Re: [PATCH 6/7] qemu: Implement virtio-pstore device
From: Michael S. Tsirkin
Date: Wed Jul 27 2016 - 20:03:26 EST
On Thu, Jul 28, 2016 at 12:08:30AM +0900, Namhyung Kim wrote:
> Add virtio pstore device to allow kernel log files saved on the host.
> It will save the log files on the directory given by pstore device
> option.
>
> $ qemu-system-x86_64 -device virtio-pstore,directory=dir-xx ...
>
> (guest) # echo c > /proc/sysrq-trigger
So if the point is handling system crashes, I suspect
virtio is the wrong protocol to use. ATM it's rather
elaborate for performance, it's likely not to work when
linux is crashing. I think you want something very very
simple that will still work when you crash. Like maybe
a serial device?
> $ ls dir-xx
> dmesg-1.enc.z dmesg-2.enc.z
>
> The log files are usually compressed using zlib. Users can see the log
> messages directly on the host or on the guest (using pstore filesystem).
So this lacks all management tools that a regular storage device
has, and these are necessary if people are to use this
in production.
For example, some kind of provision for limiting the amount of host disk
this can consume seems called for. Rate-limiting disk writes
on host also seems necessary. Handling host disk errors always
propagates error to guest but an option to e.g. stop vm might
be useful to avoid corruption.
>
> The 'directory' property is required for virtio-pstore device to work.
> It also adds 'bufsize' and 'console' (boolean) properties.
No idea what these do. Seem to be RW by guest but have no effect
otherwise.
> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Cc: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
> Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
> Cc: Anthony Liguori <aliguori@xxxxxxxxxx>
> Cc: Anton Vorontsov <anton@xxxxxxxxxx>
> Cc: Colin Cross <ccross@xxxxxxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Tony Luck <tony.luck@xxxxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Minchan Kim <minchan@xxxxxxxxxx>
> Cc: kvm@xxxxxxxxxxxxxxx
> Cc: qemu-devel@xxxxxxxxxx
> Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> ---
> hw/virtio/Makefile.objs | 2 +-
> hw/virtio/virtio-pci.c | 54 +++
> hw/virtio/virtio-pci.h | 14 +
> hw/virtio/virtio-pstore.c | 477 +++++++++++++++++++++++++
> include/hw/pci/pci.h | 1 +
> include/hw/virtio/virtio-pstore.h | 34 ++
> include/standard-headers/linux/virtio_ids.h | 1 +
> include/standard-headers/linux/virtio_pstore.h | 80 +++++
> qdev-monitor.c | 1 +
> 9 files changed, 663 insertions(+), 1 deletion(-)
> create mode 100644 hw/virtio/virtio-pstore.c
> create mode 100644 include/hw/virtio/virtio-pstore.h
> create mode 100644 include/standard-headers/linux/virtio_pstore.h
>
> diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
> index 3e2b175..aae7082 100644
> --- a/hw/virtio/Makefile.objs
> +++ b/hw/virtio/Makefile.objs
> @@ -4,4 +4,4 @@ common-obj-y += virtio-bus.o
> common-obj-y += virtio-mmio.o
>
> obj-y += virtio.o virtio-balloon.o
> -obj-$(CONFIG_LINUX) += vhost.o vhost-backend.o vhost-user.o
> +obj-$(CONFIG_LINUX) += vhost.o vhost-backend.o vhost-user.o virtio-pstore.o
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index f0677b7..d99a405 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -2414,6 +2414,59 @@ static const TypeInfo virtio_host_pci_info = {
> };
> #endif
>
> +/* virtio-pstore-pci */
> +
> +static void virtio_pstore_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
> +{
> + VirtIOPstorePCI *vps = VIRTIO_PSTORE_PCI(vpci_dev);
> + DeviceState *vdev = DEVICE(&vps->vdev);
