From 95bd55e26e97832288c088f2c0bd3618d9f9f7ff Mon Sep 17 00:00:00 2001

From: Thomas Huth <thuth@redhat.com>

Date: Mon, 15 Oct 2018 10:19:30 +0100

Subject: [PATCH 5/6] s390x/vfio: ap: Introduce VFIO AP device

RH-Author: Thomas Huth <thuth@redhat.com>

Message-id: <1539598771-16223-6-git-send-email-thuth@redhat.com>

Patchwork-id: 82700

O-Subject: [RHEL-8 qemu-kvm PATCH 5/6] s390x/vfio: ap: Introduce VFIO AP device

Bugzilla: 1508142

RH-Acked-by: David Hildenbrand <david@redhat.com>

RH-Acked-by: Cornelia Huck <cohuck@redhat.com>

RH-Acked-by: Jens Freimann <jfreimann@redhat.com>

From: Tony Krowiak <akrowiak@linux.ibm.com>

Introduces a VFIO based AP device. The device is defined via

the QEMU command line by specifying:

    -device vfio-ap,sysfsdev=<path-to-mediated-matrix-device>

There may be only one vfio-ap device configured for a guest.

The mediated matrix device is created by the VFIO AP device

driver by writing a UUID to a sysfs attribute file (see

docs/vfio-ap.txt). The mediated matrix device will be named

after the UUID. Symbolic links to the $uuid are created in

many places, so the path to the mediated matrix device $uuid

can be specified in any of the following ways:

/sys/devices/vfio_ap/matrix/$uuid

/sys/devices/vfio_ap/matrix/mdev_supported_types/vfio_ap-passthrough/devices/$uuid

/sys/bus/mdev/devices/$uuid

/sys/bus/mdev/drivers/vfio_mdev/$uuid

When the vfio-ap device is realized, it acquires and opens the

VFIO iommu group to which the mediated matrix device is

bound. This causes a VFIO group notification event to be

signaled. The vfio_ap device driver's group notification

handler will get called at which time the device driver

will configure the the AP devices to which the guest will

be granted access.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>

Tested-by: Pierre Morel <pmorel@linux.ibm.com>

Acked-by: Halil Pasic <pasic@linux.ibm.com>

Tested-by: Pierre Morel <pmorel@linux.ibm.com>

Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>

Message-Id: <20181010170309.12045-6-akrowiak@linux.ibm.com>

Reviewed-by: Thomas Huth <thuth@redhat.com>

[CH: added missing g_free and device category]

Signed-off-by: Cornelia Huck <cohuck@redhat.com>

(cherry picked from commit 2fe2942cd6ddad8ddd40fe5d16d67599c28959d7)

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 MAINTAINERS                       |   2 +

 default-configs/s390x-softmmu.mak |   1 +

 hw/vfio/Makefile.objs             |   1 +

 hw/vfio/ap.c                      | 181 ++++++++++++++++++++++++++++++++++++++

 include/hw/vfio/vfio-common.h     |   1 +

 5 files changed, 186 insertions(+)

 create mode 100644 hw/vfio/ap.c

diff --git a/MAINTAINERS b/MAINTAINERS

index 31cf6ff..99694d8 100644

--- a/MAINTAINERS

+++ b/MAINTAINERS

@@ -88,6 +88,7 @@ F: hw/char/terminal3270.c

 F: hw/intc/s390_flic.c

 F: hw/intc/s390_flic_kvm.c

 F: hw/s390x/

+F: hw/vfio/ap.c

 F: hw/vfio/ccw.c

 F: hw/watchdog/wdt_diag288.c

 F: include/hw/s390x/

@@ -1162,6 +1163,7 @@ F: hw/s390x/ap-device.c

 F: hw/s390x/ap-bridge.c

 F: include/hw/s390x/ap-device.h

 F: include/hw/s390x/ap-bridge.h

+F: hw/vfio/ap.c

 L: qemu-s390x@nongnu.org

 vhost

diff --git a/default-configs/s390x-softmmu.mak b/default-configs/s390x-softmmu.mak

index 17e871a..d6ab059 100644

--- a/default-configs/s390x-softmmu.mak

+++ b/default-configs/s390x-softmmu.mak

@@ -10,3 +10,4 @@ CONFIG_S390_FLIC_KVM=$(CONFIG_KVM)

