+
+static void sde_slot_unlock(QemuSDE *sde, CPUState *cs)
+{
+    qemu_mutex_unlock(&sde->lock);
+}
+
+/*
+ * It will always return a pointer to a preallocated sde; event number must be
+ * validated before calling this function.
+ */
+static QemuSDE *get_sde_no_check(QemuSDEState *s, int32_t event, CPUState *cs)
+{
+    QemuSDE **array = s->sde_cpus[cs->cpu_index].private_sde_array;
+    int32_t sde_index = SDEI_EVENT_TO_SLOT(event);
+    QemuSDE *sde;
+
+    if (SDEI_IS_SHARED_EVENT(event)) {
+        array = s->shared_sde_array;
+        sde_index -= PRIVATE_SLOT_COUNT;
+    }
+
+    sde = array[sde_index];
+    sde_slot_lock(sde, cs);
+    return sde;
+}
+
+static void put_sde(QemuSDE *sde, CPUState *cs)
+{
+    sde_slot_unlock(sde, cs);
+}
+
+static inline bool is_sde_nested(QemuSDECpu *sde_cpu)
+{
+    return sde_cpu->critical_running_event >= 0 &&
+           sde_cpu->normal_running_event >= 0;
+}
+
+static int32_t get_running_sde(QemuSDEState *s, CPUState *cs)
+{
+    QemuSDECpu *sde_cpu = get_sde_cpu(s, cs);
+
+    if (!sde_cpu) {
+        return SDEI_INVALID_EVENT_ID;
+    }
+
+    if (sde_cpu->critical_running_event >= 0) {
+        return sde_cpu->critical_running_event;
+    }
+    return sde_cpu->normal_running_event;
+}
+
+static void override_return_value(CPUState *cs, uint64_t *args)
+{
+    CPUARMState *env = &ARM_CPU(cs)->env;
+    int i;
+
+    for (i = 0; i < SMCCC_RETURN_REG_COUNT; i++) {
+        args[i] = env->xregs[i];
+    }
+}
+
+static void sde_save_cpu_ctx(CPUState *cs, QemuSDECpu *sde_cpu, bool critical)
+{
+    CPUARMState *env = &ARM_CPU(cs)->env;
+    QemuSDECpuCtx *ctx = &sde_cpu->ctx[critical ? 1 : 0];
+
+    memcpy(ctx->xregs, env->xregs, sizeof(ctx->xregs));
+    ctx->pc = env->pc;
+    ctx->pstate = pstate_read(env);
+}
+
+static void sde_restore_cpu_ctx(QemuSDEState *s, CPUState *cs, bool critical)
+{
+    CPUARMState *env = &ARM_CPU(cs)->env;
+    QemuSDECpu *sde_cpu = get_sde_cpu(s, cs);
+    QemuSDECpuCtx *ctx;
+
+    if (!sde_cpu) {
+        return;
+    }
+
+    ctx = &sde_cpu->ctx[critical ? 1 : 0];
+
+    /*
+     * TODO: we need to optimize to only restore affected registers by calling
+     * ioctl individialy
+     */
+    kvm_arch_get_registers(cs);
+
+    env->aarch64 = ((ctx->pstate & PSTATE_nRW) == 0);
+    memcpy(env->xregs, ctx->xregs, sizeof(ctx->xregs));
+    env->pc = ctx->pc;
+    pstate_write(env, ctx->pstate);
+    aarch64_restore_sp(env, (env->pstate & PSTATE_M) >> PSTATE_M_EL_SHIFT);
+}
+
+static void sde_restore_cpu_ctx_for_resume(QemuSDEState *s,
+                                           CPUState *cs,
+                                           bool critical,
+                                           uint64_t resume_addr)
+{
+    CPUARMState *env = &ARM_CPU(cs)->env;
+    QemuSDECpu *sde_cpu = get_sde_cpu(s, cs);
+    QemuSDECpuCtx *ctx;
+
+    if (!sde_cpu) {
+        return;
+    }
+
+    ctx = &sde_cpu->ctx[critical ? 1 : 0];
+
+    /*
+     * TODO: we need to optimize to only restore affected registers by calling
+     * ioctl individialy
+     */
+    kvm_arch_get_registers(cs);
+
+    memcpy(env->xregs, ctx->xregs, sizeof(ctx->xregs));
+    env->pc = resume_addr;
+    env->aarch64 = 1;
+    /* Constructe pstate in pstate_read() */
+    env->daif = PSTATE_D | PSTATE_A | PSTATE_I | PSTATE_F;
+    /* Clear nRW/M[4] and M[3:0] */
+    env->pstate &= ~(PSTATE_nRW | PSTATE_M);
+    /* Set exception mode to EL1h */
