Re: [PATCH kernel v11 33/34] vfio: powerpc/spapr: Register memory and define IOMMU v2
From: Gavin Shan
Date: Thu Jun 04 2015 - 20:05:23 EST
On Fri, May 29, 2015 at 06:44:57PM +1000, Alexey Kardashevskiy wrote:
>The existing implementation accounts the whole DMA window in
>the locked_vm counter. This is going to be worse with multiple
>containers and huge DMA windows. Also, real-time accounting would requite
>additional tracking of accounted pages due to the page size difference -
>IOMMU uses 4K pages and system uses 4K or 64K pages.
>
>Another issue is that actual pages pinning/unpinning happens on every
>DMA map/unmap request. This does not affect the performance much now as
>we spend way too much time now on switching context between
>guest/userspace/host but this will start to matter when we add in-kernel
>DMA map/unmap acceleration.
>
>This introduces a new IOMMU type for SPAPR - VFIO_SPAPR_TCE_v2_IOMMU.
>New IOMMU deprecates VFIO_IOMMU_ENABLE/VFIO_IOMMU_DISABLE and introduces
>2 new ioctls to register/unregister DMA memory -
>VFIO_IOMMU_SPAPR_REGISTER_MEMORY and VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY -
>which receive user space address and size of a memory region which
>needs to be pinned/unpinned and counted in locked_vm.
>New IOMMU splits physical pages pinning and TCE table update
>into 2 different operations. It requires:
>1) guest pages to be registered first
>2) consequent map/unmap requests to work only with pre-registered memory.
>For the default single window case this means that the entire guest
>(instead of 2GB) needs to be pinned before using VFIO.
>When a huge DMA window is added, no additional pinning will be
>required, otherwise it would be guest RAM + 2GB.
>
>The new memory registration ioctls are not supported by
>VFIO_SPAPR_TCE_IOMMU. Dynamic DMA window and in-kernel acceleration
>will require memory to be preregistered in order to work.
>
>The accounting is done per the user process.
>
>This advertises v2 SPAPR TCE IOMMU and restricts what the userspace
>can do with v1 or v2 IOMMUs.
>
>In order to support memory pre-registration, we need a way to track
>the use of every registered memory region and only allow unregistration
>if a region is not in use anymore. So we need a way to tell from what
>region the just cleared TCE was from.
>
>This adds a userspace view of the TCE table into iommu_table struct.
>It contains userspace address, one per TCE entry. The table is only
>allocated when the ownership over an IOMMU group is taken which means
>it is only used from outside of the powernv code (such as VFIO).
>
>Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
>[aw: for the vfio related changes]
>Acked-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
>---
>Changes:
>v11:
>* mm_iommu_put() does not return a code so this does not check it
>* moved "v2" in tce_container to pack the struct
>
>v10:
>* moved it_userspace allocation to vfio_iommu_spapr_tce as it VFIO
>specific thing
>* squashed "powerpc/iommu: Add userspace view of TCE table" into this as
>it is
>a part of IOMMU v2
>* s/tce_iommu_use_page_v2/tce_iommu_prereg_ua_to_hpa/
>* fixed some function names to have "tce_iommu_" in the beginning rather
>just "tce_"
>* as mm_iommu_mapped_inc() can now fail, check for the return code
>
>v9:
>* s/tce_get_hva_cached/tce_iommu_use_page_v2/
>
>v7:
>* now memory is registered per mm (i.e. process)
>* moved memory registration code to powerpc/mmu
>* merged "vfio: powerpc/spapr: Define v2 IOMMU" into this
>* limited new ioctls to v2 IOMMU
>* updated doc
>* unsupported ioclts return -ENOTTY instead of -EPERM
>
>v6:
>* tce_get_hva_cached() returns hva via a pointer
>
>v4:
>* updated docs
>* s/kzmalloc/vzalloc/
>* in tce_pin_pages()/tce_unpin_pages() removed @vaddr, @size and
>replaced offset with index
>* renamed vfio_iommu_type_register_memory to vfio_iommu_spapr_register_memory
>and removed duplicating vfio_iommu_spapr_register_memory
>---
> Documentation/vfio.txt | 31 ++-
> arch/powerpc/include/asm/iommu.h | 6 +
> drivers/vfio/vfio_iommu_spapr_tce.c | 512 ++++++++++++++++++++++++++++++------
> include/uapi/linux/vfio.h | 27 ++
> 4 files changed, 487 insertions(+), 89 deletions(-)
>
>diff --git a/Documentation/vfio.txt b/Documentation/vfio.txt
>index 96978ec..7dcf2b5 100644
>--- a/Documentation/vfio.txt
>+++ b/Documentation/vfio.txt
>@@ -289,10 +289,12 @@ PPC64 sPAPR implementation note
>
> This implementation has some specifics:
>
>-1) Only one IOMMU group per container is supported as an IOMMU group
>-represents the minimal entity which isolation can be guaranteed for and
>-groups are allocated statically, one per a Partitionable Endpoint (PE)
>+1) On older systems (POWER7 with P5IOC2/IODA1) only one IOMMU group per
>+container is supported as an IOMMU table is allocated at the boot time,
>+one table per a IOMMU group which is a Partitionable Endpoint (PE)
> (PE is often a PCI domain but not always).
