};
/*
+ * Expand memory region of sub-page(size < PAGE_SIZE) MMIO BAR to page
+ * size if the BAR is in an exclusive page in host so that we could map
+ * this BAR to guest. But this sub-page BAR may not occupy an exclusive
+ * page in guest. So we should set the priority of the expanded memory
+ * region to zero in case of overlap with BARs which share the same page
+ * with the sub-page BAR in guest. Besides, we should also recover the
+ * size of this sub-page BAR when its base address is changed in guest
+ * and not page aligned any more.
+ */
+static void vfio_sub_page_bar_update_mapping(PCIDevice *pdev, int bar)
+{
+ VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
+ VFIORegion *region = &vdev->bars[bar].region;
+ MemoryRegion *mmap_mr, *mr;
+ PCIIORegion *r;
+ pcibus_t bar_addr;
+ uint64_t size = region->size;
+
+ /* Make sure that the whole region is allowed to be mmapped */
+ if (region->nr_mmaps != 1 || !region->mmaps[0].mmap ||
+ region->mmaps[0].size != region->size) {
+ return;
+ }
+
+ r = &pdev->io_regions[bar];
+ bar_addr = r->addr;
+ mr = region->mem;
+ mmap_mr = ®ion->mmaps[0].mem;
+
+ /* If BAR is mapped and page aligned, update to fill PAGE_SIZE */
+ if (bar_addr != PCI_BAR_UNMAPPED &&
+ !(bar_addr & ~qemu_real_host_page_mask)) {
+ size = qemu_real_host_page_size;
+ }
+
+ memory_region_transaction_begin();
+
+ memory_region_set_size(mr, size);
+ memory_region_set_size(mmap_mr, size);
+ if (size != region->size && memory_region_is_mapped(mr)) {
+ memory_region_del_subregion(r->address_space, mr);
+ memory_region_add_subregion_overlap(r->address_space,
+ bar_addr, mr, 0);
+ }
+
+ memory_region_transaction_commit();
+}
+
+/*
* PCI config space
*/
uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len)
} else if (was_enabled && !is_enabled) {
vfio_msix_disable(vdev);
}
+ } else if (ranges_overlap(addr, len, PCI_BASE_ADDRESS_0, 24) ||
+ range_covers_byte(addr, len, PCI_COMMAND)) {
+ pcibus_t old_addr[PCI_NUM_REGIONS - 1];
+ int bar;
+
+ for (bar = 0; bar < PCI_ROM_SLOT; bar++) {
+ old_addr[bar] = pdev->io_regions[bar].addr;
+ }
+
+ pci_default_write_config(pdev, addr, val, len);
+
+ for (bar = 0; bar < PCI_ROM_SLOT; bar++) {
+ if (old_addr[bar] != pdev->io_regions[bar].addr &&
+ pdev->io_regions[bar].size > 0 &&
+ pdev->io_regions[bar].size < qemu_real_host_page_size) {
+ vfio_sub_page_bar_update_mapping(pdev, bar);
+ }
+ }
} else {
/* Write everything to QEMU to keep emulated bits correct */
pci_default_write_config(pdev, addr, val, len);