+    env->pstate |= PSTATE_MODE_EL1h;
+    env->elr_el[1] = ctx->pc;
+    env->banked_spsr[KVM_SPSR_EL1 + 1] = ctx->pstate;
+    aarch64_restore_sp(env, 1);
+}
+
+static void sde_build_cpu_ctx(CPUState *cs, QemuSDECpu *sde_cpu, QemuSDE *sde)
+{
+    CPUARMState *env = &ARM_CPU(cs)->env;
+
+    env->xregs[0] = sde->prop->event_id;
+    env->xregs[1] = sde->ep_argument;
+    env->xregs[2] = env->pc;
+    env->xregs[3] = pstate_read(env);
+    env->pc = sde->ep_address;
+    env->aarch64 = 1;
+    /* Constructe pstate in pstate_read() */
+    env->daif = PSTATE_D | PSTATE_A | PSTATE_I | PSTATE_F;
+    /* Clear nRW/M[4] and M[3:0] */
+    env->pstate &= ~(PSTATE_nRW | PSTATE_M);
+    /* Set exception mode to EL1h */
+    env->pstate |= PSTATE_MODE_EL1h;
+    aarch64_restore_sp(env, 1);
+}
+
+static void trigger_sde(CPUState *cs, run_on_cpu_data data)
+{
+    QemuSDEState *s = sde_state;
+    QemuSDECpu *sde_cpu = get_sde_cpu(s, cs);
+    int32_t event = data.host_int;
+    QemuSDE *sde;
+
+    if (!sde_cpu) {
+        return;
+    }
+
+    if (sde_cpu->masked || sde_cpu->critical_running_event >= 0) {
+        return;
+    }
+
+    sde = get_sde_no_check(s, event, cs);
+    if (sde->event_id == SDEI_INVALID_EVENT_ID) {
+        /* Some race condition happens! */
+        put_sde(sde, cs);
+        return;
+    }
+
+    if (sde_cpu->normal_running_event >= 0 && !sde->prop->is_critical) {
+        put_sde(sde, cs);
+        return;
+    }
+
+    if (!sde->enabled || !sde->pending || sde->running) {
+        /* Some race condition happens! */
+        put_sde(sde, cs);
+        return;
+    }
+
+    sde->pending = false;
+    sde->running = true;
+
+    if (sde->prop->is_critical) {
+        sde_cpu->critical_running_event = sde->prop->event_id;
+    } else {
+        sde_cpu->normal_running_event = sde->prop->event_id;
+    }
+
+    kvm_arch_get_registers(cs);
+    sde_save_cpu_ctx(cs, sde_cpu, sde->prop->is_critical);
+    sde_build_cpu_ctx(cs, sde_cpu, sde);
+    kvm_arch_put_registers(cs, 1);
+    put_sde(sde, cs);
+}
+
+static void dispatch_single(QemuSDEState *s, QemuSDE *sde, CPUState *cs)
+{
+    int32_t event = sde->prop->event_id;
+    bool pending = sde->pending;
+    bool enabled = sde->enabled;
+    CPUState *target = sde->target_cpu;
+    put_sde(sde, cs);
+
+    if (pending && enabled) {
+        /*
+         * TODO: we need to find a free-unmasked PE to trigger for shared
+         * unpinned event
+         */
+        async_run_on_cpu(target, trigger_sde,
+                         RUN_ON_CPU_HOST_INT(event));
+    }
+}
+
+static bool sde_ready_to_trigger(QemuSDE *sde, CPUState *cs, bool is_critical)
+{
+    if (sde->event_id == SDEI_INVALID_EVENT_ID) {
+        return false;
+    }
+    if (sde->prop->is_critical != is_critical) {
+        return false;
+    }
+    if (!sde->enabled || !sde->pending || sde->running ||
+        sde->target_cpu != cs) {
+        return false;
+    }
+    return true;
+}
+
+static void dispatch_cpu(QemuSDEState *s, CPUState *cs, bool is_critical)
+{
+    QemuSDE *sde;
+    int i;
+
+    for (i = 0; i < PRIVATE_SLOT_COUNT + SHARED_SLOT_COUNT; i++) {
+        sde = get_sde_no_check(s, i, cs);
+        if (!sde_ready_to_trigger(sde, cs, is_critical)) {
+            put_sde(sde, cs);
+            continue;
+        }
+        dispatch_single(s, sde, cs);
+    }
+}
+
+static int32_t sdei_alloc_event_num(QemuSDEState *s, bool is_critical,