>+Newer systems (POWER8 with IODA2) have improved hardware design which allows
>+to remove this limitation and have multiple IOMMU groups per a VFIO container.
>
> 2) The hardware supports so called DMA windows - the PCI address range
> within which DMA transfer is allowed, any attempt to access address space
>@@ -427,6 +429,29 @@ The code flow from the example above should be slightly changed:
>
> ....
>
>+5) There is v2 of SPAPR TCE IOMMU. It deprecates VFIO_IOMMU_ENABLE/
>+VFIO_IOMMU_DISABLE and implements 2 new ioctls:
>+VFIO_IOMMU_SPAPR_REGISTER_MEMORY and VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY
>+(which are unsupported in v1 IOMMU).
>+
>+PPC64 paravirtualized guests generate a lot of map/unmap requests,
>+and the handling of those includes pinning/unpinning pages and updating
>+mm::locked_vm counter to make sure we do not exceed the rlimit.
>+The v2 IOMMU splits accounting and pinning into separate operations:
>+
>+- VFIO_IOMMU_SPAPR_REGISTER_MEMORY/VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY ioctls
>+receive a user space address and size of the block to be pinned.
>+Bisecting is not supported and VFIO_IOMMU_UNREGISTER_MEMORY is expected to
>+be called with the exact address and size used for registering
>+the memory block. The userspace is not expected to call these often.
>+The ranges are stored in a linked list in a VFIO container.
>+
>+- VFIO_IOMMU_MAP_DMA/VFIO_IOMMU_UNMAP_DMA ioctls only update the actual
>+IOMMU table and do not do pinning; instead these check that the userspace
>+address is from pre-registered range.
>+
>+This separation helps in optimizing DMA for guests.
>+
> -------------------------------------------------------------------------------
>
> [1] VFIO was originally an acronym for "Virtual Function I/O" in its
>diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
>index 9d37492..f9957eb 100644
>--- a/arch/powerpc/include/asm/iommu.h
>+++ b/arch/powerpc/include/asm/iommu.h
>@@ -112,9 +112,15 @@ struct iommu_table {
> unsigned long *it_map; /* A simple allocation bitmap for now */
> unsigned long it_page_shift;/* table iommu page size */
> struct list_head it_group_list;/* List of iommu_table_group_link */
>+ unsigned long *it_userspace; /* userspace view of the table */
> struct iommu_table_ops *it_ops;
> };
>
>+#define IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry) \
>+ ((tbl)->it_userspace ? \
>+ &((tbl)->it_userspace[(entry) - (tbl)->it_offset]) : \
>+ NULL)
>+
> /* Pure 2^n version of get_order */
> static inline __attribute_const__
> int get_iommu_order(unsigned long size, struct iommu_table *tbl)
>diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
>index 7a84110..cadd9f8 100644
>--- a/drivers/vfio/vfio_iommu_spapr_tce.c
>+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
>@@ -19,8 +19,10 @@
> #include <linux/uaccess.h>
> #include <linux/err.h>
> #include <linux/vfio.h>
>+#include <linux/vmalloc.h>
> #include <asm/iommu.h>
> #include <asm/tce.h>
>+#include <asm/mmu_context.h>
>
> #define DRIVER_VERSION "0.1"
> #define DRIVER_AUTHOR "aik@xxxxxxxxx"
>@@ -81,6 +83,11 @@ static void decrement_locked_vm(long npages)
> * into DMA'ble space using the IOMMU
> */
>
>+struct tce_iommu_group {
>+ struct list_head next;
>+ struct iommu_group *grp;
>+};
>+
> /*
> * The container descriptor supports only a single group per container.
