On 23/07/2018 13:11, David Gibson wrote: > On Wed, Jun 20, 2018 at 07:10:12PM +1000, Alexey Kardashevskiy wrote: >> At the moment the PPC64/pseries guest only supports 4K/64K/16M IOMMU >> pages and POWER8 CPU supports the exact same set of page size so >> so far things worked fine. >> >> However POWER9 supports different set of sizes - 4K/64K/2M/1G and >> the last two - 2M and 1G - are not even allowed in the paravirt interface >> (RTAS DDW) so we always end up using 64K IOMMU pages, although we could >> back guest's 16MB IOMMU pages with 2MB pages on the host. >> >> This stores the supported host IOMMU page sizes in VFIOContainer and uses >> this later when creating a new DMA window. This uses the system page size >> (64k normally, 2M/16M/1G if hugepages used) as the upper limit of >> the IOMMU pagesize. >> >> This changes the type of @pagesize to uint64_t as this is what >> memory_region_iommu_get_min_page_size() returns and clz64() takes. >> >> There should be no behavioral changes on platforms other than pseries. >> The guest will keep using the IOMMU page size selected by the PHB pagesize >> property as this only changes the underlying hardware TCE table >> granularity. >> >> Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> >> --- >> Changes: >> v2: >> * fixed biggest but smaller page size calculation >> * limit IOMMU pagesize to the system pagesize > > Sorry, this fell of my radar for a bit. > > I've now applied it to ppc-for-3.1.
Alex might object that as it does not have his "rb" ;)
>
>> ---
>> include/hw/vfio/vfio-common.h | 1 +
>> hw/vfio/common.c | 3 +++
>> hw/vfio/spapr.c | 21 ++++++++++++++++++++-
>> 3 files changed, 24 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
>> index a903692..c20524d 100644
>> --- a/include/hw/vfio/vfio-common.h
>> +++ b/include/hw/vfio/vfio-common.h
>> @@ -73,6 +73,7 @@ typedef struct VFIOContainer {
>> unsigned iommu_type;
>> int error;
>> bool initialized;
>> + unsigned long pgsizes;
>> /*
>> * This assumes the host IOMMU can support only a single
>> * contiguous IOVA window. We may need to generalize that in
>> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
>> index fb396cf..40f0356 100644
>> --- a/hw/vfio/common.c
>> +++ b/hw/vfio/common.c
>> @@ -1108,6 +1108,7 @@ static int vfio_connect_container(VFIOGroup *group,
>> AddressSpace *as,
>> info.iova_pgsizes = 4096;
>> }
>> vfio_host_win_add(container, 0, (hwaddr)-1, info.iova_pgsizes);
>> + container->pgsizes = info.iova_pgsizes;
>> } else if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_IOMMU) ||
>> ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_v2_IOMMU)) {
>> struct vfio_iommu_spapr_tce_info info;
>> @@ -1172,6 +1173,7 @@ static int vfio_connect_container(VFIOGroup *group,
>> AddressSpace *as,
>> }
>>
>> if (v2) {
>> + container->pgsizes = info.ddw.pgsizes;
>> /*
>> * There is a default window in just created container.
>> * To make region_add/del simpler, we better remove this
>> @@ -1186,6 +1188,7 @@ static int vfio_connect_container(VFIOGroup *group,
>> AddressSpace *as,
>> }
>> } else {
>> /* The default table uses 4K pages */
>> + container->pgsizes = 0x1000;
>> vfio_host_win_add(container, info.dma32_window_start,
>> info.dma32_window_start +
>> info.dma32_window_size - 1,
>> diff --git a/hw/vfio/spapr.c b/hw/vfio/spapr.c
>> index 259397c..becf71a 100644
>> --- a/hw/vfio/spapr.c
>> +++ b/hw/vfio/spapr.c
>> @@ -15,6 +15,7 @@
>>
>> #include "hw/vfio/vfio-common.h"
>> #include "hw/hw.h"
>> +#include "exec/ram_addr.h"
>> #include "qemu/error-report.h"
>> #include "trace.h"
>>
>> @@ -144,9 +145,27 @@ int vfio_spapr_create_window(VFIOContainer *container,
>> {
>> int ret;
>> IOMMUMemoryRegion *iommu_mr = IOMMU_MEMORY_REGION(section->mr);
>> - unsigned pagesize = memory_region_iommu_get_min_page_size(iommu_mr);
>> + uint64_t pagesize = memory_region_iommu_get_min_page_size(iommu_mr);
>> unsigned entries, pages;
>> struct vfio_iommu_spapr_tce_create create = { .argsz = sizeof(create) };
>> + long systempagesize = qemu_getrampagesize();
>> +
>> + /*
>> + * The host might not support the guest supported IOMMU page size,
>> + * so we will use smaller physical IOMMU pages to back them.
>> + */
>> + if (pagesize > systempagesize) {
>> + pagesize = systempagesize;
>> + }
>> + pagesize = 1ULL << (63 - clz64(container->pgsizes &
>> + (pagesize | (pagesize - 1))));
>> + if (!pagesize) {
>> + error_report("Host doesn't support page size 0x%"PRIx64
>> + ", the supported mask is 0x%lx",
>> + memory_region_iommu_get_min_page_size(iommu_mr),
>> + container->pgsizes);
>> + return -EINVAL;
>> + }
>>
>> /*
>> * FIXME: For VFIO iommu types which have KVM acceleration to
>
--
Alexey
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