Re: [PATCH V2 1/1] loongarch: Change the UEFI loading mode to loongarch

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 19/2/24 11:34, Xianglai Li wrote:
> The UEFI loading mode in loongarch is very different
> from that in other architectures:loongarch's UEFI code
> is in rom, while other architectures' UEFI code is in flash.
> 
> loongarch UEFI can be loaded as follows:
> -machine virt,pflash=pflash0-format
> -bios ./QEMU_EFI.fd
> 
> Other architectures load UEFI using the following methods:
> -machine virt,pflash0=pflash0-format,pflash1=pflash1-format
> 
> loongarch's UEFI loading method makes qemu and libvirt incompatible
> when using NVRAM, and the cost of loongarch's current loading method
> far outweighs the benefits, so we decided to use the same UEFI loading
> scheme as other architectures.

This is unfortunate, since LoongArch was a fresh new target added,
we had the possibility to make this right. Are you saying libvirt
didn't accept to add support for the correct HW behavior which is
to simply load a ROM instead of a PNOR flash device? Could you
point me to the libvirt discussion please? libvirt is very good at
supporting a broad range of legacy options, so I'm surprise 'Doing
The Right Thing' is too costly.

What is really the problem here, is it your use of the the -bios
CLI option?

Thanks,

Phil.

> Cc: Andrea Bolognani <abologna@redhat.com>
> Cc: maobibo@loongson.cn
> Cc: Philippe Mathieu-Daudé <philmd@linaro.org>
> Cc: Song Gao <gaosong@loongson.cn>
> Cc: zhaotianrui@loongson.cn
> Signed-off-by: Xianglai Li <lixianglai@loongson.cn>
> Tested-by: Andrea Bolognani <abologna@redhat.com>
> ---
>   hw/loongarch/acpi-build.c   |  29 +++++++++--
>   hw/loongarch/virt.c         | 101 ++++++++++++++++++++++++++----------
>   include/hw/loongarch/virt.h |  10 ++--
>   3 files changed, 107 insertions(+), 33 deletions(-)
> 
> diff --git a/hw/loongarch/acpi-build.c b/hw/loongarch/acpi-build.c
> index a1c4198741..6c75f216ea 100644
> --- a/hw/loongarch/acpi-build.c
> +++ b/hw/loongarch/acpi-build.c
> @@ -314,16 +314,39 @@ static void build_pci_device_aml(Aml *scope, LoongArchMachineState *lams)
>   static void build_flash_aml(Aml *scope, LoongArchMachineState *lams)
>   {
>       Aml *dev, *crs;
> +    MemoryRegion *flash_mem;
>   
> -    hwaddr flash_base = VIRT_FLASH_BASE;
> -    hwaddr flash_size = VIRT_FLASH_SIZE;
> +    hwaddr flash0_base;
> +    hwaddr flash0_size;
> +
> +    hwaddr flash1_base;
> +    hwaddr flash1_size;
> +
> +    flash_mem = pflash_cfi01_get_memory(lams->flash[0]);
> +    flash0_base = flash_mem->addr;
> +    flash0_size = flash_mem->size;
> +
> +    flash_mem = pflash_cfi01_get_memory(lams->flash[1]);
> +    flash1_base = flash_mem->addr;
> +    flash1_size = flash_mem->size;
>   
>       dev = aml_device("FLS0");
>       aml_append(dev, aml_name_decl("_HID", aml_string("LNRO0015")));
>       aml_append(dev, aml_name_decl("_UID", aml_int(0)));
>   
>       crs = aml_resource_template();
> -    aml_append(crs, aml_memory32_fixed(flash_base, flash_size, AML_READ_WRITE));
> +    aml_append(crs, aml_memory32_fixed(flash0_base, flash0_size,
> +                                       AML_READ_WRITE));
> +    aml_append(dev, aml_name_decl("_CRS", crs));
> +    aml_append(scope, dev);
> +
> +    dev = aml_device("FLS1");
> +    aml_append(dev, aml_name_decl("_HID", aml_string("LNRO0015")));
> +    aml_append(dev, aml_name_decl("_UID", aml_int(1)));
> +
> +    crs = aml_resource_template();
> +    aml_append(crs, aml_memory32_fixed(flash1_base, flash1_size,
> +                                       AML_READ_WRITE));
>       aml_append(dev, aml_name_decl("_CRS", crs));
>       aml_append(scope, dev);
>   }
> diff --git a/hw/loongarch/virt.c b/hw/loongarch/virt.c
> index 0ad7d8c887..a7b9199e70 100644
