[Qemu-devel] Re: [PATCH 27/27] Add SLOF-based partition firmware for pSeries machine, allowing more boot options

[Paolo Bonzini <pbonzini@redhat.com>]

On 03/28/2011 12:30 PM, Alexander Graf wrote:
>
> On 25.03.2011, at 04:21, David Gibson wrote:
>
>> Currently, the emulated pSeries machine requires the use of the
>> -kernel parameter in order to explicitly load a guest kernel.  This
>> means booting from the virtual disk, cdrom or network is not possible.
>>
>> This patch addresses this limitation by inserting a within-partition
>> firmware image (derived from the "SLOF" free Open Firmware project).
>> If -kernel is not specified, qemu will now load the SLOF image, which
>> has access to the qemu boot device list through the device tree, and
>> can boot from any of the usual virtual devices.
>>
>> In order to support the new firmware, an extension to the emulated
>> machine/hypervisor is necessary.  Unlike Linux, which expects
>> multi-CPU entry to be handled kexec() style, the SLOF firmware expects
>> only one CPU to be active at entry, and to use a hypervisor RTAS
>> method to enable the other CPUs one by one.
>>
>> This patch also implements this 'start-cpu' method, so that SLOF can
>> start the secondary CPUs and marshal them into the kexec() holding
>> pattern ready for entry into the guest OS.  Linux should, and in the
>> future might directly use the start-cpu method to enable initially
>> disabled CPUs, but for now it does require kexec() entry.
>>
>> Signed-off-by: Benjamin Herrenschmidt<benh@kernel.crashing.org>
>> Signed-off-by: Paul Mackerras<paulus@samba.org>
>> Signed-off-by: David Gibson<dwg@au1.ibm.com>
>> ---
>> Makefile         |    2 +-
>> hw/spapr.c       |   35 +++++++++++++++++++++---
>> hw/spapr_rtas.c  |   78 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>> pc-bios/README   |    5 +++
>> pc-bios/slof.bin |  Bin 0 ->  579072 bytes
>> 5 files changed, 115 insertions(+), 5 deletions(-)
>> create mode 100644 pc-bios/slof.bin
>>
>> diff --git a/Makefile b/Makefile
>> index e0b3fea..989622b 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -214,7 +214,7 @@ pxe-rtl8139.bin pxe-virtio.bin \
>> bamboo.dtb petalogix-s3adsp1800.dtb petalogix-ml605.dtb \
>> multiboot.bin linuxboot.bin \
>> s390-zipl.rom \
>> -spapr-rtas.bin
>> +spapr-rtas.bin slof.bin
>> else
>> BLOBS=
>> endif
>> diff --git a/hw/spapr.c b/hw/spapr.c
>> index 9d611a7..c6454e6 100644
>> --- a/hw/spapr.c
>> +++ b/hw/spapr.c
>> @@ -44,6 +44,10 @@
>> #define INITRD_LOAD_ADDR        0x02800000
>> #define FDT_MAX_SIZE            0x10000
>> #define RTAS_MAX_SIZE           0x10000
>> +#define FW_MAX_SIZE             0x400000
>> +#define FW_FILE_NAME            "slof.bin"
>> +
>> +#define MIN_RAM_SLOF		512UL
>>
>> #define TIMEBASE_FREQ           512000000ULL
>>
>> @@ -56,6 +60,7 @@ static void *spapr_create_fdt(int *fdt_size, ram_addr_t ramsize,
>>                                sPAPREnvironment *spapr,
>>                                target_phys_addr_t initrd_base,
>>                                target_phys_addr_t initrd_size,
>> +                              const char *boot_device,
>>                                const char *kernel_cmdline,
>>                                target_phys_addr_t rtas_addr,
>>                                target_phys_addr_t rtas_size,
>> @@ -104,6 +109,7 @@ static void *spapr_create_fdt(int *fdt_size, ram_addr_t ramsize,
>>                         &start_prop, sizeof(start_prop))));
>>      _FDT((fdt_property(fdt, "linux,initrd-end",
>>                         &end_prop, sizeof(end_prop))));
>> +    _FDT((fdt_property_string(fdt, "qemu,boot-device", boot_device)));
>>
>>      _FDT((fdt_end_node(fdt)));
>>
>> @@ -260,7 +266,7 @@ static void ppc_spapr_init(ram_addr_t ram_size,
>>      ram_addr_t ram_offset;
>>      target_phys_addr_t fdt_addr, rtas_addr;
>>      uint32_t kernel_base, initrd_base;
>> -    long kernel_size, initrd_size, htab_size, rtas_size;
>> +    long kernel_size, initrd_size, htab_size, rtas_size, fw_size;
>>      long pteg_shift = 17;
>>      int fdt_size;
>>      char *filename;
>> @@ -392,13 +398,33 @@ static void ppc_spapr_init(ram_addr_t ram_size,
>>              initrd_size = 0;
>>          }
>>      } else {
>> -        fprintf(stderr, "pSeries machine needs -kernel for now");
>> -        exit(1);
>> +        if (ram_size<  (MIN_RAM_SLOF<<  20)) {
>> +            fprintf(stderr, "qemu: pSeries SLOF firmware requires>= "
>> +                    "%ldM guest RAM\n", MIN_RAM_SLOF);
>> +            exit(1);
>> +        }
>> +        filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, "slof.bin");
>> +        fw_size = load_image_targphys(filename, 0, FW_MAX_SIZE);
>> +        if (fw_size<  0) {
