| Message ID | 1479329194-10247-10-git-send-email-kwankhede@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 17/11/16 07:46, Kirti Wankhede wrote: > Add task structure to vfio_dma structure. Task structure is used for: > - During DMA_UNMAP, same task who mapped it or other task who shares same > address space is allowed to unmap, otherwise unmap fails. > QEMU maps few iova ranges initially, then fork threads and from the child > thread calls DMA_UNMAP on previously mapped iova. Since child shares same > address space, DMA_UNMAP is successful. > - Avoid accessing struct mm while process is exiting by acquiring > reference of task's mm during page accounting. > - It is also used to get task mlock capability and rlimit for mlock. > > Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> > Signed-off-by: Neo Jia <cjia@nvidia.com> > Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> I keep whinging that @mm should be referenced, not @current but you keep referencing @current even if you only need @mm and you are not telling why - and I am wondering what I am missing here? Something else will be used from @task later, besides just @mm? > > Change-Id: I7600f1bea6b384fd589fa72421ccf031bcfd9ac5 > --- > drivers/vfio/vfio_iommu_type1.c | 137 +++++++++++++++++++++++++--------------- > 1 file changed, 86 insertions(+), 51 deletions(-) > > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index ffe2026f1341..a0a7484cec64 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -36,6 +36,7 @@ > #include <linux/uaccess.h> > #include <linux/vfio.h> > #include <linux/workqueue.h> > +#include <linux/pid_namespace.h> > > #define DRIVER_VERSION "0.2" > #define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>" > @@ -75,6 +76,7 @@ struct vfio_dma { > unsigned long vaddr; /* Process virtual addr */ > size_t size; /* Map size (bytes) */ > int prot; /* IOMMU_READ/WRITE */ > + struct task_struct *task; > }; > > struct vfio_group { > @@ -277,41 +279,47 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, > * the iommu can only map chunks of consecutive pfns anyway, so get the > * first page and all consecutive pages with the same locking. > */ > -static long vfio_pin_pages_remote(unsigned long vaddr, long npage, > - int prot, unsigned long *pfn_base) > +static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr, > + long npage, int prot, unsigned long *pfn_base) > { > - unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; > - bool lock_cap = capable(CAP_IPC_LOCK); > + unsigned long limit; > + bool lock_cap = ns_capable(task_active_pid_ns(dma->task)->user_ns, > + CAP_IPC_LOCK); > + struct mm_struct *mm; > long ret, i; > bool rsvd; > > - if (!current->mm) > + mm = get_task_mm(dma->task); > + if (!mm) > return -ENODEV; > > - ret = vaddr_get_pfn(current->mm, vaddr, prot, pfn_base); > + ret = vaddr_get_pfn(mm, vaddr, prot, pfn_base); > if (ret) > - return ret; > + goto pin_pg_remote_exit; > > rsvd = is_invalid_reserved_pfn(*pfn_base); > + limit = task_rlimit(dma->task, RLIMIT_MEMLOCK) >> PAGE_SHIFT; > > - if (!rsvd && !lock_cap && current->mm->locked_vm + 1 > limit) { > + if (!rsvd && !lock_cap && mm->locked_vm + 1 > limit) { > put_pfn(*pfn_base, prot); > pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__, > limit << PAGE_SHIFT); > - return -ENOMEM; > + ret = -ENOMEM; > + goto pin_pg_remote_exit; > } > > if (unlikely(disable_hugepages)) { > if (!rsvd) > - vfio_lock_acct(current, 1); > - return 1; > + vfio_lock_acct(dma->task, 1); > + ret = 1; > + goto pin_pg_remote_exit; > } > > /* Lock all the consecutive pages from pfn_base */ > for (i = 1, vaddr += PAGE_SIZE; i < npage; i++, vaddr += PAGE_SIZE) { > unsigned long pfn = 0; > > - ret = vaddr_get_pfn(current->mm, vaddr, prot, &pfn); > + ret = vaddr_get_pfn(mm, vaddr, prot, &pfn); > if (ret) > break; > > @@ -321,8 +329,7 @@ static long vfio_pin_pages_remote(unsigned long vaddr, long npage, > break; > } > > - if (!rsvd && !lock_cap && > - current->mm->locked_vm + i + 1 > limit) { > + if (!rsvd && !lock_cap && mm->locked_vm + i + 1 > limit) { > put_pfn(pfn, prot); > pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", > __func__, limit << PAGE_SHIFT); > @@ -331,13 +338,16 @@ static long vfio_pin_pages_remote(unsigned long vaddr, long npage, > } > > if (!rsvd) > - vfio_lock_acct(current, i); > + vfio_lock_acct(dma->task, i); > + ret = i; > > - return i; > +pin_pg_remote_exit: > + mmput(mm); > + return ret; > } > > -static long vfio_unpin_pages_remote(unsigned long pfn, long npage, > - int prot, bool do_accounting) > +static long vfio_unpin_pages_remote(struct vfio_dma *dma, unsigned long pfn, > + long npage, int prot, bool do_accounting) > { > unsigned long unlocked = 0; > long i; > @@ -346,7 +356,7 @@ static long vfio_unpin_pages_remote(unsigned long pfn, long npage, > unlocked += put_pfn(pfn++, prot); > > if (do_accounting) > - vfio_lock_acct(current, -unlocked); > + vfio_lock_acct(dma->task, -unlocked); > > return unlocked; > } > @@ -400,7 +410,7 @@ static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma) > if (WARN_ON(!unmapped)) > break; > > - unlocked += vfio_unpin_pages_remote(phys >> PAGE_SHIFT, > + unlocked += vfio_unpin_pages_remote(dma, phys >> PAGE_SHIFT, > unmapped >> PAGE_SHIFT, > dma->prot, false); > iova += unmapped; > @@ -408,13 +418,14 @@ static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma) > cond_resched(); > } > > - vfio_lock_acct(current, -unlocked); > + vfio_lock_acct(dma->task, -unlocked); > } > > static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma) > { > vfio_unmap_unpin(iommu, dma); > vfio_unlink_dma(iommu, dma); > + put_task_struct(dma->task); > kfree(dma); > } > > @@ -510,6 +521,12 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, > while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) { > if (!iommu->v2 && unmap->iova > dma->iova) > break; > + /* > + * Task with same address space who mapped this iova range is > + * allowed to unmap the iova range. > + */ > + if (dma->task->mm != current->mm) > + break; > unmapped += dma->size; > vfio_remove_dma(iommu, dma); > } > @@ -576,17 +593,55 @@ unwind: > return ret; > } > > +static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma, > + size_t map_size) > +{ > + dma_addr_t iova = dma->iova; > + unsigned long vaddr = dma->vaddr; > + size_t size = map_size; > + long npage; > + unsigned long pfn; > + int ret = 0; > + > + while (size) { > + /* Pin a contiguous chunk of memory */ > + npage = vfio_pin_pages_remote(dma, vaddr + dma->size, > + size >> PAGE_SHIFT, dma->prot, > + &pfn); > + if (npage <= 0) { > + WARN_ON(!npage); > + ret = (int)npage; > + break; > + } > + > + /* Map it! */ > + ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage, > + dma->prot); > + if (ret) { > + vfio_unpin_pages_remote(dma, pfn, npage, > + dma->prot, true); > + break; > + } > + > + size -= npage << PAGE_SHIFT; > + dma->size += npage << PAGE_SHIFT; > + } > + > + if (ret) > + vfio_remove_dma(iommu, dma); > + > + return ret; > +} > + > static int vfio_dma_do_map(struct vfio_iommu *iommu, > struct vfio_iommu_type1_dma_map *map) > { > dma_addr_t iova = map->iova; > unsigned long vaddr = map->vaddr; > size_t size = map->size; > - long npage; > int ret = 0, prot = 0; > uint64_t mask; > struct vfio_dma *dma; > - unsigned long pfn; > > /* Verify that none of our __u64 fields overflow */ > if (map->size != size || map->vaddr != vaddr || map->iova != iova) > @@ -612,47 +667,27 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, > mutex_lock(&iommu->lock); > > if (vfio_find_dma(iommu, iova, size)) { > - mutex_unlock(&iommu->lock); > - return -EEXIST; > + ret = -EEXIST; > + goto out_unlock; > } > > dma = kzalloc(sizeof(*dma), GFP_KERNEL); > if (!dma) { > - mutex_unlock(&iommu->lock); > - return -ENOMEM; > + ret = -ENOMEM; > + goto out_unlock; > } > > dma->iova = iova; > dma->vaddr = vaddr; > dma->prot = prot; > + get_task_struct(current); > + dma->task = current; > > /* Insert zero-sized and grow as we map chunks of it */ > vfio_link_dma(iommu, dma); > > - while (size) { > - /* Pin a contiguous chunk of memory */ > - npage = vfio_pin_pages_remote(vaddr + dma->size, > - size >> PAGE_SHIFT, prot, &pfn); > - if (npage <= 0) { > - WARN_ON(!npage); > - ret = (int)npage; > - break; > - } > - > - /* Map it! */ > - ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage, prot); > - if (ret) { > - vfio_unpin_pages_remote(pfn, npage, prot, true); > - break; > - } > - > - size -= npage << PAGE_SHIFT; > - dma->size += npage << PAGE_SHIFT; > - } > - > - if (ret) > - vfio_remove_dma(iommu, dma); > - > + ret = vfio_pin_map_dma(iommu, dma, size); > +out_unlock: > mutex_unlock(&iommu->lock); > return ret; > } >
