[Qemu-devel] [PULL v2 0/3] Initial vfio-platform support

[Qemu-devel] [PULL v2 0/3] Initial vfio-platform support

[Alex Williamson]

The following changes since commit 2e29dd7c44db30e3d3c108ab2a622cbdac6d16f0:

  Merge remote-tracking branch 'remotes/jnsnow/tags/ide-pull-request' into staging (2015-06-08 14:07:32 +0100)

are available in the git repository at:


  git://github.com/awilliam/qemu-vfio.git tags/vfio-update-20150609.0

for you to fetch changes up to 7a8d15d7702444be715b6ae32574659483c0c158:

  hw/vfio/platform: calxeda xgmac device (2015-06-09 08:17:17 -0600)

----------------------------------------------------------------
Initial VFIO platform device support, v2 (Eric Auger, et al.)

----------------------------------------------------------------
Eric Auger (3):
      hw/vfio/platform: vfio-platform skeleton
      hw/vfio/platform: add irq assignment
      hw/vfio/platform: calxeda xgmac device

 hw/vfio/Makefile.objs                |   2 +
 hw/vfio/calxeda-xgmac.c              |  55 ++++
 hw/vfio/platform.c                   | 616 +++++++++++++++++++++++++++++++++++
 include/hw/vfio/vfio-calxeda-xgmac.h |  46 +++
 include/hw/vfio/vfio-common.h        |   1 +
 include/hw/vfio/vfio-platform.h      |  75 +++++
 trace-events                         |  12 +
 7 files changed, 807 insertions(+)
 create mode 100644 hw/vfio/calxeda-xgmac.c
 create mode 100644 hw/vfio/platform.c
 create mode 100644 include/hw/vfio/vfio-calxeda-xgmac.h
 create mode 100644 include/hw/vfio/vfio-platform.h

[Qemu-devel] [PULL v2 1/3] hw/vfio/platform: vfio-platform skeleton

[Alex Williamson]

From: Eric Auger <eric.auger@linaro.org>

Minimal VFIO platform implementation supporting register space
user mapping but not IRQ assignment.

Signed-off-by: Kim Phillips <kim.phillips@linaro.org>
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Vikram Sethi <vikrams@codeaurora.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 hw/vfio/Makefile.objs           |    1 
 hw/vfio/platform.c              |  287 +++++++++++++++++++++++++++++++++++++++
 include/hw/vfio/vfio-common.h   |    1 
 include/hw/vfio/vfio-platform.h |   44 ++++++
 trace-events                    |    5 +
 5 files changed, 338 insertions(+)
 create mode 100644 hw/vfio/platform.c
 create mode 100644 include/hw/vfio/vfio-platform.h

