From: Alex Williamson <alex.williamson@redhat.com>
To: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, cohuck@redhat.com, jgg@ziepe.ca
Subject: [PATCH v2 1/3] vfio/type1: Support faulting PFNMAP vmas
Date: Tue, 05 May 2020 15:54:44 -0600 [thread overview]
Message-ID: <158871568480.15589.17339878308143043906.stgit@gimli.home> (raw)
In-Reply-To: <158871401328.15589.17598154478222071285.stgit@gimli.home>
With conversion to follow_pfn(), DMA mapping a PFNMAP range depends on
the range being faulted into the vma. Add support to manually provide
that, in the same way as done on KVM with hva_to_pfn_remapped().
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
drivers/vfio/vfio_iommu_type1.c | 36 +++++++++++++++++++++++++++++++++---
1 file changed, 33 insertions(+), 3 deletions(-)
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index cc1d64765ce7..4a4cb7cd86b2 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -317,6 +317,32 @@ static int put_pfn(unsigned long pfn, int prot)
return 0;
}
+static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm,
+ unsigned long vaddr, unsigned long *pfn,
+ bool write_fault)
+{
+ int ret;
+
+ ret = follow_pfn(vma, vaddr, pfn);
+ if (ret) {
+ bool unlocked = false;
+
+ ret = fixup_user_fault(NULL, mm, vaddr,
+ FAULT_FLAG_REMOTE |
+ (write_fault ? FAULT_FLAG_WRITE : 0),
+ &unlocked);
+ if (unlocked)
+ return -EAGAIN;
+
+ if (ret)
+ return ret;
+
+ ret = follow_pfn(vma, vaddr, pfn);
+ }
+
+ return ret;
+}
+
static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
int prot, unsigned long *pfn)
{
@@ -339,12 +365,16 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
vaddr = untagged_addr(vaddr);
+retry:
vma = find_vma_intersection(mm, vaddr, vaddr + 1);
if (vma && vma->vm_flags & VM_PFNMAP) {
- if (!follow_pfn(vma, vaddr, pfn) &&
- is_invalid_reserved_pfn(*pfn))
- ret = 0;
+ ret = follow_fault_pfn(vma, mm, vaddr, pfn, prot & IOMMU_WRITE);
+ if (ret == -EAGAIN)
+ goto retry;
+
+ if (!ret && !is_invalid_reserved_pfn(*pfn))
+ ret = -EFAULT;
}
done:
up_read(&mm->mmap_sem);
next prev parent reply other threads:[~2020-05-05 21:54 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 21:54 [PATCH v2 0/3] vfio-pci: Block user access to disabled device MMIO Alex Williamson
2020-05-05 21:54 ` Alex Williamson [this message]
2020-05-07 21:24 ` [PATCH v2 1/3] vfio/type1: Support faulting PFNMAP vmas Peter Xu
2020-05-07 21:47 ` Alex Williamson
2020-05-07 23:54 ` Jason Gunthorpe
2020-05-08 2:19 ` Peter Xu
2020-05-08 12:10 ` Jason Gunthorpe
2020-05-08 14:30 ` Peter Xu
2020-05-08 15:05 ` Jason Gunthorpe
2020-05-08 15:42 ` Alex Williamson
2020-05-08 16:05 ` Peter Xu
2020-05-08 18:39 ` Peter Xu
2020-05-05 21:54 ` [PATCH v2 2/3] vfio-pci: Fault mmaps to enable vma tracking Alex Williamson
2020-05-07 21:47 ` Peter Xu
2020-05-07 22:03 ` Alex Williamson
2020-05-07 22:22 ` Peter Xu
2020-05-07 23:56 ` Jason Gunthorpe
2020-05-08 2:16 ` Peter Xu
2020-05-08 6:44 ` Jason Wang
2020-05-08 14:27 ` Peter Xu
2020-05-08 12:08 ` Jason Gunthorpe
2020-05-08 14:26 ` Peter Xu
2020-05-05 21:55 ` [PATCH v2 3/3] vfio-pci: Invalidate mmaps and block MMIO access on disabled memory Alex Williamson
2020-05-22 2:39 ` Qian Cai
2020-05-22 4:18 ` Alex Williamson
2020-05-07 21:59 ` [PATCH v2 0/3] vfio-pci: Block user access to disabled device MMIO Peter Xu
2020-05-07 22:34 ` Alex Williamson
2020-05-08 2:31 ` Peter Xu
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