+                                    bool is_shared, int intid)
+{
+    int index;
+    int start = 0;
+    int count = PRIVATE_SLOT_COUNT;
+    int32_t event;
+    QemuSDEProp *sde_props = s->sde_props_state;
+
+    if (is_shared) {
+        start = PRIVATE_SLOT_COUNT;
+        count = PRIVATE_SLOT_COUNT + SHARED_SLOT_COUNT;
+    }
+
+    qemu_mutex_lock(&s->sdei_interrupt_bind_lock);
+    for (index = start; index < count; index++) {
+        qemu_mutex_lock(&sde_props[index].lock);
+        if (sde_props[index].interrupt == intid) {
+            event = sde_props[index].event_id;
+            qemu_mutex_unlock(&sde_props[index].lock);
+            qemu_mutex_unlock(&s->sdei_interrupt_bind_lock);
+            return event;
+        }
+        qemu_mutex_unlock(&sde_props[index].lock);
+    }
+
+    for (index = start; index < count; index++) {
+        qemu_mutex_lock(&sde_props[index].lock);
+        if (sde_props[index].event_id < 0) {
+            event = sde_props[index].event_id = 0x40000000 | index;
+            sde_props[index].interrupt = intid;
+            sde_props[index].is_shared = is_shared;
+            sde_props[index].is_critical = is_critical;
+            s->irq_map[intid] = event;
+            qemu_mutex_unlock(&sde_props[index].lock);
+            qemu_mutex_unlock(&s->sdei_interrupt_bind_lock);
+            return event;
+        }
+        qemu_mutex_unlock(&sde_props[index].lock);
+    }
+    qemu_mutex_unlock(&s->sdei_interrupt_bind_lock);
+    return SDEI_OUT_OF_RESOURCE;
+}
+
+static int32_t sdei_free_event_num_locked(QemuSDEState *s, QemuSDEProp *prop)
+{
+    if (atomic_read(&prop->refcount) > 0) {
+        return SDEI_DENIED;
+    }
+
+    s->irq_map[prop->interrupt] = SDEI_INVALID_EVENT_ID;
+    prop->event_id = SDEI_INVALID_EVENT_ID;
+    prop->interrupt = SDEI_INVALID_INTERRUPT;
+    return SDEI_SUCCESS;
+}
+
+typedef int64_t (*sdei_single_function)(QemuSDEState *s,
+                                        CPUState *cs,
+                                        struct kvm_run *run);
+
+static int64_t sdei_version(QemuSDEState *s, CPUState *cs, struct kvm_run *run)
+{
+    return (1ULL << SDEI_VERSION_MAJOR_SHIFT) |
+           (0ULL << SDEI_VERSION_MINOR_SHIFT);
+}
+
+static int64_t unregister_single_sde(QemuSDEState *s, int32_t event,
+                                     CPUState *cs, bool force)
+{
+    QemuSDE     *sde;
+    QemuSDEProp *prop;
+    int         ret = 0;
+
+    prop = get_sde_prop(s, event);
+    if (!prop) {
+        return SDEI_INVALID_PARAMETERS;
+    }
+
+    sde = get_sde_no_check(s, event, cs);
+    if (sde->event_id == SDEI_INVALID_EVENT_ID) {
+        put_sde(sde, cs);
+        put_sde_prop(prop);
+        return SDEI_DENIED;
+    }
+
+    if (sde->running && !force) {
+        sde->unregister_pending = true;
+        ret = SDEI_PENDING;
+    } else {
+        atomic_dec(&prop->refcount);
+        sde->event_id = SDEI_INVALID_EVENT_ID;
+        sde->enabled = false;
+        sde->running = false;
+        sde->pending = false;
+        sde->unregister_pending = false;
+    }
+    put_sde(sde, cs);
+    put_sde_prop(prop);
+    return ret;
+}
+
+static int64_t sdei_private_reset_common(QemuSDEState *s, CPUState *cs,
+                                         bool force)
+{
+    int64_t ret = SDEI_SUCCESS;
+    int i;
+
+    for (i = 0; i < PRIVATE_SLOT_COUNT; i++) {
+        int64_t ret1;