> * Required by the API as the container is not supplied with the IOMMU group
>@@ -88,11 +95,84 @@ static void decrement_locked_vm(long npages)
> */
> struct tce_container {
> struct mutex lock;
>- struct iommu_group *grp;
> bool enabled;
>+ bool v2;
> unsigned long locked_pages;
>+ struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
>+ struct list_head group_list;
> };
>
>+static long tce_iommu_unregister_pages(struct tce_container *container,
>+ __u64 vaddr, __u64 size)
>+{
>+ struct mm_iommu_table_group_mem_t *mem;
>+
>+ if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK))
>+ return -EINVAL;
>+
>+ mem = mm_iommu_lookup(vaddr, size >> PAGE_SHIFT);
>+ if (!mem)
>+ return -EINVAL;
>+
>+ return mm_iommu_put(mem);
>+}
>+
>+static long tce_iommu_register_pages(struct tce_container *container,
>+ __u64 vaddr, __u64 size)
>+{
>+ long ret = 0;
>+ struct mm_iommu_table_group_mem_t *mem = NULL;
>+ unsigned long entries = size >> PAGE_SHIFT;
>+
>+ if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK) ||
>+ ((vaddr + size) < vaddr))
>+ return -EINVAL;
>+
>+ ret = mm_iommu_get(vaddr, entries, &mem);
>+ if (ret)
>+ return ret;
>+
>+ container->enabled = true;
>+
>+ return 0;
>+}
>+
>+static long tce_iommu_userspace_view_alloc(struct iommu_table *tbl)
>+{
>+ unsigned long cb = _ALIGN_UP(sizeof(tbl->it_userspace[0]) *
>+ tbl->it_size, PAGE_SIZE);
>+ unsigned long *uas;
>+ long ret;
>+
>+ BUG_ON(tbl->it_userspace);
>+
>+ ret = try_increment_locked_vm(cb >> PAGE_SHIFT);
>+ if (ret)
>+ return ret;
>+
>+ uas = vzalloc(cb);
>+ if (!uas) {
>+ decrement_locked_vm(cb >> PAGE_SHIFT);
>+ return -ENOMEM;
>+ }
>+ tbl->it_userspace = uas;
>+
>+ return 0;
>+}
>+
>+static void tce_iommu_userspace_view_free(struct iommu_table *tbl)
>+{
>+ unsigned long cb = _ALIGN_UP(sizeof(tbl->it_userspace[0]) *
>+ tbl->it_size, PAGE_SIZE);
>+
>+ if (!tbl->it_userspace)
>+ return;
>+
>+ vfree(tbl->it_userspace);
>+ tbl->it_userspace = NULL;
>+ decrement_locked_vm(cb >> PAGE_SHIFT);
>+}
>+
> static bool tce_page_is_contained(struct page *page, unsigned page_shift)
> {
> /*
>@@ -103,18 +183,18 @@ static bool tce_page_is_contained(struct page *page, unsigned page_shift)
> return (PAGE_SHIFT + compound_order(compound_head(page))) >= page_shift;
> }
>
>+static inline bool tce_groups_attached(struct tce_container *container)
>+{
>+ return !list_empty(&container->group_list);
>+}
>+
> static long tce_iommu_find_table(struct tce_container *container,
> phys_addr_t ioba, struct iommu_table **ptbl)
> {
> long i;
>- struct iommu_table_group *table_group;
>-
>- table_group = iommu_group_get_iommudata(container->grp);
>- if (!table_group)
>- return -1;
>
> for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
>- struct iommu_table *tbl = table_group->tables[i];
>+ struct iommu_table *tbl = container->tables[i];
>
> if (tbl) {
> unsigned long entry = ioba >> tbl->it_page_shift;
>@@ -136,9 +216,7 @@ static int tce_iommu_enable(struct tce_container *container)
> int ret = 0;
> unsigned long locked;
> struct iommu_table_group *table_group;
>-
>- if (!container->grp)
>- return -ENXIO;
>+ struct tce_iommu_group *tcegrp;
>
> if (!current->mm)
> return -ESRCH; /* process exited */
>@@ -175,7 +253,12 @@ static int tce_iommu_enable(struct tce_container *container)
> * as there is no way to know how much we should increment
> * the locked_vm counter.
