On 7/1/20 2:40 PM, Philippe Mathieu-Daudé wrote: > On 7/1/20 2:25 PM, Jason Andryuk wrote: >> On Wed, Jul 1, 2020 at 3:03 AM Paul Durrant <xadimg...@gmail.com> wrote: >>> >>>> -----Original Message----- >>>> From: Philippe Mathieu-Daudé <phi...@redhat.com> >>>> Sent: 30 June 2020 18:27 >>>> To: p...@xen.org; xen-de...@lists.xenproject.org; qemu-devel@nongnu.org >>>> Cc: 'Eduardo Habkost' <ehabk...@redhat.com>; 'Michael S. Tsirkin' >>>> <m...@redhat.com>; 'Paul Durrant' >>>> <pdurr...@amazon.com>; 'Jason Andryuk' <jandr...@gmail.com>; 'Paolo >>>> Bonzini' <pbonz...@redhat.com>; >>>> 'Richard Henderson' <r...@twiddle.net> >>>> Subject: Re: [PATCH 2/2] xen: cleanup unrealized flash devices >>>> >>>> On 6/30/20 5:44 PM, Paul Durrant wrote: >>>>>> -----Original Message----- >>>>>> From: Philippe Mathieu-Daudé <phi...@redhat.com> >>>>>> Sent: 30 June 2020 16:26 >>>>>> To: Paul Durrant <p...@xen.org>; xen-de...@lists.xenproject.org; >>>>>> qemu-devel@nongnu.org >>>>>> Cc: Eduardo Habkost <ehabk...@redhat.com>; Michael S. Tsirkin >>>>>> <m...@redhat.com>; Paul Durrant >>>>>> <pdurr...@amazon.com>; Jason Andryuk <jandr...@gmail.com>; Paolo Bonzini >>>>>> <pbonz...@redhat.com>; >>>>>> Richard Henderson <r...@twiddle.net> >>>>>> Subject: Re: [PATCH 2/2] xen: cleanup unrealized flash devices >>>>>> >>>>>> On 6/24/20 2:18 PM, Paul Durrant wrote: >>>>>>> From: Paul Durrant <pdurr...@amazon.com> >>>>>>> >>>>>>> The generic pc_machine_initfn() calls pc_system_flash_create() which >>>>>>> creates >>>>>>> 'system.flash0' and 'system.flash1' devices. These devices are then >>>>>>> realized >>>>>>> by pc_system_flash_map() which is called from pc_system_firmware_init() >>>>>>> which >>>>>>> itself is called via pc_memory_init(). The latter however is not called >>>>>>> when >>>>>>> xen_enable() is true and hence the following assertion fails: >>>>>>> >>>>>>> qemu-system-i386: hw/core/qdev.c:439: qdev_assert_realized_properly: >>>>>>> Assertion `dev->realized' failed >>>>>>> >>>>>>> These flash devices are unneeded when using Xen so this patch avoids the >>>>>>> assertion by simply removing them using >>>>>>> pc_system_flash_cleanup_unused(). >>>>>>> >>>>>>> Reported-by: Jason Andryuk <jandr...@gmail.com> >>>>>>> Fixes: ebc29e1beab0 ("pc: Support firmware configuration with >>>>>>> -blockdev") >>>>>>> Signed-off-by: Paul Durrant <pdurr...@amazon.com> >>>>>>> Tested-by: Jason Andryuk <jandr...@gmail.com> >>>>>>> --- >>>>>>> Cc: Paolo Bonzini <pbonz...@redhat.com> >>>>>>> Cc: Richard Henderson <r...@twiddle.net> >>>>>>> Cc: Eduardo Habkost <ehabk...@redhat.com> >>>>>>> Cc: "Michael S. Tsirkin" <m...@redhat.com> >>>>>>> Cc: Marcel Apfelbaum <marcel.apfelb...@gmail.com> >>>>>>> --- >>>>>>> hw/i386/pc_piix.c | 9 ++++++--- >>>>>>> hw/i386/pc_sysfw.c | 2 +- >>>>>>> include/hw/i386/pc.h | 1 + >>>>>>> 3 files changed, 8 insertions(+), 4 deletions(-) >>>>>>> >>>>>>> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c >>>>>>> index 1497d0e4ae..977d40afb8 100644 >>>>>>> --- a/hw/i386/pc_piix.c >>>>>>> +++ b/hw/i386/pc_piix.c >>>>>>> @@ -186,9 +186,12 @@ static void pc_init1(MachineState *machine, >>>>>>> if (!xen_enabled()) { >>>>>>> pc_memory_init(pcms, system_memory, >>>>>>> rom_memory, &ram_memory); >>>>>>> - } else if (machine->kernel_filename != NULL) { >>>>>>> - /* For xen HVM direct kernel boot, load linux here */ >>>>>>> - xen_load_linux(pcms); >>>>>>> + } else { >>>>>>> + pc_system_flash_cleanup_unused(pcms); >>>>>> >>>>>> TIL pc_system_flash_cleanup_unused(). >>>>>> >>>>>> What about restricting at the source? >>>>>> >>>>> >>>>> And leave the devices in place? They are not relevant for Xen, so why not >>>>> clean up? >>>> >>>> No, I meant to not create them in the first place, instead of >>>> create+destroy. >>>> >>>> Anyway what you did works, so I don't have any problem. >>> >>> IIUC Jason originally tried restricting creation but encountered a problem >>> because xen_enabled() would always return false at that point, because >>> machine creation occurs before accelerators are initialized. >> >> Correct. Quoting my previous email: >> """ >> Removing the call to pc_system_flash_create() from pc_machine_initfn() >> lets QEMU startup and run a Xen HVM again. xen_enabled() doesn't work >> there since accelerators have not been initialized yes, I guess? > > Ah, I missed that. You pointed at the bug here :) > > I think pc_system_flash_create() shouldn't be called in init() but > realize().
