On 9/1/21 6:01 PM, Philippe Mathieu-Daudé wrote: > On 8/23/21 11:20 AM, David Hildenbrand wrote: >> On 23.08.21 10:54, Philippe Mathieu-Daudé wrote: >>> Per Peter Maydell [*]: >>> >>> 'info mtree' monitor command was designed on the assumption that >>> there's really only one or two interesting address spaces, and >>> with more recent developments that's just not the case any more. >>> >>> Similarly about how the FlatView are sorted using a GHashTable, >>> sort the AddressSpace objects to remove the duplications (AS >>> using the same root MemoryRegion). >>> >>> This drastically reduce 'info mtree' on some boards. >> >> s/reduce/reduces the output of/ >> >>> >>> Before: >>> >>> $ (echo info mtree; echo q) \ >>> | qemu-system-aarch64 -S -monitor stdio -M raspi3b \ >>> | wc -l >>> 423 >>> >>> After: >>> >>> $ (echo info mtree; echo q) \ >>> | qemu-system-aarch64 -S -monitor stdio -M raspi3b \ >>> | wc -l >>> 106 >>> >>> (qemu) info mtree >>> address-space: I/O >>> 0000000000000000-000000000000ffff (prio 0, i/o): io >>> >>> address-space: cpu-memory-0 >>> address-space: cpu-memory-1 >>> address-space: cpu-memory-2 >>> address-space: cpu-memory-3 >>> address-space: cpu-secure-memory-0 >>> address-space: cpu-secure-memory-1 >>> address-space: cpu-secure-memory-2 >>> address-space: cpu-secure-memory-3 >> >> We can still distinguish from a completely empty AS, because we don't >> have an empty line here, correct? > > Yes: > > (qemu) info mtree > address-space: I/O > 0000000000000000-000000000000ffff (prio 0, i/o): io
Wrong answer because there is 1 MR here. We can create address_space_init() with NULL MR, because memory_region_ref() checks for NULL mr, but QEMU aborts quickly: (gdb) bt #0 memory_region_get_flatview_root (mr=0x0) at softmmu/memory.c:685 #1 0x0000555555eec7ef in address_space_update_topology (as=0x5555567f2a20 <address_space_io>) at softmmu/memory.c:1073 #2 address_space_init (as=0x5555567f2a20 <address_space_io2>, root=0x0, name=<optimized out>) at softmmu/memory.c:2934 #3 0x0000555555edc7a9 in memory_map_init () at softmmu/physmem.c:2672 #4 cpu_exec_init_all () at softmmu/physmem.c:3070 #5 0x0000555555ef5480 in qemu_create_machine (qdict=0x7fffffffcec0) at softmmu/vl.c:2126 #6 qemu_init (argc=<optimized out>, argv=0x7fffffffd0e8, envp=<optimized out>) at softmmu/vl.c:3639 #7 0x00005555559c2fe9 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at softmmu/main.c:49 What is your "completely empty AS" case?