diff mbox series

[PULL,11/25] intel_iommu: fix operator in vtd_switch_address_space

Message ID 20190204142638.27021-12-mst@redhat.com
State New
Headers show
Series [PULL,01/25] virtio: add checks for the size of the indirect table | expand

Commit Message

Michael S. Tsirkin Feb. 4, 2019, 2:43 p.m. UTC 
From: Peter Xu <peterx@redhat.com>

When calculating use_iommu, we wanted to first detect whether DMAR is
enabled, then check whether PT is enabled if DMAR is enabled.  However
in the current code we used "&" rather than "&&" so the ordering
requirement is lost (instead it'll be an "AND" operation).  This could
introduce errors dumped in QEMU console when rebooting a guest with
both assigned device and vIOMMU, like:

  qemu-system-x86_64: vtd_dev_to_context_entry: invalid root entry:
  rsvd=0xf000ff53f000e2c3, val=0xf000ff53f000ff53 (reserved nonzero)

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/i386/intel_iommu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 8b72735650..6d5cc1d039 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -1153,7 +1153,7 @@  static bool vtd_switch_address_space(VTDAddressSpace *as)
 
     assert(as);
 
-    use_iommu = as->iommu_state->dmar_enabled & !vtd_dev_pt_enabled(as);
+    use_iommu = as->iommu_state->dmar_enabled && !vtd_dev_pt_enabled(as);
 
     trace_vtd_switch_address_space(pci_bus_num(as->bus),
                                    VTD_PCI_SLOT(as->devfn),