> */
>- table_group = iommu_group_get_iommudata(container->grp);
>+ if (!tce_groups_attached(container))
>+ return -ENODEV;
>+
>+ tcegrp = list_first_entry(&container->group_list,
>+ struct tce_iommu_group, next);
>+ table_group = iommu_group_get_iommudata(tcegrp->grp);
> if (!table_group)
> return -ENODEV;
>
>@@ -211,7 +294,7 @@ static void *tce_iommu_open(unsigned long arg)
> {
> struct tce_container *container;
>
>- if (arg != VFIO_SPAPR_TCE_IOMMU) {
>+ if ((arg != VFIO_SPAPR_TCE_IOMMU) && (arg != VFIO_SPAPR_TCE_v2_IOMMU)) {
> pr_err("tce_vfio: Wrong IOMMU type\n");
> return ERR_PTR(-EINVAL);
> }
>@@ -221,18 +304,45 @@ static void *tce_iommu_open(unsigned long arg)
> return ERR_PTR(-ENOMEM);
>
> mutex_init(&container->lock);
>+ INIT_LIST_HEAD_RCU(&container->group_list);
>+
>+ container->v2 = arg == VFIO_SPAPR_TCE_v2_IOMMU;
>
> return container;
> }
>
>+static int tce_iommu_clear(struct tce_container *container,
>+ struct iommu_table *tbl,
>+ unsigned long entry, unsigned long pages);
>+static void tce_iommu_free_table(struct iommu_table *tbl);
>+
> static void tce_iommu_release(void *iommu_data)
> {
> struct tce_container *container = iommu_data;
>+ struct iommu_table_group *table_group;
>+ struct tce_iommu_group *tcegrp;
>+ long i;
>
>- WARN_ON(container->grp);
>+ while (tce_groups_attached(container)) {
>+ tcegrp = list_first_entry(&container->group_list,
>+ struct tce_iommu_group, next);
>+ table_group = iommu_group_get_iommudata(tcegrp->grp);
>+ tce_iommu_detach_group(iommu_data, tcegrp->grp);
>+ }
>
>- if (container->grp)
>- tce_iommu_detach_group(iommu_data, container->grp);
>+ /*
>+ * If VFIO created a table, it was not disposed
>+ * by tce_iommu_detach_group() so do it now.
>+ */
>+ for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
>+ struct iommu_table *tbl = container->tables[i];
>+
>+ if (!tbl)
>+ continue;
>+
>+ tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
>+ tce_iommu_free_table(tbl);
>+ }
>
> tce_iommu_disable(container);
> mutex_destroy(&container->lock);
>@@ -249,6 +359,47 @@ static void tce_iommu_unuse_page(struct tce_container *container,
> put_page(page);
> }
>
>+static int tce_iommu_prereg_ua_to_hpa(unsigned long tce, unsigned long size,
>+ unsigned long *phpa, struct mm_iommu_table_group_mem_t **pmem)
>+{
>+ long ret = 0;
>+ struct mm_iommu_table_group_mem_t *mem;
>+
>+ mem = mm_iommu_lookup(tce, size);
>+ if (!mem)
>+ return -EINVAL;
>+
>+ ret = mm_iommu_ua_to_hpa(mem, tce, phpa);
>+ if (ret)
>+ return -EINVAL;
>+
>+ *pmem = mem;
>+
>+ return 0;
>+}
>+
>+static void tce_iommu_unuse_page_v2(struct iommu_table *tbl,
>+ unsigned long entry)
>+{
>+ struct mm_iommu_table_group_mem_t *mem = NULL;
>+ int ret;
>+ unsigned long hpa = 0;
>+ unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry);
>+
>+ if (!pua || !current || !current->mm)
>+ return;
>+
>+ ret = tce_iommu_prereg_ua_to_hpa(*pua, IOMMU_PAGE_SIZE(tbl),
>+ &hpa, &mem);
>+ if (ret)
>+ pr_debug("%s: tce %lx at #%lx was not cached, ret=%d\n",
>+ __func__, *pua, entry, ret);
>+ if (mem)
>+ mm_iommu_mapped_dec(mem);
>+
>+ *pua = 0;
>+}
>+
> static int tce_iommu_clear(struct tce_container *container,
> struct iommu_table *tbl,
> unsigned long entry, unsigned long pages)
>@@ -267,6 +418,11 @@ static int tce_iommu_clear(struct tce_container *container,
> if (direction == DMA_NONE)
> continue;
>
>+ if (container->v2) {
>+ tce_iommu_unuse_page_v2(tbl, entry);
>+ continue;
>+ }
>+
> tce_iommu_unuse_page(container, oldhpa);
> }
>
>@@ -333,6 +489,64 @@ static long tce_iommu_build(struct tce_container *container,
> return ret;
> }
>
>+static long tce_iommu_build_v2(struct tce_container *container,
>+ struct iommu_table *tbl,
>+ unsigned long entry, unsigned long tce, unsigned long pages,
>+ enum dma_data_direction direction)
>+{
>+ long i, ret = 0;
>+ struct page *page;
>+ unsigned long hpa;
>+ enum dma_data_direction dirtmp;
>+
>+ for (i = 0; i < pages; ++i) {
>+ struct mm_iommu_table_group_mem_t *mem = NULL;