> + Error *err = NULL;
> +
> + qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
> + object_property_set_bool(OBJECT(vdev), true, "realized", &err);
> + if (err) {
> + error_propagate(errp, err);
> + return;
> + }
> +}
> +
> +static void virtio_pstore_pci_class_init(ObjectClass *klass, void *data)
> +{
> + DeviceClass *dc = DEVICE_CLASS(klass);
> + VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
> + PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
> +
> + k->realize = virtio_pstore_pci_realize;
> + set_bit(DEVICE_CATEGORY_MISC, dc->categories);
> +
> + pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
> + pcidev_k->device_id = PCI_DEVICE_ID_VIRTIO_PSTORE;
> + pcidev_k->revision = VIRTIO_PCI_ABI_VERSION;
> + pcidev_k->class_id = PCI_CLASS_OTHERS;
> +}
> +
> +static void virtio_pstore_pci_instance_init(Object *obj)
> +{
> + VirtIOPstorePCI *dev = VIRTIO_PSTORE_PCI(obj);
> +
> + virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
> + TYPE_VIRTIO_PSTORE);
> + object_property_add_alias(obj, "directory", OBJECT(&dev->vdev),
> + "directory", &error_abort);
> + object_property_add_alias(obj, "bufsize", OBJECT(&dev->vdev),
> + "bufsize", &error_abort);
> + object_property_add_alias(obj, "console", OBJECT(&dev->vdev),
> + "console", &error_abort);
> +}
> +
> +static const TypeInfo virtio_pstore_pci_info = {
> + .name = TYPE_VIRTIO_PSTORE_PCI,
> + .parent = TYPE_VIRTIO_PCI,
> + .instance_size = sizeof(VirtIOPstorePCI),
> + .instance_init = virtio_pstore_pci_instance_init,
> + .class_init = virtio_pstore_pci_class_init,
> +};
> +
> /* virtio-pci-bus */
>
> static void virtio_pci_bus_new(VirtioBusState *bus, size_t bus_size,
> @@ -2483,6 +2536,7 @@ static void virtio_pci_register_types(void)
> #ifdef CONFIG_VHOST_SCSI
> type_register_static(&vhost_scsi_pci_info);
> #endif
> + type_register_static(&virtio_pstore_pci_info);
> }
>
> type_init(virtio_pci_register_types)
> diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
> index e4548c2..b4c039f 100644
> --- a/hw/virtio/virtio-pci.h
> +++ b/hw/virtio/virtio-pci.h
> @@ -31,6 +31,7 @@
> #ifdef CONFIG_VHOST_SCSI
> #include "hw/virtio/vhost-scsi.h"
> #endif
> +#include "hw/virtio/virtio-pstore.h"
>
> typedef struct VirtIOPCIProxy VirtIOPCIProxy;
> typedef struct VirtIOBlkPCI VirtIOBlkPCI;
> @@ -44,6 +45,7 @@ typedef struct VirtIOInputPCI VirtIOInputPCI;
> typedef struct VirtIOInputHIDPCI VirtIOInputHIDPCI;
> typedef struct VirtIOInputHostPCI VirtIOInputHostPCI;
> typedef struct VirtIOGPUPCI VirtIOGPUPCI;
> +typedef struct VirtIOPstorePCI VirtIOPstorePCI;
>
> /* virtio-pci-bus */
>
> @@ -311,6 +313,18 @@ struct VirtIOGPUPCI {
> VirtIOGPU vdev;
> };
>
> +/*
> + * virtio-pstore-pci: This extends VirtioPCIProxy.
> + */
> +#define TYPE_VIRTIO_PSTORE_PCI "virtio-pstore-pci"
> +#define VIRTIO_PSTORE_PCI(obj) \
> + OBJECT_CHECK(VirtIOPstorePCI, (obj), TYPE_VIRTIO_PSTORE_PCI)
> +
> +struct VirtIOPstorePCI {
> + VirtIOPCIProxy parent_obj;
> + VirtIOPstore vdev;
> +};
> +
> /* Virtio ABI version, if we increment this, we break the guest driver. */
> #define VIRTIO_PCI_ABI_VERSION 0
>
> diff --git a/hw/virtio/virtio-pstore.c b/hw/virtio/virtio-pstore.c
> new file mode 100644
> index 0000000..2ca7786
> --- /dev/null
> +++ b/hw/virtio/virtio-pstore.c
> @@ -0,0 +1,477 @@
> +/*
> + * Virtio Pstore Device
> + *
> + * Copyright (C) 2016 LG Electronics
> + *
> + * Authors:
> + * Namhyung Kim <namhyung@xxxxxxxxx>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.
We generally ask new code to be v2 or later.
> See
> + * the COPYING file in the top-level directory.
