Commit 5f503cd9 authored by Pankaj Gupta's avatar Pankaj Gupta Committed by Michael S. Tsirkin
Browse files

virtio-pmem: add virtio device 



This is the implementation of virtio-pmem device. Support will require
machine changes for the architectures that will support it, so it will
not yet be compiled. It can be unlocked with VIRTIO_PMEM_SUPPORTED per
machine and disabled globally via VIRTIO_PMEM.

We cannot use the "addr" property as that is already used e.g. for
virtio-pci/pci devices. And we will have e.g. virtio-pmem-pci as a proxy.
So we have to choose a different one (unfortunately). "memaddr" it is.
That name should ideally be used by all other virtio-* based memory
devices in the future.
    -device virtio-pmem-pci,id=p0,bus=bux0,addr=0x01,memaddr=0x1000000...

Acked-by: default avatarMarkus Armbruster <armbru@redhat.com>
[ QAPI bits ]
Signed-off-by: default avatarPankaj Gupta <pagupta@redhat.com>
[ MemoryDevice/MemoryRegion changes, cleanups, addr property "memaddr",
  split up patches, unplug handler ]
Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Message-Id: <20190619094907.10131-2-pagupta@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: default avatarCornelia Huck <cohuck@redhat.com>
parent d85d65cc

hw/virtio/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -29,3 +29,13 @@ config VIRTIO_CRYPTO 
    bool

    default y

    depends on VIRTIO



config VIRTIO_PMEM_SUPPORTED

    bool



config VIRTIO_PMEM

    bool

    default y

    depends on VIRTIO

    depends on VIRTIO_PMEM_SUPPORTED

    select MEM_DEVICE

hw/virtio/Makefile.objs

+1 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ common-obj-$(CONFIG_VIRTIO_MMIO) += virtio-mmio.o 
obj-$(CONFIG_VIRTIO_BALLOON) += virtio-balloon.o

obj-$(CONFIG_VIRTIO_CRYPTO) += virtio-crypto.o

obj-$(call land,$(CONFIG_VIRTIO_CRYPTO),$(CONFIG_VIRTIO_PCI)) += virtio-crypto-pci.o

obj-$(CONFIG_VIRTIO_PMEM) += virtio-pmem.o

obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock.o



ifeq ($(CONFIG_VIRTIO_PCI),y)

hw/virtio/virtio-pmem.c

0 → 100644
+189 −0
Original line number Diff line number Diff line 
/*

 * Virtio PMEM device

 *

 * Copyright (C) 2018-2019 Red Hat, Inc.

 *

 * Authors:

 *  Pankaj Gupta <pagupta@redhat.com>

 *  David Hildenbrand <david@redhat.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2.

 * See the COPYING file in the top-level directory.

 */



#include "qemu/osdep.h"

#include "qapi/error.h"

#include "qemu-common.h"

#include "qemu/error-report.h"

#include "hw/virtio/virtio-pmem.h"

#include "hw/virtio/virtio-access.h"

#include "standard-headers/linux/virtio_ids.h"

#include "standard-headers/linux/virtio_pmem.h"

#include "block/aio.h"

#include "block/thread-pool.h"



typedef struct VirtIODeviceRequest {

    VirtQueueElement elem;

    int fd;

    VirtIOPMEM *pmem;

    VirtIODevice *vdev;

    struct virtio_pmem_req req;

    struct virtio_pmem_resp resp;

} VirtIODeviceRequest;



static int worker_cb(void *opaque)

{

    VirtIODeviceRequest *req_data = opaque;

    int err = 0;



    /* flush raw backing image */

    err = fsync(req_data->fd);

    if (err != 0) {

        err = 1;

    }



    virtio_stw_p(req_data->vdev, &req_data->resp.ret, err);



    return 0;

}



static void done_cb(void *opaque, int ret)

{

    VirtIODeviceRequest *req_data = opaque;

    int len = iov_from_buf(req_data->elem.in_sg, req_data->elem.in_num, 0,

                              &req_data->resp, sizeof(struct virtio_pmem_resp));



    /* Callbacks are serialized, so no need to use atomic ops. */

    virtqueue_push(req_data->pmem->rq_vq, &req_data->elem, len);

    virtio_notify((VirtIODevice *)req_data->pmem, req_data->pmem->rq_vq);

    g_free(req_data);

