On Wed, May 08, 2024 at 07:55:07PM +0200, Bernhard Beschow wrote: > 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 <shen...@gmail.com>
Acked-by: Michael S. Tsirkin <m...@redhat.com> feel free to queue > --- > include/hw/i386/pc.h | 1 + > hw/i386/pc.c | 1 + > hw/i386/pc_piix.c | 3 +++ > hw/i386/pc_q35.c | 2 ++ > hw/i386/pc_sysfw.c | 8 +++++++- > 5 files changed, 14 insertions(+), 1 deletion(-) > > diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h > index e52290916c..ad9c3d9ba8 100644 > --- a/include/hw/i386/pc.h > +++ b/include/hw/i386/pc.h > @@ -119,6 +119,7 @@ struct PCMachineClass { > bool enforce_aligned_dimm; > bool broken_reserved_end; > bool enforce_amd_1tb_hole; > + bool isa_bios_alias; > > /* generate legacy CPU hotplug AML */ > bool legacy_cpu_hotplug; > diff --git a/hw/i386/pc.c b/hw/i386/pc.c > index 46235466d7..4878705af7 100644 > --- a/hw/i386/pc.c > +++ b/hw/i386/pc.c > @@ -1812,6 +1812,7 @@ static void pc_machine_class_init(ObjectClass *oc, void > *data) > pcmc->has_reserved_memory = true; > pcmc->enforce_aligned_dimm = true; > pcmc->enforce_amd_1tb_hole = true; > + pcmc->isa_bios_alias = true; > /* BIOS ACPI tables: 128K. Other BIOS datastructures: less than 4K > reported > * to be used at the moment, 32K should be enough for a while. */ > pcmc->acpi_data_size = 0x20000 + 0x8000; > diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c > index 8850c49c66..d4e9deb509 100644 > --- a/hw/i386/pc_piix.c > +++ b/hw/i386/pc_piix.c > @@ -525,12 +525,15 @@ DEFINE_I440FX_MACHINE(v9_1, "pc-i440fx-9.1", NULL, > > static void pc_i440fx_9_0_machine_options(MachineClass *m) > { > + PCMachineClass *pcmc = PC_MACHINE_CLASS(m); > + > pc_i440fx_9_1_machine_options(m); > m->alias = NULL; > m->is_default = false; > > compat_props_add(m->compat_props, hw_compat_9_0, hw_compat_9_0_len); > compat_props_add(m->compat_props, pc_compat_9_0, pc_compat_9_0_len); > + pcmc->isa_bios_alias = false; > } > > DEFINE_I440FX_MACHINE(v9_0, "pc-i440fx-9.0", NULL, > diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c > index bb53a51ac1..bd7db4abac 100644 > --- a/hw/i386/pc_q35.c > +++ b/hw/i386/pc_q35.c > @@ -378,10 +378,12 @@ DEFINE_Q35_MACHINE(v9_1, "pc-q35-9.1", NULL, > > static void pc_q35_9_0_machine_options(MachineClass *m) > { > + PCMachineClass *pcmc = PC_MACHINE_CLASS(m); > pc_q35_9_1_machine_options(m); > m->alias = NULL; > compat_props_add(m->compat_props, hw_compat_9_0, hw_compat_9_0_len); > compat_props_add(m->compat_props, pc_compat_9_0, pc_compat_9_0_len); > + pcmc->isa_bios_alias = false; > } > > DEFINE_Q35_MACHINE(v9_0, "pc-q35-9.0", NULL, > diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c > index 82d37cb376..ac88ad4eb9 100644 > --- a/hw/i386/pc_sysfw.c > +++ b/hw/i386/pc_sysfw.c > @@ -135,6 +135,7 @@ static void pc_system_flash_map(PCMachineState *pcms, > MemoryRegion *rom_memory) > { > X86MachineState *x86ms = X86_MACHINE(pcms); > + PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms); > hwaddr total_size = 0; > int i; > BlockBackend *blk; > @@ -184,7 +185,12 @@ static void pc_system_flash_map(PCMachineState *pcms, > > if (i == 0) { > flash_mem = pflash_cfi01_get_memory(system_flash); > - pc_isa_bios_init(&x86ms->isa_bios, rom_memory, flash_mem); > + if (pcmc->isa_bios_alias) { > + x86_isa_bios_init(&x86ms->isa_bios, rom_memory, flash_mem, > + true); > + } else { > + pc_isa_bios_init(&x86ms->isa_bios, rom_memory, flash_mem); > + } > > /* Encrypt the pflash boot ROM */ > if (sev_enabled()) { > -- > 2.45.0