linux-kernel - [PATCH v1 12/14] vfio/type1: Support batching of device mappings

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <161524017090.3480.6508004360325488879.stgit@gimli.home>
Date:   Mon, 08 Mar 2021 14:49:31 -0700
From:   Alex Williamson <alex.williamson@...hat.com>
To:     alex.williamson@...hat.com
Cc:     cohuck@...hat.com, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, jgg@...dia.com, peterx@...hat.com
Subject: [PATCH v1 12/14] vfio/type1: Support batching of device mappings

Populate the page array to the extent available to enable batching.

Signed-off-by: Alex Williamson <alex.williamson@...hat.com>
---
 drivers/vfio/vfio_iommu_type1.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index e89f11141dee..d499bccfbe3f 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -628,6 +628,8 @@ static int vaddr_get_pfns(struct vfio_iommu *iommu, struct vfio_dma *dma,
 	vma = find_vma_intersection(mm, vaddr, vaddr + 1);
 
 	if (vma && vma->vm_flags & VM_PFNMAP) {
+		unsigned long count, i;
+
 		if ((dma->prot & IOMMU_WRITE && !(vma->vm_flags & VM_WRITE)) ||
 		    (dma->prot & IOMMU_READ && !(vma->vm_flags & VM_READ))) {
 			ret = -EFAULT;
@@ -678,7 +680,13 @@ static int vaddr_get_pfns(struct vfio_iommu *iommu, struct vfio_dma *dma,
 
 		*pfn = ((vaddr - vma->vm_start) >> PAGE_SHIFT) +
 							dma->pfnmap->base_pfn;
-		ret = 1;
+		count = min_t(long,
+			      (vma->vm_end - vaddr) >> PAGE_SHIFT, npages);
+
+		for (i = 0; i < count; i++)
+			pages[i] = pfn_to_page(*pfn + i);
+
+		ret = count;
 	}
 done:
 	mmap_read_unlock(mm);