Using a separate communication channel for MMIO helps
with improving Performance
Signed-off-by: Elena Ufimtseva <elena.ufimts...@oracle.com>
Signed-off-by: Jagannathan Raman <jag.ra...@oracle.com>
Signed-off-by: John G Johnson <john.g.john...@oracle.com>
---
New patch in v3
hw/proxy/qemu-proxy.c | 39 +++++++++++++++++++++++++++------------
include/hw/proxy/qemu-proxy.h | 1 +
include/io/mpqemu-link.h | 7 +++++++
io/mpqemu-link.c | 2 ++
qdev-monitor.c | 1 +
remote/remote-main.c | 18 +++++++++++++-----
6 files changed, 51 insertions(+), 17 deletions(-)
diff --git a/hw/proxy/qemu-proxy.c b/hw/proxy/qemu-proxy.c
index 691b991..74aecd3 100644
--- a/hw/proxy/qemu-proxy.c
+++ b/hw/proxy/qemu-proxy.c
@@ -201,20 +201,22 @@ static int make_argv(char *command_str, char **argv, int
argc)
int remote_spawn(PCIProxyDev *pdev, const char *command, Error **errp)
{
pid_t rpid;
- int fd[2] = {-1, -1};
+ int fd[2], mmio[2];
Error *local_error = NULL;
char *argv[64];
int argc = 0, _argc;
char *sfd;
char *exec_dir;
int rc = -EINVAL;
+ struct timeval timeout = {.tv_sec = 10, .tv_usec = 0};
if (pdev->managed) {
/* Child is forked by external program (such as libvirt). */
return rc;
}
- if (socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
+ if (socketpair(AF_UNIX, SOCK_STREAM, 0, fd) ||
+ socketpair(AF_UNIX, SOCK_STREAM, 0, mmio)) {
error_setg(errp, "Unable to create unix socket.");
return rc;
}
@@ -222,6 +224,8 @@ int remote_spawn(PCIProxyDev *pdev, const char *command,
Error **errp)
argc = add_argv(exec_dir, argv, argc);
sfd = g_strdup_printf("%d", fd[1]);
argc = add_argv(sfd, argv, argc);
+ sfd = g_strdup_printf("%d", mmio[1]);
+ argc = add_argv(sfd, argv, argc);
_argc = argc;
argc = make_argv((char *)command, argv, argc);
@@ -231,22 +235,32 @@ int remote_spawn(PCIProxyDev *pdev, const char *command,
Error **errp)
if (rpid == -1) {
error_setg(errp, "Unable to spawn emulation program.");
close(fd[0]);
+ close(mmio[0]);
goto fail;
}
if (rpid == 0) {
close(fd[0]);
+ close(mmio[0]);
execvp(argv[0], (char *const *)argv);
exit(1);
}
pdev->remote_pid = rpid;
pdev->rsocket = fd[1];
pdev->socket = fd[0];
+ pdev->mmio_sock = mmio[0];
+
+ if (setsockopt(mmio[0], SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout,
+ sizeof(timeout)) < 0) {
+ error_setg(errp, "Unable to set timeout for socket");
+ goto fail;
+ }
rc = 0;
fail:
close(fd[1]);
+ close(mmio[1]);
for (int i = 0; i < _argc; i++) {
g_free(argv[i]);
@@ -443,6 +457,9 @@ static void init_proxy(PCIDevice *dev, char *command, bool
need_spawn, Error **e
mpqemu_init_channel(pdev->mpqemu_link, &pdev->mpqemu_link->com,
pdev->socket);
+ mpqemu_init_channel(pdev->mpqemu_link, &pdev->mpqemu_link->mmio,
+ pdev->mmio_sock);
+
configure_memory_sync(pdev->sync, pdev->mpqemu_link);
}
@@ -503,8 +520,7 @@ static void send_bar_access_msg(PCIProxyDev *dev,
MemoryRegion *mr,
unsigned size, bool memory)
{
MPQemuLinkState *mpqemu_link = dev->mpqemu_link;
- MPQemuMsg msg;
- int wait;
+ MPQemuMsg msg, ret;
memset(&msg, 0, sizeof(MPQemuMsg));
@@ -518,19 +534,18 @@ static void send_bar_access_msg(PCIProxyDev *dev,
MemoryRegion *mr,
msg.cmd = BAR_WRITE;
msg.data1.bar_access.val = *val;
} else {
- wait = GET_REMOTE_WAIT;
-
msg.cmd = BAR_READ;
- msg.num_fds = 1;
- msg.fds[0] = wait;
}
- mpqemu_msg_send(mpqemu_link, &msg, mpqemu_link->com);
+ mpqemu_msg_send(mpqemu_link, &msg, mpqemu_link->mmio);
- if (!write) {
- *val = wait_for_remote(wait);
- PUT_REMOTE_WAIT(wait);
