Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 679 insertions, 0 deletions

diff --git a/hw/intc/s390_flic_kvm.c b/hw/intc/s390_flic_kvm.c
new file mode 100644
index 000000000..efe505418
--- /dev/null
+++ b/hw/intc/s390_flic_kvm.c
@@ -0,0 +1,679 @@
+/*
+ * QEMU S390x KVM floating interrupt controller (flic)
+ *
+ * Copyright 2014 IBM Corp.
+ * Author(s): Jens Freimann <jfrei@linux.vnet.ibm.com>
+ *            Cornelia Huck <cornelia.huck@de.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#include "qemu/osdep.h"
+#include "kvm/kvm_s390x.h"
+#include <sys/ioctl.h>
+#include "qemu/error-report.h"
+#include "qemu/module.h"
+#include "qapi/error.h"
+#include "sysemu/kvm.h"
+#include "hw/s390x/s390_flic.h"
+#include "hw/s390x/adapter.h"
+#include "hw/s390x/css.h"
+#include "migration/qemu-file-types.h"
+#include "trace.h"
+#include "qom/object.h"
+
+#define FLIC_SAVE_INITIAL_SIZE qemu_real_host_page_size
+#define FLIC_FAILED (-1UL)
+#define FLIC_SAVEVM_VERSION 1
+
+struct KVMS390FLICState{
+    S390FLICState parent_obj;
+
+    uint32_t fd;
+    bool clear_io_supported;
+};
+
+static KVMS390FLICState *s390_get_kvm_flic(S390FLICState *fs)
+{
+    static KVMS390FLICState *flic;
+
+    if (!flic) {
+        /* we only have one flic device, so this is fine to cache */
+        flic = KVM_S390_FLIC(fs);
+    }
+    return flic;
+}
+
+/**
+ * flic_get_all_irqs - store all pending irqs in buffer
+ * @buf: pointer to buffer which is passed to kernel
+ * @len: length of buffer
+ * @flic: pointer to flic device state
+ *
+ * Returns: -ENOMEM if buffer is too small,
+ * -EINVAL if attr.group is invalid,
+ * -EFAULT if copying to userspace failed,
+ * on success return number of stored interrupts
+ */
+static int flic_get_all_irqs(KVMS390FLICState *flic,
+                             void *buf, int len)
+{
+    struct kvm_device_attr attr = {
+        .group = KVM_DEV_FLIC_GET_ALL_IRQS,
+        .addr = (uint64_t) buf,
+        .attr = len,
+    };
+    int rc;
+
+    rc = ioctl(flic->fd, KVM_GET_DEVICE_ATTR, &attr);
+
+    return rc == -1 ? -errno : rc;
+}
+
+static void flic_enable_pfault(KVMS390FLICState *flic)
+{
+    struct kvm_device_attr attr = {
+        .group = KVM_DEV_FLIC_APF_ENABLE,
+    };
+    int rc;
+
+    rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
+
+    if (rc) {
+        fprintf(stderr, "flic: couldn't enable pfault\n");
+    }
+}
+
+static void flic_disable_wait_pfault(KVMS390FLICState *flic)
+{
+    struct kvm_device_attr attr = {
+        .group = KVM_DEV_FLIC_APF_DISABLE_WAIT,
+    };
+    int rc;
+
+    rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
+
+    if (rc) {
+        fprintf(stderr, "flic: couldn't disable pfault\n");
+    }
+}
+
+/** flic_enqueue_irqs - returns 0 on success
+ * @buf: pointer to buffer which is passed to kernel
+ * @len: length of buffer
+ * @flic: pointer to flic device state
+ *
+ * Returns: -EINVAL if attr.group is unknown
+ */
+static int flic_enqueue_irqs(void *buf, uint64_t len,
+                            KVMS390FLICState *flic)
+{
+    int rc;
+    struct kvm_device_attr attr = {
+        .group = KVM_DEV_FLIC_ENQUEUE,
+        .addr = (uint64_t) buf,
+        .attr = len,
+    };
+
+    rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
+
+    return rc ? -errno : 0;
+}
+
+static void kvm_s390_inject_flic(S390FLICState *fs, struct kvm_s390_irq *irq)
+{
+    static bool use_flic = true;
+    int r;
+
+    if (use_flic) {
+        r = flic_enqueue_irqs(irq, sizeof(*irq), s390_get_kvm_flic(fs));
