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Re: [Qemu-devel] [PATCH v4] hw/pc: Support system flash memory with -pfl
From: |
Jordan Justen |
Subject: |
Re: [Qemu-devel] [PATCH v4] hw/pc: Support system flash memory with -pflash parameter |
Date: |
Sat, 23 Jul 2011 17:18:11 -0700 |
On Sat, Jul 23, 2011 at 15:26, Anthony Liguori <address@hidden> wrote:
> On 07/23/2011 05:06 PM, Jordan Justen wrote:
>>
>> On Sat, Jul 23, 2011 at 14:25, Anthony Liguori<address@hidden>
>> wrote:
>>>
>>> On 07/23/2011 03:19 PM, Jordan Justen wrote:
>>>>
>>>> On Sat, Jul 23, 2011 at 08:51, Anthony Liguori<address@hidden>
>>>> wrote:
>>>>>
>>>>> On 07/08/2011 02:37 PM, Jordan Justen wrote:
>>>>>>
>>>>>> If -pflash is specified and -bios is specified then pflash will
>>>>>> be mapped just below the system rom using hw/pflash_cfi01.c.
>>>>>>
>>>>>> If -pflash is specified on the command line, but -bios is
>>>>>> not specified, then 'bios.bin' will NOT be loaded, and
>>>>>> instead the -pflash flash image will be mapped just below
>>>>>> 4GB in place of the normal rom image.
>>>>>
>>>>> This is way too tied to the pc platform to be this generic.
>>>>>
>>>>> I think a better approach would be to default to having unit=0 of
>>>>> IF_PFLASH
>>>>> default to a read-only BDS that points to bios.bin. -bios would just
>>>>> be
>>>>> a
>>>>> short cut to use a different file name but you should be able to
>>>>> override
>>>>> with -drive too.
>>>>>
>>>>> And to really simplify things, you could add a readonly flag to -bios
>>>>> such
>>>>> that you could do:
>>>>>
>>>>> -bios foo.img,readonly=off
>>>>>
>>>>> Which is what I think you're looking for semantically.
>>>>
>>>> There seemed to be some feedback on the list interested in preserving
>>>> a read-only firmware, and just adding a flash region.
>>>>
>>>> So, for example, the firmware could be read from a common system
>>>> location like is generally done with bios.bin today, and VM instance
>>>> specific flash region could still be added.
>>>
>>> You can have multiple flash regions.
>>
>> So, is your recommendation that we support N pflash images in
>> x86/x86-64? Instance/index 0 is mapped just under 4GB, and the rest
>> follow below this?
>
> No. There should be a flash device, pflash index 0 is fine, but it should
> be mapped under 4GB and also in the legacy BIOS space.
>
> This is the PC firmware flash. By default it should be read-only and it
> should be created by using ${prefix}/share/bios.bin. But it should be
> possible to override both the filename and the read-only flag.
>
> In terms of other flash devices, I don't think it's that simple. Flash is
> tied to the mobo layout so I don't think index > 0 really makes sense unless
> you allow a specific mapping address. I doubt that's terribly useful.
I think VM's have a different situation than real hardware. I'm not
sure an all ROM or all flash decision will work well for qemu. In
most cases it may work better to make a ROM image available just below
4GB, and add a flash image below this ROM.
This allows the qemu's firmware to be updated as usual in
${prefix}/share/bios.bin, but still allows a flash memory to be
available below this. (The flash below the ROM could be used only for
storing UEFI variables.)
Otherwise when a new qemu is released along with a new firmware image,
the VM instance using writable flash will continue to use the old
firmware image.
-Jordan
>
> Regards,
>
> Anthony Liguori
>
>>
>> This seems like a good plan, although I can't see a usage for more
>> than 2 instances.
>>
>> -Jordan
>>
>>> You're introducing two modes. In one mode, we emulate a flash device and
>>> expose it for the BIOS ROM. In the second mode, we don't emulate a
>>> device
>>> but we expose the BIOS ROM based on a file in a shared read-only
>>> location.
