[Xen-changelog] [xen master] x2APIC: translate IO-APIC entries when enabling the IOMMU

[patchbot@xxxxxxx]

commit 0e606c1bc0e5b8ecdf699203fbe6dd29f396a41b
Author:     Roger Pau Monné <roger.pau@xxxxxxxxxx>
AuthorDate: Fri Oct 25 16:00:10 2019 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Oct 25 16:00:10 2019 +0200

    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@xxxxxxxxxx>
    Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    Release-acked-by: Juergen Gross <jgross@xxxxxxxx>
---
 xen/arch/x86/apic.c           | 11 ++++++++++-
 xen/arch/x86/io_apic.c        |  5 +++--
 xen/include/asm-x86/io_apic.h |  3 ++-
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/xen/arch/x86/apic.c b/xen/arch/x86/apic.c
index 0607eb92a8..a5f7b05d5a 100644
--- 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 5d25862bd8..37eabc16c9 100644
--- 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 0b041f0565..998905186b 100644
--- 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);
 
--
generated by git-patchbot for /home/xen/git/xen.git#master

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