> From: Peter Xu [mailto:pet...@redhat.com] > Sent: Friday, January 13, 2017 11:06 AM > > From: Aviv Ben-David <bd.a...@gmail.com> > > This capability asks the guest to invalidate cache before each map operation. > We can use this invalidation to trap map operations in the hypervisor. > > Signed-off-by: Aviv Ben-David <bd.a...@gmail.com> > Signed-off-by: Peter Xu <pet...@redhat.com> > --- > hw/i386/intel_iommu.c | 5 +++++ > hw/i386/intel_iommu_internal.h | 1 + > include/hw/i386/intel_iommu.h | 2 ++ > 3 files changed, 8 insertions(+) > > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > index ec62239..2868e37 100644 > --- a/hw/i386/intel_iommu.c > +++ b/hw/i386/intel_iommu.c > @@ -2107,6 +2107,7 @@ static Property vtd_properties[] = { > DEFINE_PROP_ON_OFF_AUTO("eim", IntelIOMMUState, intr_eim, > ON_OFF_AUTO_AUTO), > DEFINE_PROP_BOOL("x-buggy-eim", IntelIOMMUState, buggy_eim, false), > + DEFINE_PROP_BOOL("cache-mode", IntelIOMMUState, cache_mode_enabled, > FALSE), > DEFINE_PROP_END_OF_LIST(), > }; > > @@ -2488,6 +2489,10 @@ static void vtd_init(IntelIOMMUState *s) > s->ecap |= VTD_ECAP_DT; > } > > + if (s->cache_mode_enabled) { > + s->cap |= VTD_CAP_CM; > + } > +
I think some of my old comments are not answered: 1) Better to use caching_mode to follow spec 2) Does it make sense to automatically set this flag if any VFIO device has been statically assigned when starting Qemu? Also for hot-add device path, some check of caching mode is required. If not set, should we fail hot-add operation? I don't think we have such physical platform with some devices behind IOMMU while others not. > vtd_reset_context_cache(s); > vtd_reset_iotlb(s); > > diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h > index 356f188..4104121 100644 > --- a/hw/i386/intel_iommu_internal.h > +++ b/hw/i386/intel_iommu_internal.h > @@ -202,6 +202,7 @@ > #define VTD_CAP_MAMV (VTD_MAMV << 48) > #define VTD_CAP_PSI (1ULL << 39) > #define VTD_CAP_SLLPS ((1ULL << 34) | (1ULL << 35)) > +#define VTD_CAP_CM (1ULL << 7) > > /* Supported Adjusted Guest Address Widths */ > #define VTD_CAP_SAGAW_SHIFT 8 > diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h > index 405c9d1..749eef9 100644 > --- a/include/hw/i386/intel_iommu.h > +++ b/include/hw/i386/intel_iommu.h > @@ -257,6 +257,8 @@ struct IntelIOMMUState { > uint8_t womask[DMAR_REG_SIZE]; /* WO (write only - read returns 0) */ > uint32_t version; > > + bool cache_mode_enabled; /* RO - is cap CM enabled? */ > + > dma_addr_t root; /* Current root table pointer */ > bool root_extended; /* Type of root table (extended or not) > */ > bool dmar_enabled; /* Set if DMA remapping is enabled */ > -- > 2.7.4