Re: [Qemu-devel] [PATCH v9 3/3] pc: Support system flash memory with pflash

[Jordan Justen]

On Mon, Jan 9, 2012 at 01:28, Kevin Wolf <address@hidden> wrote:
> Am 19.12.2011 23:19, schrieb Anthony Liguori:
>> On 12/19/2011 03:25 PM, Jordan Justen wrote:
>>> On Mon, Dec 19, 2011 at 11:41, Anthony Liguori<address@hidden>  wrote:
>>>> On 12/15/2011 02:51 PM, Jordan Justen wrote:
>>>>>
>>>>> If a pflash image is found, then it is used for the system
>>>>> firmware image.
>>>>>
>>>>> If a pflash image is not initially found, then a read-only
>>>>> pflash device is created using the -bios filename.
>>>>>
>>>>> KVM cannot execute from a pflash region currently.
>>>>> Therefore, when KVM is enabled, a (read-only) ram memory
>>>>> region is created and filled with the contents of the
>>>>> pflash drive.
>>>>>
>>>>> Signed-off-by: Jordan Justen<address@hidden>
>>>>> Cc: Anthony Liguori<address@hidden>
>>>>> ---
>>>>>   Makefile.target                    |    1 +
>>>>>   default-configs/i386-softmmu.mak   |    1 +
>>>>>   default-configs/x86_64-softmmu.mak |    1 +
>>>>>   hw/boards.h                        |    1 +
>>>>>   hw/pc.c                            |   55 +-------
>>>>>   hw/pc.h                            |    4 +
>>>>>   hw/pc_sysfw.c                      |  255
>>>>> ++++++++++++++++++++++++++++++++++++
>>>>>   vl.c                               |    2 +-
>>>>>   8 files changed, 269 insertions(+), 51 deletions(-)
>>>>>   create mode 100644 hw/pc_sysfw.c
>>>>>
>>>>> diff --git a/Makefile.target b/Makefile.target
>>>>> index a111521..b1dc882 100644
>>>>> --- a/Makefile.target
>>>>> +++ b/Makefile.target
>>>>> @@ -236,6 +236,7 @@ obj-i386-y += vmport.o
>>>>>   obj-i386-y += device-hotplug.o pci-hotplug.o smbios.o wdt_ib700.o
>>>>>   obj-i386-y += debugcon.o multiboot.o
>>>>>   obj-i386-y += pc_piix.o
>>>>> +obj-i386-y += pc_sysfw.o
>>>>>   obj-i386-$(CONFIG_KVM) += kvmclock.o
>>>>>   obj-i386-$(CONFIG_SPICE) += qxl.o qxl-logger.o qxl-render.o
>>>>>
>>>>> diff --git a/default-configs/i386-softmmu.mak
>>>>> b/default-configs/i386-softmmu.mak
>>>>> index e67ebb3..cd407a9 100644
>>>>> --- a/default-configs/i386-softmmu.mak
>>>>> +++ b/default-configs/i386-softmmu.mak
>>>>> @@ -22,3 +22,4 @@ CONFIG_SOUND=y
>>>>>   CONFIG_HPET=y
>>>>>   CONFIG_APPLESMC=y
>>>>>   CONFIG_I8259=y
>>>>> +CONFIG_PFLASH_CFI01=y
>>>>> diff --git a/default-configs/x86_64-softmmu.mak
>>>>> b/default-configs/x86_64-softmmu.mak
>>>>> index b75757e..47734ea 100644
>>>>> --- a/default-configs/x86_64-softmmu.mak
>>>>> +++ b/default-configs/x86_64-softmmu.mak
>>>>> @@ -22,3 +22,4 @@ CONFIG_SOUND=y
>>>>>   CONFIG_HPET=y
>>>>>   CONFIG_APPLESMC=y
>>>>>   CONFIG_I8259=y
>>>>> +CONFIG_PFLASH_CFI01=y
>>>>> diff --git a/hw/boards.h b/hw/boards.h
>>>>> index 716fd7b..45a31a1 100644
>>>>> --- a/hw/boards.h
>>>>> +++ b/hw/boards.h
>>>>> @@ -33,6 +33,7 @@ typedef struct QEMUMachine {
>>>>>   } QEMUMachine;
>>>>>
>>>>>   int qemu_register_machine(QEMUMachine *m);
>>>>> +QEMUMachine *find_default_machine(void);
>>>>>
>>>>>   extern QEMUMachine *current_machine;
>>>>>
>>>>> diff --git a/hw/pc.c b/hw/pc.c
>>>>> index cc6cfad..e5550ca 100644
>>>>> --- a/hw/pc.c
>>>>> +++ b/hw/pc.c
>>>>> @@ -57,10 +57,6 @@
>>>>>   #define DPRINTF(fmt, ...)