>+ unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl,
>+ entry + i);
>+
>+ ret = tce_iommu_prereg_ua_to_hpa(tce, IOMMU_PAGE_SIZE(tbl),
>+ &hpa, &mem);
>+ if (ret)
>+ break;
>+
>+ page = pfn_to_page(hpa >> PAGE_SHIFT);
>+ if (!tce_page_is_contained(page, tbl->it_page_shift)) {
>+ ret = -EPERM;
>+ break;
>+ }
>+
>+ /* Preserve offset within IOMMU page */
>+ hpa |= tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
>+ dirtmp = direction;
>+
>+ /* The registered region is being unregistered */
>+ if (mm_iommu_mapped_inc(mem))
>+ break;
>+
>+ ret = iommu_tce_xchg(tbl, entry + i, &hpa, &dirtmp);
>+ if (ret) {
>+ /* dirtmp cannot be DMA_NONE here */
>+ tce_iommu_unuse_page_v2(tbl, entry + i);
>+ pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
>+ __func__, entry << tbl->it_page_shift,
>+ tce, ret);
>+ break;
>+ }
>+
>+ if (dirtmp != DMA_NONE)
>+ tce_iommu_unuse_page_v2(tbl, entry + i);
>+
>+ *pua = tce;
>+
>+ tce += IOMMU_PAGE_SIZE(tbl);
>+ }
>+
>+ if (ret)
>+ tce_iommu_clear(container, tbl, entry, i);
>+
>+ return ret;
>+}
>+
> static long tce_iommu_create_table(struct tce_container *container,
> struct iommu_table_group *table_group,
> int num,
>@@ -358,6 +572,12 @@ static long tce_iommu_create_table(struct tce_container *container,
> WARN_ON(!ret && !(*ptbl)->it_ops->free);
> WARN_ON(!ret && ((*ptbl)->it_allocated_size != table_size));
>
>+ if (!ret && container->v2) {
>+ ret = tce_iommu_userspace_view_alloc(*ptbl);
>+ if (ret)
>+ (*ptbl)->it_ops->free(*ptbl);
>+ }
>+
> if (ret)
> decrement_locked_vm(table_size >> PAGE_SHIFT);
>
>@@ -368,6 +588,7 @@ static void tce_iommu_free_table(struct iommu_table *tbl)
> {
> unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT;
>
>+ tce_iommu_userspace_view_free(tbl);
> tbl->it_ops->free(tbl);
> decrement_locked_vm(pages);
> }
>@@ -383,6 +604,7 @@ static long tce_iommu_ioctl(void *iommu_data,
> case VFIO_CHECK_EXTENSION:
> switch (arg) {
> case VFIO_SPAPR_TCE_IOMMU:
>+ case VFIO_SPAPR_TCE_v2_IOMMU:
> ret = 1;
> break;
> default:
>@@ -394,12 +616,15 @@ static long tce_iommu_ioctl(void *iommu_data,
>
> case VFIO_IOMMU_SPAPR_TCE_GET_INFO: {
> struct vfio_iommu_spapr_tce_info info;
>+ struct tce_iommu_group *tcegrp;
> struct iommu_table_group *table_group;
>
>- if (WARN_ON(!container->grp))
>+ if (!tce_groups_attached(container))
> return -ENXIO;
>
>- table_group = iommu_group_get_iommudata(container->grp);
>+ tcegrp = list_first_entry(&container->group_list,
>+ struct tce_iommu_group, next);
>+ table_group = iommu_group_get_iommudata(tcegrp->grp);
>
> if (!table_group)
> return -ENXIO;
>@@ -468,11 +693,18 @@ static long tce_iommu_ioctl(void *iommu_data,
> if (ret)
> return ret;
>
>- ret = tce_iommu_build(container, tbl,
>- param.iova >> tbl->it_page_shift,
>- param.vaddr,
>- param.size >> tbl->it_page_shift,
>- direction);
>+ if (container->v2)
>+ ret = tce_iommu_build_v2(container, tbl,
>+ param.iova >> tbl->it_page_shift,
>+ param.vaddr,
>+ param.size >> tbl->it_page_shift,
>+ direction);
>+ else
>+ ret = tce_iommu_build(container, tbl,
>+ param.iova >> tbl->it_page_shift,
>+ param.vaddr,
>+ param.size >> tbl->it_page_shift,
>+ direction);
>
> iommu_flush_tce(tbl);
>
>@@ -518,7 +750,61 @@ static long tce_iommu_ioctl(void *iommu_data,
>
> return ret;
> }
>+ case VFIO_IOMMU_SPAPR_REGISTER_MEMORY: {
>+ struct vfio_iommu_spapr_register_memory param;
>+
>+ if (!container->v2)
>+ break;
>+
>+ minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
>+ size);
>+
>+ if (copy_from_user(¶m, (void __user *)arg, minsz))
>+ return -EFAULT;
>+
>+ if (param.argsz < minsz)
>+ return -EINVAL;
>+
>+ /* No flag is supported now */
>+ if (param.flags)
>+ return -EINVAL;
>+
>+ mutex_lock(&container->lock);
>+ ret = tce_iommu_register_pages(container, param.vaddr,
>+ param.size);
>+ mutex_unlock(&container->lock);
>+
>+ return ret;
>+ }
>+ case VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY: {
>+ struct vfio_iommu_spapr_register_memory param;
>+
>+ if (!container->v2)
>+ break;
>+