}



static void virtio_pmem_flush(VirtIODevice *vdev, VirtQueue *vq)

{

    VirtIODeviceRequest *req_data;

    VirtIOPMEM *pmem = VIRTIO_PMEM(vdev);

    HostMemoryBackend *backend = MEMORY_BACKEND(pmem->memdev);

    ThreadPool *pool = aio_get_thread_pool(qemu_get_aio_context());



    req_data = virtqueue_pop(vq, sizeof(VirtIODeviceRequest));

    if (!req_data) {

        virtio_error(vdev, "virtio-pmem missing request data");

        return;

    }



    if (req_data->elem.out_num < 1 || req_data->elem.in_num < 1) {

        virtio_error(vdev, "virtio-pmem request not proper");

        g_free(req_data);

        return;

    }

    req_data->fd   = memory_region_get_fd(&backend->mr);

    req_data->pmem = pmem;

    req_data->vdev = vdev;

    thread_pool_submit_aio(pool, worker_cb, req_data, done_cb, req_data);

}



static void virtio_pmem_get_config(VirtIODevice *vdev, uint8_t *config)

{

    VirtIOPMEM *pmem = VIRTIO_PMEM(vdev);

    struct virtio_pmem_config *pmemcfg = (struct virtio_pmem_config *) config;



    virtio_stq_p(vdev, &pmemcfg->start, pmem->start);

    virtio_stq_p(vdev, &pmemcfg->size, memory_region_size(&pmem->memdev->mr));

}



static uint64_t virtio_pmem_get_features(VirtIODevice *vdev, uint64_t features,

                                        Error **errp)

{

    return features;

}



static void virtio_pmem_realize(DeviceState *dev, Error **errp)

{

    VirtIODevice *vdev = VIRTIO_DEVICE(dev);

    VirtIOPMEM *pmem = VIRTIO_PMEM(dev);



    if (!pmem->memdev) {

        error_setg(errp, "virtio-pmem memdev not set");

        return;

    }



    if (host_memory_backend_is_mapped(pmem->memdev)) {

        char *path = object_get_canonical_path_component(OBJECT(pmem->memdev));

        error_setg(errp, "can't use already busy memdev: %s", path);

        g_free(path);

        return;

    }



    host_memory_backend_set_mapped(pmem->memdev, true);

    virtio_init(vdev, TYPE_VIRTIO_PMEM, VIRTIO_ID_PMEM,

                sizeof(struct virtio_pmem_config));

    pmem->rq_vq = virtio_add_queue(vdev, 128, virtio_pmem_flush);

}



static void virtio_pmem_unrealize(DeviceState *dev, Error **errp)

{

    VirtIODevice *vdev = VIRTIO_DEVICE(dev);

    VirtIOPMEM *pmem = VIRTIO_PMEM(dev);



    host_memory_backend_set_mapped(pmem->memdev, false);

    virtio_cleanup(vdev);

}



static void virtio_pmem_fill_device_info(const VirtIOPMEM *pmem,

                                         VirtioPMEMDeviceInfo *vi)

{

    vi->memaddr = pmem->start;

    vi->size = pmem->memdev ? memory_region_size(&pmem->memdev->mr) : 0;

    vi->memdev = object_get_canonical_path(OBJECT(pmem->memdev));

}



static MemoryRegion *virtio_pmem_get_memory_region(VirtIOPMEM *pmem,

                                                   Error **errp)

{

    if (!pmem->memdev) {

        error_setg(errp, "'%s' property must be set", VIRTIO_PMEM_MEMDEV_PROP);

        return NULL;

    }



    return &pmem->memdev->mr;

}



static Property virtio_pmem_properties[] = {

    DEFINE_PROP_UINT64(VIRTIO_PMEM_ADDR_PROP, VirtIOPMEM, start, 0),

    DEFINE_PROP_LINK(VIRTIO_PMEM_MEMDEV_PROP, VirtIOPMEM, memdev,

                     TYPE_MEMORY_BACKEND, HostMemoryBackend *),

    DEFINE_PROP_END_OF_LIST(),

};



static void virtio_pmem_class_init(ObjectClass *klass, void *data)