diff --git a/hw/vfio/Makefile.objs b/hw/vfio/Makefile.objs
index e31f30e..c5c76fe 100644
--- a/hw/vfio/Makefile.objs
+++ b/hw/vfio/Makefile.objs
@@ -1,4 +1,5 @@
 ifeq ($(CONFIG_LINUX), y)
 obj-$(CONFIG_SOFTMMU) += common.o
 obj-$(CONFIG_PCI) += pci.o
+obj-$(CONFIG_SOFTMMU) += platform.o
 endif
diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
new file mode 100644
index 0000000..569a675
--- /dev/null
+++ b/hw/vfio/platform.c
@@ -0,0 +1,287 @@
+/*
+ * vfio based device assignment support - platform devices
+ *
+ * Copyright Linaro Limited, 2014
+ *
+ * Authors:
+ *  Kim Phillips <kim.phillips@linaro.org>
+ *  Eric Auger <eric.auger@linaro.org>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ * Based on vfio based PCI device assignment support:
+ *  Copyright Red Hat, Inc. 2012
+ */
+
+#include <linux/vfio.h>
+#include <sys/ioctl.h>
+
+#include "hw/vfio/vfio-platform.h"
+#include "qemu/error-report.h"
+#include "qemu/range.h"
+#include "sysemu/sysemu.h"
+#include "exec/memory.h"
+#include "hw/sysbus.h"
+#include "trace.h"
+#include "hw/platform-bus.h"
+
+/* VFIO skeleton */
+
+static void vfio_platform_compute_needs_reset(VFIODevice *vbasedev)
+{
+    vbasedev->needs_reset = true;
+}
+
+/* not implemented yet */
+static int vfio_platform_hot_reset_multi(VFIODevice *vbasedev)
+{
+    return -1;
+}
+
+/**
+ * vfio_populate_device - Allocate and populate MMIO region
+ * structs according to driver returned information
+ * @vbasedev: the VFIO device handle
+ *
+ */
+static int vfio_populate_device(VFIODevice *vbasedev)
+{
+    int i, ret = -1;
+    VFIOPlatformDevice *vdev =
+        container_of(vbasedev, VFIOPlatformDevice, vbasedev);
+
+    if (!(vbasedev->flags & VFIO_DEVICE_FLAGS_PLATFORM)) {
+        error_report("vfio: Um, this isn't a platform device");
+        return ret;
+    }
+
+    vdev->regions = g_malloc0_n(vbasedev->num_regions,
+                                sizeof(VFIORegion *));
+
+    for (i = 0; i < vbasedev->num_regions; i++) {
+        struct vfio_region_info reg_info = { .argsz = sizeof(reg_info) };
+        VFIORegion *ptr;
+
+        vdev->regions[i] = g_malloc0(sizeof(VFIORegion));
+        ptr = vdev->regions[i];
+        reg_info.index = i;
+        ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
+        if (ret) {
+            error_report("vfio: Error getting region %d info: %m", i);
+            goto reg_error;
+        }
+        ptr->flags = reg_info.flags;
+        ptr->size = reg_info.size;
+        ptr->fd_offset = reg_info.offset;
+        ptr->nr = i;
+        ptr->vbasedev = vbasedev;
+
+        trace_vfio_platform_populate_regions(ptr->nr,
+                            (unsigned long)ptr->flags,
+                            (unsigned long)ptr->size,
+                            ptr->vbasedev->fd,
+                            (unsigned long)ptr->fd_offset);
+    }
+
+    return 0;
+reg_error:
+    for (i = 0; i < vbasedev->num_regions; i++) {
+        g_free(vdev->regions[i]);
+    }
+    g_free(vdev->regions);
+    return ret;
+}
+
+/* specialized functions for VFIO Platform devices */
+static VFIODeviceOps vfio_platform_ops = {
+    .vfio_compute_needs_reset = vfio_platform_compute_needs_reset,
+    .vfio_hot_reset_multi = vfio_platform_hot_reset_multi,
+};
+
+/**
+ * vfio_base_device_init - perform preliminary VFIO setup
+ * @vbasedev: the VFIO device handle
+ *
+ * Implement the VFIO command sequence that allows to discover
+ * assigned device resources: group extraction, device
+ * fd retrieval, resource query.
+ * Precondition: the device name must be initialized
+ */
+static int vfio_base_device_init(VFIODevice *vbasedev)
+{
+    VFIOGroup *group;
+    VFIODevice *vbasedev_iter;
+    char path[PATH_MAX], iommu_group_path[PATH_MAX], *group_name;
+    ssize_t len;
+    struct stat st;
+    int groupid;
+    int ret;
+
+    /* name must be set prior to the call */
+    if (!vbasedev->name || strchr(vbasedev->name, '/')) {
+        return -EINVAL;
+    }
+
+    /* Check that the host device exists */
+    g_snprintf(path, sizeof(path), "/sys/bus/platform/devices/%s/",
+               vbasedev->name);
+
+    if (stat(path, &st) < 0) {
+        error_report("vfio: error: no such host device: %s", path);
+        return -errno;
+    }
+
+    g_strlcat(path, "iommu_group", sizeof(path));
+    len = readlink(path, iommu_group_path, sizeof(iommu_group_path));
+    if (len < 0 || len >= sizeof(iommu_group_path)) {
+        error_report("vfio: error no iommu_group for device");
+        return len < 0 ? -errno : -ENAMETOOLONG;
+    }
+
+    iommu_group_path[len] = 0;
+    group_name = basename(iommu_group_path);
+
+    if (sscanf(group_name, "%d", &groupid) != 1) {
+        error_report("vfio: error reading %s: %m", path);
+        return -errno;
+    }
+
+    trace_vfio_platform_base_device_init(vbasedev->name, groupid);
+
+    group = vfio_get_group(groupid, &address_space_memory);
+    if (!group) {
+        error_report("vfio: failed to get group %d", groupid);
+        return -ENOENT;
+    }
+
+    g_snprintf(path, sizeof(path), "%s", vbasedev->name);
+
+    QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
+        if (strcmp(vbasedev_iter->name, vbasedev->name) == 0) {
+            error_report("vfio: error: device %s is already attached", path);
+            vfio_put_group(group);
+            return -EBUSY;
+        }
+    }
+    ret = vfio_get_device(group, path, vbasedev);
+    if (ret) {
+        error_report("vfio: failed to get device %s", path);
+        vfio_put_group(group);
+        return ret;
+    }
+
+    ret = vfio_populate_device(vbasedev);
+    if (ret) {
+        error_report("vfio: failed to populate device %s", path);
+        vfio_put_group(group);
+    }
+
+    return ret;
+}
+
+/**
+ * vfio_map_region - initialize the 2 memory regions for a given
+ * MMIO region index
+ * @vdev: the VFIO platform device handle
+ * @nr: the index of the region
+ *
+ * Init the top memory region and the mmapped memory region beneath
+ * VFIOPlatformDevice is used since VFIODevice is not a QOM Object
+ * and could not be passed to memory region functions
+*/
+static void vfio_map_region(VFIOPlatformDevice *vdev, int nr)
+{
+    VFIORegion *region = vdev->regions[nr];
+    uint64_t size = region->size;
+    char name[64];
+
+    if (!size) {
+        return;
+    }
+
+    g_snprintf(name, sizeof(name), "VFIO %s region %d",
+               vdev->vbasedev.name, nr);
+
+    /* A "slow" read/write mapping underlies all regions */
+    memory_region_init_io(&region->mem, OBJECT(vdev), &vfio_region_ops,
+                          region, name, size);
+
+    g_strlcat(name, " mmap", sizeof(name));
+
+    if (vfio_mmap_region(OBJECT(vdev), region, &region->mem,
+                         &region->mmap_mem, &region->mmap, size, 0, name)) {
+        error_report("%s unsupported. Performance may be slow", name);
+    }
+}
+
+/**
+ * vfio_platform_realize  - the device realize function
+ * @dev: device state pointer
+ * @errp: error
+ *
+ * initialize the device, its memory regions and IRQ structures
+ * IRQ are started separately
+ */
+static void vfio_platform_realize(DeviceState *dev, Error **errp)
+{
+    VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(dev);
+    SysBusDevice *sbdev = SYS_BUS_DEVICE(dev);
+    VFIODevice *vbasedev = &vdev->vbasedev;
+    int i, ret;
+
+    vbasedev->type = VFIO_DEVICE_TYPE_PLATFORM;
+    vbasedev->ops = &vfio_platform_ops;
+
+    trace_vfio_platform_realize(vbasedev->name, vdev->compat);
+
+    ret = vfio_base_device_init(vbasedev);
+    if (ret) {
+        error_setg(errp, "vfio: vfio_base_device_init failed for %s",
+                   vbasedev->name);
+        return;
+    }
+
+    for (i = 0; i < vbasedev->num_regions; i++) {
+        vfio_map_region(vdev, i);
+        sysbus_init_mmio(sbdev, &vdev->regions[i]->mem);
+    }
+}
+
+static const VMStateDescription vfio_platform_vmstate = {
+    .name = TYPE_VFIO_PLATFORM,
+    .unmigratable = 1,
+};
+
+static Property vfio_platform_dev_properties[] = {
+    DEFINE_PROP_STRING("host", VFIOPlatformDevice, vbasedev.name),
+    DEFINE_PROP_BOOL("x-mmap", VFIOPlatformDevice, vbasedev.allow_mmap, true),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vfio_platform_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = vfio_platform_realize;
+    dc->props = vfio_platform_dev_properties;
+    dc->vmsd = &vfio_platform_vmstate;
+    dc->desc = "VFIO-based platform device assignment";
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+}
+
+static const TypeInfo vfio_platform_dev_info = {
+    .name = TYPE_VFIO_PLATFORM,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(VFIOPlatformDevice),
+    .class_init = vfio_platform_class_init,
+    .class_size = sizeof(VFIOPlatformDeviceClass),
+    .abstract   = true,
+};
+
+static void register_vfio_platform_dev_type(void)
+{
+    type_register_static(&vfio_platform_dev_info);
+}
+
+type_init(register_vfio_platform_dev_type)
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 0d1fb80..59a321d 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -42,6 +42,7 @@
 
