> From: Peter Xu [mailto:pet...@redhat.com] > Sent: Wednesday, December 14, 2016 10:54 AM > > On Wed, Dec 14, 2016 at 04:48:42AM +0200, Michael S. Tsirkin wrote: > > On Wed, Dec 14, 2016 at 10:09:04AM +0800, Peter Xu wrote: > > > Currently vt-d Context Entry (CE) only allows 39/48 bits address width. > > > If guest software configured more than that, we complain and report. > > > > > > Signed-off-by: Peter Xu <pet...@redhat.com> > > > --- > > > hw/i386/intel_iommu.c | 17 ++++++++++++++++- > > > hw/i386/intel_iommu_internal.h | 2 ++ > > > 2 files changed, 18 insertions(+), 1 deletion(-) > > > > > > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > > > index 5f3e351..517a2a3 100644 > > > --- a/hw/i386/intel_iommu.c > > > +++ b/hw/i386/intel_iommu.c > > > @@ -599,9 +599,19 @@ static inline uint32_t > vtd_get_level_from_context_entry(VTDContextEntry *ce) > > > return 2 + (ce->hi & VTD_CONTEXT_ENTRY_AW); > > > } > > > > > > +/* Return 0 if failed to fetch valid aw */ > > > static inline uint32_t vtd_get_agaw_from_context_entry(VTDContextEntry > > > *ce) > > > { > > > - return 30 + (ce->hi & VTD_CONTEXT_ENTRY_AW) * 9; > > > + uint8_t aw = (ce->hi & VTD_CONTEXT_ENTRY_AW); > > > + /* > > > + * According to vt-d spec 10.4.2 bits 12:8, SAGAW only allows > > > + * 39/48 bits. > > > + */ > > > + if (aw > VTD_CE_AW_48BIT) { > > > > 5-level is almost sure to allow more. I don't see the point of this test. > > Please check above comment - spec only allow 3/4 level page table. > > My version of vt-d spec is 2016 Oct. I suppose that's new enough... >
It is in the works and will be published in January. Thanks Kevin