 # Disabled for Red Hat Enterprise Linux:

 # CONFIG_VFIO_CCW=$(CONFIG_LINUX)

 CONFIG_WDT_DIAG288=y

+CONFIG_VFIO_AP=$(CONFIG_LINUX)

diff --git a/hw/vfio/Makefile.objs b/hw/vfio/Makefile.objs

index b25ca64..a6b6039 100644

--- a/hw/vfio/Makefile.objs

+++ b/hw/vfio/Makefile.objs

@@ -3,4 +3,5 @@ obj-$(CONFIG_SOFTMMU) += common.o

 obj-$(CONFIG_PCI) += pci.o pci-quirks.o display.o

 obj-$(CONFIG_VFIO_CCW) += ccw.o

 obj-$(CONFIG_SOFTMMU) += spapr.o

+obj-$(CONFIG_VFIO_AP) += ap.o

 endif

diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c

new file mode 100644

index 0000000..3962bb7

--- /dev/null

+++ b/hw/vfio/ap.c

@@ -0,0 +1,181 @@

+/*

+ * VFIO based AP matrix device assignment

+ *

+ * Copyright 2018 IBM Corp.

+ * Author(s): Tony Krowiak <akrowiak@linux.ibm.com>

+ *            Halil Pasic <pasic@linux.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 <linux/vfio.h>

+#include <sys/ioctl.h>

+#include "qemu/osdep.h"

+#include "qapi/error.h"

+#include "hw/sysbus.h"

+#include "hw/vfio/vfio.h"

+#include "hw/vfio/vfio-common.h"

+#include "hw/s390x/ap-device.h"

+#include "qemu/error-report.h"

+#include "qemu/queue.h"

+#include "qemu/option.h"

+#include "qemu/config-file.h"

+#include "cpu.h"

+#include "kvm_s390x.h"

+#include "sysemu/sysemu.h"

+#include "hw/s390x/ap-bridge.h"

+#include "exec/address-spaces.h"

+

+#define VFIO_AP_DEVICE_TYPE      "vfio-ap"

+

+typedef struct VFIOAPDevice {

+    APDevice apdev;

+    VFIODevice vdev;

+} VFIOAPDevice;

+

+#define VFIO_AP_DEVICE(obj) \

+        OBJECT_CHECK(VFIOAPDevice, (obj), VFIO_AP_DEVICE_TYPE)

+

+static void vfio_ap_compute_needs_reset(VFIODevice *vdev)

+{

+    vdev->needs_reset = false;

+}

+

+/*

+ * We don't need vfio_hot_reset_multi and vfio_eoi operations for

+ * vfio-ap device now.

+ */

+struct VFIODeviceOps vfio_ap_ops = {

+    .vfio_compute_needs_reset = vfio_ap_compute_needs_reset,

+};

+

+static void vfio_ap_put_device(VFIOAPDevice *vapdev)

+{

+    g_free(vapdev->vdev.name);

+    vfio_put_base_device(&vapdev->vdev);

+}

+

+static VFIOGroup *vfio_ap_get_group(VFIOAPDevice *vapdev, Error **errp)

+{

+    GError *gerror = NULL;

+    char *symlink, *group_path;

+    int groupid;

+

+    symlink = g_strdup_printf("%s/iommu_group", vapdev->vdev.sysfsdev);

+    group_path = g_file_read_link(symlink, &gerror);

+    g_free(symlink);

+

+    if (!group_path) {

+        error_setg(errp, "%s: no iommu_group found for %s: %s",

+                   VFIO_AP_DEVICE_TYPE, vapdev->vdev.sysfsdev, gerror->message);

+        return NULL;

+    }

+

+    if (sscanf(basename(group_path), "%d", &groupid) != 1) {

+        error_setg(errp, "vfio: failed to read %s", group_path);