 enum {
     VFIO_DEVICE_TYPE_PCI = 0,
+    VFIO_DEVICE_TYPE_PLATFORM = 1,
 };
 
 typedef struct VFIORegion {
diff --git a/include/hw/vfio/vfio-platform.h b/include/hw/vfio/vfio-platform.h
new file mode 100644
index 0000000..338f0c6
--- /dev/null
+++ b/include/hw/vfio/vfio-platform.h
@@ -0,0 +1,44 @@
+/*
+ * vfio based device assignment support - platform devices
+ *
+ * Copyright Linaro Limited, 2014
+ *
+ * Authors:
+ *  Kim Phillips <kim.phillips@linaro.org>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ * Based on vfio based PCI device assignment support:
+ *  Copyright Red Hat, Inc. 2012
+ */
+
+#ifndef HW_VFIO_VFIO_PLATFORM_H
+#define HW_VFIO_VFIO_PLATFORM_H
+
+#include "hw/sysbus.h"
+#include "hw/vfio/vfio-common.h"
+
+#define TYPE_VFIO_PLATFORM "vfio-platform"
+
+typedef struct VFIOPlatformDevice {
+    SysBusDevice sbdev;
+    VFIODevice vbasedev; /* not a QOM object */
+    VFIORegion **regions;
+    char *compat; /* compatibility string */
+} VFIOPlatformDevice;
+
+typedef struct VFIOPlatformDeviceClass {
+    /*< private >*/
+    SysBusDeviceClass parent_class;
+    /*< public >*/
+} VFIOPlatformDeviceClass;
+
+#define VFIO_PLATFORM_DEVICE(obj) \
+     OBJECT_CHECK(VFIOPlatformDevice, (obj), TYPE_VFIO_PLATFORM)
+#define VFIO_PLATFORM_DEVICE_CLASS(klass) \
+     OBJECT_CLASS_CHECK(VFIOPlatformDeviceClass, (klass), TYPE_VFIO_PLATFORM)
+#define VFIO_PLATFORM_DEVICE_GET_CLASS(obj) \
+     OBJECT_GET_CLASS(VFIOPlatformDeviceClass, (obj), TYPE_VFIO_PLATFORM)
+
+#endif /*HW_VFIO_VFIO_PLATFORM_H*/
diff --git a/trace-events b/trace-events
index a589650..e1a34ec 100644
--- a/trace-events
+++ b/trace-events
@@ -1564,6 +1564,11 @@ vfio_put_group(int fd) "close group->fd=%d"
 vfio_get_device(const char * name, unsigned int flags, unsigned int num_regions, unsigned int num_irqs) "Device %s flags: %u, regions: %u, irqs: %u"
 vfio_put_base_device(int fd) "close vdev->fd=%d"
 
+# hw/vfio/platform.c
+vfio_platform_populate_regions(int region_index, unsigned long flag, unsigned long size, int fd, unsigned long offset) "- region %d flags = 0x%lx, size = 0x%lx, fd= %d, offset = 0x%lx"
+vfio_platform_base_device_init(char *name, int groupid) "%s belongs to group #%d"
+vfio_platform_realize(char *name, char *compat) "vfio device %s, compat = %s"
+
 #hw/acpi/memory_hotplug.c
 mhp_acpi_invalid_slot_selected(uint32_t slot) "0x%"PRIx32
 mhp_acpi_ejecting_invalid_slot(uint32_t slot) "0x%"PRIx32

[Qemu-devel] [PULL v2 2/3] hw/vfio/platform: add irq assignment

[Alex Williamson]

From: Eric Auger <eric.auger@linaro.org>

This patch adds the code requested to assign interrupts to
a guest. The interrupts are mediated through user handled
eventfds only.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Vikram Sethi <vikrams@codeaurora.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 hw/vfio/platform.c              |  331 +++++++++++++++++++++++++++++++++++++++
 include/hw/vfio/vfio-platform.h |   31 ++++
 trace-events                    |    7 +
 3 files changed, 368 insertions(+), 1 deletion(-)

diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
index 569a675..35266a8 100644
--- a/hw/vfio/platform.c
+++ b/hw/vfio/platform.c
@@ -22,10 +22,299 @@
 #include "qemu/range.h"
 #include "sysemu/sysemu.h"
 #include "exec/memory.h"
+#include "qemu/queue.h"
 #include "hw/sysbus.h"
 #include "trace.h"
 #include "hw/platform-bus.h"
 
