[RFC,v4,12/49] multi-process: remote process initialization

Commit Message

Jag Raman Oct. 24, 2019, 9:08 a.m. UTC

Adds the handler to process message from QEMU,
Initialize remote process main loop, handles SYNC_SYSMEM
message by updating its "system_memory" container using
shared file descriptors received from QEMU.

Signed-off-by: John G Johnson <[e-mail]>
Signed-off-by: Elena Ufimtseva <[e-mail]>
Signed-off-by: Jagannathan Raman <[e-mail]>
---
 v1 -> v2:
   - Separate thread for message processing is removed

 v2 -> v3:
   - Added multi-channel support in the remote end

 remote/remote-main.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)

Comments

Stefan Hajnoczi Nov. 13, 2019, 4:38 p.m. UTC | #1

On Thu, Oct 24, 2019 at 05:08:53AM -0400, Jagannathan Raman wrote:
>  int main(int argc, char *argv[])
>  {
> +    Error *err = NULL;
> +
>      module_call_init(MODULE_INIT_QOM);
>  
> +    bdrv_init_with_whitelist();
> +
> +    if (qemu_init_main_loop(&err)) {
> +        error_report_err(err);
> +        return -EBUSY;
> +    }
> +
> +    qemu_init_cpu_loop();
> +
> +    page_size_init();
> +
>      current_machine = MACHINE(REMOTE_MACHINE(object_new(TYPE_REMOTE_MACHINE)));
>  
> +    mpqemu_link = mpqemu_link_create();
> +    if (!mpqemu_link) {
> +        printf("Could not create MPQemu link\n");
> +        return -1;
> +    }
> +
> +    mpqemu_init_channel(mpqemu_link, &mpqemu_link->com, STDIN_FILENO);
> +    mpqemu_link_set_callback(mpqemu_link, process_msg);
> +
> +    mpqemu_start_coms(mpqemu_link);

Can you use util/main-loop.c instead of an mpqemu-specific event loop?
I think that file is needed anyway because lots of QEMU code depends on
it.

Patch

diff --git a/remote/remote-main.c b/remote/remote-main.c
index bf44310..7689b57 100644
--- a/remote/remote-main.c
+++ b/remote/remote-main.c
@@ -26,6 +26,7 @@ 
 #include "qemu-common.h"
 
 #include <stdio.h>
+#include <unistd.h>
 
 #include "qemu/module.h"
 #include "remote/pcihost.h"
@@ -33,12 +34,91 @@ 
 #include "hw/boards.h"
 #include "hw/qdev-core.h"
 #include "qemu/main-loop.h"
+#include "remote/memory.h"
+#include "io/mpqemu-link.h"
+#include "qapi/error.h"
+#include "qemu/main-loop.h"
+#include "sysemu/cpus.h"
+#include "qemu-common.h"
+#include "hw/pci/pci.h"
+#include "qemu/thread.h"
+#include "qemu/main-loop.h"
+#include "qemu/config-file.h"
+#include "sysemu/sysemu.h"
+#include "block/block.h"
+
+static MPQemuLinkState *mpqemu_link;
+PCIDevice *remote_pci_dev;
+
+static void process_msg(GIOCondition cond, MPQemuChannel *chan)
+{
+    MPQemuMsg *msg = NULL;
+    Error *err = NULL;
+
+    if ((cond & G_IO_HUP) || (cond & G_IO_ERR)) {
+        error_setg(&err, "socket closed, cond is %d", cond);
+        goto finalize_loop;
+    }
+
+    msg = g_malloc0(sizeof(MPQemuMsg));
+
+    if (mpqemu_msg_recv(mpqemu_link, msg, chan) < 0) {
+        error_setg(&err, "Failed to receive message");
+        goto finalize_loop;
+    }
+
+    switch (msg->cmd) {
+    case INIT:
+        break;
+    case CONF_WRITE:
+        break;
+    case CONF_READ:
+        break;
+    default:
+        error_setg(&err, "Unknown command");
+        goto finalize_loop;
+    }
+
+    g_free(msg);
+
+    return;
+
+finalize_loop:
+    error_report_err(err);
+    g_free(msg);
+    mpqemu_link_finalize(mpqemu_link);
+    mpqemu_link = NULL;
+}
 
 int main(int argc, char *argv[])
 {
+    Error *err = NULL;
+
     module_call_init(MODULE_INIT_QOM);
 
+    bdrv_init_with_whitelist();
+
+    if (qemu_init_main_loop(&err)) {
+        error_report_err(err);
+        return -EBUSY;
+    }
+
+    qemu_init_cpu_loop();
+
+    page_size_init();
+
     current_machine = MACHINE(REMOTE_MACHINE(object_new(TYPE_REMOTE_MACHINE)));
 
+    mpqemu_link = mpqemu_link_create();
+    if (!mpqemu_link) {
+        printf("Could not create MPQemu link\n");
+        return -1;
+    }
+
+    mpqemu_init_channel(mpqemu_link, &mpqemu_link->com, STDIN_FILENO);
+    mpqemu_link_set_callback(mpqemu_link, process_msg);
+
+    mpqemu_start_coms(mpqemu_link);
+
     return 0;
 }