[Xen-devel] [PATCH v3 2/4] x2APIC: simplify resume

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

There's no need to save and restore the IO-APIC entries, the entries
prior to suspension have already been saved by ioapic_suspend, and
will be restored by ioapic_resume. Note that at the point where
resume_x2apic gets called the IO-APIC has not yet resumed, and hence
all entries should be masked.

Note this shouldn't introduce any functional change.

Suggested-by: Jan Beulich <jbeulich@xxxxxxxx>
Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
I'm Ccing Marek since I think he usually tests suspend/resume. Could
you give this patch a try?
---
Cc: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
---
Changes since v2:
 - New in this version.
---
 xen/arch/x86/apic.c | 27 ---------------------------
 1 file changed, 27 deletions(-)

diff --git a/xen/arch/x86/apic.c b/xen/arch/x86/apic.c
index 6cdb50cf41..0607eb92a8 100644
--- a/xen/arch/x86/apic.c
+++ b/xen/arch/x86/apic.c
@@ -492,35 +492,8 @@ static void __enable_x2apic(void)
 
 static void resume_x2apic(void)
 {
-    struct IO_APIC_route_entry **ioapic_entries = NULL;
-
-    ASSERT(x2apic_enabled);
-
-    ioapic_entries = alloc_ioapic_entries();
-    if ( !ioapic_entries )
-    {
-        printk("Allocate ioapic_entries failed\n");
-        goto out;
-    }
-
-    if ( save_IO_APIC_setup(ioapic_entries) )
-    {
-        printk("Saving IO-APIC state failed\n");
-        goto out;
-    }
-
-    mask_8259A();
-    mask_IO_APIC_setup(ioapic_entries);
-
     iommu_enable_x2apic();
     __enable_x2apic();
-
-    restore_IO_APIC_setup(ioapic_entries);
-    unmask_8259A();
-
-out:
-    if ( ioapic_entries )
-        free_ioapic_entries(ioapic_entries);
 }
 
 void setup_local_APIC(void)
-- 
2.23.0


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