On Mon, Nov 12, 2018 at 04:51:22PM +0800, Peter Xu wrote: > On Fri, Nov 09, 2018 at 07:49:47PM +0800, Yu Zhang wrote: > > This patch updates vtd_lookup_iotlb() to search cached mappings only > > for all page levels supported by address width of current vIOMMU. Also, > > to cover 57-bit width, the shift of source id(VTD_IOTLB_SID_SHIFT) and > > of page level(VTD_IOTLB_LVL_SHIFT) are enlarged by 9 - the stride of > > one paging structure level. > > > > Signed-off-by: Yu Zhang <yu.c.zh...@linux.intel.com> > > --- > > Cc: "Michael S. Tsirkin" <m...@redhat.com> > > Cc: Marcel Apfelbaum <marcel.apfelb...@gmail.com> > > Cc: Paolo Bonzini <pbonz...@redhat.com> > > Cc: Richard Henderson <r...@twiddle.net> > > Cc: Eduardo Habkost <ehabk...@redhat.com> > > Cc: Peter Xu <pet...@redhat.com> > > --- > > hw/i386/intel_iommu.c | 5 +++-- > > hw/i386/intel_iommu_internal.h | 7 ++----- > > 2 files changed, 5 insertions(+), 7 deletions(-) > > > > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > > index 9cdf755..ce7e17e 100644 > > --- a/hw/i386/intel_iommu.c > > +++ b/hw/i386/intel_iommu.c > > @@ -254,11 +254,12 @@ static uint64_t vtd_get_iotlb_gfn(hwaddr addr, > > uint32_t level) > > static VTDIOTLBEntry *vtd_lookup_iotlb(IntelIOMMUState *s, uint16_t > > source_id, > > hwaddr addr) > > { > > - VTDIOTLBEntry *entry; > > + VTDIOTLBEntry *entry = NULL; > > uint64_t key; > > int level; > > + int max_level = (s->aw_bits - VTD_PAGE_SHIFT_4K) / VTD_SL_LEVEL_BITS; > > > > - for (level = VTD_SL_PT_LEVEL; level < VTD_SL_PML4_LEVEL; level++) { > > + for (level = VTD_SL_PT_LEVEL; level < max_level; level++) { > > My understanding of current IOTLB is that it only caches the last > level of mapping, say: > > - level 1: 4K page > - level 2: 2M page > - level 3: 1G page > > So we don't check against level=4 even if x-aw-bits=48 is specified. > > Here does it mean that we're going to have... 512G iommu huge pages? >
No. My bad, I misunderstood this routine. And now I believe we do not need this patch. :-) Thanks, Peter. > > key = vtd_get_iotlb_key(vtd_get_iotlb_gfn(addr, level), > > source_id, level); > > entry = g_hash_table_lookup(s->iotlb, &key); > > diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h > > index a7ef24b..bdf2b7c 100644 > > --- a/hw/i386/intel_iommu_internal.h > > +++ b/hw/i386/intel_iommu_internal.h > > @@ -114,8 +114,8 @@ > > VTD_INTERRUPT_ADDR_FIRST + 1) > > > > /* The shift of source_id in the key of IOTLB hash table */ > > -#define VTD_IOTLB_SID_SHIFT 36 > > -#define VTD_IOTLB_LVL_SHIFT 52 > > +#define VTD_IOTLB_SID_SHIFT 45 > > +#define VTD_IOTLB_LVL_SHIFT 61 > > #define VTD_IOTLB_MAX_SIZE 1024 /* Max size of the hash table > > */ > > > > /* IOTLB_REG */ > > @@ -450,9 +450,6 @@ typedef struct VTDRootEntry VTDRootEntry; > > #define VTD_SL_LEVEL_BITS 9 > > > > /* Second Level Paging Structure */ > > -#define VTD_SL_PML4_LEVEL 4 > > -#define VTD_SL_PDP_LEVEL 3 > > -#define VTD_SL_PD_LEVEL 2 > > #define VTD_SL_PT_LEVEL 1 > > #define VTD_SL_PT_ENTRY_NR 512 > > > > -- > > 1.9.1 > > > > Regards, > > -- > Peter Xu > B.R. Yu