>>>>>   #endif
>>>>>
>>>>> -#define BIOS_FILENAME "bios.bin"
>>>>> -
>>>>> -#define PC_MAX_BIOS_SIZE (4 * 1024 * 1024)
>>>>> -
>>>>>   /* Leave a chunk of memory at the top of RAM for the BIOS ACPI tables.
>>>>>   */
>>>>>   #define ACPI_DATA_SIZE       0x10000
>>>>>   #define BIOS_CFG_IOPORT 0x510
>>>>> @@ -974,11 +970,9 @@ void pc_memory_init(MemoryRegion *system_memory,
>>>>>                       MemoryRegion **ram_memory,
>>>>>                       int system_firmware_enabled)
>>>>>   {
>>>>> -    char *filename;
>>>>> -    int ret, linux_boot, i;
>>>>> -    MemoryRegion *ram, *bios, *isa_bios, *option_rom_mr;
>>>>> +    int linux_boot, i;
>>>>> +    MemoryRegion *ram, *option_rom_mr;
>>>>>       MemoryRegion *ram_below_4g, *ram_above_4g;
>>>>> -    int bios_size, isa_bios_size;
>>>>>       void *fw_cfg;
>>>>>
>>>>>       linux_boot = (kernel_filename != NULL);
>>>>> @@ -1003,43 +997,9 @@ void pc_memory_init(MemoryRegion *system_memory,
>>>>>                                       ram_above_4g);
>>>>>       }
>>>>>
>>>>> -    /* BIOS load */
>>>>> -    if (bios_name == NULL)
>>>>> -        bios_name = BIOS_FILENAME;
>>>>> -    filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
>>>>> -    if (filename) {
>>>>> -        bios_size = get_image_size(filename);
>>>>> -    } else {
>>>>> -        bios_size = -1;
>>>>> -    }
>>>>> -    if (bios_size<= 0 ||
>>>>> -        (bios_size % 65536) != 0) {
>>>>> -        goto bios_error;
>>>>> -    }
>>>>> -    bios = g_malloc(sizeof(*bios));
>>>>> -    memory_region_init_ram(bios, NULL, "pc.bios", bios_size);
>>>>> -    memory_region_set_readonly(bios, true);
>>>>> -    ret = rom_add_file_fixed(bios_name, (uint32_t)(-bios_size), -1);
>>>>> -    if (ret != 0) {
>>>>> -    bios_error:
>>>>> -        fprintf(stderr, "qemu: could not load PC BIOS '%s'\n",
>>>>> bios_name);
>>>>> -        exit(1);
>>>>> -    }
>>>>> -    if (filename) {
>>>>> -        g_free(filename);
>>>>> -    }
>>>>> -    /* map the last 128KB of the BIOS in ISA space */
>>>>> -    isa_bios_size = bios_size;
>>>>> -    if (isa_bios_size>    (128 * 1024))
>>>>> -        isa_bios_size = 128 * 1024;
>>>>> -    isa_bios = g_malloc(sizeof(*isa_bios));
>>>>> -    memory_region_init_alias(isa_bios, "isa-bios", bios,
>>>>> -                             bios_size - isa_bios_size, isa_bios_size);
>>>>> -    memory_region_add_subregion_overlap(rom_memory,
>>>>> -                                        0x100000 - isa_bios_size,
>>>>> -                                        isa_bios,
>>>>> -                                        1);
>>>>> -    memory_region_set_readonly(isa_bios, true);
>>>>> +
>>>>> +    /* Initialize ROM or flash ranges for PC firmware */
>>>>> +    pc_system_firmware_init(rom_memory, system_firmware_enabled);
>>>>>
>>>>>       option_rom_mr = g_malloc(sizeof(*option_rom_mr));
>>>>>       memory_region_init_ram(option_rom_mr, NULL, "pc.rom", PC_ROM_SIZE);
>>>>> @@ -1048,11 +1008,6 @@ void pc_memory_init(MemoryRegion *system_memory,
>>>>>                                           option_rom_mr,
>>>>>                                           1);
>>>>>
>>>>> -    /* map all the bios at the top of memory */
>>>>> -    memory_region_add_subregion(rom_memory,
>>>>> -                                (uint32_t)(-bios_size),
>>>>> -                                bios);
>>>>> -
>>>>>       fw_cfg = bochs_bios_init();
>>>>>       rom_set_fw(fw_cfg);
>>>>>
>>>>> diff --git a/hw/pc.h b/hw/pc.h
>>>>> index 49471cb..727e231 100644
>>>>> --- a/hw/pc.h
>>>>> +++ b/hw/pc.h
>>>>> @@ -246,6 +246,10 @@ static inline bool isa_ne2000_init(int base, int irq,
>>>>> NICInfo *nd)
>>>>>       return true;
>>>>>   }
>>>>>
>>>>> +/* pc_sysfw.c */
>>>>> +void pc_system_firmware_init(MemoryRegion *rom_memory,
>>>>> +                             int system_firmware_enabled);
>>>>> +
>>>>>   /* e820 types */
