[21/36] xen/console: introduce use of 'is_console' flag

Commit Message

Denis Mukhin via B4 Relay Nov. 26, 2024, 11:22 p.m. UTC

From: Denis Mukhin <[e-mail]>

The code now inspects d->is_console flag to decide whether the console focus
should move to the domain w/ console after administrator presses <Ctrl+aaa>.

To do that max_init_domid is updated in domain_create().

Console owner domain switch logic updated accordingly.

Signed-off-by: Denis Mukhin <[e-mail]>
---
 xen/arch/x86/pv/shim.c     |  2 ++
 xen/common/domain.c        | 14 ++++++++++++++
 xen/drivers/char/console.c | 14 ++++++++++----
 3 files changed, 26 insertions(+), 4 deletions(-)

Patch

diff --git a/xen/arch/x86/pv/shim.c b/xen/arch/x86/pv/shim.c
index 17cb30620290c76cf42251f70cfa4199c0e165d1..a55c1d2a1e616f8979677a198eb9caabc3afc6bf 100644
--- a/xen/arch/x86/pv/shim.c
+++ b/xen/arch/x86/pv/shim.c
@@ -238,6 +238,8 @@  void __init pv_shim_setup_dom(struct domain *d, l4_pgentry_t *l4start,
      * guest from depleting the shim memory pool.
      */
     d->max_pages = domain_tot_pages(d);
+
+    d->is_console = true;
 }
 
 static void write_start_info(struct domain *d)
diff --git a/xen/common/domain.c b/xen/common/domain.c
index d8f6829db50dabba7464004b39eea39f6970f800..56f5d3b2031c52d567bfcf839740600320d952e9 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -682,6 +682,8 @@  struct domain *domain_create(domid_t domid,
 
         old_hwdom = hardware_domain;
         hardware_domain = d;
+
+        d->is_console = true;
     }
 
     TRACE_TIME(TRC_DOM0_DOM_ADD, d->domain_id);
@@ -818,6 +820,18 @@  struct domain *domain_create(domid_t domid,
 
     memcpy(d->handle, config->handle, sizeof(d->handle));
 
+    /*
+     * Housekeeping for physical console forwarding to the domain.
+     */
+    if ( !is_system_domain(d) && max_init_domid < domid )
+        max_init_domid = domid;
+
+    /*
+     * NB: flag is already set for PV shim and hardware domain, check whether
+     * virtual UART is present.
+     */
+    d->is_console |= domain_has_vuart(d);
+
     return d;
 
  fail:
diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index 60c055396b697869b04b9132b0dcfa832fabe932..8cbac54c66044ae8581e486a782102b75c8bfaa9 100644
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -1,8 +1,8 @@ 
 /******************************************************************************
  * console.c
- * 
+ *
  * Emergency console I/O for Xen and the domain-0 guest OS.
- * 
+ *
  * Copyright (c) 2002-2004, K A Fraser.
  *
  * Added printf_ratelimit
@@ -509,14 +509,20 @@  static void console_find_owner(void)
             domid = get_initial_domain_id();
         else
             domid = next_rx - 1;
+
         d = rcu_lock_domain_by_id(domid);
-        if ( d )
+        if ( d == NULL )
+            continue;
+
+        if ( d->is_console )
         {
             rcu_unlock_domain(d);
             console_owner = next_rx;
             printk("*** Serial input to DOM%u", domid);
             break;
         }
+
+        rcu_unlock_domain(d);
     }
 
     if ( switch_code )
@@ -814,7 +820,7 @@  static int printk_prefix_check(char *p, char **pp)
     return ((atomic_read(&print_everything) != 0) ||
             (loglvl < lower_thresh) ||
             ((loglvl < upper_thresh) && printk_ratelimit()));
-} 
+}
 
 static int cf_check parse_console_timestamps(const char *s)
 {