+        if (r == -ENOSYS) {
+            use_flic = false;
+        }
+        if (!r) {
+            return;
+        }
+    }
+    /* fallback to legacy KVM IOCTL in case FLIC fails */
+    kvm_s390_floating_interrupt_legacy(irq);
+}
+
+static void kvm_s390_inject_service(S390FLICState *fs, uint32_t parm)
+{
+        struct kvm_s390_irq irq = {
+        .type = KVM_S390_INT_SERVICE,
+        .u.ext.ext_params = parm,
+    };
+
+    kvm_s390_inject_flic(fs, &irq);
+}
+
+static void kvm_s390_inject_io(S390FLICState *fs, uint16_t subchannel_id,
+                               uint16_t subchannel_nr, uint32_t io_int_parm,
+                               uint32_t io_int_word)
+{
+    struct kvm_s390_irq irq = {
+        .u.io.subchannel_id = subchannel_id,
+        .u.io.subchannel_nr = subchannel_nr,
+        .u.io.io_int_parm = io_int_parm,
+        .u.io.io_int_word = io_int_word,
+    };
+
+    if (io_int_word & IO_INT_WORD_AI) {
+        irq.type = KVM_S390_INT_IO(1, 0, 0, 0);
+    } else {
+        irq.type = KVM_S390_INT_IO(0, (subchannel_id & 0xff00) >> 8,
+                                      (subchannel_id & 0x0006),
+                                      subchannel_nr);
+    }
+    kvm_s390_inject_flic(fs, &irq);
+}
+
+static void kvm_s390_inject_crw_mchk(S390FLICState *fs)
+{
+    struct kvm_s390_irq irq = {
+        .type = KVM_S390_MCHK,
+        .u.mchk.cr14 = CR14_CHANNEL_REPORT_SC,
+        .u.mchk.mcic = s390_build_validity_mcic() | MCIC_SC_CP,
+    };
+
+    kvm_s390_inject_flic(fs, &irq);
+}
+
+static int kvm_s390_clear_io_flic(S390FLICState *fs, uint16_t subchannel_id,
+                           uint16_t subchannel_nr)
+{
+    KVMS390FLICState *flic = s390_get_kvm_flic(fs);
+    int rc;
+    uint32_t sid = subchannel_id << 16 | subchannel_nr;
+    struct kvm_device_attr attr = {
+        .group = KVM_DEV_FLIC_CLEAR_IO_IRQ,
+        .addr = (uint64_t) &sid,
+        .attr = sizeof(sid),
+    };
+    if (unlikely(!flic->clear_io_supported)) {
+        return -ENOSYS;
+    }
+    rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
+    return rc ? -errno : 0;
+}
+
+static int kvm_s390_modify_ais_mode(S390FLICState *fs, uint8_t isc,
+                                    uint16_t mode)
+{
+    KVMS390FLICState *flic = s390_get_kvm_flic(fs);
+    struct kvm_s390_ais_req req = {
+        .isc = isc,
+        .mode = mode,
+    };
+    struct kvm_device_attr attr = {
+        .group = KVM_DEV_FLIC_AISM,
+        .addr = (uint64_t)&req,
+    };
+
+    if (!fs->ais_supported) {
+        return -ENOSYS;
+    }
+
+    return ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr) ? -errno : 0;
+}
+
+static int kvm_s390_inject_airq(S390FLICState *fs, uint8_t type,
+                                uint8_t isc, uint8_t flags)
+{
+    KVMS390FLICState *flic = s390_get_kvm_flic(fs);
+    uint32_t id = css_get_adapter_id(type, isc);
+    struct kvm_device_attr attr = {
+        .group = KVM_DEV_FLIC_AIRQ_INJECT,
+        .attr = id,
+    };
+
+    if (!fs->ais_supported) {
+        return -ENOSYS;
+    }
+
+    return ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr) ? -errno : 0;
+}
+
+/**
+ * __get_all_irqs - store all pending irqs in buffer
+ * @flic: pointer to flic device state
+ * @buf: pointer to pointer to a buffer
+ * @len: length of buffer
+ *
+ * Returns: return value of flic_get_all_irqs
+ * Note: Retry and increase buffer size until flic_get_all_irqs
+ * either returns a value >= 0 or a negative error code.
+ * -ENOMEM is an exception, which means the buffer is too small
+ * and we should try again. Other negative error codes can be
+ * -EFAULT and -EINVAL which we ignore at this point
+ */
+static int __get_all_irqs(KVMS390FLICState *flic,
+                          void **buf, int len)
+{
+    int r;
+
+    do {
+        /* returns -ENOMEM if buffer is too small and number
+         * of queued interrupts on success */
+        r = flic_get_all_irqs(flic, *buf, len);
+        if (r >= 0) {
+            break;
+        }
+        len *= 2;
+        *buf = g_try_realloc(*buf, len);
+        if (!buf) {
+            return -ENOMEM;
+        }
+    } while (r == -ENOMEM && len <= KVM_S390_FLIC_MAX_BUFFER);
+
+    return r;
+}
+
+static int kvm_s390_register_io_adapter(S390FLICState *fs, uint32_t id,
+                                        uint8_t isc, bool swap,
+                                        bool is_maskable, uint8_t flags)
+{
+    struct kvm_s390_io_adapter adapter = {
+        .id = id,
+        .isc = isc,
+        .maskable = is_maskable,
+        .swap = swap,
+        .flags = flags,
+    };
+    KVMS390FLICState *flic = KVM_S390_FLIC(fs);
+    int r;
+    struct kvm_device_attr attr = {
+        .group = KVM_DEV_FLIC_ADAPTER_REGISTER,
+        .addr = (uint64_t)&adapter,
+    };
+
+    if (!kvm_gsi_routing_enabled()) {
+        /* nothing to do */
+        return 0;
+    }
+
+    r = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
+
+    return r ? -errno : 0;
+}
+
+static int kvm_s390_io_adapter_map(S390FLICState *fs, uint32_t id,
+                                   uint64_t map_addr, bool do_map)
+{
+    struct kvm_s390_io_adapter_req req = {
+        .id = id,
+        .type = do_map ? KVM_S390_IO_ADAPTER_MAP : KVM_S390_IO_ADAPTER_UNMAP,
+        .addr = map_addr,
+    };
+    struct kvm_device_attr attr = {
+        .group = KVM_DEV_FLIC_ADAPTER_MODIFY,
+        .addr = (uint64_t)&req,
+    };
+    KVMS390FLICState *flic = s390_get_kvm_flic(fs);
+    int r;
+
+    if (!kvm_gsi_routing_enabled()) {
+        /* nothing to do */
+        return 0;
+    }
+
+    r = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
+    return r ? -errno : 0;
+}
+
+static int kvm_s390_add_adapter_routes(S390FLICState *fs,
+                                       AdapterRoutes *routes)
+{
+    int ret, i;
+    uint64_t ind_offset = routes->adapter.ind_offset;
+
+    if (!kvm_gsi_routing_enabled()) {
+        return -ENOSYS;
+    }
+
+    for (i = 0; i < routes->num_routes; i++) {
+        ret = kvm_irqchip_add_adapter_route(kvm_state, &routes->adapter);
+        if (ret < 0) {
+            goto out_undo;
+        }
+        routes->gsi[i] = ret;
+        routes->adapter.ind_offset++;
+    }
+    kvm_irqchip_commit_routes(kvm_state);
+
+    /* Restore passed-in structure to original state. */
+    routes->adapter.ind_offset = ind_offset;
+    return 0;
+out_undo:
+    while (--i >= 0) {
+        kvm_irqchip_release_virq(kvm_state, routes->gsi[i]);
+        routes->gsi[i] = -1;
+    }
+    routes->adapter.ind_offset = ind_offset;
+    return ret;
+}
+
