[PATCH v2] gnttab: Add gntdev device mappings for FreeBSD
Akshay Jaggi
akshay1994.leo at gmail.com
Wed Aug 17 12:07:49 UTC 2016
Add grant table userspace device mappings for
FreeBSD (enables support for qdisk backend
on FreeBSD Dom0).
Signed-off-by: Akshay Jaggi <akshay1994.leo at gmail.com>
---
Changed since v1:
* fix coding style
* remove O_CLOEXEC
* remove SET_MAX_GRANTS ioctl
* update freebsd/gntdev.h to latest version
* replace alloca with malloc
---
tools/include/xen-sys/FreeBSD/gntdev.h | 191 ++++++++++++++++++++
tools/libs/gnttab/Makefile | 2 +-
tools/libs/gnttab/freebsd.c | 318 +++++++++++++++++++++++++++++++++
3 files changed, 510 insertions(+), 1 deletion(-)
create mode 100644 tools/include/xen-sys/FreeBSD/gntdev.h
create mode 100644 tools/libs/gnttab/freebsd.c
diff --git a/tools/include/xen-sys/FreeBSD/gntdev.h b/tools/include/xen-sys/FreeBSD/gntdev.h
new file mode 100644
index 0000000..5f31e21
--- /dev/null
+++ b/tools/include/xen-sys/FreeBSD/gntdev.h
@@ -0,0 +1,191 @@
+/*-
+ * Copyright (c) 2016 Akshay Jaggi <jaggi at FreeBSD.org>
+ * All rights reserved.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 THE AUTHOR 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.
+ *
+ * gntdev.h
+ *
+ * Interface to /dev/xen/gntdev.
+ *
+ * This device provides the user with two kinds of functionalities:
+ * 1. Grant Allocation
+ * Allocate a page of our own memory, and share it with a foreign domain.
+ * 2. Grant Mapping
+ * Map a grant allocated by a foreign domain, into our own memory.
+ *
+ *
+ * Grant Allocation
+ *
+ * Steps to allocate a grant:
+ * 1. Do an `IOCTL_GNTDEV_ALLOC_GREF ioctl`, with
+ * - `domid`, as the domain-id of the foreign domain
+ * - `flags`, ORed with GNTDEV_ALLOC_FLAG_WRITABLE if you want the foreign
+ * domain to have write access to the shared memory
+ * - `count`, with the number of pages to share with the foreign domain
+ *
+ * Ensure that the structure you allocate has enough memory to store
+ * all the allocated grant-refs, i.e., you need to allocate
+ * (sizeof(struct ioctl_gntdev_alloc_gref) + (count - 1)*sizeof(uint32_t))
+ * bytes of memory.
+ *
+ * 2. Mmap the address given in `index` after a successful ioctl.
+ * This will give you access to the granted pages.
+ *
+ * Note:
+ * 1. The grant is not removed until all three of the following conditions
+ * are met
+ * - The region is not mmaped. That is, munmap() has been called if
+ * the region was mmapped previously.
+ * - IOCTL_GNTDEV_DEALLOC_GREF ioctl has been performed. After you
+ * perform this ioctl, you can no longer mmap or set notify on
+ * the grant.
+ * - The foreign domain has stopped using the grant.
+ * 2. Granted pages can only belong to one mmap region.
+ * 3. Every page of granted memory is a unit in itself. What this means
+ * is that you can set a unmap notification for each of the granted
+ * pages, individually; you can mmap and dealloc-ioctl a contiguous
+ * range of allocated grants (even if alloc-ioctls were performed
+ * individually), etc.
+ *
+ *
+ * Grant Mapping
+ *
+ * Steps to map a grant:
+ * 1. Do a `IOCTL_GNTDEV_MAP_GRANT_REF` ioctl, with
+ * - `count`, as the number of foreign grants to map
+ * - `refs[i].domid`, as the domain id of the foreign domain
+ * - `refs[i].ref`, as the grant-ref for the grant to be mapped
+ *
+ * 2. Mmap the address given in `index` after a successful ioctl.