>> +            hw_error("qemu: could not load LPAR rtas '%s'\n", filename);
>> +            exit(1);
>> +        }
>> +        qemu_free(filename);
>> +        kernel_base = 0x100;
>> +        initrd_base = 0;
>> +        initrd_size = 0;
>> +
>> +        /* SLOF will startup the secondary CPUs using RTAS,
>> +           rather than expecting a kexec() style entry */
>> +        for (i = 0; i<  smp_cpus; i++) {
>> +            envs[i]->halted = 1;
>> +        }
>>      }
>>
>>      /* Prepare the device tree */
>>      fdt = spapr_create_fdt(&fdt_size, ram_size, cpu_model, envs, spapr,
>> -                           initrd_base, initrd_size, kernel_cmdline,
>> +                           initrd_base, initrd_size,
>> +                           boot_device, kernel_cmdline,
>>                             rtas_addr, rtas_size, pteg_shift + 7);
>>      assert(fdt != NULL);
>>
>> @@ -409,6 +435,7 @@ static void ppc_spapr_init(ram_addr_t ram_size,
>>      envs[0]->gpr[3] = fdt_addr;
>>      envs[0]->gpr[5] = 0;
>>      envs[0]->hreset_vector = kernel_base;
>> +    envs[0]->halted = 0;
>> }
>>
>> static QEMUMachine spapr_machine = {
>> diff --git a/hw/spapr_rtas.c b/hw/spapr_rtas.c
>> index 7226853..16b6542 100644
>> --- a/hw/spapr_rtas.c
>> +++ b/hw/spapr_rtas.c
>> @@ -90,6 +90,81 @@ static void rtas_power_off(sPAPREnvironment *spapr,
>>      rtas_st(rets, 0, 0);
>> }
>>
>> +static void rtas_query_cpu_stopped_state(sPAPREnvironment *spapr,
>> +                                         uint32_t token, uint32_t nargs,
>> +                                         target_ulong args,
>> +                                         uint32_t nret, target_ulong rets)
>> +{
>> +    target_ulong id;
>> +    CPUState *env;
>> +
>> +    if (nargs != 1 || nret != 2) {
>> +        rtas_st(rets, 0, -3);
>> +        return;
>> +    }
>> +
>> +    id = rtas_ld(args, 0);
>> +    for (env = first_cpu; env; env = env->next_cpu) {
>> +        if (env->cpu_index != id) {
>> +            continue;
>> +        }
>> +
>> +        if (env->halted) {
>> +            rtas_st(rets, 1, 0);
>> +        } else {
>> +            rtas_st(rets, 1, 2);
>> +        }
>> +
>> +        rtas_st(rets, 0, 0);
>> +        return;
>> +    }
>> +
>> +    /* Didn't find a matching cpu */
>> +    rtas_st(rets, 0, -3);
>> +}
>> +
>> +static void rtas_start_cpu(sPAPREnvironment *spapr,
>> +                           uint32_t token, uint32_t nargs,
>> +                           target_ulong args,
>> +                           uint32_t nret, target_ulong rets)
>> +{
>> +    target_ulong id, start, r3;
>> +    CPUState *env;
>> +
>> +    if (nargs != 3 || nret != 1) {
>> +        rtas_st(rets, 0, -3);
>> +        return;
>> +    }
>> +
>> +    id = rtas_ld(args, 0);
>> +    start = rtas_ld(args, 1);
>> +    r3 = rtas_ld(args, 2);
>> +
>> +    for (env = first_cpu; env; env = env->next_cpu) {
>> +        if (env->cpu_index != id) {
>> +            continue;
>> +        }
>> +
>> +        if (!env->halted) {
>> +            rtas_st(rets, 0, -1);
>> +            return;
>> +        }
>> +
>> +        env->msr = (1ULL<<  MSR_SF) | (1ULL<<  MSR_ME);
>> +        env->nip = start;
>> +        env->gpr[3] = r3;
>> +        env->halted = 0;
>> +
>> +        qemu_cpu_kick(env);
>> +
>> +        rtas_st(rets, 0, 0);
>> +        return;
>> +    }
>> +
>> +    /* Didn't find a matching cpu */
>> +    rtas_st(rets, 0, -3);
>> +}
>> +
>> static struct rtas_call {
>>      const char *name;
>>      spapr_rtas_fn fn;
>> @@ -196,5 +271,8 @@ static void register_core_rtas(void)
>>      spapr_rtas_register("display-character", rtas_display_character);
>>      spapr_rtas_register("get-time-of-day", rtas_get_time_of_day);
>>      spapr_rtas_register("power-off", rtas_power_off);
>> +    spapr_rtas_register("query-cpu-stopped-state",
>> +                        rtas_query_cpu_stopped_state);
>> +    spapr_rtas_register("start-cpu", rtas_start_cpu);
>> }
>> device_init(register_core_rtas);
>> diff --git a/pc-bios/README b/pc-bios/README
>> index 3fc0944..646a31a 100644
>> --- a/pc-bios/README
>> +++ b/pc-bios/README
>> @@ -13,6 +13,11 @@
>>    The included image for PowerPC (for 32 and 64 bit PPC CPUs), Sparc32
>>    and Sparc64 are built from OpenBIOS SVN revision 1018.
>>
>> +- SLOF (Slimline Open Firmware) is a free IEEE 1275 Open Firmware
>> +  implementation for certain IBM POWER hardware.  The sources are at
>> +  https://github.com/dgibson/SLOF, and the image currently in qemu is
>> +  built from git tag qemu-slof-20110323.
>> +
>> - The PXE roms come from Rom-o-Matic gPXE 0.9.9 with BANNER_TIMEOUT=0
>
> Is this a line removal?

No, it's a bug in your mailer. :)

Glad to see Thunderbird isn't the only one that butcher replies to 
patches (in addition to patches of course).

Paolo