+/*
+ * Functions used whatever the injection method
+ */
+
+/**
+ * vfio_init_intp - allocate, initialize the IRQ struct pointer
+ * and add it into the list of IRQs
+ * @vbasedev: the VFIO device handle
+ * @info: irq info struct retrieved from VFIO driver
+ */
+static VFIOINTp *vfio_init_intp(VFIODevice *vbasedev,
+                                struct vfio_irq_info info)
+{
+    int ret;
+    VFIOPlatformDevice *vdev =
+        container_of(vbasedev, VFIOPlatformDevice, vbasedev);
+    SysBusDevice *sbdev = SYS_BUS_DEVICE(vdev);
+    VFIOINTp *intp;
+
+    intp = g_malloc0(sizeof(*intp));
+    intp->vdev = vdev;
+    intp->pin = info.index;
+    intp->flags = info.flags;
+    intp->state = VFIO_IRQ_INACTIVE;
+
+    sysbus_init_irq(sbdev, &intp->qemuirq);
+
+    /* Get an eventfd for trigger */
+    ret = event_notifier_init(&intp->interrupt, 0);
+    if (ret) {
+        g_free(intp);
+        error_report("vfio: Error: trigger event_notifier_init failed ");
+        return NULL;
+    }
+
+    QLIST_INSERT_HEAD(&vdev->intp_list, intp, next);
+    return intp;
+}
+
+/**
+ * vfio_set_trigger_eventfd - set VFIO eventfd handling
+ *
+ * @intp: IRQ struct handle
+ * @handler: handler to be called on eventfd signaling
+ *
+ * Setup VFIO signaling and attach an optional user-side handler
+ * to the eventfd
+ */
+static int vfio_set_trigger_eventfd(VFIOINTp *intp,
+                                    eventfd_user_side_handler_t handler)
+{
+    VFIODevice *vbasedev = &intp->vdev->vbasedev;
+    struct vfio_irq_set *irq_set;
+    int argsz, ret;
+    int32_t *pfd;
+
+    argsz = sizeof(*irq_set) + sizeof(*pfd);
+    irq_set = g_malloc0(argsz);
+    irq_set->argsz = argsz;
+    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER;
+    irq_set->index = intp->pin;
+    irq_set->start = 0;
+    irq_set->count = 1;
+    pfd = (int32_t *)&irq_set->data;
+    *pfd = event_notifier_get_fd(&intp->interrupt);
+    qemu_set_fd_handler(*pfd, (IOHandler *)handler, NULL, intp);
+    ret = ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, irq_set);
+    g_free(irq_set);
+    if (ret < 0) {
+        error_report("vfio: Failed to set trigger eventfd: %m");
+        qemu_set_fd_handler(*pfd, NULL, NULL, NULL);
+    }
+    return ret;
+}
+
+/*
+ * Functions only used when eventfds are handled on user-side
+ * ie. without irqfd
+ */
+
+/**
+ * vfio_mmap_set_enabled - enable/disable the fast path mode
+ * @vdev: the VFIO platform device
+ * @enabled: the target mmap state
+ *
+ * enabled = true ~ fast path = MMIO region is mmaped (no KVM TRAP);
+ * enabled = false ~ slow path = MMIO region is trapped and region callbacks
+ * are called; slow path enables to trap the device IRQ status register reset
+*/
+
+static void vfio_mmap_set_enabled(VFIOPlatformDevice *vdev, bool enabled)
+{
+    int i;
+
+    trace_vfio_platform_mmap_set_enabled(enabled);
+
+    for (i = 0; i < vdev->vbasedev.num_regions; i++) {
+        VFIORegion *region = vdev->regions[i];
+
+        memory_region_set_enabled(&region->mmap_mem, enabled);
+    }
+}
+
+/**
+ * vfio_intp_mmap_enable - timer function, restores the fast path
+ * if there is no more active IRQ
+ * @opaque: actually points to the VFIO platform device
+ *
+ * Called on mmap timer timout, this function checks whether the
+ * IRQ is still active and if not, restores the fast path.
+ * by construction a single eventfd is handled at a time.
+ * if the IRQ is still active, the timer is re-programmed.
+ */
+static void vfio_intp_mmap_enable(void *opaque)
+{
+    VFIOINTp *tmp;
+    VFIOPlatformDevice *vdev = (VFIOPlatformDevice *)opaque;
+
+    qemu_mutex_lock(&vdev->intp_mutex);
+    QLIST_FOREACH(tmp, &vdev->intp_list, next) {
+        if (tmp->state == VFIO_IRQ_ACTIVE) {
+            trace_vfio_platform_intp_mmap_enable(tmp->pin);
+            /* re-program the timer to check active status later */
+            timer_mod(vdev->mmap_timer,
+                      qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
+                          vdev->mmap_timeout);
+            qemu_mutex_unlock(&vdev->intp_mutex);
+            return;
+        }
+    }
+    vfio_mmap_set_enabled(vdev, true);
+    qemu_mutex_unlock(&vdev->intp_mutex);
+}
+
+/**
+ * vfio_intp_inject_pending_lockheld - Injects a pending IRQ
+ * @opaque: opaque pointer, in practice the VFIOINTp handle
+ *
+ * The function is called on a previous IRQ completion, from
+ * vfio_platform_eoi, while the intp_mutex is locked.
+ * Also in such situation, the slow path already is set and
+ * the mmap timer was already programmed.
+ */
+static void vfio_intp_inject_pending_lockheld(VFIOINTp *intp)
+{
+    trace_vfio_platform_intp_inject_pending_lockheld(intp->pin,
+                              event_notifier_get_fd(&intp->interrupt));
+
+    intp->state = VFIO_IRQ_ACTIVE;
+
+    /* trigger the virtual IRQ */
+    qemu_set_irq(intp->qemuirq, 1);
+}
+
+/**
+ * vfio_intp_interrupt - The user-side eventfd handler
+ * @opaque: opaque pointer which in practice is the VFIOINTp handle
+ *
+ * the function is entered in event handler context:
+ * the vIRQ is injected into the guest if there is no other active
+ * or pending IRQ.
+ */
+static void vfio_intp_interrupt(VFIOINTp *intp)
+{
+    int ret;
+    VFIOINTp *tmp;
+    VFIOPlatformDevice *vdev = intp->vdev;
+    bool delay_handling = false;
+
+    qemu_mutex_lock(&vdev->intp_mutex);
+    if (intp->state == VFIO_IRQ_INACTIVE) {
+        QLIST_FOREACH(tmp, &vdev->intp_list, next) {
+            if (tmp->state == VFIO_IRQ_ACTIVE ||
+                tmp->state == VFIO_IRQ_PENDING) {
+                delay_handling = true;
+                break;
+            }
+        }
+    }
+    if (delay_handling) {
+        /*
+         * the new IRQ gets a pending status and is pushed in
+         * the pending queue
+         */
+        intp->state = VFIO_IRQ_PENDING;
+        trace_vfio_intp_interrupt_set_pending(intp->pin);
+        QSIMPLEQ_INSERT_TAIL(&vdev->pending_intp_queue,
+                             intp, pqnext);
+        ret = event_notifier_test_and_clear(&intp->interrupt);
+        qemu_mutex_unlock(&vdev->intp_mutex);
+        return;
+    }
+
+    trace_vfio_platform_intp_interrupt(intp->pin,
+                              event_notifier_get_fd(&intp->interrupt));
+
+    ret = event_notifier_test_and_clear(&intp->interrupt);
+    if (!ret) {
+        error_report("Error when clearing fd=%d (ret = %d)\n",
+                     event_notifier_get_fd(&intp->interrupt), ret);
+    }
+
+    intp->state = VFIO_IRQ_ACTIVE;
+
+    /* sets slow path */
+    vfio_mmap_set_enabled(vdev, false);
+
+    /* trigger the virtual IRQ */
+    qemu_set_irq(intp->qemuirq, 1);
+
+    /*
+     * Schedule the mmap timer which will restore fastpath when no IRQ
+     * is active anymore
+     */
+    if (vdev->mmap_timeout) {
+        timer_mod(vdev->mmap_timer,
+                  qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
+                      vdev->mmap_timeout);
+    }
+    qemu_mutex_unlock(&vdev->intp_mutex);
+}
+
+/**
+ * vfio_platform_eoi - IRQ completion routine
+ * @vbasedev: the VFIO device handle
+ *
+ * De-asserts the active virtual IRQ and unmasks the physical IRQ
+ * (effective for level sensitive IRQ auto-masked by the  VFIO driver).
+ * Then it handles next pending IRQ if any.
+ * eoi function is called on the first access to any MMIO region
+ * after an IRQ was triggered, trapped since slow path was set.
+ * It is assumed this access corresponds to the IRQ status
+ * register reset. With such a mechanism, a single IRQ can be
+ * handled at a time since there is no way to know which IRQ
+ * was completed by the guest (we would need additional details
+ * about the IRQ status register mask).
+ */
+static void vfio_platform_eoi(VFIODevice *vbasedev)
+{
+    VFIOINTp *intp;
+    VFIOPlatformDevice *vdev =
+        container_of(vbasedev, VFIOPlatformDevice, vbasedev);
+
+    qemu_mutex_lock(&vdev->intp_mutex);
+    QLIST_FOREACH(intp, &vdev->intp_list, next) {
+        if (intp->state == VFIO_IRQ_ACTIVE) {
+            trace_vfio_platform_eoi(intp->pin,
+                                event_notifier_get_fd(&intp->interrupt));
+            intp->state = VFIO_IRQ_INACTIVE;
+
+            /* deassert the virtual IRQ */
+            qemu_set_irq(intp->qemuirq, 0);
+
+            if (intp->flags & VFIO_IRQ_INFO_AUTOMASKED) {
+                /* unmasks the physical level-sensitive IRQ */
+                vfio_unmask_single_irqindex(vbasedev, intp->pin);
+            }
+
+            /* a single IRQ can be active at a time */
+            break;
+        }
+    }
+    /* in case there are pending IRQs, handle the first one */
+    if (!QSIMPLEQ_EMPTY(&vdev->pending_intp_queue)) {
+        intp = QSIMPLEQ_FIRST(&vdev->pending_intp_queue);
+        vfio_intp_inject_pending_lockheld(intp);
+        QSIMPLEQ_REMOVE_HEAD(&vdev->pending_intp_queue, pqnext);
+    }
+    qemu_mutex_unlock(&vdev->intp_mutex);
+}
+
+/**
+ * vfio_start_eventfd_injection - starts the virtual IRQ injection using
+ * user-side handled eventfds
+ * @intp: the IRQ struct pointer
+ */
+
+static int vfio_start_eventfd_injection(VFIOINTp *intp)
+{
+    int ret;
+
+    ret = vfio_set_trigger_eventfd(intp, vfio_intp_interrupt);
+    if (ret) {
+        error_report("vfio: Error: Failed to pass IRQ fd to the driver: %m");
+    }
+    return ret;
+}
+
 /* VFIO skeleton */
 
