vfio: drop worqueue patch n/a for 4.8.x

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

2 files changed, 0 insertions, 232 deletions

diff --git a/queue/series b/queue/series
index 17006d7..49b7f63 100644
--- a/queue/series
+++ b/queue/series
@@ -167,7 +167,6 @@ crypto-algif_aead-Require-setkey-before-accept-2.patch
 dm-era-save-spacemap-metadata-root-after-the-pre-com.patch
 dm-rq-check-blk_mq_register_dev-return-value-in-dm_m.patch
 dm-thin-fix-a-memory-leak-when-passing-discard-bio-d.patch
-vfio-type1-Remove-locked-page-accounting-workqueue.patch
 IB-core-Fix-sysfs-registration-error-flow.patch
 IB-core-For-multicast-functions-verify-that-LIDs-are.patch
 IB-IPoIB-ibX-failed-to-create-mcg-debug-file.patch
diff --git a/queue/vfio-type1-Remove-locked-page-accounting-workqueue.patch b/queue/vfio-type1-Remove-locked-page-accounting-workqueue.patch
deleted file mode 100644
index 2bc013a..0000000
--- a/queue/vfio-type1-Remove-locked-page-accounting-workqueue.patch
+++ /dev/null
@@ -1,231 +0,0 @@
-From 0cfef2b7410b64d7a430947e0b533314c4f97153 Mon Sep 17 00:00:00 2001
-From: Alex Williamson <alex.williamson@redhat.com>
-Date: Thu, 13 Apr 2017 14:10:15 -0600
-Subject: [PATCH] vfio/type1: Remove locked page accounting workqueue
-
-commit 0cfef2b7410b64d7a430947e0b533314c4f97153 upstream.
-
-If the mmap_sem is contented then the vfio type1 IOMMU backend will
-defer locked page accounting updates to a workqueue task.  This has a
-few problems and depending on which side the user tries to play, they
-might be over-penalized for unmaps that haven't yet been accounted or
-race the workqueue to enter more mappings than they're allowed.  The
-original intent of this workqueue mechanism seems to be focused on
-reducing latency through the ioctl, but we cannot do so at the cost
-of correctness.  Remove this workqueue mechanism and update the
-callers to allow for failure.  We can also now recheck the limit under
-write lock to make sure we don't exceed it.
-
-vfio_pin_pages_remote() also now necessarily includes an unwind path
-which we can jump to directly if the consecutive page pinning finds
-that we're exceeding the user's memory limits.  This avoids the
-current lazy approach which does accounting and mapping up to the
-fault, only to return an error on the next iteration to unwind the
-entire vfio_dma.
-
-Cc: stable@vger.kernel.org
-Reviewed-by: Peter Xu <peterx@redhat.com>
-Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
-Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
-
-diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
-index 32d2633092a3..a8a079ba9477 100644
---- a/drivers/vfio/vfio_iommu_type1.c
-+++ b/drivers/vfio/vfio_iommu_type1.c
-@@ -246,69 +246,46 @@ static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn)
- 	return ret;
- }
- 
--struct vwork {
--	struct mm_struct	*mm;
--	long			npage;
--	struct work_struct	work;
--};
--
--/* delayed decrement/increment for locked_vm */
--static void vfio_lock_acct_bg(struct work_struct *work)
--{
--	struct vwork *vwork = container_of(work, struct vwork, work);
--	struct mm_struct *mm;
--
--	mm = vwork->mm;
--	down_write(&mm->mmap_sem);
--	mm->locked_vm += vwork->npage;
--	up_write(&mm->mmap_sem);
--	mmput(mm);
--	kfree(vwork);
--}
--
--static void vfio_lock_acct(struct task_struct *task, long npage)
-+static int vfio_lock_acct(struct task_struct *task, long npage, bool *lock_cap)
- {
--	struct vwork *vwork;
- 	struct mm_struct *mm;
- 	bool is_current;
-+	int ret;
- 
- 	if (!npage)
--		return;
-+		return 0;
- 
- 	is_current = (task->mm == current->mm);
- 
- 	mm = is_current ? task->mm : get_task_mm(task);
- 	if (!mm)
--		return; /* process exited */
-+		return -ESRCH; /* process exited */
- 
--	if (down_write_trylock(&mm->mmap_sem)) {
--		mm->locked_vm += npage;
--		up_write(&mm->mmap_sem);
--		if (!is_current)
