now dummy nic works with qemu for basic mmio/pio read/write :-)

dummy_nic/Makefile

 CFLAGS += -Wall -Wextra -Wno-unused-parameter -O3
+
+dummy_nic: dummy_nic.o poll.o utils.o
+
 all: dummy_nic
 
 clean:

dummy_nic/dummy_nic.c

@@ -21,127 +21,20 @@
  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-#include <errno.h>
-#include <fcntl.h>
 #include <stdlib.h>
 #include <stdio.h>
-#include <stdbool.h>
-#include <sys/un.h>
+#include <string.h>
 #include <sys/socket.h>
-#include <sys/mman.h>
 #include <unistd.h>
 
-#include "../proto/cosim_pcie_proto.h"
+#include "dummy_nic.h"
 
-#define D2H_ELEN (4096 + 64)
-#define D2H_ENUM 1024
+uint8_t *d2h_queue;
+size_t d2h_pos;
 
-#define H2D_ELEN (64)
-#define H2D_ENUM 1024
+uint8_t *h2d_queue;
+size_t h2d_pos;
 
-static int uxsocket_init(const char *path)
-{
-    int fd;
-    struct sockaddr_un saun;
-
-    if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
-        perror("uxsocket_init: socket failed");
-        goto error_exit;
-    }
-
-    memset(&saun, 0, sizeof(saun));
-    saun.sun_family = AF_UNIX;
-    memcpy(saun.sun_path, path, strlen(path));
-    if (bind(fd, (struct sockaddr *) &saun, sizeof(saun))) {
-        perror("uxsocket_init: bind failed");
-        goto error_close;
-    }
-
-    if (listen(fd, 5)) {
-        perror("uxsocket_init: listen failed");
-        goto error_close;
-    }
-
-    return fd;
-
-error_close:
-    close(fd);
-error_exit:
-    return -1;
-}
-
-static int uxsocket_send(int connfd, void *data, size_t len, int fd)
-{
-    ssize_t tx;
-    struct iovec iov = {
-        .iov_base = data,
-        .iov_len = len,
-    };
-    union {
-        char buf[CMSG_SPACE(sizeof(int))];
-        struct cmsghdr align;
-    } u;
-    struct msghdr msg = {
-        .msg_name = NULL,
-        .msg_namelen = 0,
-        .msg_iov = &iov,
-        .msg_iovlen = 1,
-        .msg_control = u.buf,
-        .msg_controllen = 0,
-        .msg_flags = 0,
-    };
-    struct cmsghdr *cmsg = &u.align;
-
-    if (fd >= 0) {
-        msg.msg_controllen = sizeof(u.buf);
-
-        cmsg->cmsg_level = SOL_SOCKET;
-        cmsg->cmsg_type = SCM_RIGHTS;
-        cmsg->cmsg_len = CMSG_LEN(sizeof(int));
-
-        *(int *) CMSG_DATA(cmsg) = fd;
-    }
-
-    if((tx = sendmsg(connfd, &msg, 0)) != (ssize_t) len) {
-        fprintf(stderr, "tx == %zd\n", tx);
-        return -1;
-    }
-
-    return 0;
-}
-
-static int shm_create(const char *path, size_t size, void **addr)
-{
-    int fd;
-    void *p;
-
-    if ((fd = open(path, O_CREAT | O_RDWR, 0666)) == -1) {
-        perror("util_create_shmsiszed: open failed");
-        goto error_out;
-    }
-    if (ftruncate(fd, size) != 0) {
-        perror("util_create_shmsiszed: ftruncate failed");
-        goto error_remove;
-    }
-
-    if ((p = mmap(NULL, size, PROT_READ | PROT_WRITE,
-        MAP_SHARED | MAP_POPULATE, fd, 0)) == (void *) -1)
-    {
-        perror("util_create_shmsiszed: mmap failed");
-        goto error_remove;
-    }
-
-    memset(p, 0, size);
-
-    *addr = p;
-    return fd;
-
-error_remove:
-    close(fd);
-    unlink(path);
-error_out:
-    return -1;
-}
 
 int main(int argc, char *argv[])
 {
@@ -166,6 +59,11 @@ int main(int argc, char *argv[])
     d2h_off = 0;
     h2d_off = (uint64_t) D2H_ELEN * D2H_ENUM;
 
+    d2h_queue = (uint8_t *) shmptr + d2h_off;
+    h2d_queue = (uint8_t *) shmptr + h2d_off;
+
+    d2h_pos = h2d_pos = 0;
+
     struct cosim_pcie_proto_dev_intro di;
     memset(&di, 0, sizeof(di));
 