{

    DeviceClass *dc = DEVICE_CLASS(klass);

    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);

    VirtIOPMEMClass *vpc = VIRTIO_PMEM_CLASS(klass);



    dc->props = virtio_pmem_properties;



    vdc->realize = virtio_pmem_realize;

    vdc->unrealize = virtio_pmem_unrealize;

    vdc->get_config = virtio_pmem_get_config;

    vdc->get_features = virtio_pmem_get_features;



    vpc->fill_device_info = virtio_pmem_fill_device_info;

    vpc->get_memory_region = virtio_pmem_get_memory_region;

}



static TypeInfo virtio_pmem_info = {

    .name          = TYPE_VIRTIO_PMEM,

    .parent        = TYPE_VIRTIO_DEVICE,

    .class_size    = sizeof(VirtIOPMEMClass),

    .class_init    = virtio_pmem_class_init,

    .instance_size = sizeof(VirtIOPMEM),

};



static void virtio_register_types(void)

{

    type_register_static(&virtio_pmem_info);

}



type_init(virtio_register_types)

include/hw/virtio/virtio-pmem.h

0 → 100644
+49 −0
Original line number Diff line number Diff line 
/*

 * Virtio PMEM device

 *

 * Copyright (C) 2018-2019 Red Hat, Inc.

 *

 * Authors:

 *  Pankaj Gupta <pagupta@redhat.com>

 *  David Hildenbrand <david@redhat.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2.

 * See the COPYING file in the top-level directory.

 */



#ifndef HW_VIRTIO_PMEM_H

#define HW_VIRTIO_PMEM_H



#include "hw/virtio/virtio.h"

#include "sysemu/hostmem.h"



#define TYPE_VIRTIO_PMEM "virtio-pmem"



#define VIRTIO_PMEM(obj) \

        OBJECT_CHECK(VirtIOPMEM, (obj), TYPE_VIRTIO_PMEM)

#define VIRTIO_PMEM_CLASS(oc) \

        OBJECT_CLASS_CHECK(VirtIOPMEMClass, (oc), TYPE_VIRTIO_PMEM)

#define VIRTIO_PMEM_GET_CLASS(obj) \

        OBJECT_GET_CLASS(VirtIOPMEMClass, (obj), TYPE_VIRTIO_PMEM)



#define VIRTIO_PMEM_ADDR_PROP "memaddr"

#define VIRTIO_PMEM_MEMDEV_PROP "memdev"



typedef struct VirtIOPMEM {

    VirtIODevice parent_obj;



    VirtQueue *rq_vq;

    uint64_t start;

    HostMemoryBackend *memdev;

} VirtIOPMEM;



typedef struct VirtIOPMEMClass {

    /* private */

    VirtIODevice parent;



    /* public */

    void (*fill_device_info)(const VirtIOPMEM *pmem, VirtioPMEMDeviceInfo *vi);

    MemoryRegion *(*get_memory_region)(VirtIOPMEM *pmem, Error **errp);

} VirtIOPMEMClass;



#endif

qapi/misc.json

+27 −1
Original line number Diff line number Diff line
@@ -2738,16 +2738,42 @@ 
          }

}



##

# @VirtioPMEMDeviceInfo:

#

# VirtioPMEM state information

#

# @id: device's ID

#

# @memaddr: physical address in memory, where device is mapped

#

# @size: size of memory that the device provides

#

# @memdev: memory backend linked with device

#

# Since: 4.1

##

{ 'struct': 'VirtioPMEMDeviceInfo',

  'data': { '*id': 'str',

            'memaddr': 'size',

            'size': 'size',

            'memdev': 'str'

          }

}



##

# @MemoryDeviceInfo:

#

# Union containing information about a memory device

#

# nvdimm is included since 2.12. virtio-pmem is included since 4.1.

#

# Since: 2.1

##

{ 'union': 'MemoryDeviceInfo',

  'data': { 'dimm': 'PCDIMMDeviceInfo',

            'nvdimm': 'PCDIMMDeviceInfo'

            'nvdimm': 'PCDIMMDeviceInfo',

            'virtio-pmem': 'VirtioPMEMDeviceInfo'

          }

}