> + *
> + */
> +
> +#include <stdio.h>
> +
> +#include "qemu/osdep.h"
> +#include "qemu/iov.h"
> +#include "qemu-common.h"
> +#include "qemu/cutils.h"
> +#include "qemu/error-report.h"
> +#include "sysemu/kvm.h"
> +#include "qapi/visitor.h"
> +#include "qapi-event.h"
> +#include "trace.h"
> +
> +#include "hw/virtio/virtio.h"
> +#include "hw/virtio/virtio-bus.h"
> +#include "hw/virtio/virtio-access.h"
> +#include "hw/virtio/virtio-pstore.h"
> +
> +
> +static void virtio_pstore_to_filename(VirtIOPstore *s, char *buf, size_t sz,
> + struct virtio_pstore_req *req)
> +{
> + const char *basename;
> + unsigned long long id = 0;
> + unsigned int flags = le32_to_cpu(req->flags);
> +
> + switch (le16_to_cpu(req->type)) {
> + case VIRTIO_PSTORE_TYPE_DMESG:
> + basename = "dmesg";
> + id = s->id++;
> + break;
> + case VIRTIO_PSTORE_TYPE_CONSOLE:
> + basename = "console";
> + if (s->console_id) {
> + id = s->console_id;
> + } else {
> + id = s->console_id = s->id++;
> + }
> + break;
> + default:
> + basename = "unknown";
> + break;
> + }
> +
> + snprintf(buf, sz, "%s/%s-%llu%s", s->directory, basename, id,
> + flags & VIRTIO_PSTORE_FL_COMPRESSED ? ".enc.z" : "");
> +}
> +
> +static void virtio_pstore_from_filename(VirtIOPstore *s, char *name,
> + char *buf, size_t sz,
> + struct virtio_pstore_fileinfo *info)
> +{
> + snprintf(buf, sz, "%s/%s", s->directory, name);
if this does not fit, buf will not be 0 terminated and can
generally be corrupted.
> +
> + if (g_str_has_prefix(name, "dmesg-")) {
> + info->type = VIRTIO_PSTORE_TYPE_DMESG;
> + name += strlen("dmesg-");
> + } else if (g_str_has_prefix(name, "console-")) {
> + info->type = VIRTIO_PSTORE_TYPE_CONSOLE;
> + name += strlen("console-");
> + } else if (g_str_has_prefix(name, "unknown-")) {
> + info->type = VIRTIO_PSTORE_TYPE_UNKNOWN;
> + name += strlen("unknown-");
> + }
> +
> + qemu_strtoull(name, NULL, 0, &info->id);
> +
> + info->flags = 0;
> + if (g_str_has_suffix(name, ".enc.z")) {
> + info->flags |= VIRTIO_PSTORE_FL_COMPRESSED;
> + }
> +}
> +
> +static ssize_t virtio_pstore_do_open(VirtIOPstore *s)
> +{
> + s->dirp = opendir(s->directory);
> + if (s->dirp == NULL) {
> + return -1;
> + }
> +
> + return 0;
> +}
> +
> +static ssize_t virtio_pstore_do_read(VirtIOPstore *s, struct iovec *in_sg,
> + unsigned int in_num,
> + struct virtio_pstore_res *res)
> +{
> + char path[PATH_MAX];
> + int fd;
> + ssize_t len;
> + struct stat stbuf;
> + struct dirent *dent;
> + int sg_num = in_num;
> + struct iovec sg[sg_num];
> + struct virtio_pstore_fileinfo info;
> + size_t offset = sizeof(*res) + sizeof(info);
> +
> + if (s->dirp == NULL) {
> + return -1;
> + }
> +
> + dent = readdir(s->dirp);
> + while (dent) {
> + if (dent->d_name[0] != '.') {
> + break;
> + }
> + dent = readdir(s->dirp);
> + }
> +
> + if (dent == NULL) {
> + return 0;
> + }
> +
> + /* skip res and fileinfo */
> + sg_num = iov_copy(sg, sg_num, in_sg, in_num, offset,
> + iov_size(in_sg, in_num) - offset);
> +
> + virtio_pstore_from_filename(s, dent->d_name, path, sizeof(path), &info);
> + fd = open(path, O_RDONLY);
> + if (fd < 0) {
> + error_report("cannot open %s", path);
> + return -1;
> + }
> +
> + if (fstat(fd, &stbuf) < 0) {
> + len = -1;
> + goto out;
> + }
> +
> + len = readv(fd, sg, sg_num);
> + if (len < 0) {
> + if (errno == EAGAIN) {
