vfio_pci: Enable memory accesses before calling pci_map_rom (0cfd027b) · Commits · 戴 / test

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: ("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>

drivers/vfio/pci/vfio_pci.c

+14 −5

Original line number	Diff line number	Diff line
		@@ -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:

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