 static void vfio_platform_compute_needs_reset(VFIODevice *vbasedev)
@@ -41,12 +330,13 @@ static int vfio_platform_hot_reset_multi(VFIODevice *vbasedev)
 
 /**
  * vfio_populate_device - Allocate and populate MMIO region
- * structs according to driver returned information
+ * and IRQ structs according to driver returned information
  * @vbasedev: the VFIO device handle
  *
  */
 static int vfio_populate_device(VFIODevice *vbasedev)
 {
+    VFIOINTp *intp, *tmp;
     int i, ret = -1;
     VFIOPlatformDevice *vdev =
         container_of(vbasedev, VFIOPlatformDevice, vbasedev);
@@ -84,7 +374,38 @@ static int vfio_populate_device(VFIODevice *vbasedev)
                             (unsigned long)ptr->fd_offset);
     }
 
+    vdev->mmap_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL,
+                                    vfio_intp_mmap_enable, vdev);
+
+    QSIMPLEQ_INIT(&vdev->pending_intp_queue);
+
+    for (i = 0; i < vbasedev->num_irqs; i++) {
+        struct vfio_irq_info irq = { .argsz = sizeof(irq) };
+
+        irq.index = i;
+        ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_IRQ_INFO, &irq);
+        if (ret) {
+            error_printf("vfio: error getting device %s irq info",
+                         vbasedev->name);
+            goto irq_err;
+        } else {
+            trace_vfio_platform_populate_interrupts(irq.index,
+                                                    irq.count,
+                                                    irq.flags);
+            intp = vfio_init_intp(vbasedev, irq);
+            if (!intp) {
+                error_report("vfio: Error installing IRQ %d up", i);
+                goto irq_err;
+            }
+        }
+    }
     return 0;
+irq_err:
+    timer_del(vdev->mmap_timer);
+    QLIST_FOREACH_SAFE(intp, &vdev->intp_list, next, tmp) {
+        QLIST_REMOVE(intp, next);
+        g_free(intp);
+    }
 reg_error:
     for (i = 0; i < vbasedev->num_regions; i++) {
         g_free(vdev->regions[i]);
@@ -97,6 +418,7 @@ reg_error:
 static VFIODeviceOps vfio_platform_ops = {
     .vfio_compute_needs_reset = vfio_platform_compute_needs_reset,
     .vfio_hot_reset_multi = vfio_platform_hot_reset_multi,
+    .vfio_eoi = vfio_platform_eoi,
 };
 