--			mmput(mm);
--		return;
--	}
-+	ret = down_write_killable(&mm->mmap_sem);
-+	if (!ret) {
-+		if (npage > 0) {
-+			if (lock_cap ? !*lock_cap :
-+			    !has_capability(task, CAP_IPC_LOCK)) {
-+				unsigned long limit;
-+
-+				limit = task_rlimit(task,
-+						RLIMIT_MEMLOCK) >> PAGE_SHIFT;
-+
-+				if (mm->locked_vm + npage > limit)
-+					ret = -ENOMEM;
-+			}
-+		}
-+
-+		if (!ret)
-+			mm->locked_vm += npage;
- 
--	if (is_current) {
--		mm = get_task_mm(task);
--		if (!mm)
--			return;
-+		up_write(&mm->mmap_sem);
- 	}
- 
--	/*
--	 * Couldn't get mmap_sem lock, so must setup to update
--	 * mm->locked_vm later. If locked_vm were atomic, we
--	 * wouldn't need this silliness
--	 */
--	vwork = kmalloc(sizeof(struct vwork), GFP_KERNEL);
--	if (WARN_ON(!vwork)) {
-+	if (!is_current)
- 		mmput(mm);
--		return;
--	}
--	INIT_WORK(&vwork->work, vfio_lock_acct_bg);
--	vwork->mm = mm;
--	vwork->npage = npage;
--	schedule_work(&vwork->work);
-+
-+	return ret;
- }
- 
- /*
-@@ -405,7 +382,7 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
- static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
- 				  long npage, unsigned long *pfn_base)
- {
--	unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
-+	unsigned long pfn = 0, limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
- 	bool lock_cap = capable(CAP_IPC_LOCK);
- 	long ret, pinned = 0, lock_acct = 0;
- 	bool rsvd;
-@@ -442,8 +419,6 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
- 	/* Lock all the consecutive pages from pfn_base */
- 	for (vaddr += PAGE_SIZE, iova += PAGE_SIZE; pinned < npage;
- 	     pinned++, vaddr += PAGE_SIZE, iova += PAGE_SIZE) {
--		unsigned long pfn = 0;
--
- 		ret = vaddr_get_pfn(current->mm, vaddr, dma->prot, &pfn);
- 		if (ret)
- 			break;
-@@ -460,14 +435,25 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
- 				put_pfn(pfn, dma->prot);
- 				pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
- 					__func__, limit << PAGE_SHIFT);
--				break;
-+				ret = -ENOMEM;
-+				goto unpin_out;
- 			}
- 			lock_acct++;
- 		}
- 	}
- 
- out:
--	vfio_lock_acct(current, lock_acct);
-+	ret = vfio_lock_acct(current, lock_acct, &lock_cap);
-+
-+unpin_out:
-+	if (ret) {
-+		if (!rsvd) {
-+			for (pfn = *pfn_base ; pinned ; pfn++, pinned--)
-+				put_pfn(pfn, dma->prot);
-+		}
-+
-+		return ret;
-+	}
- 
- 	return pinned;
- }
-@@ -488,7 +474,7 @@ static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova,
- 	}
- 
- 	if (do_accounting)
--		vfio_lock_acct(dma->task, locked - unlocked);
-+		vfio_lock_acct(dma->task, locked - unlocked, NULL);
- 
- 	return unlocked;
- }
-@@ -522,8 +508,14 @@ static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr,
- 		goto pin_page_exit;
- 	}
- 
--	if (!rsvd && do_accounting)
--		vfio_lock_acct(dma->task, 1);
-+	if (!rsvd && do_accounting) {
-+		ret = vfio_lock_acct(dma->task, 1, &lock_cap);
-+		if (ret) {
-+			put_pfn(*pfn_base, dma->prot);
-+			goto pin_page_exit;
-+		}
-+	}
-+
- 	ret = 1;
- 
- pin_page_exit:
-@@ -543,7 +535,7 @@ static int vfio_unpin_page_external(struct vfio_dma *dma, dma_addr_t iova,
- 	unlocked = vfio_iova_put_vfio_pfn(dma, vpfn);
- 
- 	if (do_accounting)
--		vfio_lock_acct(dma->task, -unlocked);
-+		vfio_lock_acct(dma->task, -unlocked, NULL);
- 
- 	return unlocked;
- }
-@@ -740,7 +732,7 @@ static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,
- 
- 	dma->iommu_mapped = false;
- 	if (do_accounting) {
--		vfio_lock_acct(dma->task, -unlocked);
-+		vfio_lock_acct(dma->task, -unlocked, NULL);
- 		return 0;
- 	}
- 	return unlocked;
-@@ -1382,7 +1374,7 @@ static void vfio_iommu_unmap_unpin_reaccount(struct vfio_iommu *iommu)
- 			if (!is_invalid_reserved_pfn(vpfn->pfn))
- 				locked++;
- 		}
--		vfio_lock_acct(dma->task, locked - unlocked);
-+		vfio_lock_acct(dma->task, locked - unlocked, NULL);
- 	}
- }
- 
--- 
-2.12.0
-