x2APIC: translate IO-APIC entries when enabling the IOMMU

When interrupt remapping is enabled as part of enabling x2APIC the
IO-APIC entries also need to be translated to the new format and added
to the interrupt remapping table.

This prevents IOMMU interrupt remapping faults when booting on
hardware that has unmasked IO-APIC pins.

Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Juergen Gross <jgross@suse.com>

diff --git a/xen/arch/x86/apic.c b/xen/arch/x86/apic.c
index 0607eb92a89b3c206754e7921bfbf58a75daf80b..a5f7b05d5a07dc573ccb20b78e1fba44a3928b7c 100644 (file)
--- a/xen/arch/x86/apic.c
+++ b/xen/arch/x86/apic.c
@@ -860,6 +860,7 @@ void __init x2apic_bsp_setup(void)
 {
     struct IO_APIC_route_entry **ioapic_entries = NULL;
     const char *orig_name;
+    bool intremap_enabled;
 
     if ( !cpu_has_x2apic )
         return;
@@ -902,11 +903,13 @@ void __init x2apic_bsp_setup(void)
     switch ( iommu_enable_x2apic() )
     {
     case 0:
+        intremap_enabled = true;
         break;
     case -ENXIO: /* ACPI_DMAR_X2APIC_OPT_OUT set */
         if ( !x2apic_enabled )
         {
             printk("Not enabling x2APIC (upon firmware request)\n");
+            intremap_enabled = false;
             goto restore_out;
         }
         /* fall through */
@@ -917,6 +920,7 @@ void __init x2apic_bsp_setup(void)
 
         printk(XENLOG_ERR
                "Failed to enable Interrupt Remapping: Will not enable x2APIC.\n");
+        intremap_enabled = false;
         goto restore_out;
     }
 
@@ -934,7 +938,12 @@ void __init x2apic_bsp_setup(void)
         printk("Switched to APIC driver %s\n", genapic.name);
 
 restore_out:
-    restore_IO_APIC_setup(ioapic_entries);
+    /*
+     * NB: do not use raw mode when restoring entries if the iommu has been
+     * enabled during the process, because the entries need to be translated
+     * and added to the remapping table in that case.
+     */
+    restore_IO_APIC_setup(ioapic_entries, !intremap_enabled);
     unmask_8259A();
 
 out:

diff --git a/xen/arch/x86/io_apic.c b/xen/arch/x86/io_apic.c
index 5d25862bd8bbd05b11c54dcfc75d7e09abb0ab1c..37eabc16c93fca8dd65c0fade0fb9d3d2e3edf8b 100644 (file)
--- a/xen/arch/x86/io_apic.c
+++ b/xen/arch/x86/io_apic.c
@@ -379,7 +379,8 @@ void mask_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries)
 /*
  * Restore IO APIC entries which was saved in ioapic_entries.
  */
-int restore_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries)
+int restore_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries,
+                          bool raw)
 {
     int apic, pin;
 
@@ -394,7 +395,7 @@ int restore_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries)
             return -ENOMEM;
 
         for (pin = 0; pin < nr_ioapic_entries[apic]; pin++)
-           ioapic_write_entry(apic, pin, 1, ioapic_entries[apic][pin]);
+           ioapic_write_entry(apic, pin, raw, ioapic_entries[apic][pin]);
     }
 
     return 0;

diff --git a/xen/include/asm-x86/io_apic.h b/xen/include/asm-x86/io_apic.h
index 0b041f05651a86c56918ce56c341bdfb822d1a99..998905186bbb7c29882172e5e40048aba3820a37 100644 (file)
--- a/xen/include/asm-x86/io_apic.h
+++ b/xen/include/asm-x86/io_apic.h
@@ -197,7 +197,8 @@ extern struct IO_APIC_route_entry **alloc_ioapic_entries(void);
 extern void free_ioapic_entries(struct IO_APIC_route_entry **ioapic_entries);
 extern int save_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries);
 extern void mask_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries);
-extern int restore_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries);
+extern int restore_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries,
+                                 bool raw);
 
 unsigned highest_gsi(void);