>>>>>   #define E820_RAM        1
>>>>>   #define E820_RESERVED   2
>>>>> diff --git a/hw/pc_sysfw.c b/hw/pc_sysfw.c
>>>>> new file mode 100644
>>>>> index 0000000..20027b2
>>>>> --- /dev/null
>>>>> +++ b/hw/pc_sysfw.c
>>>>> @@ -0,0 +1,255 @@
>>>>> +/*
>>>>> + * QEMU PC System Firmware
>>>>> + *
>>>>> + * Copyright (c) 2003-2004 Fabrice Bellard
>>>>> + * Copyright (c) 2011 Intel Corporation
>>>>> + *
>>>>> + * Permission is hereby granted, free of charge, to any person obtaining
>>>>> a copy
>>>>> + * of this software and associated documentation files (the "Software"),
>>>>> to deal
>>>>> + * in the Software without restriction, including without limitation the
>>>>> rights
>>>>> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or
>>>>> sell
>>>>> + * copies of the Software, and to permit persons to whom the Software is
>>>>> + * furnished to do so, subject to the following conditions:
>>>>> + *
>>>>> + * The above copyright notice and this permission notice shall be
>>>>> included in
>>>>> + * all copies or substantial portions of the Software.
>>>>> + *
>>>>> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
>>>>> EXPRESS OR
>>>>> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
>>>>> MERCHANTABILITY,
>>>>> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
>>>>> SHALL
>>>>> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
>>>>> OTHER
>>>>> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
>>>>> ARISING FROM,
>>>>> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
>>>>> IN
>>>>> + * THE SOFTWARE.
>>>>> + */
>>>>> +
>>>>> +#include "hw.h"
>>>>> +#include "pc.h"
>>>>> +#include "hw/boards.h"
>>>>> +#include "loader.h"
>>>>> +#include "sysemu.h"
>>>>> +#include "flash.h"
>>>>> +#include "kvm.h"
>>>>> +
>>>>> +#define BIOS_FILENAME "bios.bin"
>>>>> +
>>>>> +static void pc_isa_bios_init(MemoryRegion *rom_memory,
>>>>> +                             MemoryRegion *flash_mem,
>>>>> +                             int ram_size)
>>>>> +{
>>>>> +    int isa_bios_size;
>>>>> +    MemoryRegion *isa_bios;
>>>>> +    uint64_t flash_size;
>>>>> +    void *flash_ptr, *isa_bios_ptr;
>>>>> +
>>>>> +    flash_size = memory_region_size(flash_mem);
>>>>> +
>>>>> +    /* map the last 128KB of the BIOS in ISA space */
>>>>> +    isa_bios_size = flash_size;
>>>>> +    if (isa_bios_size>    (128 * 1024)) {
>>>>> +        isa_bios_size = 128 * 1024;
>>>>> +    }
>>>>> +    isa_bios = g_malloc(sizeof(*isa_bios));
>>>>> +    memory_region_init_ram(isa_bios, NULL, "isa-bios", isa_bios_size);
>>>>> +    memory_region_add_subregion_overlap(rom_memory,
>>>>> +                                        0x100000 - isa_bios_size,
>>>>> +                                        isa_bios,
>>>>> +                                        1);
>>>>> +
>>>>> +    /* copy ISA rom image from top of flash memory */
>>>>> +    flash_ptr = memory_region_get_ram_ptr(flash_mem);
>>>>> +    isa_bios_ptr = memory_region_get_ram_ptr(isa_bios);
>>>>> +    memcpy(isa_bios_ptr,
>>>>> +           ((uint8_t*)flash_ptr) + (flash_size - isa_bios_size),
>>>>> +           isa_bios_size);
>>>>> +
>>>>> +    memory_region_set_readonly(isa_bios, true);
>>>>> +}
>>>>> +
>>>>> +static void pc_fw_add_pflash_drv(void)
>>>>> +{
>>>>> +    QemuOpts *opts;
>>>>> +    QEMUMachine *machine;
>>>>> +    char *filename;
>>>>> +
>>>>> +    if (bios_name == NULL) {
>>>>> +        bios_name = BIOS_FILENAME;
>>>>> +    }
>>>>> +    filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
>>>>> +
>>>>> +    opts = drive_add(IF_PFLASH, -1, filename, "readonly=on");
>>>>> +    if (opts == NULL) {
>>>>> +      return;
>>>>> +    }
>>>>> +
>>>>> +    machine = find_default_machine();
>>>>> +    if (machine == NULL) {
>>>>> +      return;
>>>>> +    }
>>>>> +
>>>>> +    drive_init(opts, machine->use_scsi);
>>>>> +}
>>>>> +
>>>>> +static void pc_system_flash_init(MemoryRegion *rom_memory,