>+ minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
>+ size);
>+
>+ if (copy_from_user(¶m, (void __user *)arg, minsz))
>+ return -EFAULT;
>+
>+ if (param.argsz < minsz)
>+ return -EINVAL;
>+
>+ /* No flag is supported now */
>+ if (param.flags)
>+ return -EINVAL;
>+
>+ mutex_lock(&container->lock);
>+ ret = tce_iommu_unregister_pages(container, param.vaddr, param.size);
>+ mutex_unlock(&container->lock);
Complain from checkpatch.pl:
WARNING: line over 80 characters
#600: FILE: drivers/vfio/vfio_iommu_spapr_tce.c:799:
+ ret = tce_iommu_unregister_pages(container, param.vaddr, param.size);
Thanks,
Gavin
>+
>+ return ret;
>+ }
> case VFIO_IOMMU_ENABLE:
>+ if (container->v2)
>+ break;
>+
> mutex_lock(&container->lock);
> ret = tce_iommu_enable(container);
> mutex_unlock(&container->lock);
>@@ -526,16 +812,27 @@ static long tce_iommu_ioctl(void *iommu_data,
>
>
> case VFIO_IOMMU_DISABLE:
>+ if (container->v2)
>+ break;
>+
> mutex_lock(&container->lock);
> tce_iommu_disable(container);
> mutex_unlock(&container->lock);
> return 0;
>- case VFIO_EEH_PE_OP:
>- if (!container->grp)
>- return -ENODEV;
>
>- return vfio_spapr_iommu_eeh_ioctl(container->grp,
>- cmd, arg);
>+ case VFIO_EEH_PE_OP: {
>+ struct tce_iommu_group *tcegrp;
>+
>+ ret = 0;
>+ list_for_each_entry(tcegrp, &container->group_list, next) {
>+ ret = vfio_spapr_iommu_eeh_ioctl(tcegrp->grp,
>+ cmd, arg);
>+ if (ret)
>+ return ret;
>+ }
>+ return ret;
>+ }
>+
> }
>
> return -ENOTTY;
>@@ -547,14 +844,17 @@ static void tce_iommu_release_ownership(struct tce_container *container,
> int i;
>
> for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
>- struct iommu_table *tbl = table_group->tables[i];
>+ struct iommu_table *tbl = container->tables[i];
>
> if (!tbl)
> continue;
>
> tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
>+ tce_iommu_userspace_view_free(tbl);
> if (tbl->it_map)
> iommu_release_ownership(tbl);
>+
>+ container->tables[i] = NULL;
> }
> }
>
>@@ -569,7 +869,10 @@ static int tce_iommu_take_ownership(struct tce_container *container,
> if (!tbl || !tbl->it_map)
> continue;
>
>- rc = iommu_take_ownership(tbl);
>+ rc = tce_iommu_userspace_view_alloc(tbl);
>+ if (!rc)
>+ rc = iommu_take_ownership(tbl);
>+
> if (rc) {
> for (j = 0; j < i; ++j)
> iommu_release_ownership(
>@@ -579,6 +882,9 @@ static int tce_iommu_take_ownership(struct tce_container *container,
> }
> }
>
>+ for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
>+ container->tables[i] = table_group->tables[i];
>+
> return 0;
> }
>
>@@ -592,18 +898,8 @@ static void tce_iommu_release_ownership_ddw(struct tce_container *container,
> return;
> }
>
>- for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
>- /* Store table pointer as unset_window resets it */
>- struct iommu_table *tbl = table_group->tables[i];
>-
>- if (!tbl)
>- continue;
>-
>+ for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
> table_group->ops->unset_window(table_group, i);
>- tce_iommu_clear(container, tbl,
>- tbl->it_offset, tbl->it_size);
>- tce_iommu_free_table(tbl);
>- }
>
> table_group->ops->release_ownership(table_group);
> }
>@@ -611,7 +907,7 @@ static void tce_iommu_release_ownership_ddw(struct tce_container *container,
> static long tce_iommu_take_ownership_ddw(struct tce_container *container,
> struct iommu_table_group *table_group)
> {
>- long ret;
>+ long i, ret = 0;
> struct iommu_table *tbl = NULL;
>
> if (!table_group->ops->create_table || !table_group->ops->set_window ||
>@@ -622,23 +918,45 @@ static long tce_iommu_take_ownership_ddw(struct tce_container *container,
>
> table_group->ops->take_ownership(table_group);
>
>- ret = tce_iommu_create_table(container,
>- table_group,
>- 0, /* window number */
>- IOMMU_PAGE_SHIFT_4K,
>- table_group->tce32_size,
>- 1, /* default levels */
>- &tbl);
>- if (!ret) {
>- ret = table_group->ops->set_window(table_group, 0, tbl);
>+ /*
>+ * If it the first group attached, check if there is
>+ * a default DMA window and create one if none as
>+ * the userspace expects it to exist.