 /**
@@ -228,6 +550,7 @@ static void vfio_platform_realize(DeviceState *dev, Error **errp)
     VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(dev);
     SysBusDevice *sbdev = SYS_BUS_DEVICE(dev);
     VFIODevice *vbasedev = &vdev->vbasedev;
+    VFIOINTp *intp;
     int i, ret;
 
     vbasedev->type = VFIO_DEVICE_TYPE_PLATFORM;
@@ -246,6 +569,10 @@ static void vfio_platform_realize(DeviceState *dev, Error **errp)
         vfio_map_region(vdev, i);
         sysbus_init_mmio(sbdev, &vdev->regions[i]->mem);
     }
+
+    QLIST_FOREACH(intp, &vdev->intp_list, next) {
+        vfio_start_eventfd_injection(intp);
+    }
 }
 
 static const VMStateDescription vfio_platform_vmstate = {
@@ -256,6 +583,8 @@ static const VMStateDescription vfio_platform_vmstate = {
 static Property vfio_platform_dev_properties[] = {
     DEFINE_PROP_STRING("host", VFIOPlatformDevice, vbasedev.name),
     DEFINE_PROP_BOOL("x-mmap", VFIOPlatformDevice, vbasedev.allow_mmap, true),
+    DEFINE_PROP_UINT32("mmap-timeout-ms", VFIOPlatformDevice,
+                       mmap_timeout, 1100),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/include/hw/vfio/vfio-platform.h b/include/hw/vfio/vfio-platform.h
index 338f0c6..26b2ad6 100644
--- a/include/hw/vfio/vfio-platform.h
+++ b/include/hw/vfio/vfio-platform.h
@@ -18,14 +18,45 @@
 
 #include "hw/sysbus.h"
 #include "hw/vfio/vfio-common.h"
+#include "qemu/event_notifier.h"
+#include "qemu/queue.h"
+#include "hw/irq.h"
 
 #define TYPE_VFIO_PLATFORM "vfio-platform"
 
+enum {
+    VFIO_IRQ_INACTIVE = 0,
+    VFIO_IRQ_PENDING = 1,
+    VFIO_IRQ_ACTIVE = 2,
+    /* VFIO_IRQ_ACTIVE_AND_PENDING cannot happen with VFIO */
+};
+
+typedef struct VFIOINTp {
+    QLIST_ENTRY(VFIOINTp) next; /* entry for IRQ list */
+    QSIMPLEQ_ENTRY(VFIOINTp) pqnext; /* entry for pending IRQ queue */
+    EventNotifier interrupt; /* eventfd triggered on interrupt */
+    EventNotifier unmask; /* eventfd for unmask on QEMU bypass */
+    qemu_irq qemuirq;
+    struct VFIOPlatformDevice *vdev; /* back pointer to device */
+    int state; /* inactive, pending, active */
+    uint8_t pin; /* index */
+    uint32_t flags; /* IRQ info flags */
+} VFIOINTp;
+
+/* function type for user side eventfd handler */
+typedef void (*eventfd_user_side_handler_t)(VFIOINTp *intp);
+
 typedef struct VFIOPlatformDevice {
     SysBusDevice sbdev;
     VFIODevice vbasedev; /* not a QOM object */
     VFIORegion **regions;
+    QLIST_HEAD(, VFIOINTp) intp_list; /* list of IRQs */
+    /* queue of pending IRQs */
+    QSIMPLEQ_HEAD(pending_intp_queue, VFIOINTp) pending_intp_queue;
     char *compat; /* compatibility string */
+    uint32_t mmap_timeout; /* delay to re-enable mmaps after interrupt */
+    QEMUTimer *mmap_timer; /* allows fast-path resume after IRQ hit */
+    QemuMutex intp_mutex; /* protect the intp_list IRQ state */
 } VFIOPlatformDevice;
 
 typedef struct VFIOPlatformDeviceClass {
diff --git a/trace-events b/trace-events
index e1a34ec..7af9f19 100644
--- a/trace-events
+++ b/trace-events
@@ -1568,6 +1568,13 @@ vfio_put_base_device(int fd) "close vdev->fd=%d"
 vfio_platform_populate_regions(int region_index, unsigned long flag, unsigned long size, int fd, unsigned long offset) "- region %d flags = 0x%lx, size = 0x%lx, fd= %d, offset = 0x%lx"
 vfio_platform_base_device_init(char *name, int groupid) "%s belongs to group #%d"
 vfio_platform_realize(char *name, char *compat) "vfio device %s, compat = %s"
+vfio_platform_eoi(int pin, int fd) "EOI IRQ pin %d (fd=%d)"
+vfio_platform_mmap_set_enabled(bool enabled) "fast path = %d"
+vfio_platform_intp_mmap_enable(int pin) "IRQ #%d still active, stay in slow path"
+vfio_platform_intp_interrupt(int pin, int fd) "Inject IRQ #%d (fd = %d)"
+vfio_platform_intp_inject_pending_lockheld(int pin, int fd) "Inject pending IRQ #%d (fd = %d)"
+vfio_platform_populate_interrupts(int pin, int count, int flags) "- IRQ index %d: count %d, flags=0x%x"
+vfio_intp_interrupt_set_pending(int index) "irq %d is set PENDING"
 
 #hw/acpi/memory_hotplug.c
 mhp_acpi_invalid_slot_selected(uint32_t slot) "0x%"PRIx32