>>>
>>> I'm suggesting always emulating a flash device, but by default make the
>>> device read-only and have it be loaded from a file in a shared read-only
>>> location.
>>>
>>> That means we have a single code path and a consistent view from a
>>> management tooling perspective. IOW, management tools will always see
>>> that
>>> there is a BIOS block device, and they need to worry about making sure
>>> that
>>> BIOS block device is there.
>>>
>>>>
>>>> If the entire firmware is moved to a separate VM instance specific
>>>> flash, then firmware update also gets complicated. It is no longer
>>>> just a matter of updating the qemu firmware package in your distro's
>>>> package management system.
>>>
>>> I think the bit your misunderstanding is that you should default the
>>> firmware to be created from a common file as a read-only device.
>>>
>>> Regards,
>>>
>>> Anthony Liguori
>>>
>>>>
>>>> What about taking your idea, but adding a second drive that would be
>>>> mapped just below the 1st if it is specified with -drive?
>>>>
>>>> Thanks,
>>>>
>>>> -Jordan
>>>>
>>>>>
>>>>> Regards,
>>>>>
>>>>> Anthony Liguori
>>>>>
>>>>>>
>>>>>> Signed-off-by: Jordan Justen<address@hidden>
>>>>>> Reviewed-by: Aurelien Jarno<address@hidden>
>>>>>
>>>>>
>>>>>
>>>>>> ---
>>>>>> default-configs/i386-softmmu.mak | 1 +
>>>>>> default-configs/x86_64-softmmu.mak | 1 +
>>>>>> hw/pc.c | 161
>>>>>> +++++++++++++++++++++++++++---------
>>>>>> 3 files changed, 125 insertions(+), 38 deletions(-)
>>>>>>
>>>>>> diff --git a/default-configs/i386-softmmu.mak
>>>>>> b/default-configs/i386-softmmu.mak
>>>>>> index 55589fa..8697cd4 100644
>>>>>> --- a/default-configs/i386-softmmu.mak
>>>>>> +++ b/default-configs/i386-softmmu.mak
>>>>>> @@ -21,3 +21,4 @@ CONFIG_PIIX_PCI=y
>>>>>> CONFIG_SOUND=y
>>>>>> CONFIG_HPET=y
>>>>>> CONFIG_APPLESMC=y
>>>>>> +CONFIG_PFLASH_CFI01=y
>>>>>> diff --git a/default-configs/x86_64-softmmu.mak
>>>>>> b/default-configs/x86_64-softmmu.mak
>>>>>> index 8895028..eca9284 100644
>>>>>> --- a/default-configs/x86_64-softmmu.mak
>>>>>> +++ b/default-configs/x86_64-softmmu.mak
>>>>>> @@ -21,3 +21,4 @@ CONFIG_PIIX_PCI=y
>>>>>> CONFIG_SOUND=y
>>>>>> CONFIG_HPET=y
>>>>>> CONFIG_APPLESMC=y
>>>>>> +CONFIG_PFLASH_CFI01=y
>>>>>> diff --git a/hw/pc.c b/hw/pc.c
>>>>>> index a3e8539..e25354f 100644
>>>>>> --- a/hw/pc.c
>>>>>> +++ b/hw/pc.c
>>>>>> @@ -41,6 +41,7 @@
>>>>>> #include "sysemu.h"
>>>>>> #include "blockdev.h"
>>>>>> #include "ui/qemu-spice.h"
>>>>>> +#include "flash.h"
>>>>>>
>>>>>> /* output Bochs bios info messages */
>>>>>> //#define DEBUG_BIOS
>>>>>> @@ -957,70 +958,154 @@ void pc_cpus_init(const char *cpu_model)
>>>>>> }
>>>>>> }
>>>>>>
>>>>>> -void pc_memory_init(const char *kernel_filename,
>>>>>> - const char *kernel_cmdline,
>>>>>> - const char *initrd_filename,