On Thu, 17 Nov 2016 16:41:14 +1100 Alexey Kardashevskiy <aik@ozlabs.ru> wrote: > On 17/11/16 07:46, Kirti Wankhede wrote: > > Add task structure to vfio_dma structure. Task structure is used for: > > - During DMA_UNMAP, same task who mapped it or other task who shares same > > address space is allowed to unmap, otherwise unmap fails. > > QEMU maps few iova ranges initially, then fork threads and from the child > > thread calls DMA_UNMAP on previously mapped iova. Since child shares same > > address space, DMA_UNMAP is successful. > > - Avoid accessing struct mm while process is exiting by acquiring > > reference of task's mm during page accounting. > > - It is also used to get task mlock capability and rlimit for mlock. > > > > Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> > > Signed-off-by: Neo Jia <cjia@nvidia.com> > > Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> > > > I keep whinging that @mm should be referenced, not @current but you keep > referencing @current even if you only need @mm and you are not telling why > - and I am wondering what I am missing here? Something else will be used > from @task later, besides just @mm? Yes, we reference @current from vfio_dma_do_map() and this is stored on the struct vfio_dma. A reference to current is held because the external page pinning in vfio_pin_page_external() needs to test the capabilities of the task for CAP_IPC_LOCK to know whether locked memory limits are in effect for the task even when it's not @current (ie. an asynchronous call from the vendor driver regardless of what task is currently running). There are also various get_task_mm() taken temporarily when we're working with the mm of that task. Do you spot any issues with this behavior? Thanks, Alex -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 11/17/2016 11:11 AM, Alexey Kardashevskiy wrote: > On 17/11/16 07:46, Kirti Wankhede wrote: >> Add task structure to vfio_dma structure. Task structure is used for: >> - During DMA_UNMAP, same task who mapped it or other task who shares same >> address space is allowed to unmap, otherwise unmap fails. >> QEMU maps few iova ranges initially, then fork threads and from the child >> thread calls DMA_UNMAP on previously mapped iova. Since child shares same >> address space, DMA_UNMAP is successful. >> - Avoid accessing struct mm while process is exiting by acquiring >> reference of task's mm during page accounting. >> - It is also used to get task mlock capability and rlimit for mlock. >> >> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> >> Signed-off-by: Neo Jia <cjia@nvidia.com> >> Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> > > > I keep whinging that @mm should be referenced, not @current but you keep > referencing @current even if you only need @mm and you are not telling why > - and I am wondering what I am missing here? Something else will be used > from @task later, besides just @mm? > > Hey Alexey, I updated briefly in commit description. Let me try to explain it again in detail. Its true we need mm, but we also need task structure for 2 reasons: - Avoid accessing struct mm while process is exiting by acquiring reference of task's mm during page accounting. If you see vfio_lock_acct(), where reference to mm is taken from task structure, get_task_mm(task), to make sure that mm of this task is still valid and task not in exiting process. If process is exiting, mm would be NULL and we don't have to do page accounting. This patch is to re-org and prepare the code for next patch, 10/22. vfio_pin_pages()/ vfio_unpin_pages() for mediated devices would get called from vendor driver. Those could be initiated by other process, but for pin/unpin, these APIs should use the mm of the task who mapped it. So in these calls we should check that we get the valid reference of mm, that we would get from task structure. - It is also used to get task mlock capability and rlimit for mlock. These are again used for page accounting and page accounting should be done with reference to the task who mapped the iova range. We get these from task structure. Thanks, Kirti -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 17/11/16 17:12, Alex Williamson wrote: > On