> --- a/hw/loongarch/virt.c
> +++ b/hw/loongarch/virt.c
> @@ -54,7 +54,9 @@ struct loaderparams {
>       const char *initrd_filename;
>   };
>   
> -static void virt_flash_create(LoongArchMachineState *lams)
> +static PFlashCFI01 *virt_flash_create1(LoongArchMachineState *lams,
> +                                       const char *name,
> +                                       const char *alias_prop_name)
>   {
>       DeviceState *dev = qdev_new(TYPE_PFLASH_CFI01);
>   
> @@ -66,45 +68,78 @@ static void virt_flash_create(LoongArchMachineState *lams)
>       qdev_prop_set_uint16(dev, "id1", 0x18);
>       qdev_prop_set_uint16(dev, "id2", 0x00);
>       qdev_prop_set_uint16(dev, "id3", 0x00);
> -    qdev_prop_set_string(dev, "name", "virt.flash");
> -    object_property_add_child(OBJECT(lams), "virt.flash", OBJECT(dev));
> -    object_property_add_alias(OBJECT(lams), "pflash",
> +    qdev_prop_set_string(dev, "name", name);
> +    object_property_add_child(OBJECT(lams), name, OBJECT(dev));
> +    object_property_add_alias(OBJECT(lams), alias_prop_name,
>                                 OBJECT(dev), "drive");
> +    return PFLASH_CFI01(dev);
> +}
>   
> -    lams->flash = PFLASH_CFI01(dev);
> +static void virt_flash_create(LoongArchMachineState *lams)
> +{
> +    lams->flash[0] = virt_flash_create1(lams, "virt.flash0", "pflash0");
> +    lams->flash[1] = virt_flash_create1(lams, "virt.flash1", "pflash1");
>   }
>   
> -static void virt_flash_map(LoongArchMachineState *lams,
> -                           MemoryRegion *sysmem)
> +static void virt_flash_map1(PFlashCFI01 *flash,
> +                            hwaddr base, hwaddr size,
> +                            MemoryRegion *sysmem)
>   {
> -    PFlashCFI01 *flash = lams->flash;
>       DeviceState *dev = DEVICE(flash);
> -    hwaddr base = VIRT_FLASH_BASE;
> -    hwaddr size = VIRT_FLASH_SIZE;
> +    BlockBackend *blk;
> +    hwaddr real_size = size;
> +
> +    blk = pflash_cfi01_get_blk(flash);
> +    if (blk) {
> +        real_size = blk_getlength(blk);
> +        assert(real_size && real_size <= size);
> +    }
>   
> -    assert(QEMU_IS_ALIGNED(size, VIRT_FLASH_SECTOR_SIZE));
> -    assert(size / VIRT_FLASH_SECTOR_SIZE <= UINT32_MAX);
> +    assert(QEMU_IS_ALIGNED(real_size, VIRT_FLASH_SECTOR_SIZE));
> +    assert(real_size / VIRT_FLASH_SECTOR_SIZE <= UINT32_MAX);
>   
> -    qdev_prop_set_uint32(dev, "num-blocks", size / VIRT_FLASH_SECTOR_SIZE);
> +    qdev_prop_set_uint32(dev, "num-blocks", real_size / VIRT_FLASH_SECTOR_SIZE);
>       sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
>       memory_region_add_subregion(sysmem, base,
>                                   sysbus_mmio_get_region(SYS_BUS_DEVICE(dev), 0));
> +}
>   
> +static void virt_flash_map(LoongArchMachineState *lams,
> +                           MemoryRegion *sysmem)
> +{
> +    PFlashCFI01 *flash0 = lams->flash[0];
> +    PFlashCFI01 *flash1 = lams->flash[1];
> +
> +    virt_flash_map1(flash0, VIRT_FLASH0_BASE, VIRT_FLASH0_SIZE, sysmem);
> +    virt_flash_map1(flash1, VIRT_FLASH1_BASE, VIRT_FLASH1_SIZE, sysmem);
>   }
>   
>   static void fdt_add_flash_node(LoongArchMachineState *lams)
>   {
>       MachineState *ms = MACHINE(lams);
>       char *nodename;
> +    MemoryRegion *flash_mem;
> +
> +    hwaddr flash0_base;
> +    hwaddr flash0_size;
>   
> -    hwaddr flash_base = VIRT_FLASH_BASE;
> -    hwaddr flash_size = VIRT_FLASH_SIZE;
> +    hwaddr flash1_base;
> +    hwaddr flash1_size;
>   
> -    nodename = g_strdup_printf("/flash@%" PRIx64, flash_base);
> +    flash_mem = pflash_cfi01_get_memory(lams->flash[0]);
> +    flash0_base = flash_mem->addr;
> +    flash0_size = flash_mem->size;
> +
> +    flash_mem = pflash_cfi01_get_memory(lams->flash[1]);
> +    flash1_base = flash_mem->addr;