> + len = 0;
> + }
> + goto out;
> + }
> +
> + info.id = cpu_to_le64(info.id);
> + info.type = cpu_to_le16(info.type);
> + info.flags = cpu_to_le32(info.flags);
> + info.len = cpu_to_le32(len);
> + info.time_sec = cpu_to_le64(stbuf.st_ctim.tv_sec);
> + info.time_nsec = cpu_to_le32(stbuf.st_ctim.tv_nsec);
> +
> + iov_from_buf(in_sg, in_num, sizeof(*res), &info, sizeof(info));
> + len += sizeof(info);
> +
> + out:
> + close(fd);
> + return len;
> +}
> +
> +static ssize_t virtio_pstore_do_write(VirtIOPstore *s, struct iovec *out_sg,
> + unsigned int out_num,
> + struct virtio_pstore_req *req)
> +{
> + char path[PATH_MAX];
> + int fd;
> + ssize_t len;
> + unsigned short type;
> + int flags = O_WRONLY | O_CREAT;
> +
> + /* we already consume the req */
> + iov_discard_front(&out_sg, &out_num, sizeof(*req));
> +
> + virtio_pstore_to_filename(s, path, sizeof(path), req);
> +
> + type = le16_to_cpu(req->type);
> +
> + if (type == VIRTIO_PSTORE_TYPE_DMESG) {
> + flags |= O_TRUNC;
> + } else if (type == VIRTIO_PSTORE_TYPE_CONSOLE) {
> + flags |= O_APPEND;
> + }
> +
> + fd = open(path, flags, 0644);
> + if (fd < 0) {
> + error_report("cannot open %s", path);
> + return -1;
> + }
> + len = writev(fd, out_sg, out_num);
> + close(fd);
> +
> + return len;
All this is blocking VM until host io completes.
> +}
> +
> +static ssize_t virtio_pstore_do_close(VirtIOPstore *s)
> +{
> + if (s->dirp == NULL) {
> + return 0;
> + }
> +
> + closedir(s->dirp);
> + s->dirp = NULL;
> +
> + return 0;
> +}
> +
> +static ssize_t virtio_pstore_do_erase(VirtIOPstore *s,
> + struct virtio_pstore_req *req)
> +{
> + char path[PATH_MAX];
> +
> + virtio_pstore_to_filename(s, path, sizeof(path), req);
> +
> + return unlink(path);
> +}
> +
> +static void virtio_pstore_handle_io(VirtIODevice *vdev, VirtQueue *vq)
> +{
> + VirtIOPstore *s = VIRTIO_PSTORE(vdev);
> + VirtQueueElement *elem;
> + struct virtio_pstore_req req;
> + struct virtio_pstore_res res;
> + ssize_t len = 0;
> + int ret;
> +
> + for (;;) {
> + elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
> + if (!elem) {
> + return;
> + }
> +
> + if (elem->out_num < 1 || elem->in_num < 1) {
> + error_report("request or response buffer is missing");
> + exit(1);
> + }
> +
> + len = iov_to_buf(elem->out_sg, elem->out_num, 0, &req, sizeof(req));
> + if (len != (ssize_t)sizeof(req)) {
> + error_report("invalid request size: %ld", (long)len);
> + exit(1);
> + }
> + res.cmd = req.cmd;
> + res.type = req.type;
> +
> + switch (le16_to_cpu(req.cmd)) {
> + case VIRTIO_PSTORE_CMD_OPEN:
> + ret = virtio_pstore_do_open(s);
> + break;
> + case VIRTIO_PSTORE_CMD_READ:
> + ret = virtio_pstore_do_read(s, elem->in_sg, elem->in_num, &res);
> + if (ret > 0) {
> + len = ret;
> + ret = 0;
> + }
> + break;
> + case VIRTIO_PSTORE_CMD_WRITE:
> + ret = virtio_pstore_do_write(s, elem->out_sg, elem->out_num, &req);
> + break;
> + case VIRTIO_PSTORE_CMD_CLOSE:
> + ret = virtio_pstore_do_close(s);
> + break;
> + case VIRTIO_PSTORE_CMD_ERASE:
> + ret = virtio_pstore_do_erase(s, &req);
> + break;
> + default:
> + ret = -1;
> + break;
> + }
> +
> + res.ret = ret;
> +
> + iov_from_buf(elem->in_sg, elem->in_num, 0, &res, sizeof(res));
> + virtqueue_push(vq, elem, sizeof(res) + len);
this is wrong - len should be # of bytes written into guest memory.