+ * This will give you access to the mapped pages.
+ *
+ * Note:
+ * 1. The map hypercall is not made till the region is mmapped.
+ * 2. The unit is defined by the map ioctl. This means that only one
+ * unmap notification can be set on a group of pages that were
+ * mapped together in one ioctl, and also no single mmaping of contiguous
+ * grant-maps is possible.
+ * 3. You can mmap the same grant-map region multiple times.
+ * 4. The grant is not unmapped until both of the following conditions are met
+ * - The region is not mmaped. That is, munmap() has been called for
+ * as many times as the grant was mmapped.
+ * - IOCTL_GNTDEV_UNMAP_GRANT_REF ioctl has been called.
+ * 5. IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR ioctl gives index and count of
+ * a grant-map from the virtual address of the location where the grant
+ * is mmapped.
+ *
+ *
+ * IOCTL_GNTDEV_SET_UNMAP_NOTIFY
+ * This ioctl allows us to set notifications to be made when the grant is
+ * either unmapped (in case of a mapped grant), or when it is ready to be
+ * deallocated by us, ie, the grant is no more mmapped, and the dealloc
+ * ioctl has been called (in case of an allocated grant). OR `action` with
+ * the required notification masks, and fill in the appropriate fields.
+ * - UNMAP_NOTIFY_CLEAR_BYTE clears the byte at `index`, where index is
+ * the address of the byte in file address space.
+ * - UNMAP_NOTIFY_SEND_EVENT sends an event channel notification on
+ * `event_channel_port`
+ * In case of multiple notify ioctls, only the last one survives.
+ *
+ */
+
+#ifndef __XEN_GNTDEV_H__
+#define __XEN_GNTDEV_H__
+
+#include <sys/types.h>
+
+#define IOCTL_GNTDEV_SET_UNMAP_NOTIFY \
+ _IOW('E', 0, struct ioctl_gntdev_unmap_notify)
+struct ioctl_gntdev_unmap_notify {
+ /* IN parameters */
+ uint64_t index;
+ uint32_t action;
+ uint32_t event_channel_port;
+};
+
+#define UNMAP_NOTIFY_CLEAR_BYTE 0x1
+#define UNMAP_NOTIFY_SEND_EVENT 0x2
+
+/*-------------------- Grant Allocation IOCTLs ------------------------------*/
+
+#define IOCTL_GNTDEV_ALLOC_GREF \
+ _IOWR('E', 1, struct ioctl_gntdev_alloc_gref)
+struct ioctl_gntdev_alloc_gref {
+ /* IN parameters */
+ uint16_t domid;
+ uint16_t flags;
+ uint32_t count;
+ /* OUT parameters */
+ uint64_t index;
+ /* Variable OUT parameter */
+ uint32_t gref_ids[1];
+};
+
+#define GNTDEV_ALLOC_FLAG_WRITABLE 1
+
+#define IOCTL_GNTDEV_DEALLOC_GREF \
+ _IOW('E', 2, struct ioctl_gntdev_dealloc_gref)
+struct ioctl_gntdev_dealloc_gref {
+ /* IN parameters */
+ uint64_t index;
+ uint32_t count;
+};
+
+/*-------------------- Grant Mapping IOCTLs ---------------------------------*/
+
+struct ioctl_gntdev_grant_ref {