@@ -197,7 +95,7 @@ int main(int argc, char *argv[])
     printf("host info received\n");
 
     while (1) {
-        pause();
+        poll_h2d();
     }
     close(pci_lfd);
 

dummy_nic/dummy_nic.h

+/*
+ * Copyright 2020 Max Planck Institute for Software Systems
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <stddef.h>
+#include <stdio.h>
+
+#include "../proto/cosim_pcie_proto.h"
+
+#define D2H_ELEN (4096 + 64)
+#define D2H_ENUM 1024
+
+#define H2D_ELEN (4096 + 64)
+#define H2D_ENUM 1024
+
+extern uint8_t *d2h_queue;
+extern size_t d2h_pos;
+
+extern uint8_t *h2d_queue;
+extern size_t h2d_pos;
+
+/* poll.c */
+void poll_h2d(void);
+
+/* utils.c */
+int uxsocket_init(const char *path);
+int uxsocket_send(int connfd, void *data, size_t len, int fd);
+int shm_create(const char *path, size_t size, void **addr);

dummy_nic/poll.c

+/*
+ * Copyright 2020 Max Planck Institute for Software Systems
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "dummy_nic.h"
+
+static volatile union cosim_pcie_proto_d2h *d2h_alloc(void)
+{
+    volatile union cosim_pcie_proto_d2h *msg =
+        (volatile union cosim_pcie_proto_d2h *)
+        (d2h_queue + d2h_pos * D2H_ELEN);
+
+    if ((msg->dummy.own_type & COSIM_PCIE_PROTO_D2H_OWN_MASK) !=
+            COSIM_PCIE_PROTO_D2H_OWN_DEV)
+    {
+        fprintf(stderr, "d2h_alloc: no entry available\n");
+        abort();
+    }
+
+    d2h_pos = (d2h_pos + 1) % D2H_ENUM;
+    return msg;
+}
+
+static void h2d_read(volatile struct cosim_pcie_proto_h2d_read *read)
+{
+    volatile union cosim_pcie_proto_d2h *msg;
+    volatile struct cosim_pcie_proto_d2h_readcomp *rc;
+    uint64_t val;
+
+    msg = d2h_alloc();
+    rc = &msg->readcomp;
+
+    val = read->offset + 42;
+    printf("read(bar=%u, off=%lu, len=%u) = %lu\n", read->bar, read->offset,
+            read->len, val);
+
+    memcpy((void *) rc->data, &val, read->len);
+    rc->req_id = read->req_id;
+
+    //WMB();
+    rc->own_type = COSIM_PCIE_PROTO_D2H_MSG_READCOMP |
+        COSIM_PCIE_PROTO_D2H_OWN_HOST;
+}
+
+static void h2d_write(volatile struct cosim_pcie_proto_h2d_write *write)
+{
+    volatile union cosim_pcie_proto_d2h *msg;
+    volatile struct cosim_pcie_proto_d2h_writecomp *wc;
+    uint64_t val;
+
+    msg = d2h_alloc();
+    wc = &msg->writecomp;
+
+    val = 0;
+    memcpy(&val, (void *) write->data, write->len);
+
+    printf("write(bar=%u, off=%lu, len=%u, val=%lu)\n", write->bar,
+            write->offset, write->len, val);
+
+    wc->req_id = write->req_id;
+
+    //WMB();
+    wc->own_type = COSIM_PCIE_PROTO_D2H_MSG_WRITECOMP |
+        COSIM_PCIE_PROTO_D2H_OWN_HOST;
+}
+
+void poll_h2d(void)
+{
+    volatile union cosim_pcie_proto_h2d *msg =
+        (volatile union cosim_pcie_proto_h2d *)
+        (h2d_queue + h2d_pos * H2D_ELEN);
+    uint8_t type;
+
+    /* message not ready */
+    if ((msg->dummy.own_type & COSIM_PCIE_PROTO_H2D_OWN_MASK) !=
+            COSIM_PCIE_PROTO_H2D_OWN_DEV)
+        return;
+
+    type = msg->dummy.own_type & COSIM_PCIE_PROTO_H2D_MSG_MASK;
+    switch (type) {
+        case COSIM_PCIE_PROTO_H2D_MSG_READ:
+            h2d_read(&msg->read);
+            break;
+
+        case COSIM_PCIE_PROTO_H2D_MSG_WRITE:
+            h2d_write(&msg->write);
+            break;
+
+        default:
+            fprintf(stderr, "poll_h2d: unsupported type=%u\n", type);
+    }
+
+    //WMB();
+    msg->dummy.own_type = type | COSIM_PCIE_PROTO_H2D_OWN_HOST;
+
+    h2d_pos = (h2d_pos + 1) % H2D_ENUM;
+}

