From: Keir Fraser <keir.fraser@citrix.com>
Date: Mon, 7 Sep 2009 12:49:35 +0000 (+0100)
Subject: vt-d: avoid obtaining iommu->register_lock too early in
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~13368
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success//%22http:/www.example.com/cgi/success/?a=commitdiff_plain;h=4fe3160cbc7c4e71a85db069186ca26407acba77;p=xen.git

vt-d: avoid obtaining iommu->register_lock too early in
dma_msi_set_affinity()

If set_desc_affinity() fails, the current code doesn't release the
spinlock. We should obtain the lock at a later place.

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 b5131d86df..30370df584 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -826,7 +826,6 @@ static void dma_msi_set_affinity(unsigned int irq, cpumask_t mask)
     struct irq_desc *desc = irq_to_desc(irq);
     struct irq_cfg *cfg = desc->chip_data;
 
-    spin_lock_irqsave(&iommu->register_lock, flags);
 #ifdef CONFIG_X86
     dest = set_desc_affinity(desc, mask);
     if (dest == BAD_APICID){
@@ -862,6 +861,7 @@ static void dma_msi_set_affinity(unsigned int irq, cpumask_t mask)
     msg.address_lo |= dest << MSI_TARGET_CPU_SHIFT;
 #endif
 
+    spin_lock_irqsave(&iommu->register_lock, flags);
     dmar_writel(iommu->reg, DMAR_FEDATA_REG, msg.data);
     dmar_writel(iommu->reg, DMAR_FEADDR_REG, msg.address_lo);
     dmar_writel(iommu->reg, DMAR_FEUADDR_REG, msg.address_hi);