[PATCH] x86/IO-APIC: fix setting of destinations

[PATCH] x86/IO-APIC: fix setting of destinations

[Jan Beulich]

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In commit a85da715cf ("x86/IO-APIC: adjust setting of destinations") I
made a pretty blatant mistake: get_apic_id() can be used there only
when running APICs in physical mode. For both flat and clustered modes
the change was wrong, causing different kinds of boot problems on
affected systems. Don't revert that change though, but use TARGET_CPUS
(equaling cpu_online_map, and with there only being a single online CPU
fulfilling the original commits intention).

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/io_apic.c
+++ b/xen/arch/x86/io_apic.c
@@ -1039,7 +1039,7 @@ static void __init setup_IO_APIC_irqs(vo
                 disable_8259A_irq(irq_to_desc(irq));
 
             desc = irq_to_desc(irq);
-            SET_DEST(entry, logical, get_apic_id());
+            SET_DEST(entry, logical, cpu_mask_to_apicid(TARGET_CPUS));
             spin_lock_irqsave(&ioapic_lock, flags);
             __ioapic_write_entry(apic, pin, 0, entry);
             set_native_irq_info(irq, TARGET_CPUS);




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x86/IO-APIC: fix setting of destinations

In commit a85da715cf ("x86/IO-APIC: adjust setting of destinations") I
made a pretty blatant mistake: get_apic_id() can be used there only
when running APICs in physical mode. For both flat and clustered modes
the change was wrong, causing different kinds of boot problems on
affected systems. Don't revert that change though, but use TARGET_CPUS
(equaling cpu_online_map, and with there only being a single online CPU
fulfilling the original commits intention).

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/io_apic.c
+++ b/xen/arch/x86/io_apic.c
@@ -1039,7 +1039,7 @@ static void __init setup_IO_APIC_irqs(vo
                 disable_8259A_irq(irq_to_desc(irq));
 
             desc = irq_to_desc(irq);
-            SET_DEST(entry, logical, get_apic_id());
+            SET_DEST(entry, logical, cpu_mask_to_apicid(TARGET_CPUS));
             spin_lock_irqsave(&ioapic_lock, flags);
             __ioapic_write_entry(apic, pin, 0, entry);
             set_native_irq_info(irq, TARGET_CPUS);

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Re: [PATCH] x86/IO-APIC: fix setting of destinations

[Boris Ostrovsky]

On 11/19/2015 04:46 AM, Jan Beulich wrote:
> In commit a85da715cf ("x86/IO-APIC: adjust setting of destinations") I
> made a pretty blatant mistake: get_apic_id() can be used there only
> when running APICs in physical mode. For both flat and clustered modes
> the change was wrong, causing different kinds of boot problems on
> affected systems. Don't revert that change though, but use TARGET_CPUS
> (equaling cpu_online_map, and with there only being a single online CPU
> fulfilling the original commits intention).
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
>
> --- a/xen/arch/x86/io_apic.c
> +++ b/xen/arch/x86/io_apic.c
> @@ -1039,7 +1039,7 @@ static void __init setup_IO_APIC_irqs(vo
>                   disable_8259A_irq(irq_to_desc(irq));
>   
>               desc = irq_to_desc(irq);
> -            SET_DEST(entry, logical, get_apic_id());
> +            SET_DEST(entry, logical, cpu_mask_to_apicid(TARGET_CPUS));
>               spin_lock_irqsave(&ioapic_lock, flags);
>               __ioapic_write_entry(apic, pin, 0, entry);
>               set_native_irq_info(irq, TARGET_CPUS);


Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

(One of our systems started failing and I bisected it yesterday to 
a85da715c but didn't get to actually debug it. Now I don't need to).

-boris

Re: [PATCH] x86/IO-APIC: fix setting of destinations

[Andrew Cooper]

On 19/11/15 09:46, Jan Beulich wrote:
> In commit a85da715cf ("x86/IO-APIC: adjust setting of destinations") I
> made a pretty blatant mistake: get_apic_id() can be used there only
> when running APICs in physical mode. For both flat and clustered modes
> the change was wrong, causing different kinds of boot problems on
> affected systems. Don't revert that change though, but use TARGET_CPUS
> (equaling cpu_online_map, and with there only being a single online CPU
> fulfilling the original commits intention).
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

I also missed that while reviewing.

Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

>
> --- a/xen/arch/x86/io_apic.c
> +++ b/xen/arch/x86/io_apic.c
> @@ -1039,7 +1039,7 @@ static void __init setup_IO_APIC_irqs(vo
>                  disable_8259A_irq(irq_to_desc(irq));
>  
>              desc = irq_to_desc(irq);
> -            SET_DEST(entry, logical, get_apic_id());
> +            SET_DEST(entry, logical, cpu_mask_to_apicid(TARGET_CPUS));
>              spin_lock_irqsave(&ioapic_lock, flags);
>              __ioapic_write_entry(apic, pin, 0, entry);
>              set_native_irq_info(irq, TARGET_CPUS);
>
>
>