+        ret1 = unregister_single_sde(s, i, cs, force);
+        /* Ignore other return values in reset interface */
+        if (ret1 == SDEI_PENDING) {
+            ret = SDEI_DENIED;
+        }
+    }
+
+    return ret;
+}
+
+static int64_t sdei_shared_reset_common(QemuSDEState *s, CPUState *cs,
+                                        bool force)
+{
+    int             i;
+    QemuSDEProp     *prop;
+    int32_t         start_event = PRIVATE_SLOT_COUNT;
+    int64_t         ret = SDEI_SUCCESS;
+
+    for (i = start_event; i < PRIVATE_SLOT_COUNT + SHARED_SLOT_COUNT; i++) {
+        int64_t ret1 = unregister_single_sde(s, i, cs, force);
+        /* Ignore other return values in reset interface */
+        if (ret1 == SDEI_PENDING) {
+            ret = SDEI_DENIED;
+        }
+    }
+    if (ret) {
+        return ret;
+    }
+
+    qemu_mutex_lock(&s->sdei_interrupt_bind_lock);
+    for (i = 0; i < PRIVATE_SLOT_COUNT + SHARED_SLOT_COUNT; i++) {
+        prop = get_sde_prop(s, i);
+        if (!prop || prop->interrupt == SDEI_INVALID_INTERRUPT) {
+            if (prop) {
+                put_sde_prop(prop);
+            }
+            continue;
+        }
+        ret |= sdei_free_event_num_locked(s, prop);
+        put_sde_prop(prop);
+    }
+    qemu_mutex_unlock(&s->sdei_interrupt_bind_lock);
+
+    return ret ? SDEI_DENIED : SDEI_SUCCESS;
+}
+
+#define SDEI_EV_REGISTER_RM_MASK 1ULL
+
+static int64_t sdei_event_register(QemuSDEState *s, CPUState *cs,
+                                   struct kvm_run *run)
+{
+    QemuSDE *sde;
+    QemuSDEProp *prop;
+    CPUState *target = cs;
+    uint64_t *args = (uint64_t *)run->hypercall.args;
+    int32_t event = args[1];
+    uint64_t rm_mode = SDEI_EVENT_REGISTER_RM_PE;
+
+    prop = get_sde_prop(s, event);
+    if (!prop) {
+        return SDEI_INVALID_PARAMETERS;
+    }
+
+    sde = get_sde_no_check(s, event, cs);
+    if (sde->event_id != SDEI_INVALID_EVENT_ID) {
+        put_sde(sde, cs);
+        put_sde_prop(prop);
+        return SDEI_DENIED;
+    }
+
+    if (prop->is_shared) {
+        rm_mode = args[4] & SDEI_EV_REGISTER_RM_MASK;
+        if (rm_mode == SDEI_EVENT_REGISTER_RM_PE) {
+            target = arm_get_cpu_by_id(args[5]);
+            if (!target) {
+                put_sde_prop(prop);
+                return SDEI_INVALID_PARAMETERS;
+            }
+        }
+    }
+
+    sde->target_cpu = target;
+    sde->ep_address = args[2];
+    sde->ep_argument = args[3];
+    sde->prop = prop;
+    sde->routing_mode = rm_mode;
+    sde->event_id = prop->event_id;
+
+    put_sde(sde, cs);
+    atomic_inc(&prop->refcount);
+    put_sde_prop(prop);
+
+    return SDEI_SUCCESS;
+}
+
+static int64_t sdei_event_enable(QemuSDEState *s, CPUState *cs,
+                                 struct kvm_run *run)
+{
+    QemuSDE *sde;
+    uint64_t *args = (uint64_t *)(run->hypercall.args);
+    int32_t event = args[1];
+
+    if (!is_valid_event_number(event)) {
+        return SDEI_INVALID_PARAMETERS;
+    }
+    sde = get_sde_no_check(s, event, cs);
+    if (sde->event_id == SDEI_INVALID_EVENT_ID) {
+        put_sde(sde, cs);
+        return SDEI_INVALID_PARAMETERS;
+    }
+
+    sde->enabled = true;
+    dispatch_single(s, sde, cs);
+    return SDEI_SUCCESS;
+}
+
+static int64_t sdei_event_disable(QemuSDEState *s, CPUState *cs,
+                                  struct kvm_run *run)
+{
+    QemuSDE *sde;
+    uint64_t *args = (uint64_t *)run->hypercall.args;
