[Xen-changelog] [xen master] libxl: preserve console tty across soft reset

[patchbot@xxxxxxx]

commit 841e86b8e11bc1afa625f18af7b7757d278bd20e
Author:     Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
AuthorDate: Wed Mar 22 14:59:44 2017 +0100
Commit:     Wei Liu <wei.liu2@xxxxxxxxxx>
CommitDate: Thu Mar 23 12:01:24 2017 +0000

    libxl: preserve console tty across soft reset
    
    On soft reset we remove the domain from xenstore and introduce it back to
    have everything reconnected. Console, however, stays attached (as 
xenconsoled
    checks if the domain is dying and our domain is not) but we lose the
    information about tty:
    
    before soft reset:
       console = ""
        ...
        type = "xenconsoled"
        output = "pty"
        tty = "/dev/pts/1"
        ...
    
    after:
       console = ""
        ...
        type = "xenconsoled"
        output = "pty"
        tty = ""
        ...
    
    The issue applies to both HVM and PVH but for HVM guests serial console
    through QEMU is usually in use and for PVH we don't have it.
    
    Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
    Acked-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
 tools/libxl/libxl_console.c  |  5 ++++-
 tools/libxl/libxl_create.c   | 10 ++++++++++
 tools/libxl/libxl_internal.h |  1 +
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/tools/libxl/libxl_console.c b/tools/libxl/libxl_console.c
index cbc70b7..446e766 100644
--- a/tools/libxl/libxl_console.c
+++ b/tools/libxl/libxl_console.c
@@ -316,7 +316,10 @@ int libxl__device_console_add(libxl__gc *gc, uint32_t 
domid,
     flexarray_append(ro_front, "output");
     flexarray_append(ro_front, console->output);
     flexarray_append(ro_front, "tty");
-    flexarray_append(ro_front, "");
+    if (state && state->console_tty)
+        flexarray_append(ro_front, state->console_tty);
+    else
+        flexarray_append(ro_front, "");
 
     if (state) {
         flexarray_append(ro_front, "port");
diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index 95fd96b..46b80b2 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -1697,6 +1697,7 @@ static int do_domain_soft_reset(libxl_ctx *ctx,
     libxl__domain_build_state *state;
     libxl__domain_save_state *dss;
     char *dom_path, *xs_store_mfn, *xs_console_mfn;
+    const char *console_tty;
     uint32_t domid_out;
     int rc;
 
@@ -1737,6 +1738,15 @@ static int do_domain_soft_reset(libxl_ctx *ctx,
     state->console_mfn = xs_console_mfn ? atol(xs_console_mfn): 0;
     free(xs_console_mfn);
 
+    rc = libxl__xs_read_mandatory(gc, XBT_NULL,
+                                  GCSPRINTF("%s/console/tty", dom_path),
+                                  &console_tty);
+    if (rc) {
+        LOGD(ERROR, domid_soft_reset, "failed to read console/tty.");
+        goto out;
+    }
+    state->console_tty = libxl__strdup(gc, console_tty);
+
     dss->ao = ao;
     dss->domid = dss->dsps.domid = domid_soft_reset;
     dss->dsps.dm_savefile = GCSPRINTF(LIBXL_DEVICE_MODEL_SAVE_FILE".%d",
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 25cb08a..f1d8f9a 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -1123,6 +1123,7 @@ typedef struct {
     uint32_t console_port;
     uint32_t console_domid;
     unsigned long console_mfn;
+    char *console_tty;
 
     char *saved_state;
 
--
generated by git-patchbot for /home/xen/git/xen.git#master

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