> +
> + virtio_notify(vdev, vq);
> + g_free(elem);
> +
> + if (ret < 0) {
> + return;
> + }
> + }
> +}
> +
> +static void virtio_pstore_device_realize(DeviceState *dev, Error **errp)
> +{
> + VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> + VirtIOPstore *s = VIRTIO_PSTORE(dev);
> +
> + virtio_init(vdev, "virtio-pstore", VIRTIO_ID_PSTORE,
> + sizeof(struct virtio_pstore_config));
> +
> + s->id = 1;
> + s->console_id = 0;
> +
> + s->vq[0] = virtio_add_queue(vdev, 128, virtio_pstore_handle_io);
> + s->vq[1] = virtio_add_queue(vdev, 128, virtio_pstore_handle_io);
> +}
> +
> +static void virtio_pstore_device_unrealize(DeviceState *dev, Error **errp)
> +{
> + VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> +
> + virtio_cleanup(vdev);
> +}
> +
> +static void virtio_pstore_get_config(VirtIODevice *vdev, uint8_t *config_data)
> +{
> + VirtIOPstore *dev = VIRTIO_PSTORE(vdev);
> + struct virtio_pstore_config config;
> +
> + config.bufsize = cpu_to_le32(dev->bufsize);
> + if (dev->console) {
> + config.flags |= cpu_to_le32(VIRTIO_PSTORE_CONFIG_FL_CONSOLE);
> + }
> +
> + memcpy(config_data, &config, sizeof(struct virtio_pstore_config));
> +}
> +
> +static void virtio_pstore_set_config(VirtIODevice *vdev,
> + const uint8_t *config_data)
> +{
> + VirtIOPstore *dev = VIRTIO_PSTORE(vdev);
> + struct virtio_pstore_config config;
> +
> + memcpy(&config, config_data, sizeof(struct virtio_pstore_config));
> +
> + dev->bufsize = le32_to_cpu(config.bufsize);
> +}
> +
> +static uint64_t get_features(VirtIODevice *vdev, uint64_t f, Error **errp)
> +{
> + return f;
> +}
> +
> +static void pstore_get_directory(Object *obj, Visitor *v,
> + const char *name, void *opaque,
> + Error **errp)
> +{
> + VirtIOPstore *s = opaque;
> +
> + visit_type_str(v, name, &s->directory, errp);
> +}
> +
> +static void pstore_set_directory(Object *obj, Visitor *v,
> + const char *name, void *opaque,
> + Error **errp)
> +{
> + VirtIOPstore *s = opaque;
> + Error *local_err = NULL;
> + char *value;
> +
> + visit_type_str(v, name, &value, &local_err);
> + if (local_err) {
> + error_propagate(errp, local_err);
> + return;
> + }
> +
> + g_free(s->directory);
> + s->directory = value;
> +}
> +
> +static void pstore_release_directory(Object *obj, const char *name,
> + void *opaque)
> +{
> + VirtIOPstore *s = opaque;
> +
> + g_free(s->directory);
> + s->directory = NULL;
> +}
> +
> +static void pstore_get_bufsize(Object *obj, Visitor *v,
> + const char *name, void *opaque,
> + Error **errp)
> +{
> + VirtIOPstore *s = opaque;
> + uint64_t value = s->bufsize;
> +
> + visit_type_size(v, name, &value, errp);
> +}
> +
> +static void pstore_set_bufsize(Object *obj, Visitor *v,
> + const char *name, void *opaque,
> + Error **errp)
> +{
> + VirtIOPstore *s = opaque;
> + Error *error = NULL;
> + uint64_t value;
> +
> + visit_type_size(v, name, &value, &error);
> + if (error) {
> + error_propagate(errp, error);
> + return;
> + }
> +
> + if (value < 4096) {
