[Xen-changelog] [xen master] x86/IRQ: desc->affinity should strictly represent the requested value

[patchbot@xxxxxxx]

commit 4a9dfab767e2f5d1b7b919b07099f3fc87a67fb6
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Mon Jul 22 11:42:32 2019 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Mon Jul 22 11:42:32 2019 +0200

    x86/IRQ: desc->affinity should strictly represent the requested value
    
    desc->arch.cpu_mask reflects the actual set of target CPUs. Don't ever
    fiddle with desc->affinity itself, except to store caller requested
    values. Note that assign_irq_vector() now takes a NULL incoming CPU mask
    to mean "all CPUs" now, rather than just "all currently online CPUs".
    This way no further affinity adjustment is needed after onlining further
    CPUs.
    
    This renders both set_native_irq_info() uses (which weren't using proper
    locking anyway) redundant - drop the function altogether.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/io_apic.c |  2 --
 xen/arch/x86/irq.c     | 26 ++++++++++++++++----------
 xen/include/xen/irq.h  |  5 -----
 3 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/xen/arch/x86/io_apic.c b/xen/arch/x86/io_apic.c
index 7705ffc113..02e3a263a6 100644
--- a/xen/arch/x86/io_apic.c
+++ b/xen/arch/x86/io_apic.c
@@ -1039,7 +1039,6 @@ static void __init setup_IO_APIC_irqs(void)
             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);
             spin_unlock_irqrestore(&ioapic_lock, flags);
         }
     }
@@ -2248,7 +2247,6 @@ int io_apic_set_pci_routing (int ioapic, int pin, int 
irq, int edge_level, int a
 
     spin_lock_irqsave(&ioapic_lock, flags);
     __ioapic_write_entry(ioapic, pin, 0, entry);
-    set_native_irq_info(irq, TARGET_CPUS);
     spin_unlock(&ioapic_lock);
 
     spin_lock(&desc->lock);
diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c
index a55f3d4af8..1acc351c67 100644
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -589,11 +589,16 @@ int assign_irq_vector(int irq, const cpumask_t *mask)
 
     spin_lock_irqsave(&vector_lock, flags);
     ret = __assign_irq_vector(irq, desc, mask ?: TARGET_CPUS);
-    if (!ret) {
+    if ( !ret )
+    {
         ret = desc->arch.vector;
-        cpumask_copy(desc->affinity, desc->arch.cpu_mask);
+        if ( mask )
+            cpumask_copy(desc->affinity, mask);
+        else
+            cpumask_setall(desc->affinity);
     }
     spin_unlock_irqrestore(&vector_lock, flags);
+
     return ret;
 }
 
@@ -2345,9 +2350,10 @@ static void dump_irqs(unsigned char key)
 
         spin_lock_irqsave(&desc->lock, flags);
 
-        printk("   IRQ:%4d aff:%*pb vec:%02x %-15s status=%03x ",
-               irq, nr_cpu_ids, cpumask_bits(desc->affinity), 
desc->arch.vector,
-               desc->handler->typename, desc->status);
+        printk("   IRQ:%4d aff:{%*pbl}/{%*pbl} vec:%02x %-15s status=%03x ",
+               irq, nr_cpu_ids, cpumask_bits(desc->affinity),
+               nr_cpu_ids, cpumask_bits(desc->arch.cpu_mask),
+               desc->arch.vector, desc->handler->typename, desc->status);
 
         if ( ssid )
             printk("Z=%-25s ", ssid);
@@ -2435,8 +2441,7 @@ void fixup_irqs(const cpumask_t *mask, bool verbose)
                 release_old_vec(desc);
         }
 
-        cpumask_copy(&affinity, desc->affinity);
-        if ( !desc->action || cpumask_subset(&affinity, mask) )
+        if ( !desc->action || cpumask_subset(desc->affinity, mask) )
         {
             spin_unlock(&desc->lock);
             continue;
@@ -2469,12 +2474,13 @@ void fixup_irqs(const cpumask_t *mask, bool verbose)
             desc->arch.move_in_progress = 0;
         }
 
-        cpumask_and(&affinity, &affinity, mask);
-        if ( cpumask_empty(&affinity) )
+        if ( !cpumask_intersects(mask, desc->affinity) )
         {
             break_affinity = true;
-            cpumask_copy(&affinity, mask);
+            cpumask_setall(&affinity);
         }
+        else
+            cpumask_copy(&affinity, desc->affinity);
 
         if ( desc->handler->disable )
             desc->handler->disable(desc);
diff --git a/xen/include/xen/irq.h b/xen/include/xen/irq.h
index 586b78393a..0f91884d57 100644
--- a/xen/include/xen/irq.h
+++ b/xen/include/xen/irq.h
@@ -162,11 +162,6 @@ extern irq_desc_t *domain_spin_lock_irq_desc(
 extern irq_desc_t *pirq_spin_lock_irq_desc(
     const struct pirq *, unsigned long *pflags);
 
-static inline void set_native_irq_info(unsigned int irq, const cpumask_t *mask)
-{
-    cpumask_copy(irq_to_desc(irq)->affinity, mask);
-}
-
 unsigned int set_desc_affinity(struct irq_desc *, const cpumask_t *);
 
 #ifndef arch_hwdom_irqs
--
generated by git-patchbot for /home/xen/git/xen.git#master

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