[Qemu-devel] [PULL v2 3/3] hw/vfio/platform: calxeda xgmac device

[Alex Williamson]

From: Eric Auger <eric.auger@linaro.org>

The platform device class has become abstract. This patch introduces
a calxeda xgmac device that derives from it.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 hw/vfio/Makefile.objs                |    1 +
 hw/vfio/calxeda-xgmac.c              |   55 ++++++++++++++++++++++++++++++++++
 include/hw/vfio/vfio-calxeda-xgmac.h |   46 ++++++++++++++++++++++++++++
 3 files changed, 102 insertions(+)
 create mode 100644 hw/vfio/calxeda-xgmac.c
 create mode 100644 include/hw/vfio/vfio-calxeda-xgmac.h

diff --git a/hw/vfio/Makefile.objs b/hw/vfio/Makefile.objs
index c5c76fe..d540c9d 100644
--- a/hw/vfio/Makefile.objs
+++ b/hw/vfio/Makefile.objs
@@ -2,4 +2,5 @@ ifeq ($(CONFIG_LINUX), y)
 obj-$(CONFIG_SOFTMMU) += common.o
 obj-$(CONFIG_PCI) += pci.o
 obj-$(CONFIG_SOFTMMU) += platform.o
+obj-$(CONFIG_SOFTMMU) += calxeda-xgmac.o
 endif
diff --git a/hw/vfio/calxeda-xgmac.c b/hw/vfio/calxeda-xgmac.c
new file mode 100644
index 0000000..eb914f0
--- /dev/null
+++ b/hw/vfio/calxeda-xgmac.c
@@ -0,0 +1,55 @@
+/*
+ * calxeda xgmac VFIO device
+ *
+ * Copyright Linaro Limited, 2014
+ *
+ * Authors:
+ *  Eric Auger <eric.auger@linaro.org>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "hw/vfio/vfio-calxeda-xgmac.h"
+
+static void calxeda_xgmac_realize(DeviceState *dev, Error **errp)
+{
+    VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(dev);
+    VFIOCalxedaXgmacDeviceClass *k = VFIO_CALXEDA_XGMAC_DEVICE_GET_CLASS(dev);
+
+    vdev->compat = g_strdup("calxeda,hb-xgmac");
+
+    k->parent_realize(dev, errp);
+}
+
+static const VMStateDescription vfio_platform_calxeda_xgmac_vmstate = {
+    .name = TYPE_VFIO_CALXEDA_XGMAC,
+    .unmigratable = 1,
+};
+
+static void vfio_calxeda_xgmac_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VFIOCalxedaXgmacDeviceClass *vcxc =
+        VFIO_CALXEDA_XGMAC_DEVICE_CLASS(klass);
+    vcxc->parent_realize = dc->realize;
+    dc->realize = calxeda_xgmac_realize;
+    dc->desc = "VFIO Calxeda XGMAC";
+    dc->vmsd = &vfio_platform_calxeda_xgmac_vmstate;
+}
+
+static const TypeInfo vfio_calxeda_xgmac_dev_info = {
+    .name = TYPE_VFIO_CALXEDA_XGMAC,
+    .parent = TYPE_VFIO_PLATFORM,
+    .instance_size = sizeof(VFIOCalxedaXgmacDevice),
+    .class_init = vfio_calxeda_xgmac_class_init,
+    .class_size = sizeof(VFIOCalxedaXgmacDeviceClass),
+};
+
+static void register_calxeda_xgmac_dev_type(void)
+{
+    type_register_static(&vfio_calxeda_xgmac_dev_info);
+}
+
+type_init(register_calxeda_xgmac_dev_type)
diff --git a/include/hw/vfio/vfio-calxeda-xgmac.h b/include/hw/vfio/vfio-calxeda-xgmac.h
new file mode 100644
index 0000000..f994775
--- /dev/null
+++ b/include/hw/vfio/vfio-calxeda-xgmac.h
@@ -0,0 +1,46 @@
+/*
+ * VFIO calxeda xgmac device
+ *
+ * Copyright Linaro Limited, 2014
+ *
+ * Authors:
+ *  Eric Auger <eric.auger@linaro.org>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef HW_VFIO_VFIO_CALXEDA_XGMAC_H
+#define HW_VFIO_VFIO_CALXEDA_XGMAC_H
+
+#include "hw/vfio/vfio-platform.h"
+
+#define TYPE_VFIO_CALXEDA_XGMAC "vfio-calxeda-xgmac"
+
+/**
+ * This device exposes:
+ * - a single MMIO region corresponding to its register space
+ * - 3 IRQS (main and 2 power related IRQs)
+ */
+typedef struct VFIOCalxedaXgmacDevice {
+    VFIOPlatformDevice vdev;
+} VFIOCalxedaXgmacDevice;
+
+typedef struct VFIOCalxedaXgmacDeviceClass {
+    /*< private >*/
+    VFIOPlatformDeviceClass parent_class;
+    /*< public >*/
+    DeviceRealize parent_realize;
+} VFIOCalxedaXgmacDeviceClass;
+
+#define VFIO_CALXEDA_XGMAC_DEVICE(obj) \
+     OBJECT_CHECK(VFIOCalxedaXgmacDevice, (obj), TYPE_VFIO_CALXEDA_XGMAC)
+#define VFIO_CALXEDA_XGMAC_DEVICE_CLASS(klass) \
+     OBJECT_CLASS_CHECK(VFIOCalxedaXgmacDeviceClass, (klass), \
+                        TYPE_VFIO_CALXEDA_XGMAC)
+#define VFIO_CALXEDA_XGMAC_DEVICE_GET_CLASS(obj) \
+     OBJECT_GET_CLASS(VFIOCalxedaXgmacDeviceClass, (obj), \
+                      TYPE_VFIO_CALXEDA_XGMAC)
+
+#endif

Re: [Qemu-devel] [PULL v2 0/3] Initial vfio-platform support

[Peter Maydell]

On 9 June 2015 at 16:55, Alex Williamson <alex.williamson@redhat.com> wrote:
> The following changes since commit 2e29dd7c44db30e3d3c108ab2a622cbdac6d16f0:
>
>   Merge remote-tracking branch 'remotes/jnsnow/tags/ide-pull-request' into staging (2015-06-08 14:07:32 +0100)
>
> are available in the git repository at:
>
>
>   git://github.com/awilliam/qemu-vfio.git tags/vfio-update-20150609.0
>
> for you to fetch changes up to 7a8d15d7702444be715b6ae32574659483c0c158:
>
>   hw/vfio/platform: calxeda xgmac device (2015-06-09 08:17:17 -0600)
>
> ----------------------------------------------------------------
> Initial VFIO platform device support, v2 (Eric Auger, et al.)
>
> ----------------------------------------------------------------



Applied, thanks.

