On Fri, Nov 09, 2018 at 07:49:45PM +0800, Yu Zhang wrote: > Currently, vIOMMU is using the value of IOVA address width, instead of > the host address width(HAW) to calculate the number of reserved bits in > data structures such as root entries, context entries, and entries of > DMA paging structures etc. > > However values of IOVA address width and of the HAW may not equal. For > example, a 48-bit IOVA can only be mapped to host addresses no wider than > 46 bits. Using 48, instead of 46 to calculate the reserved bit may result > in an invalid IOVA being accepted. > > To fix this, a new field - haw_bits is introduced in struct IntelIOMMUState, > whose value is initialized based on the maximum physical address set to > guest CPU. Also, definitions such as VTD_HOST_AW_39/48BIT etc. are renamed > to clarify.
IIRC I raised this question some time ago somewhere but no one remembered to follow that up. Thanks for fixing it. It looks mostly good to me, only one tiny comment below... [...] > @@ -887,6 +887,7 @@ static int vtd_page_walk_level(dma_addr_t addr, uint64_t > start, > uint64_t iova = start; > uint64_t iova_next; > int ret = 0; > + uint8_t haw = info->as->iommu_state->haw_bits; For now vtd_page_walk_info->aw_bits caches the GAW information and we use a single vtd_page_walk_info during one page walk, maybe we can also do the same for HAW instead of fetching it every time here from info->as->iommu_state->haw_bits? Regards, -- Peter Xu