>+ */
>+ if (!tce_groups_attached(container) && !container->tables[0]) {
>+ ret = tce_iommu_create_table(container,
>+ table_group,
>+ 0, /* window number */
>+ IOMMU_PAGE_SHIFT_4K,
>+ table_group->tce32_size,
>+ 1, /* default levels */
>+ &tbl);
> if (ret)
>- tce_iommu_free_table(tbl);
>+ goto release_exit;
> else
>- table_group->tables[0] = tbl;
>+ container->tables[0] = tbl;
> }
>
>- if (ret)
>- table_group->ops->release_ownership(table_group);
>+ /* Set all windows to the new group */
>+ for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
>+ tbl = container->tables[i];
>+
>+ if (!tbl)
>+ continue;
>+
>+ /* Set the default window to a new group */
>+ ret = table_group->ops->set_window(table_group, i, tbl);
>+ if (ret)
>+ goto release_exit;
>+ }
>+
>+ return 0;
>+
>+release_exit:
>+ for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
>+ table_group->ops->unset_window(table_group, i);
>+
>+ table_group->ops->release_ownership(table_group);
>
> return ret;
> }
>@@ -649,29 +967,44 @@ static int tce_iommu_attach_group(void *iommu_data,
> int ret;
> struct tce_container *container = iommu_data;
> struct iommu_table_group *table_group;
>+ struct tce_iommu_group *tcegrp = NULL;
>
> mutex_lock(&container->lock);
>
> /* pr_debug("tce_vfio: Attaching group #%u to iommu %p\n",
> iommu_group_id(iommu_group), iommu_group); */
>- if (container->grp) {
>- pr_warn("tce_vfio: Only one group per IOMMU container is allowed, existing id=%d, attaching id=%d\n",
>- iommu_group_id(container->grp),
>- iommu_group_id(iommu_group));
>- ret = -EBUSY;
>- goto unlock_exit;
>- }
>-
>- if (container->enabled) {
>- pr_err("tce_vfio: attaching group #%u to enabled container\n",
>- iommu_group_id(iommu_group));
>- ret = -EBUSY;
>- goto unlock_exit;
>- }
>-
> table_group = iommu_group_get_iommudata(iommu_group);
>- if (!table_group) {
>- ret = -ENXIO;
>+
>+ if (tce_groups_attached(container) && (!table_group->ops ||
>+ !table_group->ops->take_ownership ||
>+ !table_group->ops->release_ownership)) {
>+ ret = -EBUSY;
>+ goto unlock_exit;
>+ }
>+
>+ /* Check if new group has the same iommu_ops (i.e. compatible) */
>+ list_for_each_entry(tcegrp, &container->group_list, next) {
>+ struct iommu_table_group *table_group_tmp;
>+
>+ if (tcegrp->grp == iommu_group) {
>+ pr_warn("tce_vfio: Group %d is already attached\n",
>+ iommu_group_id(iommu_group));
>+ ret = -EBUSY;
>+ goto unlock_exit;
>+ }
>+ table_group_tmp = iommu_group_get_iommudata(tcegrp->grp);
>+ if (table_group_tmp->ops != table_group->ops) {
>+ pr_warn("tce_vfio: Group %d is incompatible with group %d\n",
>+ iommu_group_id(iommu_group),
>+ iommu_group_id(tcegrp->grp));
>+ ret = -EPERM;
>+ goto unlock_exit;
>+ }
>+ }
>+
>+ tcegrp = kzalloc(sizeof(*tcegrp), GFP_KERNEL);
>+ if (!tcegrp) {
>+ ret = -ENOMEM;
> goto unlock_exit;
> }
>
>@@ -681,10 +1014,15 @@ static int tce_iommu_attach_group(void *iommu_data,
> else
> ret = tce_iommu_take_ownership_ddw(container, table_group);
>
>- if (!ret)
>- container->grp = iommu_group;
>+ if (!ret) {
>+ tcegrp->grp = iommu_group;
