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Diffstat (limited to 'samples/shadow_ioeventfd_server.c')
| -rw-r--r-- | samples/shadow_ioeventfd_server.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/samples/shadow_ioeventfd_server.c b/samples/shadow_ioeventfd_server.c new file mode 100644 index 0000000..a737831 --- /dev/null +++ b/samples/shadow_ioeventfd_server.c @@ -0,0 +1,175 @@ +/* + * Copyright (c) 2022, Nutanix Inc. All rights reserved. + * Author: Thanos Makatos <thanos@nutanix.com> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * 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. + * * Neither the name of Nutanix 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 <COPYRIGHT HOLDER> 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. + * + */ + +/* + * shadow_ioeventfd_server.c: an example of how to use a shadow ioeventfd. + * There is no Linux kernel driver, use samples/shadow_ioeventfd_speed_test.c + * in the guest instead. + */ + +#include <stdio.h> +#include <err.h> +#include <stdlib.h> +#include <errno.h> +#include <assert.h> +#include <sys/poll.h> +#include <sys/eventfd.h> +#include <sys/mman.h> +#include <sys/syscall.h> + +#include "libvfio-user.h" +#include "common.h" + +static void +_log(vfu_ctx_t *vfu_ctx UNUSED, int level UNUSED, char const *msg) +{ + fprintf(stderr, "%s\n", msg); +} + +static ssize_t +bar0_cb(vfu_ctx_t *vfu_ctx UNUSED, char * const buf UNUSED, + size_t count UNUSED, loff_t offset UNUSED, + const bool is_write UNUSED) +{ + return count; +} + +int +main(int argc, char *argv[]) +{ + int ret; + vfu_ctx_t *vfu_ctx; + struct pollfd fds[2]; /* one for vfu_ctx, one for shadow_ioeventfd */ + int fd, bar0_fd; + + if (argc != 2) { + errx(EXIT_FAILURE, "missing vfio-user socket path"); + } + + vfu_ctx = vfu_create_ctx(VFU_TRANS_SOCK, argv[1], + LIBVFIO_USER_FLAG_ATTACH_NB, NULL, + VFU_DEV_TYPE_PCI); + + if (vfu_ctx == NULL) { + err(EXIT_FAILURE, "failed to initialize device emulation"); + } + + ret = vfu_setup_log(vfu_ctx, _log, LOG_ERR); + if (ret < 0) { + err(EXIT_FAILURE, "failed to setup log"); + } + + ret = vfu_pci_init(vfu_ctx, VFU_PCI_TYPE_CONVENTIONAL, + PCI_HEADER_TYPE_NORMAL, 0); + if (ret < 0) { + err(EXIT_FAILURE, "vfu_pci_init() failed"); + } + + vfu_pci_set_id(vfu_ctx, 0x4e58, 0, 0x0, 0x0); + + ret = vfu_setup_region(vfu_ctx, VFU_PCI_DEV_BAR0_REGION_IDX, + sysconf(_SC_PAGE_SIZE), &bar0_cb, + VFU_REGION_FLAG_RW | VFU_REGION_FLAG_MEM, NULL, 0, + -1, 0); + if (ret < 0) { + err(EXIT_FAILURE, "failed to setup region"); + } + + ret = vfu_realize_ctx(vfu_ctx); + if (ret < 0) { + err(EXIT_FAILURE, "failed to realize device"); + } + + fds[0] = (struct pollfd) { + .fd = vfu_get_poll_fd(vfu_ctx), + .events = POLLIN | POLLOUT + }; + ret = poll(fds, 1, -1); + assert(ret == 1); + ret = vfu_attach_ctx(vfu_ctx); + if (ret < 0) { + err(EXIT_FAILURE, "failed to attach device"); + } + + fd = eventfd(0, 0); + if (fd == -1) { + err(EXIT_FAILURE, "failed to create eventfd"); + } + bar0_fd = syscall(SYS_memfd_create, "BAR0", 0); + if (bar0_fd == -1) { + err(EXIT_FAILURE, "failed to create BAR0 file"); + } + ret = ftruncate(bar0_fd, sysconf(_SC_PAGESIZE)); + if (ret == -1) { + err(EXIT_FAILURE, "failed to truncate BAR0 file"); + } + ret = vfu_create_ioeventfd(vfu_ctx, VFU_PCI_DEV_BAR0_REGION_IDX, + fd, 0, 4, + 0, false, bar0_fd, 0); + if (ret == -1) { + err(EXIT_FAILURE, "failed to create shadow ioeventfd"); + } + + fds[0] = (struct pollfd) { + .fd = vfu_get_poll_fd(vfu_ctx), + .events = POLLIN + }; + fds[1] = (struct pollfd) { + .fd = fd, + .events = POLLIN + }; + + do { + ret = poll(fds, 2, -1); + if (ret < 0) { + err(EXIT_FAILURE, "failed to poll(2)"); + } + assert(ret > 0); + if (fds[0].revents & (POLLIN)) { + ret = vfu_run_ctx(vfu_ctx); + if (ret < 0) { + if (errno == EAGAIN) { + continue; + } + if (errno == ENOTCONN) { + return 0; + } + err(EXIT_FAILURE, "vfu_run_ctx() failed"); + } + } + if (fds[1].revents & POLLIN) { + eventfd_t value; + eventfd_read(fd, &value); + bar0_cb(vfu_ctx, NULL, 4, 0, true); + } + } while (true); + return 0; +} + +/* ex: set tabstop=4 shiftwidth=4 softtabstop=4 expandtab: */ |