> + error_report("Warning: too small buffer size: %"PRIu64, value);
> + }
> +
> + s->bufsize = value;
> +}
> +
> +static void pstore_get_console(Object *obj, Visitor *v,
> + const char *name, void *opaque,
> + Error **errp)
> +{
> + VirtIOPstore *s = opaque;
> + bool value = s->console;
> +
> + visit_type_bool(v, name, &value, errp);
> +}
> +
> +static void pstore_set_console(Object *obj, Visitor *v,
> + const char *name, void *opaque,
> + Error **errp)
> +{
> + VirtIOPstore *s = opaque;
> + Error *error = NULL;
> + bool value;
> +
> + visit_type_bool(v, name, &value, &error);
> + if (error) {
> + error_propagate(errp, error);
> + return;
> + }
> +
> + s->console = value;
> +}
> +
> +static Property virtio_pstore_properties[] = {
> + DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void virtio_pstore_instance_init(Object *obj)
> +{
> + VirtIOPstore *s = VIRTIO_PSTORE(obj);
> +
> + object_property_add(obj, "directory", "str",
> + pstore_get_directory, pstore_set_directory,
> + pstore_release_directory, s, NULL);
> + object_property_add(obj, "bufsize", "size",
> + pstore_get_bufsize, pstore_set_bufsize, NULL, s, NULL);
> + object_property_add(obj, "console", "bool",
> + pstore_get_console, pstore_set_console, NULL, s, NULL);
> +}
> +
> +static void virtio_pstore_class_init(ObjectClass *klass, void *data)
> +{
> + DeviceClass *dc = DEVICE_CLASS(klass);
> + VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
> +
> + dc->props = virtio_pstore_properties;
> + set_bit(DEVICE_CATEGORY_MISC, dc->categories);
> + vdc->realize = virtio_pstore_device_realize;
> + vdc->unrealize = virtio_pstore_device_unrealize;
> + vdc->get_config = virtio_pstore_get_config;
> + vdc->set_config = virtio_pstore_set_config;
> + vdc->get_features = get_features;
> +}
> +
> +static const TypeInfo virtio_pstore_info = {
> + .name = TYPE_VIRTIO_PSTORE,
> + .parent = TYPE_VIRTIO_DEVICE,
> + .instance_size = sizeof(VirtIOPstore),
> + .instance_init = virtio_pstore_instance_init,
> + .class_init = virtio_pstore_class_init,
> +};
> +
> +static void virtio_register_types(void)
> +{
> + type_register_static(&virtio_pstore_info);
> +}
> +
> +type_init(virtio_register_types)
> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> index 74d797d..000e1e9 100644
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -79,6 +79,7 @@
> #define PCI_DEVICE_ID_VIRTIO_SCSI 0x1004
> #define PCI_DEVICE_ID_VIRTIO_RNG 0x1005
> #define PCI_DEVICE_ID_VIRTIO_9P 0x1009
> +#define PCI_DEVICE_ID_VIRTIO_PSTORE 0x100a
>
> #define PCI_VENDOR_ID_REDHAT 0x1b36
> #define PCI_DEVICE_ID_REDHAT_BRIDGE 0x0001
> diff --git a/include/hw/virtio/virtio-pstore.h b/include/hw/virtio/virtio-pstore.h
> new file mode 100644
> index 0000000..d188a48
> --- /dev/null
> +++ b/include/hw/virtio/virtio-pstore.h
> @@ -0,0 +1,34 @@
> +/*
> + * Virtio Pstore Support
> + *
> + * Authors:
> + * Namhyung Kim <namhyung@xxxxxxxxx>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2. See
> + * the COPYING file in the top-level directory.