>+ list_add(&tcegrp->next, &container->group_list);
>+ }
>
> unlock_exit:
>+ if (ret && tcegrp)
>+ kfree(tcegrp);
>+
> mutex_unlock(&container->lock);
>
> return ret;
>@@ -695,24 +1033,26 @@ static void tce_iommu_detach_group(void *iommu_data,
> {
> struct tce_container *container = iommu_data;
> struct iommu_table_group *table_group;
>+ bool found = false;
>+ struct tce_iommu_group *tcegrp;
>
> mutex_lock(&container->lock);
>- if (iommu_group != container->grp) {
>- pr_warn("tce_vfio: detaching group #%u, expected group is #%u\n",
>- iommu_group_id(iommu_group),
>- iommu_group_id(container->grp));
>+
>+ list_for_each_entry(tcegrp, &container->group_list, next) {
>+ if (tcegrp->grp == iommu_group) {
>+ found = true;
>+ break;
>+ }
>+ }
>+
>+ if (!found) {
>+ pr_warn("tce_vfio: detaching unattached group #%u\n",
>+ iommu_group_id(iommu_group));
> goto unlock_exit;
> }
>
>- if (container->enabled) {
>- pr_warn("tce_vfio: detaching group #%u from enabled container, forcing disable\n",
>- iommu_group_id(container->grp));
>- tce_iommu_disable(container);
>- }
>-
>- /* pr_debug("tce_vfio: detaching group #%u from iommu %p\n",
>- iommu_group_id(iommu_group), iommu_group); */
>- container->grp = NULL;
>+ list_del(&tcegrp->next);
>+ kfree(tcegrp);
>
> table_group = iommu_group_get_iommudata(iommu_group);
> BUG_ON(!table_group);
>diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
>index b57b750..8fdcfb9 100644
>--- a/include/uapi/linux/vfio.h
>+++ b/include/uapi/linux/vfio.h
>@@ -36,6 +36,8 @@
> /* Two-stage IOMMU */
> #define VFIO_TYPE1_NESTING_IOMMU 6 /* Implies v2 */
>
>+#define VFIO_SPAPR_TCE_v2_IOMMU 7
>+
> /*
> * The IOCTL interface is designed for extensibility by embedding the
> * structure length (argsz) and flags into structures passed between
>@@ -495,6 +497,31 @@ struct vfio_eeh_pe_op {
>
> #define VFIO_EEH_PE_OP _IO(VFIO_TYPE, VFIO_BASE + 21)
>
>+/**
>+ * VFIO_IOMMU_SPAPR_REGISTER_MEMORY - _IOW(VFIO_TYPE, VFIO_BASE + 17, struct vfio_iommu_spapr_register_memory)
>+ *
>+ * Registers user space memory where DMA is allowed. It pins
>+ * user pages and does the locked memory accounting so
>+ * subsequent VFIO_IOMMU_MAP_DMA/VFIO_IOMMU_UNMAP_DMA calls
>+ * get faster.
>+ */
>+struct vfio_iommu_spapr_register_memory {
>+ __u32 argsz;
>+ __u32 flags;
>+ __u64 vaddr; /* Process virtual address */
>+ __u64 size; /* Size of mapping (bytes) */
>+};
>+#define VFIO_IOMMU_SPAPR_REGISTER_MEMORY _IO(VFIO_TYPE, VFIO_BASE + 17)
>+
>+/**
>+ * VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY - _IOW(VFIO_TYPE, VFIO_BASE + 18, struct vfio_iommu_spapr_register_memory)
>+ *
>+ * Unregisters user space memory registered with
>+ * VFIO_IOMMU_SPAPR_REGISTER_MEMORY.
>+ * Uses vfio_iommu_spapr_register_memory for parameters.
>+ */
>+#define VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY _IO(VFIO_TYPE, VFIO_BASE + 18)
>+
> /* ***************************************************************** */
>
> #endif /* _UAPIVFIO_H */
>--
>2.4.0.rc3.8.gfb3e7d5
>
--
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