Thu, 17 Nov 2016 16:41:14 +1100 > Alexey Kardashevskiy <aik@ozlabs.ru> wrote: > >> On 17/11/16 07:46, Kirti Wankhede wrote: >>> Add task structure to vfio_dma structure. Task structure is used for: >>> - During DMA_UNMAP, same task who mapped it or other task who shares same >>> address space is allowed to unmap, otherwise unmap fails. >>> QEMU maps few iova ranges initially, then fork threads and from the child >>> thread calls DMA_UNMAP on previously mapped iova. Since child shares same >>> address space, DMA_UNMAP is successful. >>> - Avoid accessing struct mm while process is exiting by acquiring >>> reference of task's mm during page accounting. >>> - It is also used to get task mlock capability and rlimit for mlock. >>> >>> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> >>> Signed-off-by: Neo Jia <cjia@nvidia.com> >>> Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> >> >> >> I keep whinging that @mm should be referenced, not @current but you keep >> referencing @current even if you only need @mm and you are not telling why >> - and I am wondering what I am missing here? Something else will be used >> from @task later, besides just @mm? > > Yes, we reference @current from vfio_dma_do_map() and this is stored > on the struct vfio_dma. A reference to current is held because the > external page pinning in vfio_pin_page_external() needs to test the > capabilities of the task for CAP_IPC_LOCK to know whether locked memory Ah, that's it - capable(CAP_IPC_LOCK) is checking @current, missed that. > limits are in effect for the task even when it's not @current (ie. an > asynchronous call from the vendor driver regardless of what task is > currently running). There are also various get_task_mm() taken > temporarily when we're working with the mm of that task. Do you spot > any issues with this behavior? Thanks, No, now I am fine, thanks!
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index ffe2026f1341..a0a7484cec64 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -36,6 +36,7 @@ #include <linux/uaccess.h> #include <linux/vfio.h> #include <linux/workqueue.h> +#include <linux/pid_namespace.h> #define DRIVER_VERSION "0.2" #define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>" @@ -75,6 +76,7 @@ struct vfio_dma { unsigned long vaddr; /* Process virtual addr */ size_t size; /* Map size (bytes) */ int prot; /* IOMMU_READ/WRITE */ + struct task_struct *task; }; struct vfio_group { @@ -277,41 +279,47 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, * the iommu can only map chunks of consecutive pfns anyway, so get the * first page and all consecutive pages with the same locking. */ -static long vfio_pin_pages_remote(unsigned long vaddr, long npage, - int prot, unsigned long *pfn_base) +static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr, + long npage, int prot, unsigned long *pfn_base) { - unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; - bool lock_cap = capable(CAP_IPC_LOCK); + unsigned long limit; + bool lock_cap = ns_capable(task_active_pid_ns(dma->task)->user_ns, + CAP_IPC_LOCK); + struct mm_struct *mm; long ret, i; bool rsvd; - if (!current->mm) + mm = get_task_mm(dma->task); + if (!mm) return -ENODEV; - ret = vaddr_get_pfn(current->mm, vaddr, prot, pfn_base); + ret = vaddr_get_pfn(mm, vaddr, prot, pfn_base); if (ret) - return ret; + goto pin_pg_remote_exit; rsvd = is_invalid_reserved_pfn(*pfn_base); + limit = task_rlimit(dma->task, RLIMIT_MEMLOCK) >> PAGE_SHIFT; - if (!rsvd && !lock_cap && current->mm->locked_vm + 1 > limit) { + if (!rsvd && !lock_cap && mm->locked_vm + 1 > limit) { put_pfn(*pfn_base, prot); pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__, limit << PAGE_SHIFT); - return -ENOMEM; + ret = -ENOMEM; + goto pin_pg_remote_exit; } if (unlikely(disable_hugepages)) { if (!rsvd) - vfio_lock_acct(current, 1); - return 1; + vfio_lock_acct(dma->task, 1); + ret = 1; + goto pin_pg_remote_exit; } /* Lock all the consecutive pages from pfn_base */ for (i = 1, vaddr += PAGE_SIZE; i < npage; i++, vaddr += PAGE_SIZE) { unsigned long pfn = 0; - ret = vaddr_get_pfn(current->mm, vaddr, prot, &pfn); + ret = vaddr_get_pfn(mm, vaddr, prot, &pfn); if (ret) break; @@ -321,8 +329,7 @@ static long vfio_pin_pages_remote(unsigned long vaddr, long npage, break; } - if (!rsvd && !lock_cap && - current->mm->locked_vm + i + 1 > limit) { + if (!rsvd && !lock_cap && mm->locked_vm + i + 1 > limit) { put_pfn(pfn, prot); pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__, limit << PAGE_SHIFT); @@ -331,13 +338,16 @@ static long vfio_pin_pages_remote(unsigned long vaddr, long npage, } if (!rsvd) - vfio_lock_acct(current, i); + vfio_lock_acct(dma->task, i); + ret = i; - return i; +pin_pg_remote_exit: + mmput(mm); + return ret; } -static long vfio_unpin_pages_remote(unsigned long pfn, long npage, - int prot, bool do_accounting) +static long vfio_unpin_pages_remote(struct vfio_dma *dma, unsigned long pfn, + long npage, int prot, bool do_accounting) { unsigned long unlocked = 0; long i; @@ -346,7 +356,7 @@ static long vfio_unpin_pages_remote(unsigned long pfn, long npage, unlocked += put_pfn(pfn++, prot); if (do_accounting) - vfio_lock_acct(current, -unlocked); + vfio_lock_acct(dma->task, -unlocked); return unlocked; } @@ -400,7 +410,7 @@ static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma) if (WARN_ON(!unmapped)) break; - unlocked += vfio_unpin_pages_remote(phys >> PAGE_SHIFT, + unlocked += vfio_unpin_pages_remote(dma, phys >> PAGE_SHIFT, unmapped >> PAGE_SHIFT, dma->prot, false); iova += unmapped; @@ -408,13 +418,14 @@ static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma) cond_resched(); } - vfio_lock_acct(current, -unlocked); + vfio_lock_acct(dma->task, -unlocked); } static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma) { vfio_unmap_unpin(iommu, dma); vfio_unlink_dma(iommu, dma); + put_task_struct(dma->task); kfree(dma); } @@ -510,6 +521,12 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) { if (!iommu->v2 && unmap->iova > dma->iova) break; + /* + * Task with same address space who mapped this iova range is + * allowed to unmap the iova range. + */ + if (dma->task->mm != current->mm) + break; unmapped += dma->size; vfio_remove_dma(iommu, dma); } @@ -576,17 +593,55 @@ unwind: return ret; } +static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma, + size_t map_size) +{ + dma_addr_t iova = dma->iova; + unsigned long vaddr = dma->vaddr; + size_t size = map_size; + long npage; + unsigned long pfn; + int ret = 0; + + while (size) { + /* Pin a contiguous chunk of memory */ + npage = vfio_pin_pages_remote(dma, vaddr + dma->size, + size >> PAGE_SHIFT, dma->prot, + &pfn); + if (npage <= 0) { + WARN_ON(!npage); + ret = (int)npage; + break; + } + + /* Map it! */ + ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage, + dma->prot); + if (ret) { + vfio_unpin_pages_remote(dma, pfn, npage, + dma->prot, true); + break; + } + + size -= npage << PAGE_SHIFT; + dma->size += npage << PAGE_SHIFT; + } + + if (ret) + vfio_remove_dma(iommu, dma); + + return ret; +} + static int vfio_dma_do_map(struct vfio_iommu *iommu, struct vfio_iommu_type1_dma_map *map) { dma_addr_t iova = map->iova; unsigned long vaddr = map->vaddr; size_t size = map->size; - long npage; int ret = 0, prot = 0; uint64_t mask; struct vfio_dma *dma; - unsigned long pfn; /* Verify that none of our __u64 fields overflow */ if (map->size != size || map->vaddr != vaddr || map->iova != iova) @@ -612,47 +667,27 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, mutex_lock(&iommu->lock); if (vfio_find_dma(iommu, iova, size)) { - mutex_unlock(&iommu->lock); - return -EEXIST; + ret = -EEXIST; + goto out_unlock; } dma = kzalloc(sizeof(*dma), GFP_KERNEL); if (!dma) { - mutex_unlock(&iommu->lock); - return -ENOMEM; + ret = -ENOMEM; + goto out_unlock; } dma->iova = iova; dma->vaddr = vaddr; dma->prot = prot; + get_task_struct(current); + dma->task = current; /* Insert zero-sized and grow as we map chunks of it */ vfio_link_dma(iommu, dma); - while (size) { - /* Pin a contiguous chunk of memory */ - npage = vfio_pin_pages_remote(vaddr + dma->size, - size >> PAGE_SHIFT, prot, &pfn); - if (npage <= 0) { - WARN_ON(!npage); - ret = (int)npage; - break; - } - - /* Map it! */ - ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage, prot); - if (ret) { - vfio_unpin_pages_remote(pfn, npage, prot, true); - break; - } - - size -= npage << PAGE_SHIFT; - dma->size += npage << PAGE_SHIFT; - } - - if (ret) - vfio_remove_dma(iommu, dma); - + ret = vfio_pin_map_dma(iommu, dma, size); +out_unlock: mutex_unlock(&iommu->lock); return ret; }