Commit eb3fb613 authored Nov 05, 2020 by Jason Gunthorpe Committed by Greg Kroah-Hartman Dec 29, 2020

vfio-pci: Use io_remap_pfn_range() for PCI IO memory



[ Upstream commit 7b06a56d468b756ad6bb43ac21b11e474ebc54a0 ]

commit f8f6ae5d077a ("mm: always have io_remap_pfn_range() set
pgprot_decrypted()") allows drivers using mmap to put PCI memory mapped
BAR space into userspace to work correctly on AMD SME systems that default
to all memory encrypted.

Since vfio_pci_mmap_fault() is working with PCI memory mapped BAR space it
should be calling io_remap_pfn_range() otherwise it will not work on SME
systems.

Fixes: 11c4cd07ba11 ("vfio-pci: Fault mmaps to enable vma tracking")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Peter Xu <peterx@redhat.com>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent e84062a6

drivers/vfio/pci/vfio_pci.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1403,7 +1403,7 @@ static int vfio_pci_mmap_fault(struct vm_area_struct vma, struct vm_fault vmf)

		mutex_unlock(&vdev->vma_lock);

		if (remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
		if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
		vma->vm_end - vma->vm_start, vma->vm_page_prot))
		ret = VM_FAULT_SIGBUS;