Hi, David.
On Wed, Jan 16, 2019 at 12:35:17PM +0100, David Hildenbrand wrote:
> From: Pankaj Gupta <pagu...@redhat.com>
>
> This is the current protoype of virtio-pmem. Support will require
> machine changes for the architectures that will support it, so it will
> not yet be compiled.
>
> TODO:
> - Use separate struct for tracking requests internally
> - Move request/response structs to linux headers
> - Factor out linux header sync
> - Drop debug printfs
>
> Signed-off-by: Pankaj Gupta <pagu...@redhat.com>
> [ MemoryDevice/MemoryRegion changes, cleanups, addr property "memaddr",
> split up patches, unplug handler ]
> Signed-off-by: David Hildenbrand <da...@redhat.com>
> ---
> hw/virtio/Makefile.objs | 2 +
> hw/virtio/virtio-pmem.c | 189 ++++++++++++++++++++
> include/hw/virtio/virtio-pmem.h | 54 ++++++
> include/standard-headers/linux/virtio_ids.h | 1 +
> qapi/misc.json | 26 ++-
> 5 files changed, 271 insertions(+), 1 deletion(-)
> create mode 100644 hw/virtio/virtio-pmem.c
> create mode 100644 include/hw/virtio/virtio-pmem.h
>
> diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
> index 1b2799cfd8..5463c682f7 100644
> --- a/hw/virtio/Makefile.objs
> +++ b/hw/virtio/Makefile.objs
> @@ -9,6 +9,8 @@ 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-$(CONFIG_LINUX) += vhost.o vhost-backend.o vhost-user.o
> obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock.o
> endif
> diff --git a/hw/virtio/virtio-pmem.c b/hw/virtio/virtio-pmem.c
> new file mode 100644
> index 0000000000..6fb78acf87
> --- /dev/null
> +++ b/hw/virtio/virtio-pmem.c
> @@ -0,0 +1,189 @@
> +/*
> + * Virtio PMEM device
> + *
> + * Copyright (C) 2018 Red Hat, Inc.
> + *
> + * Authors:
> + * Pankaj Gupta <pagu...@redhat.com>
> + * David Hildenbrand <da...@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 "block/aio.h"
> +#include "block/thread-pool.h"
> +
> +typedef struct VirtIOPMEMresp {
> + int ret;
> +} VirtIOPMEMResp;
> +
> +typedef struct VirtIODeviceRequest {
> + VirtQueueElement elem;
> + int fd;
> + VirtIOPMEM *pmem;
> + VirtIOPMEMResp resp;
> +} VirtIODeviceRequest;
> +
> +static int worker_cb(void *opaque)
> +{
> + VirtIODeviceRequest *req = opaque;
> + int err = 0;
> +
> + printf("\n performing flush ...");
> + /* flush raw backing image */
> + err = fsync(req->fd);
> + printf("\n performed flush ...:errcode::%d", err);
> + if (err != 0) {
> + err = EIO;
> + }
> + req->resp.ret = err;
> +
> + return 0;
> +}
> +
> +static void done_cb(void *opaque, int ret)
> +{
> + VirtIODeviceRequest *req = opaque;
> + int len = iov_from_buf(req->elem.in_sg, req->elem.in_num, 0,
> + &req->resp, sizeof(VirtIOPMEMResp));
> +
> + /* Callbacks are serialized, so no need to use atomic ops. */
> + virtqueue_push(req->pmem->rq_vq, &req->elem, len);
> + virtio_notify((VirtIODevice *)req->pmem, req->pmem->rq_vq);
> + g_free(req);
> +}
> +
> +static void virtio_pmem_flush(VirtIODevice *vdev, VirtQueue *vq)
> +{
> + VirtIODeviceRequest *req;
> + VirtIOPMEM *pmem = VIRTIO_PMEM(vdev);
> + HostMemoryBackend *backend = MEMORY_BACKEND(pmem->memdev);
> + ThreadPool *pool = aio_get_thread_pool(qemu_get_aio_context());
> +
> + req = virtqueue_pop(vq, sizeof(VirtIODeviceRequest));
> + if (!req) {
> + virtio_error(vdev, "virtio-pmem missing request data");
> + return;
> + }
> +
> + if (req->elem.out_num < 1 || req->elem.in_num < 1) {
> + virtio_error(vdev, "virtio-pmem request not proper");
> + g_free(req);
> + return;
> + }
> + req->fd = memory_region_get_fd(&backend->mr);
> + req->pmem = pmem;
> + thread_pool_submit_aio(pool, worker_cb, req, done_cb, req);
> +}
> +
> +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;
> + } else 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;
> + }
Perhaps splitting this if-else block could improve readability:
if (!pmem->memdev) {
error_setg(...);
return;
}
if (host_memory_backend_is_mapped(pmem->memdev)) {
/* do stuff */
return;
}
/* do other stuffs */
> +
> + host_memory_backend_set_mapped(pmem->memdev, true);
> + virtio_init(vdev, TYPE_VIRTIO_PMEM, VIRTIO_ID_PMEM,
> + sizeof(struct virtio_pmem_config));
I'm not quite sure what's the QEMU style for indenting this. There
are, for example, calls to warn_report() in other source files that
are indented at the left side after the opening parenthesis.
