From 94edd1b203f3a88065ce05d9e027b24a3e8eed2f Mon Sep 17 00:00:00 2001

From: Peter Xu <peterx@redhat.com>

Date: Tue, 2 Apr 2019 07:25:28 +0100

Subject: [PATCH 4/7] intel_iommu: fix operator in vtd_switch_address_space

RH-Author: Peter Xu <peterx@redhat.com>

Message-id: <20190402072531.23771-2-peterx@redhat.com>

Patchwork-id: 85298

O-Subject: [RHEL-8.1 qemu-kvm PATCH 1/4] intel_iommu: fix operator in vtd_switch_address_space

Bugzilla: 1662272

RH-Acked-by: Wei Huang <wei@redhat.com>

RH-Acked-by: Xiao Wang <jasowang@redhat.com>

RH-Acked-by: Michael S. Tsirkin <mst@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>

(cherry picked from commit 2a078b1080917dc6143783e1dd645e188d11dc8f)

Signed-off-by: Peter Xu <peterx@redhat.com>

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 hw/i386/intel_iommu.c | 2 +-

 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c

index 12af410..7170266 100644

--- a/hw/i386/intel_iommu.c

+++ b/hw/i386/intel_iommu.c

@@ -1145,7 +1145,7 @@ 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),

-- 

1.8.3.1