+    int32_t event = args[1];
+
+    if (!is_valid_event_number(event)) {
+        return SDEI_INVALID_PARAMETERS;
+    }
+    sde = get_sde_no_check(s, event, cs);
+    if (sde->event_id == SDEI_INVALID_EVENT_ID) {
+        put_sde(sde, cs);
+        return SDEI_INVALID_PARAMETERS;
+    }
+
+    sde->enabled = false;
+    put_sde(sde, cs);
+    return SDEI_SUCCESS;
+}
+
+static int64_t sdei_event_context(QemuSDEState *s, CPUState *cs,
+                                  struct kvm_run *run)
+{
+    QemuSDECpu *sde_cpu = get_sde_cpu(s, cs);
+    uint64_t *args = (uint64_t *)(run->hypercall.args);
+    uint32_t param_id = args[1];
+    int critical;
+    QemuSDECpuCtx *ctx;
+
+    if (param_id >= SDEI_PARAM_MAX) {
+        return SDEI_INVALID_PARAMETERS;
+    }
+
+    if (!sde_cpu) {
+        return SDEI_DENIED;
+    }
+
+    if (sde_cpu->critical_running_event >= 0) {
+        critical = 1;
+    } else if (sde_cpu->normal_running_event >= 0) {
+        critical = 0;
+    } else {
+        return SDEI_DENIED;
+    }
+
+    ctx = &sde_cpu->ctx[critical];
+    return ctx->xregs[param_id];
+}
+
+static int64_t sdei_event_complete(QemuSDEState *s, CPUState *cs,
+                                   struct kvm_run *run)
+{
+    QemuSDE *sde;
+    QemuSDECpu *cpu = get_sde_cpu(s, cs);
+    int32_t event;
+    uint64_t *args = (uint64_t *)(run->hypercall.args);
+    bool is_critical;
+
+    if (!cpu) {
+        return SDEI_DENIED;
+    }
+
+    event = get_running_sde(s, cs);
+    if (event < 0) {
+        return SDEI_DENIED;
+    }
+
+    if (!is_valid_event_number(event)) {
+        error_report("BUG: running event number 0x%x is invalid!",
+                     event);
+        return SDEI_DENIED;
+    }
+    sde = get_sde_no_check(s, event, cs);
+    if (sde->event_id != event) {
+        error_report("BUG: sde event id 0x%x != running event 0x%x!",
+                     sde->event_id, event);
+        put_sde(sde, cs);
+        return SDEI_DENIED;
+    }
+
+    sde->running = false;
+    is_critical = sde->prop->is_critical;
+    if (sde->unregister_pending) {
+        atomic_dec(&sde->prop->refcount);
+        sde->event_id = SDEI_INVALID_EVENT_ID;
+        sde->unregister_pending = false;
+    }
+    put_sde(sde, cs);
+
+    sde_restore_cpu_ctx(s, cs, is_critical);
+
+    kvm_arch_put_registers(cs, 1);
+    override_return_value(cs, args);
+    if (cpu->critical_running_event >= 0) {
+        cpu->critical_running_event = SDEI_INVALID_EVENT_ID;
+    } else {
+        cpu->normal_running_event = SDEI_INVALID_EVENT_ID;
+    }
+
+    /* TODO: we should not queue more than one sde in work queue */
+    dispatch_cpu(s, cs, true);
+    if (cpu->critical_running_event < 0 && cpu->normal_running_event < 0) {
+        dispatch_cpu(s, cs, false);
+    }
+    return args[0];
+}
+
+static int64_t sdei_event_complete_and_resume(QemuSDEState *s, CPUState *cs,
+                                              struct kvm_run *run)
+{
+    QemuSDE *sde;
+    QemuSDECpu *cpu = get_sde_cpu(s, cs);
+    int32_t event;
+    uint64_t *args = (uint64_t *)(run->hypercall.args);
+    bool is_critical;
+    uint64_t resume_addr = args[1];
+
+    if (!cpu) {
+        return SDEI_DENIED;
+    }
+
+    event = get_running_sde(s, cs);
+    if (event < 0) {
+        return SDEI_DENIED;
+    }
+
+    if (!is_valid_event_number(event)) {
+        error_report("BUG: running event number 0x%x is invalid!",
