iommu/crash: Interrupt remapping is also disabled on crash

This fixes a regression side-effect caused by:
  IOMMU: properly check whether interrupt remapping is enabled
    git: fae0372140befb88d890a30704a8ec058c902af8
     hg: 26742:e1ec14bad0cb

On the crash path in nmi_shootdown_cpus(), we shut down the IOMMU, then
disable the IOAPIC.

On systems which support interrupt remapping, the variable iommu_intremap
remains set, meaning that disable_IO_APIC() issues interrupt remapping
invalidate requests.

IOAPIC interrupt remapping used to be conditional on iommu_enabled, but is now
conditional on iommu_intremap, following the above changeset.

This behaviour can be fixed by also indicating that interrupt remapping is not
enabled after shutting down the IOMMU.

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

diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index c5906abd88f28434b044383bd1f65e6d664b5d8f..93ad1224de039caa310bf2d1d194713ca1b98c4c 100644 (file)
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -603,7 +603,7 @@ void iommu_crash_shutdown(void)
     const struct iommu_ops *ops = iommu_get_ops();
     if ( iommu_enabled )
         ops->crash_shutdown();
-    iommu_enabled = 0;
+    iommu_enabled = iommu_intremap = 0;
 }
 
 int iommu_do_domctl(