>>>>>> - ram_addr_t below_4g_mem_size,
>>>>>> - ram_addr_t above_4g_mem_size)
>>>>>> +static void pc_isa_bios_init(ram_addr_t ram_offset, int ram_size)
>>>>>> {
>>>>>> - char *filename;
>>>>>> - int ret, linux_boot, i;
>>>>>> - ram_addr_t ram_addr, bios_offset, option_rom_offset;
>>>>>> - int bios_size, isa_bios_size;
>>>>>> - void *fw_cfg;
>>>>>> -
>>>>>> - linux_boot = (kernel_filename != NULL);
>>>>>> + int isa_bios_size;
>>>>>>
>>>>>> - /* allocate RAM */
>>>>>> - ram_addr = qemu_ram_alloc(NULL, "pc.ram",
>>>>>> - below_4g_mem_size + above_4g_mem_size);
>>>>>> - cpu_register_physical_memory(0, 0xa0000, ram_addr);
>>>>>> - cpu_register_physical_memory(0x100000,
>>>>>> - below_4g_mem_size - 0x100000,
>>>>>> - ram_addr + 0x100000);
>>>>>> - if (above_4g_mem_size> 0) {
>>>>>> - cpu_register_physical_memory(0x100000000ULL,
>>>>>> above_4g_mem_size,
>>>>>> - ram_addr + below_4g_mem_size);
>>>>>> + /* map the last 128KB of the BIOS in ISA space */
>>>>>> + isa_bios_size = ram_size;
>>>>>> + if (isa_bios_size> (128 * 1024)) {
>>>>>> + isa_bios_size = 128 * 1024;
>>>>>> }
>>>>>> + ram_offset = ram_offset + ram_size - isa_bios_size;
>>>>>> + cpu_register_physical_memory(0x100000 - isa_bios_size,
>>>>>> + isa_bios_size,
>>>>>> + ram_offset | IO_MEM_ROM);
>>>>>> +}
>>>>>> +
>>>>>> +static int pc_system_rom_init(void)
>>>>>> +{
>>>>>> + int ret;
>>>>>> + int bios_size;
>>>>>> + ram_addr_t bios_offset;
>>>>>> + char *filename;
>>>>>>
>>>>>> /* BIOS load */
>>>>>> - if (bios_name == NULL)
>>>>>> + 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;
>>>>>> +
>>>>>> + if (bios_size<= 0 || (bios_size % 65536) != 0) {
>>>>>> + ret = -1;
>>>>>> + } else {
>>>>>> + bios_offset = qemu_ram_alloc(NULL, "pc.bios", bios_size);
>>>>>> + ret = rom_add_file_fixed(bios_name, (uint32_t)(-bios_size),
>>>>>> -1);
>>>>>> }
>>>>>> - bios_offset = qemu_ram_alloc(NULL, "pc.bios", bios_size);
>>>>>> - 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) {
>>>>>> qemu_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;
>>>>>> - cpu_register_physical_memory(0x100000 - isa_bios_size,
>>>>>> - isa_bios_size,
>>>>>> - (bios_offset + bios_size -
>>>>>> isa_bios_size) | IO_MEM_ROM);
>>>>>>
>>>>>> - option_rom_offset = qemu_ram_alloc(NULL, "pc.rom", PC_ROM_SIZE);
>>>>>> - cpu_register_physical_memory(PC_ROM_MIN_VGA, PC_ROM_SIZE,
>>>>>> option_rom_offset);
>>>>>> + pc_isa_bios_init(bios_offset, bios_size);
>>>>>>
>>>>>> /* map all the bios at the top of memory */
>>>>>> cpu_register_physical_memory((uint32_t)(-bios_size),
>>>>>> bios_size, bios_offset |
>>>>>> IO_MEM_ROM);
>>>>>>
>>>>>> + return bios_size;
>>>>>> +}
>>>>>> +
>>>>>> +static void pc_system_flash_init(DriveInfo *pflash_drv, int rom_size)
>>>>>> +{
>>>>>> + BlockDriverState *bdrv;
>>>>>> + int64_t size;
>>>>>> + target_phys_addr_t phys_addr;
>>>>>> + ram_addr_t addr;