+ if (write) {
+ return;
}
+
+ mpqemu_msg_recv(mpqemu_link, &ret, mpqemu_link->mmio);
+
+ *val = ret.data1.mmio_ret.val;
}
void proxy_default_bar_write(void *opaque, hwaddr addr, uint64_t val,
diff --git a/include/hw/proxy/qemu-proxy.h b/include/hw/proxy/qemu-proxy.h
index ac61a9b..5e858cc 100644
--- a/include/hw/proxy/qemu-proxy.h
+++ b/include/hw/proxy/qemu-proxy.h
@@ -71,6 +71,7 @@ struct PCIProxyDev {
pid_t remote_pid;
int rsocket;
int socket;
+ int mmio_sock;
char *rid;
diff --git a/include/io/mpqemu-link.h b/include/io/mpqemu-link.h
index 16a913b..4911eea 100644
--- a/include/io/mpqemu-link.h
+++ b/include/io/mpqemu-link.h
@@ -73,6 +73,7 @@ typedef enum {
DEVICE_ADD,
DEVICE_DEL,
PROXY_PING,
+ MMIO_RETURN,
MAX,
} mpqemu_cmd_t;
@@ -107,6 +108,10 @@ typedef struct {
} set_irqfd_msg_t;
typedef struct {
+ uint64_t val;
+} mmio_ret_msg_t;
+
+typedef struct {
mpqemu_cmd_t cmd;
int bytestream;
size_t size;
@@ -116,6 +121,7 @@ typedef struct {
sync_sysmem_msg_t sync_sysmem;
bar_access_msg_t bar_access;
set_irqfd_msg_t set_irqfd;
+ mmio_ret_msg_t mmio_ret;
} data1;
int fds[REMOTE_MAX_FDS];
@@ -170,6 +176,7 @@ typedef struct MPQemuLinkState {
GMainLoop *loop;
MPQemuChannel *com;
+ MPQemuChannel *mmio;
mpqemu_link_callback callback;
} MPQemuLinkState;
diff --git a/io/mpqemu-link.c b/io/mpqemu-link.c
index 696aeb1..d91936e 100644
--- a/io/mpqemu-link.c
+++ b/io/mpqemu-link.c
@@ -77,6 +77,7 @@ void mpqemu_link_finalize(MPQemuLinkState *s)
g_main_loop_quit(s->loop);
mpqemu_destroy_channel(s->com);
+ mpqemu_destroy_channel(s->mmio);
object_unref(OBJECT(s));
}
@@ -344,6 +345,7 @@ void mpqemu_start_coms(MPQemuLinkState *s)
{
g_assert(g_source_attach(&s->com->gsrc, s->ctx));
+ g_assert(g_source_attach(&s->mmio->gsrc, s->ctx));
g_main_loop_run(s->loop);
}
diff --git a/qdev-monitor.c b/qdev-monitor.c
index e1d05e4..f38849e 100644
--- a/qdev-monitor.c
+++ b/qdev-monitor.c
@@ -711,6 +711,7 @@ DeviceState *qdev_proxy_add(const char *rid, const char
*id, char *bus,
if (old_pdev) {
pdev->rsocket = old_pdev->rsocket;
pdev->socket = old_pdev->socket;
+ pdev->mmio_sock = old_pdev->mmio_sock;
pdev->remote_pid = old_pdev->remote_pid;
} else {
pdev->rsocket = managed ? rsocket : -1;
diff --git a/remote/remote-main.c b/remote/remote-main.c
index 27e4492..0a1326d 100644
--- a/remote/remote-main.c
+++ b/remote/remote-main.c
@@ -117,8 +117,8 @@ static void process_bar_write(MPQemuMsg *msg, Error **errp)
static void process_bar_read(MPQemuMsg *msg, Error **errp)
{
bar_access_msg_t *bar_access = &msg->data1.bar_access;
+ MPQemuMsg ret = { 0 };
AddressSpace *as;
- int wait = msg->fds[0];
MemTxResult res;
uint64_t val = 0;
@@ -152,9 +152,10 @@ static void process_bar_read(MPQemuMsg *msg, Error **errp)
}
fail:
- notify_proxy(wait, val);
-
- PUT_REMOTE_WAIT(wait);
+ ret.cmd = MMIO_RETURN;
+ ret.data1.mmio_ret.val = val;
+ ret.size = sizeof(ret.data1);
+ mpqemu_msg_send(mpqemu_link, &ret, mpqemu_link->mmio);
}
static void process_device_add_msg(MPQemuMsg *msg)
@@ -497,7 +498,14 @@ int main(int argc, char *argv[])
mpqemu_init_channel(mpqemu_link, &mpqemu_link->com, fd);
- parse_cmdline(argc - 2, argv + 2, NULL);
+ fd = qemu_parse_fd(argv[2]);
+ if (fd == -1) {
+ printf("Failed to parse fd for remote process.\n");
+ return -EINVAL;
+ }
+ mpqemu_init_channel(mpqemu_link, &mpqemu_link->mmio, fd);
+
+ parse_cmdline(argc - 3, argv + 3, NULL);
mpqemu_link_set_callback(mpqemu_link, process_msg);
--
1.8.3.1