+ uint32_t domid;
+ uint32_t ref;
+};
+
+#define IOCTL_GNTDEV_MAP_GRANT_REF \
+ _IOWR('E', 3, struct ioctl_gntdev_map_grant_ref)
+struct ioctl_gntdev_map_grant_ref {
+ /* IN parameters */
+ uint32_t count;
+ uint32_t pad0;
+ /* OUT parameters */
+ uint64_t index;
+ /* Variable IN parameter */
+ struct ioctl_gntdev_grant_ref refs[1];
+};
+
+#define IOCTL_GNTDEV_UNMAP_GRANT_REF \
+ _IOW('E', 4, struct ioctl_gntdev_unmap_grant_ref)
+struct ioctl_gntdev_unmap_grant_ref {
+ /* IN parameters */
+ uint64_t index;
+ uint32_t count;
+};
+
+#define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR \
+ _IOWR('E', 5, struct ioctl_gntdev_get_offset_for_vaddr)
+struct ioctl_gntdev_get_offset_for_vaddr {
+ /* IN parameters */
+ uint64_t vaddr;
+ /* OUT parameters */
+ uint64_t offset;
+ uint32_t count;
+};
+
+#endif /* __XEN_GNTDEV_H__ */
\ No newline at end of file
diff --git a/tools/libs/gnttab/Makefile b/tools/libs/gnttab/Makefile
index af64542..69bb207 100644
--- a/tools/libs/gnttab/Makefile
+++ b/tools/libs/gnttab/Makefile
@@ -14,7 +14,7 @@ SRCS-GNTSHR += gntshr_core.c
SRCS-$(CONFIG_Linux) += $(SRCS-GNTTAB) $(SRCS-GNTSHR) linux.c
SRCS-$(CONFIG_MiniOS) += $(SRCS-GNTTAB) gntshr_unimp.c minios.c
-SRCS-$(CONFIG_FreeBSD) += gnttab_unimp.c gntshr_unimp.c
+SRCS-$(CONFIG_FreeBSD) += $(SRCS-GNTTAB) $(SRCS-GNTSHR) freebsd.c
SRCS-$(CONFIG_SunOS) += gnttab_unimp.c gntshr_unimp.c
SRCS-$(CONFIG_NetBSD) += gnttab_unimp.c gntshr_unimp.c
diff --git a/tools/libs/gnttab/freebsd.c b/tools/libs/gnttab/freebsd.c
new file mode 100644
index 0000000..c847ce8
--- /dev/null
+++ b/tools/libs/gnttab/freebsd.c
@@ -0,0 +1,318 @@
+/*
+ * Copyright (c) 2007-2008, D G Murray <Derek.Murray at cl.cam.ac.uk>
+ * Copyright (c) 2016-2017, Akshay Jaggi <jaggi at FreeBSD.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Split out from linux.c
+ */
+
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+
+#include <xen/sys/gntdev.h>
+
+#include "private.h"
+
+#define DEVXEN "/dev/xen/gntdev"
+
+#define ROUNDUP(_x,_w) (((unsigned long)(_x)+(1UL<<(_w))-1) & ~((1UL<<(_w))-1))
+
+#define GTERROR(_l, _f...) xtl_log(_l, XTL_ERROR, errno, "gnttab", _f)
+#define GSERROR(_l, _f...) xtl_log(_l, XTL_ERROR, errno, "gntshr", _f)
+
+#define PAGE_SHIFT 12
+#define PAGE_SIZE (1UL << PAGE_SHIFT)
+#define PAGE_MASK (~(PAGE_SIZE-1))
+
+int osdep_gnttab_open(xengnttab_handle *xgt)
+{
+ int fd = open(DEVXEN, O_RDWR|O_CLOEXEC);
+
+ if ( fd == -1 )
+ return -1;
+ xgt->fd = fd;
+
+ return 0;
+}
+
+int osdep_gnttab_close(xengnttab_handle *xgt)
+{
+
+ if ( xgt->fd == -1 )
+ return 0;
+
+ return close(xgt->fd);
+}
+
+int osdep_gnttab_set_max_grants(xengnttab_handle *xgt, uint32_t count)
+{
+
+ return 0;
+}