> + *
> + */
> +
> +#ifndef _QEMU_VIRTIO_PSTORE_H
> +#define _QEMU_VIRTIO_PSTORE_H
> +
> +#include "standard-headers/linux/virtio_pstore.h"
> +#include "hw/virtio/virtio.h"
> +#include "hw/pci/pci.h"
> +
> +#define TYPE_VIRTIO_PSTORE "virtio-pstore-device"
> +#define VIRTIO_PSTORE(obj) \
> + OBJECT_CHECK(VirtIOPstore, (obj), TYPE_VIRTIO_PSTORE)
> +
> +typedef struct VirtIOPstore {
> + VirtIODevice parent_obj;
> + VirtQueue *vq[2];
> + char *directory;
> + uint64_t id;
> + uint64_t console_id;
> + DIR *dirp;
> + uint64_t bufsize;
> + bool console;
> +} VirtIOPstore;
> +
> +#endif
> diff --git a/include/standard-headers/linux/virtio_ids.h b/include/standard-headers/linux/virtio_ids.h
> index 77925f5..c72a9ab 100644
> --- a/include/standard-headers/linux/virtio_ids.h
> +++ b/include/standard-headers/linux/virtio_ids.h
> @@ -41,5 +41,6 @@
> #define VIRTIO_ID_CAIF 12 /* Virtio caif */
> #define VIRTIO_ID_GPU 16 /* virtio GPU */
> #define VIRTIO_ID_INPUT 18 /* virtio input */
> +#define VIRTIO_ID_PSTORE 22 /* virtio pstore */
>
> #endif /* _LINUX_VIRTIO_IDS_H */
> diff --git a/include/standard-headers/linux/virtio_pstore.h b/include/standard-headers/linux/virtio_pstore.h
> new file mode 100644
> index 0000000..b893d15
> --- /dev/null
> +++ b/include/standard-headers/linux/virtio_pstore.h
> @@ -0,0 +1,80 @@
> +#ifndef _LINUX_VIRTIO_PSTORE_H
> +#define _LINUX_VIRTIO_PSTORE_H
> +/* This header is BSD licensed so anyone can use the definitions to implement
> + * compatible drivers/servers.
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + * notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + * notice, this list of conditions and the following disclaimer in the
> + * documentation and/or other materials provided with the distribution.
> + * 3. Neither the name of IBM nor the names of its contributors
> + * may be used to endorse or promote products derived from this software
> + * without specific prior written permission.
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE. */
> +#include "standard-headers/linux/types.h"
> +#include "standard-headers/linux/virtio_types.h"
> +#include "standard-headers/linux/virtio_ids.h"
> +#include "standard-headers/linux/virtio_config.h"
> +
> +#define VIRTIO_PSTORE_CMD_NULL 0
> +#define VIRTIO_PSTORE_CMD_OPEN 1
> +#define VIRTIO_PSTORE_CMD_READ 2
> +#define VIRTIO_PSTORE_CMD_WRITE 3
> +#define VIRTIO_PSTORE_CMD_ERASE 4
> +#define VIRTIO_PSTORE_CMD_CLOSE 5
> +
> +#define VIRTIO_PSTORE_TYPE_UNKNOWN 0
> +#define VIRTIO_PSTORE_TYPE_DMESG 1
> +#define VIRTIO_PSTORE_TYPE_CONSOLE 2
> +
> +#define VIRTIO_PSTORE_FL_COMPRESSED 1
> +
> +#define VIRTIO_PSTORE_CONFIG_FL_CONSOLE (1 << 0)
> +
> +struct virtio_pstore_req {
> + __virtio16 cmd;
> + __virtio16 type;
> + __virtio32 flags;
> + __virtio64 id;
> + __virtio32 count;
> + __virtio32 reserved;
> +};
> +
> +struct virtio_pstore_res {
> + __virtio16 cmd;
> + __virtio16 type;
> + __virtio32 ret;
> +};
> +
> +struct virtio_pstore_fileinfo {
> + __virtio64 id;
> + __virtio32 count;
> + __virtio16 type;
> + __virtio16 unused;
> + __virtio32 flags;
> + __virtio32 len;
> + __virtio64 time_sec;
> + __virtio32 time_nsec;
> + __virtio32 reserved;
> +};
> +
> +struct virtio_pstore_config {
> + __virtio32 bufsize;
> + __virtio32 flags;
> +};
> +
> +#endif /* _LINUX_VIRTIO_PSTORE_H */
> diff --git a/qdev-monitor.c b/qdev-monitor.c
> index e19617f..e1df5a9 100644
> --- a/qdev-monitor.c
> +++ b/qdev-monitor.c
> @@ -73,6 +73,7 @@ static const QDevAlias qdev_alias_table[] = {
> { "virtio-serial-pci", "virtio-serial", QEMU_ARCH_ALL & ~QEMU_ARCH_S390X },
> { "virtio-tablet-ccw", "virtio-tablet", QEMU_ARCH_S390X },
> { "virtio-tablet-pci", "virtio-tablet", QEMU_ARCH_ALL & ~QEMU_ARCH_S390X },
> + { "virtio-pstore-pci", "virtio-pstore" },
> { }
> };
>
> --
> 2.8.0