x86/vtd: Fix S3 resume following c/s 650c31d3af

c/s 650c31d3af "x86/IRQ: fix locking around vector management" adjusted the
locking in adjust_irq_affinity().

The S3 path ends up here via iommu_resume() before interrupts are enabled, at
which point spin_lock_irq() fails ASSERT(local_irq_is_enabled()); but with no
working console.

Use spin_lock_irqsave() instead to cope with interrupts already being
disabled.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>

diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
index 5d72270c5b8c2ce8917f6441bf140cb99ef6d5a5..defa74fae348771ebbabf2d239b1970fd5065513 100644 (file)
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -2135,15 +2135,16 @@ static void adjust_irq_affinity(struct acpi_drhd_unit *drhd)
                              : NUMA_NO_NODE;
     const cpumask_t *cpumask = NULL;
     struct irq_desc *desc;
+    unsigned long flags;
 
     if ( node < MAX_NUMNODES && node_online(node) &&
          cpumask_intersects(&node_to_cpumask(node), &cpu_online_map) )
         cpumask = &node_to_cpumask(node);
 
     desc = irq_to_desc(drhd->iommu->msi.irq);
-    spin_lock_irq(&desc->lock);
+    spin_lock_irqsave(&desc->lock, flags);
     dma_msi_set_affinity(desc, cpumask);
-    spin_unlock_irq(&desc->lock);
+    spin_unlock_irqrestore(&desc->lock, flags);
 }
 
 static int adjust_vtd_irq_affinities(void)