Perhaps indenting it like this is preferable?
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);
> + pmem->rq_vq = virtio_add_queue(vdev, 128, virtio_pmem_flush);
> + 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)
> diff --git a/include/hw/virtio/virtio-pmem.h b/include/hw/virtio/virtio-pmem.h
> new file mode 100644
> index 0000000000..85cee3ef39
> --- /dev/null
> +++ b/include/hw/virtio/virtio-pmem.h
> @@ -0,0 +1,54 @@
> +/*
> + * Virtio pmem device
What if "pmem" was in upper case to match the header in virtio-pmem.c?
> + *
> + * Copyright Red Hat, Inc. 2018
This is slightly different from what is in virtio-pmem.c header.
Perhaps "(C)" is missing here.
> + *
> + * Authors:
> + * Pankaj Gupta <pagu...@redhat.com>
> + * David Hildenbrand <da...@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)
This indentation is slightly different from the other two macros
below.
> +#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;
> +
> +struct virtio_pmem_config {
> + uint64_t start;
> + uint64_t size;
> +};
> +
> +#endif
> diff --git a/include/standard-headers/linux/virtio_ids.h
> b/include/standard-headers/linux/virtio_ids.h
> index 6d5c3b2d4f..346389565a 100644
> --- a/include/standard-headers/linux/virtio_ids.h
> +++ b/include/standard-headers/linux/virtio_ids.h
> @@ -43,5 +43,6 @@
> #define VIRTIO_ID_INPUT 18 /* virtio input */
> #define VIRTIO_ID_VSOCK 19 /* virtio vsock transport */
> #define VIRTIO_ID_CRYPTO 20 /* virtio crypto */
> +#define VIRTIO_ID_PMEM 25 /* virtio pmem */
>
> #endif /* _LINUX_VIRTIO_IDS_H */
> diff --git a/qapi/misc.json b/qapi/misc.json
> index 24d20a880a..8ae709636d 100644
> --- a/qapi/misc.json
> +++ b/qapi/misc.json
> @@ -2949,6 +2949,29 @@
> }
> }
>
> +##
> +# @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: 3.1
> +##
> +{ 'struct': 'VirtioPMEMDeviceInfo',
> + 'data': { '*id': 'str',
> + 'memaddr': 'size',
> + 'size': 'size',
> + 'memdev': 'str'
> + }
> +}
> +
> ##
> # @MemoryDeviceInfo:
> #
> @@ -2958,7 +2981,8 @@
> ##
> { 'union': 'MemoryDeviceInfo',
> 'data': { 'dimm': 'PCDIMMDeviceInfo',
> - 'nvdimm': 'PCDIMMDeviceInfo'
> + 'nvdimm': 'PCDIMMDeviceInfo',
> + 'virtio-pmem': 'VirtioPMEMDeviceInfo'
> }
> }
>
> --
> 2.17.2
>
>
--
Murilo