+                     event);
+        return SDEI_DENIED;
+    }
+
+    sde = get_sde_no_check(s, event, cs);
+    if (sde->event_id != event) {
+        error_report("BUG: sde event id 0x%x != running event 0x%x!",
+                     sde->event_id, event);
+        put_sde(sde, cs);
+        return SDEI_DENIED;
+    }
+
+    sde->running = false;
+    is_critical = sde->prop->is_critical;
+
+    if (sde->unregister_pending) {
+        atomic_dec(&sde->prop->refcount);
+        sde->event_id = SDEI_INVALID_EVENT_ID;
+        sde->unregister_pending = false;
+    }
+    put_sde(sde, cs);
+
+    sde_restore_cpu_ctx_for_resume(s, cs, is_critical, resume_addr);
+    kvm_arch_put_registers(cs, 1);
+
+    override_return_value(cs, args);
+    if (cpu->critical_running_event >= 0) {
+        cpu->critical_running_event = SDEI_INVALID_EVENT_ID;
+    } else {
+        cpu->normal_running_event = SDEI_INVALID_EVENT_ID;
+    }
+
+    dispatch_cpu(s, cs, true);
+    if (cpu->critical_running_event < 0 && cpu->normal_running_event < 0) {
+        dispatch_cpu(s, cs, false);
+    }
+    return args[0];
+}
+
+static int64_t sdei_event_unregister(QemuSDEState *s, CPUState *cs,
+                                     struct kvm_run *run)
+{
+    uint64_t        *args = (uint64_t *)(run->hypercall.args);
+    int32_t         event = args[1];
+
+    return unregister_single_sde(s, event, cs, false);
+}
+
+static int64_t sdei_event_status(QemuSDEState *s, CPUState *cs,
+                                 struct kvm_run *run)
+{
+    QemuSDE *sde;
+    uint64_t *args = (uint64_t *)(run->hypercall.args);
+    int32_t event = args[1];
+    int64_t status = 0;
+
+    if (!is_valid_event(s, event)) {
+        return SDEI_INVALID_PARAMETERS;
+    }
+
+    sde = get_sde_no_check(s, event, cs);
+    if (sde->event_id == SDEI_INVALID_EVENT_ID) {
+        put_sde(sde, cs);
+        return status;
+    }
+
+    status |= SDEI_EVENT_STATUS_REGISTERED;
+    if (sde->enabled) {
+        status |= SDEI_EVENT_STATUS_ENABLED;
+    }
+    if (sde->running) {
+        status |= SDEI_EVENT_STATUS_RUNNING;
+    }
+    put_sde(sde, cs);
+    return status;
+}
+
+static int64_t sdei_event_get_info(QemuSDEState *s, CPUState *cs,
+                                   struct kvm_run *run)
+{
+    QemuSDEProp *prop;
+    QemuSDE *sde;
+    uint64_t *args = (uint64_t *)(run->hypercall.args);
+    int32_t event = args[1];
+    uint32_t info = args[2];
+    int64_t ret = SDEI_INVALID_PARAMETERS;
+
+    if (info > SDEI_EVENT_INFO_EV_ROUTING_AFF) {
+        return SDEI_INVALID_PARAMETERS;
+    }
+
+    prop = get_sde_prop(s, event);
+    if (!prop) {
+        return SDEI_INVALID_PARAMETERS;
+    }
+
+    switch (info) {
+    case SDEI_EVENT_INFO_EV_TYPE:
+        ret = prop->is_shared;
+        break;
+    case SDEI_EVENT_INFO_EV_SIGNALED:
+        ret = (event == SDEI_STD_EVT_SOFTWARE_SIGNAL) ? 1 : 0;
+        break;
+    case SDEI_EVENT_INFO_EV_PRIORITY:
+        ret = prop->is_critical;
+        break;
+    case SDEI_EVENT_INFO_EV_ROUTING_MODE:
+    case SDEI_EVENT_INFO_EV_ROUTING_AFF:
+        if (!prop->is_shared) {
+            break;
+        }
+        sde = get_sde_no_check(s, event, cs);
+        if (sde->event_id == SDEI_INVALID_EVENT_ID) {
+            put_sde(sde, cs);
+            ret = SDEI_DENIED;
+            break;
+        }
+        if (info == SDEI_EVENT_INFO_EV_ROUTING_MODE) {
+            ret = sde->routing_mode;
+        } else if (sde->routing_mode == SDEI_EVENT_REGISTER_RM_PE) {
+            ret = ARM_CPU(sde->target_cpu)->mp_affinity;
+        }
+        put_sde(sde, cs);
+        break;
+    default:
+        ret = SDEI_NOT_SUPPORTED;
+    }
+    put_sde_prop(prop);
+    return ret;
+}
+
+static int64_t sdei_event_routing_set(QemuSDEState *s, CPUState *cs,
+                                      struct kvm_run *run)
+{
+    QemuSDE *sde;
+    CPUState *target = cs;
+    uint64_t *args = (uint64_t *)run->hypercall.args;
+    int32_t event = args[1];
+    uint64_t mode = args[2];
+    uint64_t affinity = args[3];
+
+    if (mode & ~1ULL) {
+        return SDEI_INVALID_PARAMETERS;
+    }
+    if (mode == SDEI_EVENT_REGISTER_RM_PE) {
+        target = arm_get_cpu_by_id(affinity);
+        if (!target) {
+            return SDEI_INVALID_PARAMETERS;
+        }
+    }
+
+    if (!is_valid_event(s, event) || !SDEI_IS_SHARED_EVENT(event)) {
+        return SDEI_INVALID_PARAMETERS;
+    }
+
+    sde = get_sde_no_check(s, event, cs);
+    if (sde->event_id == SDEI_INVALID_EVENT_ID) {
+        put_sde(sde, cs);
+        return SDEI_DENIED;
+    }
+    if (sde->enabled || sde->running ||
+        sde->pending || sde->unregister_pending) {
+        put_sde(sde, cs);
+        return SDEI_DENIED;
+    }
+
+    sde->target_cpu = target;
+    sde->routing_mode = mode;
+    put_sde(sde, cs);
+
+    return SDEI_SUCCESS;
+}
+
+static int64_t sdei_event_pe_mask(QemuSDEState *s, CPUState *cs,
+                                  struct kvm_run *run)
+{
+    QemuSDECpu *sde_cpu;
+
+    sde_cpu = get_sde_cpu(s, cs);
+    if (!sde_cpu) {
+        return SDEI_DENIED;
+    }
+
+    if (sde_cpu->masked) {
+        return 0;
+    }
+    sde_cpu->masked = true;
+    return 1;
+}
+
+static int64_t sdei_event_pe_unmask(QemuSDEState *s, CPUState *cs,
+                                    struct kvm_run *run)
+{
+    QemuSDECpu *sde_cpu;
+
+    sde_cpu = get_sde_cpu(s, cs);
+    if (!sde_cpu) {
+        return SDEI_DENIED;
+    }
+
+    sde_cpu->masked = false;
+    dispatch_cpu(s, cs, true);
+    dispatch_cpu(s, cs, false);
+    return SDEI_SUCCESS;
+}
+
+static int64_t sdei_event_interrupt_bind(QemuSDEState *s, CPUState *cs,
+                                         struct kvm_run *run)
+{
+    uint64_t *args = (uint64_t *)(run->hypercall.args);
+    uint32_t intid = args[1];
+
+    if (intid < GIC_NR_SGIS || intid >= GIC_MAXIRQ) {
+        return SDEI_INVALID_PARAMETERS;
+    }
+    return sdei_alloc_event_num(s, false, intid >= GIC_INTERNAL, intid);
+}
+
+static int64_t sdei_event_interrupt_release(QemuSDEState *s, CPUState *cs,
+                                            struct kvm_run *run)
+{
+    QemuSDEProp *prop;
+    uint64_t *args = (uint64_t *)(run->hypercall.args);
+    int32_t event = args[1];
+    int32_t ret;
+
+    qemu_mutex_lock(&s->sdei_interrupt_bind_lock);
+    prop = get_sde_prop(s, event);
+    if (!prop) {
+        qemu_mutex_unlock(&s->sdei_interrupt_bind_lock);
+        return SDEI_INVALID_PARAMETERS;
+    }
+
+    ret = sdei_free_event_num_locked(s, prop);
+    put_sde_prop(prop);
+    qemu_mutex_unlock(&s->sdei_interrupt_bind_lock);
+    return ret;
+}
+
+static int64_t sdei_event_signal(QemuSDEState *s, CPUState *cs,
+                                 struct kvm_run *run)
+{
+    QemuSDE *sde;
+    CPUState *target_cpu;
+    uint64_t *args = (uint64_t *)(run->hypercall.args);