Hmm this is a MachineClass, not qdev, so no realize(). In softmmu/vl.c we have: 4152 configure_accelerators(argv[0]); .... 4327 if (!xen_enabled()) { // so xen_enable() is working 4328 /* On 32-bit hosts, QEMU is limited by virtual address space */ 4329 if (ram_size > (2047 << 20) && HOST_LONG_BITS == 32) { 4330 error_report("at most 2047 MB RAM can be simulated"); 4331 exit(1); 4332 } 4333 } .... 4348 machine_run_board_init(current_machine); which calls in hw/core/machine.c: 1089 void machine_run_board_init(MachineState *machine) 1090 { 1091 MachineClass *machine_class = MACHINE_GET_CLASS(machine); .... 1138 machine_class->init(machine); 1139 } -> pc_machine_class_init() This should come after: -> pc_machine_initfn() -> pc_system_flash_create(pcms) > >> """ >> >> If you want to remove the creation in the first place, then I have two >> questions. Why does pc_system_flash_create()/pc_pflash_create() get >> called so early creating the pflash devices? Why aren't they just >> created as needed in pc_system_flash_map()? >> >> Regards, >> Jason >> >>> Paul >>> >>>> >>>> Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com> >>>> >>>>> >>>>> Paul >>>>> >>>>>> -- >8 -- >>>>>> --- a/hw/i386/pc.c >>>>>> +++ b/hw/i386/pc.c >>>>>> @@ -1004,24 +1004,26 @@ void pc_memory_init(PCMachineState *pcms, >>>>>> &machine->device_memory->mr); >>>>>> } >>>>>> >>>>>> - /* Initialize PC system firmware */ >>>>>> - pc_system_firmware_init(pcms, rom_memory); >>>>>> - >>>>>> - option_rom_mr = g_malloc(sizeof(*option_rom_mr)); >>>>>> - memory_region_init_ram(option_rom_mr, NULL, "pc.rom", PC_ROM_SIZE, >>>>>> - &error_fatal); >>>>>> - if (pcmc->pci_enabled) { >>>>>> - memory_region_set_readonly(option_rom_mr, true); >>>>>> - } >>>>>> - memory_region_add_subregion_overlap(rom_memory, >>>>>> - PC_ROM_MIN_VGA, >>>>>> - option_rom_mr, >>>>>> - 1); >>>>>> - >>>>>> fw_cfg = fw_cfg_arch_create(machine, >>>>>> x86ms->boot_cpus, x86ms->apic_id_limit); >>>>>> >>>>>> - rom_set_fw(fw_cfg); >>>>>> + /* Initialize PC system firmware */ >>>>>> + if (!xen_enabled()) { >>>>>> + pc_system_firmware_init(pcms, rom_memory); >>>>>> + >>>>>> + option_rom_mr = g_malloc(sizeof(*option_rom_mr)); >>>>>> + memory_region_init_ram(option_rom_mr, NULL, "pc.rom", >>>>>> PC_ROM_SIZE, >>>>>> + &error_fatal); >>>>>> + if (pcmc->pci_enabled) { >>>>>> + memory_region_set_readonly(option_rom_mr, true); >>>>>> + } >>>>>> + memory_region_add_subregion_overlap(rom_memory, >>>>>> + PC_ROM_MIN_VGA, >>>>>> + option_rom_mr, >>>>>> + 1); >>>>>> + >>>>>> + rom_set_fw(fw_cfg); >>>>>> + } >>>>>> >>>>>> if (pcmc->has_reserved_memory && machine->device_memory->base) { >>>>>> uint64_t *val = g_malloc(sizeof(*val)); >>>>>> --- >>>>>> >>>>>>> + if (machine->kernel_filename != NULL) { >>>>>>> + /* For xen HVM direct kernel boot, load linux here */ >>>>>>> + xen_load_linux(pcms); >>>>>>> + } >>>>>>> } >>>>>>> >>>>>>> gsi_state = pc_gsi_create(&x86ms->gsi, pcmc->pci_enabled); >>>>>>> diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c >>>>>>> index ec2a3b3e7e..0ff47a4b59 100644 >>>>>>> --- a/hw/i386/pc_sysfw.c >>>>>>> +++ b/hw/i386/pc_sysfw.c >>>>>>> @@ -108,7 +108,7 @@ void pc_system_flash_create(PCMachineState *pcms) >>>>>>> } >>>>>>> } >>>>>>> >>>>>>> -static void pc_system_flash_cleanup_unused(PCMachineState *pcms) >>>>>>> +void pc_system_flash_cleanup_unused(PCMachineState *pcms) >>>>>>> { >>>>>>> char *prop_name; >>>>>>> int i; >>>>>>> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h >>>>>>> index e6135c34d6..497f2b7ab7 100644 >>>>>>> --- a/include/hw/i386/pc.h >>>>>>> +++ b/include/hw/i386/pc.h >>>>>>> @@ -187,6 +187,7 @@ int cmos_get_fd_drive_type(FloppyDriveType fd0); >>>>>>> >>>>>>> /* pc_sysfw.c */ >>>>>>> void pc_system_flash_create(PCMachineState *pcms); >>>>>>> +void pc_system_flash_cleanup_unused(PCMachineState *pcms); >>>>>>> void pc_system_firmware_init(PCMachineState *pcms, MemoryRegion >>>>>>> *rom_memory); >>>>>>> >>>>>>> /* acpi-build.c */ >>>>>>> >>>>> >>>>> >>> >>> >> >