+static void kvm_s390_release_adapter_routes(S390FLICState *fs,
+                                            AdapterRoutes *routes)
+{
+    int i;
+
+    if (!kvm_gsi_routing_enabled()) {
+        return;
+    }
+
+    for (i = 0; i < routes->num_routes; i++) {
+        if (routes->gsi[i] >= 0) {
+            kvm_irqchip_release_virq(kvm_state, routes->gsi[i]);
+            routes->gsi[i] = -1;
+        }
+    }
+}
+
+/**
+ * kvm_flic_save - Save pending floating interrupts
+ * @f: QEMUFile containing migration state
+ * @opaque: pointer to flic device state
+ * @size: ignored
+ *
+ * Note: Pass buf and len to kernel. Start with one page and
+ * increase until buffer is sufficient or maxium size is
+ * reached
+ */
+static int kvm_flic_save(QEMUFile *f, void *opaque, size_t size,
+                         const VMStateField *field, JSONWriter *vmdesc)
+{
+    KVMS390FLICState *flic = opaque;
+    int len = FLIC_SAVE_INITIAL_SIZE;
+    void *buf;
+    int count;
+    int r = 0;
+
+    flic_disable_wait_pfault((struct KVMS390FLICState *) opaque);
+
+    buf = g_try_malloc0(len);
+    if (!buf) {
+        /* Storing FLIC_FAILED into the count field here will cause the
+         * target system to fail when attempting to load irqs from the
+         * migration state */
+        error_report("flic: couldn't allocate memory");
+        qemu_put_be64(f, FLIC_FAILED);
+        return -ENOMEM;
+    }
+
+    count = __get_all_irqs(flic, &buf, len);
+    if (count < 0) {
+        error_report("flic: couldn't retrieve irqs from kernel, rc %d",
+                     count);
+        /* Storing FLIC_FAILED into the count field here will cause the
+         * target system to fail when attempting to load irqs from the
+         * migration state */
+        qemu_put_be64(f, FLIC_FAILED);
+        r = count;
+    } else {
+        qemu_put_be64(f, count);
+        qemu_put_buffer(f, (uint8_t *) buf,
+                        count * sizeof(struct kvm_s390_irq));
+    }
+    g_free(buf);
+
+    return r;
+}
+
+/**
+ * kvm_flic_load - Load pending floating interrupts
+ * @f: QEMUFile containing migration state
+ * @opaque: pointer to flic device state
+ * @size: ignored
+ *
+ * Returns: value of flic_enqueue_irqs, -EINVAL on error
+ * Note: Do nothing when no interrupts where stored
+ * in QEMUFile
+ */
+static int kvm_flic_load(QEMUFile *f, void *opaque, size_t size,
+                         const VMStateField *field)
+{
+    uint64_t len = 0;
+    uint64_t count = 0;
+    void *buf = NULL;
+    int r = 0;
+
+    flic_enable_pfault((struct KVMS390FLICState *) opaque);
+
+    count = qemu_get_be64(f);
+    len = count * sizeof(struct kvm_s390_irq);
+    if (count == FLIC_FAILED) {
+        return -EINVAL;
+    }
+    if (count == 0) {
+        return 0;
+    }
+    buf = g_try_malloc0(len);
+    if (!buf) {
+        return -ENOMEM;
+    }
+
+    if (qemu_get_buffer(f, (uint8_t *) buf, len) != len) {
+        r = -EINVAL;
+        goto out_free;
+    }
+    r = flic_enqueue_irqs(buf, len, (struct KVMS390FLICState *) opaque);
+
+out_free:
+    g_free(buf);
+    return r;
+}
+
+typedef struct KVMS390FLICStateMigTmp {
+    KVMS390FLICState *parent;