-- PMM

Re: [Qemu-devel] [PULL v2 1/3] hw/vfio/platform: vfio-platform skeleton

[Gonglei]

On 2015/6/9 23:55, Alex Williamson wrote:
> +static int vfio_populate_device(VFIODevice *vbasedev)
> +{
> +    int i, ret = -1;
> +    VFIOPlatformDevice *vdev =
> +        container_of(vbasedev, VFIOPlatformDevice, vbasedev);
> +
> +    if (!(vbasedev->flags & VFIO_DEVICE_FLAGS_PLATFORM)) {
> +        error_report("vfio: Um, this isn't a platform device");
> +        return ret;
> +    }
> +
> +    vdev->regions = g_malloc0_n(vbasedev->num_regions,
> +                                sizeof(VFIORegion *));

Failed to build on SUSE11.3:

/home/qemu/hw/vfio/platform.c: In function ‘vfio_populate_device’:
/home/qemu/hw/vfio/platform.c:349: warning: implicit declaration of function ‘g_malloc0_n’
/home/qemu/hw/vfio/platform.c:349: warning: nested extern declaration of ‘g_malloc0_n’
/home/qemu/hw/vfio/platform.c:350: warning: assignment makes pointer from integer without a cast
  CC    x86_64-softmmu/hw/i386/pc_q35.o
  CC    x86_64-softmmu/hw/i386/pc_sysfw.o
  CC    x86_64-softmmu/hw/i386/acpi-build.o
  CC    x86_64-softmmu/hw/i386/kvm/pci-assign.o
  CC    x86_64-softmmu/target-i386/translate.o
  GEN   trace/generated-helpers.c
  CC    x86_64-softmmu/trace/generated-helpers.o
  LINK  x86_64-softmmu/qemu-system-x86_64
hw/vfio/platform.o: In function `vfio_populate_device':
/home/qemu/hw/vfio/platform.c:349: undefined reference to `g_malloc0_n'
collect2: ld returned 1 exit status
make[1]: *** [qemu-system-x86_64] Error 1
make: *** [subdir-x86_64-softmmu] Error 2

That's because g_malloc0_n() introduced since glib-2.24,
but QEMU just require glib-2.22.

Regards,
-Gonglei

Re: [Qemu-devel] [PULL v2 1/3] hw/vfio/platform: vfio-platform skeleton

[Eric Auger]

Gonglei,

Thanks for the report and please apologize for the inconvenience. I am
going to send a fix reverting to simple g_malloc0 then.

Best Regards

Eric

On 06/11/2015 04:21 AM, Gonglei wrote:
> On 2015/6/9 23:55, Alex Williamson wrote:
>> +static int vfio_populate_device(VFIODevice *vbasedev)
>> +{
>> +    int i, ret = -1;
>> +    VFIOPlatformDevice *vdev =
>> +        container_of(vbasedev, VFIOPlatformDevice, vbasedev);
>> +
>> +    if (!(vbasedev->flags & VFIO_DEVICE_FLAGS_PLATFORM)) {
>> +        error_report("vfio: Um, this isn't a platform device");
>> +        return ret;
>> +    }
>> +
>> +    vdev->regions = g_malloc0_n(vbasedev->num_regions,
>> +                                sizeof(VFIORegion *));
> 
> Failed to build on SUSE11.3:
> 
> /home/qemu/hw/vfio/platform.c: In function ‘vfio_populate_device’:
> /home/qemu/hw/vfio/platform.c:349: warning: implicit declaration of function ‘g_malloc0_n’
> /home/qemu/hw/vfio/platform.c:349: warning: nested extern declaration of ‘g_malloc0_n’
> /home/qemu/hw/vfio/platform.c:350: warning: assignment makes pointer from integer without a cast
>   CC    x86_64-softmmu/hw/i386/pc_q35.o
>   CC    x86_64-softmmu/hw/i386/pc_sysfw.o
>   CC    x86_64-softmmu/hw/i386/acpi-build.o
>   CC    x86_64-softmmu/hw/i386/kvm/pci-assign.o
>   CC    x86_64-softmmu/target-i386/translate.o
>   GEN   trace/generated-helpers.c
>   CC    x86_64-softmmu/trace/generated-helpers.o
>   LINK  x86_64-softmmu/qemu-system-x86_64
> hw/vfio/platform.o: In function `vfio_populate_device':
> /home/qemu/hw/vfio/platform.c:349: undefined reference to `g_malloc0_n'
> collect2: ld returned 1 exit status
> make[1]: *** [qemu-system-x86_64] Error 1
> make: *** [subdir-x86_64-softmmu] Error 2
> 
> That's because g_malloc0_n() introduced since glib-2.24,
> but QEMU just require glib-2.22.
> 
> Regards,
> -Gonglei
> 

Re: [Qemu-devel] [PULL v2 1/3] hw/vfio/platform: vfio-platform skeleton

[Peter Maydell]

On 11 June 2015 at 03:21, Gonglei <arei.gonglei@huawei.com> wrote:
> Failed to build on SUSE11.3:

> That's because g_malloc0_n() introduced since glib-2.24,
> but QEMU just require glib-2.22.

Thanks for the catch -- I do have a glib-2.22 system in my
pre-pull build tests, but it's not x86/Linux, so it won't
try to compile the vfio code, which is why it missed this.

-- PMM