From: Alex Williamson <alex.williamson@redhat.com>
To: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, cohuck@redhat.com, jgg@ziepe.ca,
peterx@redhat.com
Subject: [PATCH 1/3] vfio/type1: Support faulting PFNMAP vmas
Date: Fri, 01 May 2020 15:39:08 -0600 [thread overview]
Message-ID: <158836914801.8433.9711545991918184183.stgit@gimli.home> (raw)
In-Reply-To: <158836742096.8433.685478071796941103.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:[~2020-05-01 21:39 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-01 21:38 [PATCH 0/3] vfio-pci: Block user access to disabled device MMIO Alex Williamson
2020-05-01 21:39 ` Alex Williamson [this message]
2020-05-01 23:50 ` [PATCH 1/3] vfio/type1: Support faulting PFNMAP vmas Jason Gunthorpe
2020-05-04 14:06 ` Alex Williamson
2020-05-04 15:02 ` Jason Gunthorpe
2020-05-01 21:39 ` [PATCH 2/3] vfio-pci: Fault mmaps to enable vma tracking Alex Williamson
2020-05-01 23:25 ` Jason Gunthorpe
2020-05-04 14:20 ` Alex Williamson
2020-05-04 15:05 ` Jason Gunthorpe
2020-05-04 15:53 ` Alex Williamson
2020-05-01 21:39 ` [PATCH 3/3] vfio-pci: Invalidate mmaps and block MMIO access on disabled memory Alex Williamson
2020-05-01 23:48 ` Jason Gunthorpe
2020-05-04 18:26 ` Alex Williamson
2020-05-04 18:44 ` Jason Gunthorpe
2020-05-04 19:35 ` Alex Williamson
2020-05-04 20:01 ` Jason Gunthorpe
2020-05-05 17:12 ` Alex Williamson
2020-05-05 18:36 ` Jason Gunthorpe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=158836914801.8433.9711545991918184183.stgit@gimli.home \
--to=alex.williamson@redhat.com \
--cc=cohuck@redhat.com \
--cc=jgg@ziepe.ca \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=peterx@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).