+    uint8_t simm;
+    uint8_t nimm;
+} KVMS390FLICStateMigTmp;
+
+static int kvm_flic_ais_pre_save(void *opaque)
+{
+    KVMS390FLICStateMigTmp *tmp = opaque;
+    KVMS390FLICState *flic = tmp->parent;
+    struct kvm_s390_ais_all ais;
+    struct kvm_device_attr attr = {
+        .group = KVM_DEV_FLIC_AISM_ALL,
+        .addr = (uint64_t)&ais,
+        .attr = sizeof(ais),
+    };
+
+    if (ioctl(flic->fd, KVM_GET_DEVICE_ATTR, &attr)) {
+        error_report("Failed to retrieve kvm flic ais states");
+        return -EINVAL;
+    }
+
+    tmp->simm = ais.simm;
+    tmp->nimm = ais.nimm;
+
+    return 0;
+}
+
+static int kvm_flic_ais_post_load(void *opaque, int version_id)
+{
+    KVMS390FLICStateMigTmp *tmp = opaque;
+    KVMS390FLICState *flic = tmp->parent;
+    struct kvm_s390_ais_all ais = {
+        .simm = tmp->simm,
+        .nimm = tmp->nimm,
+    };
+    struct kvm_device_attr attr = {
+        .group = KVM_DEV_FLIC_AISM_ALL,
+        .addr = (uint64_t)&ais,
+    };
+
+    /* This can happen when the user mis-configures its guests in an
+     * incompatible fashion or without a CPU model. For example using
+     * qemu with -cpu host (which is not migration safe) and do a
+     * migration from a host that has AIS to a host that has no AIS.
+     * In that case the target system will reject the migration here.
+     */
+    if (!ais_needed(flic)) {
+        return -ENOSYS;
+    }
+
+    return ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr) ? -errno : 0;
+}
+
+static const VMStateDescription kvm_s390_flic_ais_tmp = {
+    .name = "s390-flic-ais-tmp",
+    .pre_save = kvm_flic_ais_pre_save,
+    .post_load = kvm_flic_ais_post_load,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(simm, KVMS390FLICStateMigTmp),
+        VMSTATE_UINT8(nimm, KVMS390FLICStateMigTmp),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription kvm_s390_flic_vmstate_ais = {
+    .name = "s390-flic/ais",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = ais_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_WITH_TMP(KVMS390FLICState, KVMS390FLICStateMigTmp,
+                         kvm_s390_flic_ais_tmp),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription kvm_s390_flic_vmstate = {
+    /* should have been like kvm-s390-flic,
+     * can't change without breaking compat */
+    .name = "s390-flic",
+    .version_id = FLIC_SAVEVM_VERSION,
+    .minimum_version_id = FLIC_SAVEVM_VERSION,
+    .fields = (VMStateField[]) {
+        {
+            .name = "irqs",
+            .info = &(const VMStateInfo) {
+                .name = "irqs",
+                .get = kvm_flic_load,
+                .put = kvm_flic_save,
+            },
+            .flags = VMS_SINGLE,
+        },
+        VMSTATE_END_OF_LIST()
+    },
+    .subsections = (const VMStateDescription * []) {
+        &kvm_s390_flic_vmstate_ais,
+        NULL
+    }
+};
+
+struct KVMS390FLICStateClass {
+    S390FLICStateClass parent_class;
+    DeviceRealize parent_realize;
+};
+typedef struct KVMS390FLICStateClass KVMS390FLICStateClass;
+
+DECLARE_CLASS_CHECKERS(KVMS390FLICStateClass, KVM_S390_FLIC,
