diff options
| author | Eric Auger <eric.auger@redhat.com> | 2019-02-15 17:16:06 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-29 10:21:40 +0100 |
| commit | 700983bf02309fd4417d8bcab91dc0ff758c1c03 (patch) | |
| tree | 5ff36cf4abd95988104a7710b3c1e7da1ec651c1 | |
| parent | 3880087c26c4c26698fbb1c05f3265f674554aab (diff) | |
vfio_pci: Enable memory accesses before calling pci_map_rom
[ Upstream commit 0cfd027be1d6def4a462cdc180c055143af24069 ]
pci_map_rom/pci_get_rom_size() performs memory access in the ROM.
In case the Memory Space accesses were disabled, readw() is likely
to trigger a synchronous external abort on some platforms.
In case memory accesses were disabled, re-enable them before the
call and disable them back again just after.
Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/vfio/pci/vfio_pci.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 4b62eb3b5923..7a82735d5308 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -496,6 +496,7 @@ static long vfio_pci_ioctl(void *device_data, { void __iomem *io; size_t size; + u16 orig_cmd; info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index); info.flags = 0; @@ -505,15 +506,23 @@ static long vfio_pci_ioctl(void *device_data, if (!info.size) break; - /* Is it really there? */ + /* + * Is it really there? Enable memory decode for + * implicit access in pci_map_rom(). + */ + pci_read_config_word(pdev, PCI_COMMAND, &orig_cmd); + pci_write_config_word(pdev, PCI_COMMAND, + orig_cmd | PCI_COMMAND_MEMORY); + io = pci_map_rom(pdev, &size); - if (!io || !size) { + if (io) { + info.flags = VFIO_REGION_INFO_FLAG_READ; + pci_unmap_rom(pdev, io); + } else { info.size = 0; - break; } - pci_unmap_rom(pdev, io); - info.flags = VFIO_REGION_INFO_FLAG_READ; + pci_write_config_word(pdev, PCI_COMMAND, orig_cmd); break; } case VFIO_PCI_VGA_REGION_INDEX: |