From patchwork Tue Nov 15 15:29:52 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirti Wankhede X-Patchwork-Id: 695074 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3tJBQR6RzRz9syB for ; Wed, 16 Nov 2016 02:39:27 +1100 (AEDT) Received: from localhost ([::1]:47082 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c6fpV-0007p3-4O for incoming@patchwork.ozlabs.org; Tue, 15 Nov 2016 10:39:25 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46058) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c6ffv-0008Qr-LI for qemu-devel@nongnu.org; Tue, 15 Nov 2016 10:29:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c6ffq-00043q-LV for qemu-devel@nongnu.org; Tue, 15 Nov 2016 10:29:31 -0500 Received: from hqemgate16.nvidia.com ([216.228.121.65]:11192) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1c6ffq-00043B-AU for qemu-devel@nongnu.org; Tue, 15 Nov 2016 10:29:26 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate16.nvidia.com id ; Tue, 15 Nov 2016 07:52:47 -0800 Received: from HQMAIL105.nvidia.com ([172.20.13.39]) by hqpgpgate101.nvidia.com (PGP Universal service); Tue, 15 Nov 2016 07:29:24 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Tue, 15 Nov 2016 07:29:24 -0800 Received: from HQMAIL104.nvidia.com (172.18.146.11) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1210.3; Tue, 15 Nov 2016 15:29:24 +0000 Received: from kwankhede-dev.nvidia.com (172.20.13.39) by HQMAIL104.nvidia.com (172.18.146.11) with Microsoft SMTP Server (TLS) id 15.0.1210.3 via Frontend Transport; Tue, 15 Nov 2016 15:29:21 +0000 From: Kirti Wankhede To: , , , Date: Tue, 15 Nov 2016 20:59:52 +0530 Message-ID: <1479223805-22895-10-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1479223805-22895-1-git-send-email-kwankhede@nvidia.com> References: <1479223805-22895-1-git-send-email-kwankhede@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Windows 7 or 8 X-Received-From: 216.228.121.65 Subject: [Qemu-devel] [PATCH v13 09/22] vfio iommu type1: Add task structure to vfio_dma X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jike.song@intel.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, kevin.tian@intel.com, qemu-devel@nongnu.org, Kirti Wankhede , bjsdjshi@linux.vnet.ibm.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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 Signed-off-by: Neo Jia 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..50aca95cf61e 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -36,6 +36,7 @@ #include #include #include +#include #define DRIVER_VERSION "0.2" #define DRIVER_AUTHOR "Alex Williamson " @@ -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 do_map_err; } dma = kzalloc(sizeof(*dma), GFP_KERNEL); if (!dma) { - mutex_unlock(&iommu->lock); - return -ENOMEM; + ret = -ENOMEM; + goto do_map_err; } 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); +do_map_err: mutex_unlock(&iommu->lock); return ret; }