+                       TYPE_KVM_S390_FLIC)
+
+
+static void kvm_s390_flic_realize(DeviceState *dev, Error **errp)
+{
+    KVMS390FLICState *flic_state = KVM_S390_FLIC(dev);
+    struct kvm_create_device cd = {0};
+    struct kvm_device_attr test_attr = {0};
+    int ret;
+    Error *err = NULL;
+
+    KVM_S390_FLIC_GET_CLASS(dev)->parent_realize(dev, &err);
+    if (err) {
+        error_propagate(errp, err);
+        return;
+    }
+    flic_state->fd = -1;
+
+    cd.type = KVM_DEV_TYPE_FLIC;
+    ret = kvm_vm_ioctl(kvm_state, KVM_CREATE_DEVICE, &cd);
+    if (ret < 0) {
+        error_setg_errno(errp, errno, "Creating the KVM device failed");
+        trace_flic_create_device(errno);
+        return;
+    }
+    flic_state->fd = cd.fd;
+
+    /* Check clear_io_irq support */
+    test_attr.group = KVM_DEV_FLIC_CLEAR_IO_IRQ;
+    flic_state->clear_io_supported = !ioctl(flic_state->fd,
+                                            KVM_HAS_DEVICE_ATTR, test_attr);
+}
+
+static void kvm_s390_flic_reset(DeviceState *dev)
+{
+    KVMS390FLICState *flic = KVM_S390_FLIC(dev);
+    S390FLICState *fs = S390_FLIC_COMMON(dev);
+    struct kvm_device_attr attr = {
+        .group = KVM_DEV_FLIC_CLEAR_IRQS,
+    };
+    int rc = 0;
+    uint8_t isc;
+
+    if (flic->fd == -1) {
+        return;
+    }
+
+    flic_disable_wait_pfault(flic);
+
+    if (fs->ais_supported) {
+        for (isc = 0; isc <= MAX_ISC; isc++) {
+            rc = kvm_s390_modify_ais_mode(fs, isc, SIC_IRQ_MODE_ALL);
+            if (rc) {
+                error_report("Failed to reset ais mode for isc %d: %s",
+                             isc, strerror(-rc));
+            }
+        }
+    }
+
+    rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
+    if (rc) {
+        trace_flic_reset_failed(errno);
+    }
+
+    flic_enable_pfault(flic);
+}
+
+static void kvm_s390_flic_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+    S390FLICStateClass *fsc = S390_FLIC_COMMON_CLASS(oc);
+
+    KVM_S390_FLIC_CLASS(oc)->parent_realize = dc->realize;
+    dc->realize = kvm_s390_flic_realize;
+    dc->vmsd = &kvm_s390_flic_vmstate;
+    dc->reset = kvm_s390_flic_reset;
+    fsc->register_io_adapter = kvm_s390_register_io_adapter;
+    fsc->io_adapter_map = kvm_s390_io_adapter_map;
+    fsc->add_adapter_routes = kvm_s390_add_adapter_routes;
+    fsc->release_adapter_routes = kvm_s390_release_adapter_routes;
+    fsc->clear_io_irq = kvm_s390_clear_io_flic;
+    fsc->modify_ais_mode = kvm_s390_modify_ais_mode;
+    fsc->inject_airq = kvm_s390_inject_airq;
+    fsc->inject_service = kvm_s390_inject_service;
+    fsc->inject_io = kvm_s390_inject_io;
+    fsc->inject_crw_mchk = kvm_s390_inject_crw_mchk;
+}
+
+static const TypeInfo kvm_s390_flic_info = {
+    .name          = TYPE_KVM_S390_FLIC,
+    .parent        = TYPE_S390_FLIC_COMMON,
+    .instance_size = sizeof(KVMS390FLICState),
+    .class_size    = sizeof(KVMS390FLICStateClass),
+    .class_init    = kvm_s390_flic_class_init,
+};
+
+static void kvm_s390_flic_register_types(void)
+{
+    type_register_static(&kvm_s390_flic_info);
+}
+
+type_init(kvm_s390_flic_register_types)