>>>>>> + int sector_bits, sector_size;
>>>>>> +
>>>>>> + bdrv = NULL;
>>>>>> +
>>>>>> + 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: -pflash size must be a multiple of 0x%x\n",
>>>>>> + sector_size);
>>>>>> + exit(1);
>>>>>> + }
>>>>>> +
>>>>>> + phys_addr = 0x100000000ULL - rom_size - size;
>>>>>> + addr = qemu_ram_alloc(NULL, "system.flash", size);
>>>>>> + DPRINTF("flash addr: 0x%lx\n", (int64_t)phys_addr);
>>>>>> + pflash_cfi01_register(phys_addr, addr, bdrv,
>>>>>> + sector_size, size>> sector_bits,
>>>>>> + 4, 0x0000, 0x0000, 0x0000, 0x0000, 0);
>>>>>> +
>>>>>> + if (rom_size == 0) {
>>>>>> + pc_isa_bios_init(addr, size);
>>>>>> + }
>>>>>> +}
>>>>>> +
>>>>>> +static void pc_system_firmware_init(void)
>>>>>> +{
>>>>>> + int flash_present, rom_present;
>>>>>> + int rom_size;
>>>>>> + DriveInfo *pflash_drv;
>>>>>> +
>>>>>> + pflash_drv = drive_get(IF_PFLASH, 0, 0);
>>>>>> + flash_present = (pflash_drv != NULL);
>>>>>> +
>>>>>> + /* Load rom if -bios is used or if -pflash is not used */
>>>>>> + rom_present = ((bios_name != NULL) || !flash_present);
>>>>>> +
>>>>>> + /* If rom is present, then it is mapped just below 4GB */
>>>>>> + if (rom_present) {
>>>>>> + rom_size = pc_system_rom_init();
>>>>>> + } else {
>>>>>> + rom_size = 0;
>>>>>> + }
>>>>>> +
>>>>>> + /* If flash is present, then it is mapped just below the rom, or
>>>>>> + * just below 4GB when rom is not present. */
>>>>>> + if (flash_present) {
>>>>>> + pc_system_flash_init(pflash_drv, rom_size);
>>>>>> + }
>>>>>> +}
>>>>>> +
>>>>>> +void pc_memory_init(const char *kernel_filename,
>>>>>> + const char *kernel_cmdline,
>>>>>> + const char *initrd_filename,
>>>>>> + ram_addr_t below_4g_mem_size,
>>>>>> + ram_addr_t above_4g_mem_size)
>>>>>> +{
>>>>>> + int linux_boot, i;
>>>>>> + ram_addr_t ram_addr, option_rom_offset;
>>>>>> + void *fw_cfg;
>>>>>> +
>>>>>> + linux_boot = (kernel_filename != NULL);
>>>>>> +
>>>>>> + /* allocate RAM */
>>>>>> + ram_addr = qemu_ram_alloc(NULL, "pc.ram",
>>>>>> + below_4g_mem_size + above_4g_mem_size);
>>>>>> + cpu_register_physical_memory(0, 0xa0000, ram_addr);
>>>>>> + cpu_register_physical_memory(0x100000,
>>>>>> + below_4g_mem_size - 0x100000,
>>>>>> + ram_addr + 0x100000);
>>>>>> + if (above_4g_mem_size> 0) {
>>>>>> + cpu_register_physical_memory(0x100000000ULL,
>>>>>> above_4g_mem_size,
>>>>>> + ram_addr + below_4g_mem_size);
>>>>>> + }
>>>>>> +
>>>>>> + /* Initialize ROM or flash ranges for PC firmware */
>>>>>> + pc_system_firmware_init();
>>>>>> +
>>>>>> + option_rom_offset = qemu_ram_alloc(NULL, "pc.rom", PC_ROM_SIZE);
>>>>>> + cpu_register_physical_memory(PC_ROM_MIN_VGA, PC_ROM_SIZE,
>>>>>> option_rom_offset);
>>>>>> +
>>>>>> fw_cfg = bochs_bios_init();
>>>>>> rom_set_fw(fw_cfg);
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>
>>>
>>
>
>