From: Peter Xu <pet...@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 <jasow...@redhat.com> Signed-off-by: Peter Xu <pet...@redhat.com> Reviewed-by: Michael S. Tsirkin <m...@redhat.com> Signed-off-by: Michael S. Tsirkin <m...@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 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), -- MST