+
+void *osdep_gnttab_grant_map(xengnttab_handle *xgt,
+ uint32_t count, int flags, int prot,
+ uint32_t *domids, uint32_t *refs,
+ uint32_t notify_offset,
+ evtchn_port_t notify_port)
+{
+ int i;
+ int fd = xgt->fd;
+ struct ioctl_gntdev_map_grant_ref *map;
+ void *addr = NULL;
+ int domids_stride;
+ unsigned int map_size = ROUNDUP((sizeof(*map) + (count - 1) *
+ sizeof(struct ioctl_gntdev_map_grant_ref)),
+ PAGE_SHIFT);
+
+ domids_stride = ( flags & XENGNTTAB_GRANT_MAP_SINGLE_DOMAIN ) ? 0 : 1;
+ if ( map_size <= PAGE_SIZE )
+ map = malloc(sizeof(*map) +
+ (count - 1) * sizeof(struct ioctl_gntdev_map_grant_ref));
+ else
+ {
+ map = mmap(NULL, map_size, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANON, -1, 0);
+ if ( map == MAP_FAILED )
+ {
+ GTERROR(xgt->logger, "anon mmap of map failed");
+ return NULL;
+ }
+ }
+
+ for ( i = 0; i < count; i++ )
+ {
+ map->refs[i].domid = domids[i * domids_stride];
+ map->refs[i].ref = refs[i];
+ }
+
+ map->count = count;
+
+ if ( ioctl(fd, IOCTL_GNTDEV_MAP_GRANT_REF, map) )
+ {
+ GTERROR(xgt->logger, "ioctl MAP_GRANT_REF failed");
+ goto out;
+ }
+
+ addr = mmap(NULL, PAGE_SIZE * count, prot, MAP_SHARED, fd,
+ map->index);
+ if ( addr != MAP_FAILED )
+ {
+ int rv = 0;
+ struct ioctl_gntdev_unmap_notify notify;
+
+ notify.index = map->index;
+ notify.action = 0;
+ if ( notify_offset < PAGE_SIZE * count )
+ {
+ notify.index += notify_offset;
+ notify.action |= UNMAP_NOTIFY_CLEAR_BYTE;
+ }
+ if ( notify_port != -1 ) {
+ notify.event_channel_port = notify_port;
+ notify.action |= UNMAP_NOTIFY_SEND_EVENT;
+ }
+ if ( notify.action )
+ rv = ioctl(fd, IOCTL_GNTDEV_SET_UNMAP_NOTIFY, ¬ify);
+ if ( rv )
+ {
+ GTERROR(xgt->logger, "ioctl SET_UNMAP_NOTIFY failed");
+ munmap(addr, count * PAGE_SIZE);
+ addr = MAP_FAILED;
+ }
+ }
+ if ( addr == MAP_FAILED )
+ {
+ int saved_errno = errno;
+ struct ioctl_gntdev_unmap_grant_ref unmap_grant;
+
+ /* Unmap the driver slots used to store the grant information. */
+ GTERROR(xgt->logger, "mmap failed");
+ unmap_grant.index = map->index;
+ unmap_grant.count = count;
+ ioctl(fd, IOCTL_GNTDEV_UNMAP_GRANT_REF, &unmap_grant);
+ errno = saved_errno;
+ addr = NULL;
+ }
+
+ out:
+ if ( map_size > PAGE_SIZE )
+ munmap(map, map_size);
+ else
+ free(map);
+
+ return addr;
+}
+
+int osdep_gnttab_unmap(xengnttab_handle *xgt,
+ void *start_address,
+ uint32_t count)
+{
+ int rc;
+ int fd = xgt->fd;
+ struct ioctl_gntdev_unmap_grant_ref unmap_grant;
+ struct ioctl_gntdev_get_offset_for_vaddr get_offset;
+
+ if ( start_address == NULL )
+ {
+ errno = EINVAL;
+ return -1;
+ }
+
+ /*
+ * First, it is necessary to get the offset which was initially used to
+ * mmap() the pages.