> +    flash1_size = flash_mem->size;
> +
> +    nodename = g_strdup_printf("/flash@%" PRIx64, flash0_base);
>       qemu_fdt_add_subnode(ms->fdt, nodename);
>       qemu_fdt_setprop_string(ms->fdt, nodename, "compatible", "cfi-flash");
>       qemu_fdt_setprop_sized_cells(ms->fdt, nodename, "reg",
> -                                 2, flash_base, 2, flash_size);
> +                                 2, flash0_base, 2, flash0_size,
> +                                 2, flash1_base, 2, flash1_size);
>       qemu_fdt_setprop_cell(ms->fdt, nodename, "bank-width", 4);
>       g_free(nodename);
>   }
> @@ -637,12 +672,32 @@ static void loongarch_firmware_init(LoongArchMachineState *lams)
>   {
>       char *filename = MACHINE(lams)->firmware;
>       char *bios_name = NULL;
> -    int bios_size;
> +    int bios_size, i;
> +    BlockBackend *pflash_blk0;
> +    MemoryRegion *mr;
>   
>       lams->bios_loaded = false;
>   
> +    /* Map legacy -drive if=pflash to machine properties */
> +    for (i = 0; i < ARRAY_SIZE(lams->flash); i++) {
> +        pflash_cfi01_legacy_drive(lams->flash[i],
> +                                  drive_get(IF_PFLASH, 0, i));
> +    }
> +
>       virt_flash_map(lams, get_system_memory());
>   
> +    pflash_blk0 = pflash_cfi01_get_blk(lams->flash[0]);
> +
> +    if (pflash_blk0) {
> +        if (filename) {
> +            error_report("cannot use both '-bios' and '-drive if=pflash'"
> +                         "options at once");
> +            exit(1);
> +        }
> +        lams->bios_loaded = true;
> +        return;
> +    }
> +
>       if (filename) {
>           bios_name = qemu_find_file(QEMU_FILE_TYPE_BIOS, filename);
>           if (!bios_name) {
> @@ -650,21 +705,15 @@ static void loongarch_firmware_init(LoongArchMachineState *lams)
>               exit(1);
>           }
>   
> -        bios_size = load_image_targphys(bios_name, VIRT_BIOS_BASE, VIRT_BIOS_SIZE);
> +        mr = sysbus_mmio_get_region(SYS_BUS_DEVICE(lams->flash[0]), 0);
> +        bios_size = load_image_mr(bios_name, mr);
>           if (bios_size < 0) {
>               error_report("Could not load ROM image '%s'", bios_name);
>               exit(1);
>           }
> -
>           g_free(bios_name);
> -
> -        memory_region_init_ram(&lams->bios, NULL, "loongarch.bios",
> -                               VIRT_BIOS_SIZE, &error_fatal);
> -        memory_region_set_readonly(&lams->bios, true);
> -        memory_region_add_subregion(get_system_memory(), VIRT_BIOS_BASE, &lams->bios);
>           lams->bios_loaded = true;
>       }
> -
>   }
>   
>   static void reset_load_elf(void *opaque)
> diff --git a/include/hw/loongarch/virt.h b/include/hw/loongarch/virt.h
> index 6ef9a92394..252f7df7f4 100644
> --- a/include/hw/loongarch/virt.h
> +++ b/include/hw/loongarch/virt.h
> @@ -18,10 +18,12 @@
>   
>   #define VIRT_FWCFG_BASE         0x1e020000UL
>   #define VIRT_BIOS_BASE          0x1c000000UL
> -#define VIRT_BIOS_SIZE          (4 * MiB)
> +#define VIRT_BIOS_SIZE          (16 * MiB)
>   #define VIRT_FLASH_SECTOR_SIZE  (128 * KiB)
> -#define VIRT_FLASH_BASE         0x1d000000UL
> -#define VIRT_FLASH_SIZE         (16 * MiB)
> +#define VIRT_FLASH0_BASE        VIRT_BIOS_BASE
> +#define VIRT_FLASH0_SIZE        VIRT_BIOS_SIZE
> +#define VIRT_FLASH1_BASE        0x1d000000UL
> +#define VIRT_FLASH1_SIZE        (16 * MiB)
>   
>   #define VIRT_LOWMEM_BASE        0
>   #define VIRT_LOWMEM_SIZE        0x10000000
> @@ -49,7 +51,7 @@ struct LoongArchMachineState {
>       int          fdt_size;
>       DeviceState *platform_bus_dev;
>       PCIBus       *pci_bus;
> -    PFlashCFI01  *flash;
> +    PFlashCFI01  *flash[2];
>       MemoryRegion system_iocsr;
>       MemoryRegion iocsr_mem;
>       AddressSpace as_iocsr;