qemu/include/hw/i386
Bernhard Beschow a44ea3fa7f hw/i386/pc_sysfw: Alias rather than copy isa-bios region
In the -bios case the "isa-bios" memory region is an alias to the BIOS mapped
to the top of the 4G memory boundary. Do the same in the -pflash case, but only
for new machine versions for migration compatibility. This establishes common
behavior and makes pflash commands work in the "isa-bios" region which some
real-world legacy bioses rely on.

Note that in the sev_enabled() case, the "isa-bios" memory region in the -pflash
case will now also point to encrypted memory, just like it already does in the
-bios case.

When running `info mtree` before and after this commit with
`qemu-system-x86_64 -S -drive \
if=pflash,format=raw,readonly=on,file=/usr/share/qemu/bios-256k.bin` and running
`diff -u before.mtree after.mtree` results in the following changes in the
memory tree:

   --- before.mtree
   +++ after.mtree
   @@ -71,7 +71,7 @@
        0000000000000000-ffffffffffffffff (prio -1, i/o): pci
        00000000000a0000-00000000000bffff (prio 1, i/o): vga-lowmem
        00000000000c0000-00000000000dffff (prio 1, rom): pc.rom
   -      00000000000e0000-00000000000fffff (prio 1, rom): isa-bios
   +      00000000000e0000-00000000000fffff (prio 1, romd): alias isa-bios @system.flash0 0000000000020000-000000000003ffff
        00000000000a0000-00000000000bffff (prio 1, i/o): alias smram-region @pci 00000000000a0000-00000000000bffff
        00000000000c0000-00000000000c3fff (prio 1, i/o): alias pam-pci @pci 00000000000c0000-00000000000c3fff
        00000000000c4000-00000000000c7fff (prio 1, i/o): alias pam-pci @pci 00000000000c4000-00000000000c7fff
   @@ -108,7 +108,7 @@
        0000000000000000-ffffffffffffffff (prio -1, i/o): pci
        00000000000a0000-00000000000bffff (prio 1, i/o): vga-lowmem
        00000000000c0000-00000000000dffff (prio 1, rom): pc.rom
   -      00000000000e0000-00000000000fffff (prio 1, rom): isa-bios
   +      00000000000e0000-00000000000fffff (prio 1, romd): alias isa-bios @system.flash0 0000000000020000-000000000003ffff
        00000000000a0000-00000000000bffff (prio 1, i/o): alias smram-region @pci 00000000000a0000-00000000000bffff
        00000000000c0000-00000000000c3fff (prio 1, i/o): alias pam-pci @pci 00000000000c0000-00000000000c3fff
        00000000000c4000-00000000000c7fff (prio 1, i/o): alias pam-pci @pci 00000000000c4000-00000000000c7fff
   @@ -131,11 +131,14 @@
   memory-region: pc.ram
   0000000000000000-0000000007ffffff (prio 0, ram): pc.ram

   +memory-region: system.flash0
   +  00000000fffc0000-00000000ffffffff (prio 0, romd): system.flash0
   +
   memory-region: pci
   0000000000000000-ffffffffffffffff (prio -1, i/o): pci
        00000000000a0000-00000000000bffff (prio 1, i/o): vga-lowmem
        00000000000c0000-00000000000dffff (prio 1, rom): pc.rom
   -    00000000000e0000-00000000000fffff (prio 1, rom): isa-bios
   +    00000000000e0000-00000000000fffff (prio 1, romd): alias isa-bios @system.flash0 0000000000020000-000000000003ffff

   memory-region: smram
        00000000000a0000-00000000000bffff (prio 0, ram): alias smram-low @pc.ram 00000000000a0000-00000000000bffff

Note that in both cases the "system" memory region contains the entry

  00000000fffc0000-00000000ffffffff (prio 0, romd): system.flash0

but the "system.flash0" memory region only appears standalone when "isa-bios" is
an alias.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Message-ID: <20240508175507.22270-7-shentey@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-05-22 15:53:30 +02:00
..
apic_internal.h apic, i386/tcg: add x2apic transitions 2024-02-14 06:09:32 -05:00
apic-msidef.h i386/msi: Correct mask of destination ID in MSI address 2017-12-01 18:28:15 +02:00
apic.h hw/i386/x86: Fix PIC interrupt handling if APIC is globally disabled 2024-02-14 06:09:32 -05:00
hostmem-epc.h hostmem: Add hostmem-epc as a backend for SGX EPC 2021-09-30 14:50:19 +02:00
intel_iommu.h hw/i386/intel_iommu: Fix endianness problems related to VTD_IR_TableEntry 2023-08-03 16:06:49 -04:00
microvm.h Revert "x86: don't let decompressed kernel image clobber setup_data" 2023-03-02 03:10:46 -05:00
pc.h hw/i386/pc_sysfw: Alias rather than copy isa-bios region 2024-05-22 15:53:30 +02:00
sgx-epc.h include: Include headers where needed 2023-01-08 01:54:22 -05:00
topology.h hw/i386: Fix comment style in topology.h 2023-11-07 13:08:48 +01:00
vmport.h hw/i386/vmport: Drop superfluous parenthesis around function typedef 2020-09-18 13:49:54 -04:00
x86-iommu.h include/hw/i386/x86-iommu: Fix struct X86IOMMU_MSIMessage for big endian hosts 2023-08-03 16:16:17 -04:00
x86.h hw/i386: split x86.c in multiple parts 2024-05-10 15:45:15 +02:00
xen_arch_hvm.h xen-hvm: reorganize xen-hvm and move common function to xen-hvm-common 2023-06-15 16:45:59 -07:00