>>>>> +                                 DriveInfo *pflash_drv)
>>>>> +{
>>>>> +    BlockDriverState *bdrv;
>>>>> +    int64_t size;
>>>>> +    target_phys_addr_t phys_addr;
>>>>> +    int sector_bits, sector_size;
>>>>> +    pflash_t *system_flash;
>>>>> +    MemoryRegion *flash_mem;
>>>>> +
>>>>> +    bdrv = pflash_drv->bdrv;
>>>>> +    size = bdrv_getlength(pflash_drv->bdrv);
>>>>> +    sector_bits = 12;
>>>>> +    sector_size = 1<<    sector_bits;
>>>>> +
>>>>> +    if ((size % sector_size) != 0) {
>>>>> +        fprintf(stderr,
>>>>> +                "qemu: PC system firmware (pflash) must be a multiple of
>>>>> 0x%x\n",
>>>>> +                sector_size);
>>>>> +        exit(1);
>>>>> +    }
>>>>> +
>>>>> +    phys_addr = 0x100000000ULL - size;
>>>>> +    system_flash = pflash_cfi01_register(phys_addr, NULL, "system.flash",
>>>>> size,
>>>>> +                                         bdrv, sector_size, size>>
>>>>>   sector_bits,
>>>>> +                                         1, 0x0000, 0x0000, 0x0000,
>>>>> 0x0000, 0);
>>>>> +    flash_mem = pflash_cfi01_get_memory(system_flash);
>>>>> +
>>>>> +    pc_isa_bios_init(rom_memory, flash_mem, size);
>>>>> +}
>>>>> +
>>>>> +static void pc_system_rom_init(MemoryRegion *rom_memory,
>>>>> +                               DriveInfo *pflash_drv)
>>>>> +{
>>>>> +    BlockDriverState *bdrv;
>>>>> +    int64_t size;
>>>>> +    target_phys_addr_t phys_addr;
>>>>> +    int sector_bits, sector_size;
>>>>> +    MemoryRegion *sys_rom;
>>>>> +    void *buffer;
>>>>> +    int ret;
>>>>> +
>>>>> +    bdrv = pflash_drv->bdrv;
>>>>> +    size = bdrv_getlength(pflash_drv->bdrv);
>>>>> +    sector_bits = 9;
>>>>> +    sector_size = 1<<    sector_bits;
>>>>> +
>>>>> +    if ((size % sector_size) != 0) {
>>>>> +        fprintf(stderr,
>>>>> +                "qemu: PC system rom (pflash) must be a multiple of
>>>>> 0x%x\n",
>>>>> +                sector_size);
>>>>> +        exit(1);
>>>>> +    }
>>>>> +
>>>>> +    phys_addr = 0x100000000ULL - size;
>>>>> +    sys_rom = g_malloc(sizeof(*sys_rom));
>>>>> +    memory_region_init_ram(sys_rom, NULL, "system.rom", size);
>>>>> +    buffer = memory_region_get_ram_ptr(sys_rom);
>>>>> +    memory_region_add_subregion(rom_memory, phys_addr, sys_rom);
>>>>> +
>>>>> +    /* read the rom content */
>>>>> +    ret = bdrv_read(bdrv, 0, buffer, size>>    sector_bits);
>>>>
>>>>
>>>> I think we're trying to get rid of synchronous block I/O in machine
>>>> initialization for a number of reasons.
>>>>
>>>> Kevin/Stefan, care to comment?  Will this be problematic in the future?
>>>
>>> I was hoping pc-1.1 with and without kvm could be as close as
>>> possible, but I guess I can make pc-1.1 with kvm behave the same as
>>> pc-1.0.  Then I can delete pc_system_rom_init.
>>
>> I think your general approach is right, I'm just not sure what we're going 
>> to do
>> short term about synchronous I/O in the machine init routines.  It may just 
>> be a
>> matter of structuring this in such a way that you can use an async interface.
>
> I don't think there is a problem with using the synchronous interface
> here. But I'm not sure if having any I/O in the machine init is a good
> idea with respect to migration. Didn't we already have to move some code
> there to a later stage to make sure that the destination doesn't use
> outdated data?

Since the bdrv_read call seems to be the concern here, I noticed that
in hw/pflash_cfi01.c pflash_cfi01_register there is a call to
bdrv_read.  So, it seems like it is not possible to initialize a
pflash/cfi device without a bdrv_read call being made.

So, what should pflash/cfi be doing instead?  Should these devices
somehow hold off on initializing their contents from the drive until a
later stage?  If so, is there a later call into the devices before the
firmware is launched that could be used for this later initialization
step?

-Jordan