Hi Philippe, On 10/26/20 11:54 AM, Philippe Mathieu-Daudé wrote: > Introduce device/iommu 'page_size_min' variables to make > the code clearer.
I am unclear how much the device and the iommu page size must equal. For instance, in [RFC 0/5] NVMe passthrough: Support 64kB page host, I have a 64kB host page and an MPS set to 4kB. Thanks Eric > > Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com> > --- > block/nvme.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/block/nvme.c b/block/nvme.c > index aa290996679..5abd7257cac 100644 > --- a/block/nvme.c > +++ b/block/nvme.c > @@ -690,6 +690,8 @@ static int nvme_init(BlockDriverState *bs, const char > *device, int namespace, > uint64_t deadline, now; > Error *local_err = NULL; > volatile NvmeBar *regs = NULL; > + size_t device_page_size_min; > + size_t iommu_page_size_min = 4096; > > qemu_co_mutex_init(&s->dma_map_lock); > qemu_co_queue_init(&s->dma_flush_queue); > @@ -724,7 +726,8 @@ static int nvme_init(BlockDriverState *bs, const char > *device, int namespace, > goto out; > } > > - s->page_size = MAX(4096, 1u << (12 + NVME_CAP_MPSMIN(cap))); > + device_page_size_min = 1u << (12 + NVME_CAP_MPSMIN(cap)); > + s->page_size = MAX(iommu_page_size_min, device_page_size_min); > s->doorbell_scale = (4 << NVME_CAP_DSTRD(cap)) / sizeof(uint32_t); > bs->bl.opt_mem_alignment = s->page_size; > bs->bl.request_alignment = s->page_size; >