+    int32_t event = args[1];
+
+    if (event != SDEI_STD_EVT_SOFTWARE_SIGNAL) {
+        return SDEI_INVALID_PARAMETERS;
+    }
+
+    target_cpu = arm_get_cpu_by_id(args[2]);
+    if (!target_cpu) {
+        return SDEI_INVALID_PARAMETERS;
+    }
+
+    sde = get_sde_no_check(s, event, target_cpu);
+    if (sde->event_id == SDEI_INVALID_EVENT_ID) {
+        put_sde(sde, cs);
+        return SDEI_INVALID_PARAMETERS;
+    }
+
+    sde->pending = true;
+    dispatch_single(s, sde, target_cpu);
+    return SDEI_SUCCESS;
+}
+
+#define SDEI_FEATURES_SHARED_SLOTS_SHIFT 16
+static int64_t sdei_features(QemuSDEState *s, CPUState *cs, struct kvm_run 
*run)
+{
+    uint64_t *args = (uint64_t *)(run->hypercall.args);
+    uint32_t feature = args[1];
+
+    switch (feature) {
+    case SDEI_FEATURE_BIND_SLOTS:
+        return ((SHARED_SLOT_COUNT - PLAT_SHARED_SLOT_COUNT) <<
+                 SDEI_FEATURES_SHARED_SLOTS_SHIFT) |
+               (PRIVATE_SLOT_COUNT - PLAT_PRIVATE_SLOT_COUNT);
+    default:
+        return SDEI_INVALID_PARAMETERS;
+    }
+}
+
+static int64_t sdei_private_reset(QemuSDEState *s, CPUState *cs,
+                                  struct kvm_run *run)
+{
+    return sdei_private_reset_common(s, cs, false);
+}
+
+static int64_t sdei_shared_reset(QemuSDEState *s, CPUState *cs,
+                                 struct kvm_run *run)
+{
+    return sdei_shared_reset_common(s, cs, false);
+}
+
+static sdei_single_function sdei_functions[] = {
+    sdei_version,
+    sdei_event_register,
+    sdei_event_enable,
+    sdei_event_disable,
+    sdei_event_context,
+    sdei_event_complete,
+    sdei_event_complete_and_resume,
+    sdei_event_unregister,
+    sdei_event_status,
+    sdei_event_get_info,
+    sdei_event_routing_set,
+    sdei_event_pe_mask,
+    sdei_event_pe_unmask,
+    sdei_event_interrupt_bind,
+    sdei_event_interrupt_release,
+    sdei_event_signal,
+    sdei_features,
+    sdei_private_reset,
+    sdei_shared_reset,
+};
+
+void sdei_handle_request(CPUState *cs, struct kvm_run *run)
+{
+    uint32_t func_id = run->hypercall.args[0];
+
+    if (!sde_state) {
+        run->hypercall.args[0] = SDEI_NOT_SUPPORTED;
+        return;
+    }
+
+    if (func_id < SDEI_1_0_FN_BASE || func_id > SDEI_MAX_REQ) {
+        error_report("Invalid SDEI function ID: 0x%x", func_id);
+        run->hypercall.args[0] = SDEI_INVALID_PARAMETERS;
+        return;
+    }
+
+    func_id -= SDEI_1_0_FN_BASE;
+    if (func_id < ARRAY_SIZE(sdei_functions) && sdei_functions[func_id]) {
+        run->hypercall.args[0] = sdei_functions[func_id](sde_state, cs, run);
+    } else {
+        run->hypercall.args[0] = SDEI_NOT_SUPPORTED;
+    }
+}
+
 static void sde_array_init(QemuSDE **array, int count)
 {
     int i;
diff --git a/target/arm/sdei.h b/target/arm/sdei.h
new file mode 100644
index 0000000000..828f70bbf1
--- /dev/null
+++ b/target/arm/sdei.h
@@ -0,0 +1,34 @@
+/*
+ * ARM SDEI emulation external interfaces
+ *
+ * Copyright (c) Huawei Technologies Co., Ltd. 2019. All rights reserved.
+ *
+ * Authors:
+ *    Heyi Guo <address@hidden>
+ *    Jingyi Wang <address@hidden>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef QEMU_SDEI_H
+#define QEMU_SDEI_H
+
+#include <linux/kvm.h>
+#include <linux/arm_sdei.h>
+#include "hw/core/cpu.h"
+
+#define SDEI_MAX_REQ        SDEI_1_0_FN(0x12)
+
+void sdei_handle_request(CPUState *cs, struct kvm_run *run);
+
+#endif
-- 
2.19.1