+ */
+ get_offset.vaddr = (unsigned long)start_address;
+ if ( (rc = ioctl(fd, IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR,
+ &get_offset)) )
+ return rc;
+
+ if ( get_offset.count != count )
+ {
+ errno = EINVAL;
+ return -1;
+ }
+
+ /* Next, unmap the memory. */
+ if ( (rc = munmap(start_address, count * PAGE_SIZE)) )
+ return rc;
+
+ /* Finally, unmap the driver slots used to store the grant information. */
+ unmap_grant.index = get_offset.offset;
+ unmap_grant.count = count;
+ if ( (rc = ioctl(fd, IOCTL_GNTDEV_UNMAP_GRANT_REF, &unmap_grant)) )
+ return rc;
+
+ return 0;
+}
+
+int osdep_gntshr_open(xengntshr_handle *xgs)
+{
+
+ int fd = open(DEVXEN, O_RDWR);
+ if ( fd == -1 )
+ return -1;
+ xgs->fd = fd;
+
+ return 0;
+}
+
+int osdep_gntshr_close(xengntshr_handle *xgs)
+{
+
+ if ( xgs->fd == -1 )
+ return 0;
+
+ return close(xgs->fd);
+}
+
+void *osdep_gntshr_share_pages(xengntshr_handle *xgs,
+ uint32_t domid, int count,
+ uint32_t *refs, int writable,
+ uint32_t notify_offset,
+ evtchn_port_t notify_port)
+{
+ int err;
+ int fd = xgs->fd;
+ void *area = NULL;
+ struct ioctl_gntdev_unmap_notify notify;
+ struct ioctl_gntdev_dealloc_gref gref_drop;
+ struct ioctl_gntdev_alloc_gref *gref_info = NULL;
+
+ gref_info = malloc(sizeof(*gref_info) + count * sizeof(uint32_t));
+ if ( gref_info == NULL )
+ return NULL;
+ gref_info->domid = domid;
+ gref_info->flags = writable ? GNTDEV_ALLOC_FLAG_WRITABLE : 0;
+ gref_info->count = count;
+
+ err = ioctl(fd, IOCTL_GNTDEV_ALLOC_GREF, gref_info);
+ if ( err )
+ {
+ GSERROR(xgs->logger, "ioctl failed");
+ goto out;
+ }
+
+ area = mmap(NULL, count * PAGE_SIZE, PROT_READ | PROT_WRITE,
+ MAP_SHARED, fd, gref_info->index);
+
+ if ( area == MAP_FAILED )
+ {
+ area = NULL;
+ GSERROR(xgs->logger, "mmap failed");
+ goto out_remove_fdmap;
+ }
+
+ notify.index = gref_info->index;
+ notify.action = 0;
+ if ( notify_offset < PAGE_SIZE * count )
+ {
+ notify.index += notify_offset;
+ notify.action |= UNMAP_NOTIFY_CLEAR_BYTE;
+ }
+ if ( notify_port != -1 )
+ {
+ notify.event_channel_port = notify_port;
+ notify.action |= UNMAP_NOTIFY_SEND_EVENT;
+ }
+ if ( notify.action )
+ err = ioctl(fd, IOCTL_GNTDEV_SET_UNMAP_NOTIFY, ¬ify);
+ if ( err )
+ {
+ GSERROR(xgs->logger, "ioctl SET_UNMAP_NOTIFY failed");
+ munmap(area, count * PAGE_SIZE);
+ area = NULL;
+ }
+
+ memcpy(refs, gref_info->gref_ids, count * sizeof(uint32_t));
+
+ out_remove_fdmap:
+ /*
+ * Removing the mapping from the file descriptor does not cause the
+ * pages to be deallocated until the mapping is removed.
+ */
+ gref_drop.index = gref_info->index;
+ gref_drop.count = count;
+ ioctl(fd, IOCTL_GNTDEV_DEALLOC_GREF, &gref_drop);
+ out:
+ free(gref_info);
+
+ return area;
+}
+
+int osdep_gntshr_unshare(xengntshr_handle *xgs,
+ void *start_address, uint32_t count)
+{
+
+ return munmap(start_address, count * PAGE_SIZE);
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
--
2.8.2
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