vtd: Fix a missing spin_unlock_irqrestore()

Signed-off-by: Dexuan Cui <dexuan.cui@intel.com>

diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
index 8de32f476bb5c2bb051d3e955ff5b904b69dc508..e573bafd443b8a19388009214331431fc64b3c9a 100644 (file)
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -632,7 +632,10 @@ static int iommu_set_root_entry(struct iommu *iommu)
 
     iommu->root_maddr = alloc_pgtable_maddr();
     if ( iommu->root_maddr == 0 )
+    {
+        spin_unlock_irqrestore(&iommu->register_lock, flags);
         return -ENOMEM;
+    }
 
     dmar_writeq(iommu->reg, DMAR_RTADDR_REG, iommu->root_maddr);
     cmd = iommu->gcmd | DMA_GCMD_SRTP;