Re: [Qemu-devel] [PATCH 10/10] S390: Enabling device and program selection

[Alexander Graf]

On 26.04.2013, at 19:55, Dominik Dingel wrote:

> On Fri, 26 Apr 2013 18:56:44 +0200
> Alexander Graf <address@hidden> wrote:
> 
>> 
>> On 26.04.2013, at 14:12, Dominik Dingel wrote:
>> 
>>> Pass the eboot device info and the loadparm in register 7 and 8.
>>> Use this values in the BIOS to directly boot the respective
>>> operating system.
>>> 
>>> Signed-off-by: Dominik Dingel <address@hidden>
>>> 
>>> diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
>>> index 36daa67..960ba71 100644
>>> --- a/hw/s390x/ipl.c
>>> +++ b/hw/s390x/ipl.c
>>> @@ -77,6 +77,10 @@ static void s390_ipl_from_disk(VirtIOBlkCcw *dev, 
>>> uint64_t pswaddr)
>>>    env->psw.addr = pswaddr;
>>>    env->psw.mask = IPL_PSW_MASK;
>>>    env->regs[7] = ccw_dev->sch->devno;
>>> +    env->regs[7] = (env->regs[7] << 16) | (ccw_dev->sch->schid);
>>> +    env->regs[7] = (env->regs[7] << 8) | (ccw_dev->sch->cssid);
>>> +    env->regs[7] = (env->regs[7] << 8) | (ccw_dev->sch->ssid);
>>> +    env->regs[8] = ccw_dev->loadparm;
>>>    s390_add_running_cpu(cpu);
>>> }
>>> 
>>> diff --git a/pc-bios/s390-ccw.img b/pc-bios/s390-ccw.img
>>> index 
>>> b549a86e55194bbf54e25f839e52b490ac308260..fe8d2c6b9f5d937ea156084f7eb248b17e1fa89c
>>>  100644
>>> GIT binary patch
>>> literal 17528
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>>> 
>>> literal 9432
>>> zcmeHNZ){W76+h25c_s<r5hCiA2yP;address@hidden&Zm~|TsaUfPhLLGxp
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>>> address@hidden&pG$p-#z!-_iTS}TVHP=pi#91Xc^jyp%=r23g7f-XG&3%Zl(q@
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>>> zeu2Wf{-s7wSm%hI)address@hidden(i8Po$ZXg+R(E(A0)address@hidden|f7
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>>> z8v(U0>{#iHo8<gFU&LNSkSIg+Jn98&address@hidden
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>>> zxS(;zE3iZD+|address@hidden@lM8;>(A#2rD_6`ed~W5IUZe<9l;@P(lll|k#}_`<c%o^d
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>>> address@hidden>1%nj27mVd
>>> address@hidden>*zRR+=*4g|Q<SGaW4Cr+J&F2f9f3Lmbp+}Nd{G2A5%V1t
>>> z+<address@hidden(pEd$x(b%*c^rt3^+&JJuua
>>> zKR7V3wr5}W+Wp!7k%1wR#k0>?W^_cX+pvD)SG&address@hidden
>>> zquBnjF^Y|h<_2R2M~=kyAIS`-*Jjcb%Z{e|bNv(>9NKpv+ka?q-%vXHX^&z9qlfrO
>>> zsoIFKPqAIed&j;g2CUzN>OW?vD_$>xqY9pjR0;d{Sfx+ZOAL%9sQfI%MO~+O-l`N)
>>> address@hidden@u+WC_4t1<{^hT((ecXvOz?F?zM>address@hidden(e|4JYC>7*wZsZj5E!dC|M
>>> z{bklVRDb;yeeZuKMBe{UFrH(<no>address@hidden))PTyCh)fd3rkv9FyU??zSqxG&(*
>>> zj<c0M-tDd_{(MaDM)muj)qk&|Re5x)+VJI>a;<p`s>address@hidden
>>> 
>>> diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
>>> index 53a460d..9cd3edf 100644
>>> --- a/pc-bios/s390-ccw/bootmap.c
>>> +++ b/pc-bios/s390-ccw/bootmap.c
>>> @@ -173,7 +173,7 @@ fail:
>>>    return -1;
>>> }
>>> 
>>> -int zipl_load(void)
>>> +int zipl_load(uint64_t load_parm)
>>> {
>>>    struct mbr *mbr = (void*)sec;
>>>    uint8_t *ns, *ns_end;
>>> @@ -223,7 +223,7 @@ int zipl_load(void)
>>> 
>>>    /* Run the default entry */
>>> 
>>> -    prog_table_entry = (struct scsi_blockptr *)(sec + pte_len);
>>> +    prog_table_entry = (struct scsi_blockptr *)(sec + (pte_len 
>>> *(1+load_parm)));
>>> 
>>>    return zipl_run(prog_table_entry);
>>> 
>>> diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c
>>> index fd40fa5..0c1c11c 100644
>>> --- a/pc-bios/s390-ccw/main.c
>>> +++ b/pc-bios/s390-ccw/main.c
>>> @@ -20,7 +20,7 @@ void virtio_panic(const char *string)
>>>    while (1) { }
>>> }
>>> 
>>> -static void virtio_setup(void)
>>> +static void virtio_setup(uint16_t dev_no)
>>> {
>>>    struct schib schib;
>>>    int i;
>>> @@ -35,7 +35,7 @@ static void virtio_setup(void)
>>>        if (r == 3) {
>>>            break;
>>>        }
>>> -        if (schib.pmcw.dnv) {
>>> +        if (schib.pmcw.dnv && (schib.pmcw.dev == dev_no)) {
>> 
>> What if I have no dev_no passed in? We need to support the mode where the 
>> user doesn't specify any device he wants to boot from.
> 
> There is actually no code path where you would boot the BIOS and at the 
> sametime have no device passed in.

If we drop patch 1 there is will be.

> 
>> 
>>>            if (virtio_is_blk(blk_schid)) {
>>>                found = true;
>>>                break;
>>> @@ -52,10 +52,24 @@ static void virtio_setup(void)
>>> 
>>> int main(void)
>>> {
>>> +    uint64_t boot_value;
>>> +    uint64_t load_parm;
>>> +    register uint64_t reg7 asm("7");
>>> +    register uint64_t reg8 asm("8");
>>> +    
>>> +    asm volatile(
>>> +            "   stg     %2, %0\n"
>>> +            "   stg     %3, %1\n"
>>> +            : "=m" (boot_value), "=m" (load_parm)
>>> +            : "d" (reg7), "d" (reg8)
>>> +            : "cc");
>> 
>> What is this for? If you have a local register variable, won't that value 
>> get saved automatically?
> 
> It's a real verbose way to say here in this register we have the boot 
> parameter stored in... And my confidence in understanding local register 
> variables is not so that I would hope to get it perfectly right.

Then grab yourself someone who knows :).


Alex