dummy_nic/utils.c

+/*
+ * Copyright 2020 Max Planck Institute for Software Systems
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <sys/un.h>
+#include <sys/socket.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include "dummy_nic.h"
+
+int uxsocket_init(const char *path)
+{
+    int fd;
+    struct sockaddr_un saun;
+
+    if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
+        perror("uxsocket_init: socket failed");
+        goto error_exit;
+    }
+
+    memset(&saun, 0, sizeof(saun));
+    saun.sun_family = AF_UNIX;
+    memcpy(saun.sun_path, path, strlen(path));
+    if (bind(fd, (struct sockaddr *) &saun, sizeof(saun))) {
+        perror("uxsocket_init: bind failed");
+        goto error_close;
+    }
+
+    if (listen(fd, 5)) {
+        perror("uxsocket_init: listen failed");
+        goto error_close;
+    }
+
+    return fd;
+
+error_close:
+    close(fd);
+error_exit:
+    return -1;
+}
+
+int uxsocket_send(int connfd, void *data, size_t len, int fd)
+{
+    ssize_t tx;
+    struct iovec iov = {
+        .iov_base = data,
+        .iov_len = len,
+    };
+    union {
+        char buf[CMSG_SPACE(sizeof(int))];
+        struct cmsghdr align;
+    } u;
+    struct msghdr msg = {
+        .msg_name = NULL,
+        .msg_namelen = 0,
+        .msg_iov = &iov,
+        .msg_iovlen = 1,
+        .msg_control = u.buf,
+        .msg_controllen = 0,
+        .msg_flags = 0,
+    };
+    struct cmsghdr *cmsg = &u.align;
+
+    if (fd >= 0) {
+        msg.msg_controllen = sizeof(u.buf);
+
+        cmsg->cmsg_level = SOL_SOCKET;
+        cmsg->cmsg_type = SCM_RIGHTS;
+        cmsg->cmsg_len = CMSG_LEN(sizeof(int));
+
+        *(int *) CMSG_DATA(cmsg) = fd;
+    }
+
+    if((tx = sendmsg(connfd, &msg, 0)) != (ssize_t) len) {
+        fprintf(stderr, "tx == %zd\n", tx);
+        return -1;
+    }
+
+    return 0;
+}
+
+int shm_create(const char *path, size_t size, void **addr)
+{
+    int fd;
+    void *p;
+
+    if ((fd = open(path, O_CREAT | O_RDWR, 0666)) == -1) {
+        perror("util_create_shmsiszed: open failed");
+        goto error_out;
+    }
+    if (ftruncate(fd, size) != 0) {
+        perror("util_create_shmsiszed: ftruncate failed");
+        goto error_remove;
+    }
+
+    if ((p = mmap(NULL, size, PROT_READ | PROT_WRITE,
+        MAP_SHARED | MAP_POPULATE, fd, 0)) == (void *) -1)
+    {
+        perror("util_create_shmsiszed: mmap failed");
+        goto error_remove;
+    }
+
+    memset(p, 0, size);
+
+    *addr = p;
+    return fd;
+
+error_remove:
+    close(fd);
+    unlink(path);
+error_out:
+    return -1;
+}

qemu/README.md

 1. Clone from here: `github.com:FreakyPenguin/qemu-cosim.git`
 2. Build with `./configure --target-list=x86_64-softmmu --disable-werror --extra-cflags="-I$PATH_TO_THIS_REPO/proto" --enable-cosim-pci`
-3. To run for example (only the last line is specific to this project):
+3. run dummy nic: rm -rf /tmp/cosim-pci; ./dummy_nic
+4. To run for example (only the last line is specific to this project):
 ```
 x86_64-softmmu/qemu-system-x86_64 \
     -machine q35 -cpu host \
@@ -9,3 +10,6 @@ x86_64-softmmu/qemu-system-x86_64 \
     -chardev socket,path=/tmp/cosim-pci,id=cosimcd \
     -device cosim-pci,chardev=cosimcd
 ```
+5. in vm test with:
+    * `for read: dd if=/sys/bus/pci/devices/0000\:00\:03.0/resource2 bs=1 skip=64 count=1`
+    * `for write: echo a | dd of=/sys/bus/pci/devices/0000\:00\:03.0/resource2 bs=1 seek=64 count=1`