+        g_free(group_path);

+        return NULL;

+    }

+

+    g_free(group_path);

+

+    return vfio_get_group(groupid, &address_space_memory, errp);

+}

+

+static void vfio_ap_realize(DeviceState *dev, Error **errp)

+{

+    int ret;

+    char *mdevid;

+    Error *local_err = NULL;

+    VFIOGroup *vfio_group;

+    APDevice *apdev = AP_DEVICE(dev);

+    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);

+

+    vfio_group = vfio_ap_get_group(vapdev, &local_err);

+    if (!vfio_group) {

+        goto out_err;

+    }

+

+    vapdev->vdev.ops = &vfio_ap_ops;

+    vapdev->vdev.type = VFIO_DEVICE_TYPE_AP;

+    mdevid = basename(vapdev->vdev.sysfsdev);

+    vapdev->vdev.name = g_strdup_printf("%s", mdevid);

+    vapdev->vdev.dev = dev;

+

+    ret = vfio_get_device(vfio_group, mdevid, &vapdev->vdev, &local_err);

+    if (ret) {

+        goto out_get_dev_err;

+    }

+

+    return;

+

+out_get_dev_err:

+    vfio_ap_put_device(vapdev);

+    vfio_put_group(vfio_group);

+out_err:

+    error_propagate(errp, local_err);

+}

+

+static void vfio_ap_unrealize(DeviceState *dev, Error **errp)

+{

+    APDevice *apdev = AP_DEVICE(dev);

+    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);

+    VFIOGroup *group = vapdev->vdev.group;

+

+    vfio_ap_put_device(vapdev);

+    vfio_put_group(group);

+}

+

+static Property vfio_ap_properties[] = {

+    DEFINE_PROP_STRING("sysfsdev", VFIOAPDevice, vdev.sysfsdev),

+    DEFINE_PROP_END_OF_LIST(),

+};

+

+static void vfio_ap_reset(DeviceState *dev)

+{

+    int ret;

+    APDevice *apdev = AP_DEVICE(dev);

+    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);

+

+    ret = ioctl(vapdev->vdev.fd, VFIO_DEVICE_RESET);

+    if (ret) {

+        error_report("%s: failed to reset %s device: %s", __func__,

+                     vapdev->vdev.name, strerror(ret));

+    }

+}

+

+static const VMStateDescription vfio_ap_vmstate = {

+    .name = VFIO_AP_DEVICE_TYPE,

+    .unmigratable = 1,

+};

+

+static void vfio_ap_class_init(ObjectClass *klass, void *data)

+{

+    DeviceClass *dc = DEVICE_CLASS(klass);

+

+    dc->props = vfio_ap_properties;

+    dc->vmsd = &vfio_ap_vmstate;

+    dc->desc = "VFIO-based AP device assignment";

+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);

+    dc->realize = vfio_ap_realize;

+    dc->unrealize = vfio_ap_unrealize;

+    dc->hotpluggable = false;

+    dc->reset = vfio_ap_reset;

+    dc->bus_type = TYPE_AP_BUS;

+}

+

+static const TypeInfo vfio_ap_info = {

+    .name = VFIO_AP_DEVICE_TYPE,

+    .parent = AP_DEVICE_TYPE,

+    .instance_size = sizeof(VFIOAPDevice),

+    .class_init = vfio_ap_class_init,

+};

+

+static void vfio_ap_type_init(void)

+{

+    type_register_static(&vfio_ap_info);

+}

+

+type_init(vfio_ap_type_init)

diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h

index d936014..f29df6e 100644

--- a/include/hw/vfio/vfio-common.h

+++ b/include/hw/vfio/vfio-common.h

@@ -47,6 +47,7 @@ enum {

     VFIO_DEVICE_TYPE_PCI = 0,

     VFIO_DEVICE_TYPE_PLATFORM = 1,

     VFIO_DEVICE_TYPE_CCW = 2,

+    VFIO_DEVICE_TYPE_AP = 3,

 };

 typedef struct VFIOMmap {

-- 

1.8.3.1