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authorEric Auger <eric.auger@redhat.com>2019-02-15 17:16:06 +0100
committerAlex Williamson <alex.williamson@redhat.com>2019-02-18 14:57:50 -0700
commit0cfd027be1d6def4a462cdc180c055143af24069 (patch)
tree42d345b7ae0a1c5b46cc2db984c993f3ffaa4b65 /drivers/vfio/pci
parent51ef3a004b1eb6241e56b3aa8495769a092a4dc2 (diff)
downloadlinux-0cfd027be1d6def4a462cdc180c055143af24069.tar.bz2
vfio_pci: Enable memory accesses before calling pci_map_rom
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>
Diffstat (limited to 'drivers/vfio/pci')
-rw-r--r--drivers/vfio/pci/vfio_pci.c19
1 files changed, 14 insertions, 5 deletions
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 84b593b9fb1f..a25659b5a5d1 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -759,6 +759,7 @@ 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;
@@ -774,15 +775,23 @@ static long vfio_pci_ioctl(void *device_data,
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: