Index: sys/arch/amd64/pci/pci_machdep.c
===================================================================
RCS file: /mount/openbsd/cvs/src/sys/arch/amd64/pci/pci_machdep.c,v
diff -u -p -u -p -r1.81 pci_machdep.c
--- sys/arch/amd64/pci/pci_machdep.c	23 Jan 2025 11:24:34 -0000	1.81
+++ sys/arch/amd64/pci/pci_machdep.c	16 Mar 2025 21:35:45 -0000
@@ -954,13 +954,18 @@ pci_init_extents(void)
 		 * Dell 13G servers have important devices outside the
 		 * 36-bit address space.  Until we can extract the address
 		 * ranges from ACPI, expand the allowed range to suit.
+		 *
+		 * Seabios on qemu in pc-i440fx mode may map BARs at
+		 * 0x380000000000. But it claims ACPI version 1, so acpipci
+		 * will not be used.
+		 * Expand the range to match.
 		 */
 		pcimem_ex = extent_create("pcimem", 0, 0xffffffffffffffffUL,
 		    M_DEVBUF, NULL, 0, EX_NOWAIT);
 		if (pcimem_ex == NULL)
 			return;
-		extent_alloc_region(pcimem_ex, 0x40000000000UL,
-		    0xfffffc0000000000UL, EX_NOWAIT);
+		extent_alloc_region(pcimem_ex, 0x400000000000UL,
+		    0xffffc0000000000UL, EX_NOWAIT);
 
 		for (bmp = bios_memmap; bmp->type != BIOS_MAP_END; bmp++) {
 			/*