Re: [PATCH v3 3/5] pc-bios: s390x: Use reset PSW if avaliable

2020-09-02 Thread Thomas Huth 
On 02/09/2020 10.46, Janosch Frank wrote:
> On 9/1/20 6:59 PM, Thomas Huth wrote:
>> On 31/08/2020 17.09, Janosch Frank wrote:
>>> If a blob provides a reset PSW then we should use it instead of
>>> branching to the PSW address and using our own mask.
>>>
>>> Signed-off-by: Janosch Frank 
>>> ---
>>>  pc-bios/s390-ccw/bootmap.c  |  3 ++-
>>>  pc-bios/s390-ccw/jump2ipl.c | 22 +-
>>>  pc-bios/s390-ccw/s390-ccw.h |  1 +
>>>  3 files changed, 20 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
>>> index 8747c4ea26..5a03b1eb8b 100644
>>> --- a/pc-bios/s390-ccw/bootmap.c
>>> +++ b/pc-bios/s390-ccw/bootmap.c
>>> @@ -515,7 +515,8 @@ static void zipl_run(ScsiBlockPtr *pte)
>>>  IPL_assert(entry->component_type == ZIPL_COMP_ENTRY_EXEC, "No EXEC 
>>> entry");
>>>  
>>>  /* should not return */
>>> -jump_to_IPL_code(entry->compdat.load_psw & PSW_MASK_SHORT_ADDR);
>>> +write_reset_psw(entry->compdat.load_psw);
>>> +jump_to_IPL_code(0);
>>>  }
>>>  
>>>  static void ipl_scsi(void)
>>> diff --git a/pc-bios/s390-ccw/jump2ipl.c b/pc-bios/s390-ccw/jump2ipl.c
>>> index b6aad32def..5b8352d257 100644
>>> --- a/pc-bios/s390-ccw/jump2ipl.c
>>> +++ b/pc-bios/s390-ccw/jump2ipl.c
>>> @@ -12,15 +12,21 @@
>>>  
>>>  #define KERN_IMAGE_START 0x01UL
>>>  #define RESET_PSW_MASK (PSW_MASK_SHORTPSW | PSW_MASK_64)
>>> +#define RESET_PSW ((uint64_t)_to_IPL_addr | RESET_PSW_MASK)
>>>  
>>>  static uint64_t *reset_psw = 0, save_psw, ipl_continue;
>>>  
>>> +void write_reset_psw(uint64_t psw)
>>> +{
>>> +*reset_psw = psw;
>>> +}
>>> +
>>>  static void jump_to_IPL_addr(void)
>>>  {
>>>  __attribute__((noreturn)) void (*ipl)(void) = (void *)ipl_continue;
>>>  
>>>  /* Restore reset PSW */
>>> -*reset_psw = save_psw;
>>> +write_reset_psw(save_psw);
>>>  
>>>  ipl();
>>>  /* should not return */
>>> @@ -43,9 +49,10 @@ void jump_to_IPL_code(uint64_t address)
>>>   * content of non-BIOS memory after we loaded the guest, so we
>>>   * save the original content and restore it in jump_to_IPL_2.
>>>   */
>>> -save_psw = *reset_psw;
>>> -*reset_psw = (uint64_t) _to_IPL_addr;
>>> -*reset_psw |= RESET_PSW_MASK;
>>> +if (address) {
>>> +save_psw = *reset_psw;
>>> +write_reset_psw(RESET_PSW);
>>> +}
>>>  ipl_continue = address;
>>>  debug_print_int("set IPL addr to", ipl_continue);
>>
>> In case you respin this series, I think I'd move the "ipl_continue =
>> address" into the if-statement, too, and change the debug_print_int line
>> to use address instead of ipl_continue.
> 
> Hmm, my intention was to always have something printed.
> But I guess it would make more sense to print the reset psw addr in the
> ~address case.

I meant to only move the "ipl_continue = address" line and keep the
debug_print_int() at its current place (you just have to replace
ipl_continue there). But you're right, it would make more sense to print
the PSW at address 0 in that case instead.

 Thomas

Re: [PATCH v3 3/5] pc-bios: s390x: Use reset PSW if avaliable

2020-09-02 Thread Janosch Frank 
On 9/1/20 6:59 PM, Thomas Huth wrote:
> On 31/08/2020 17.09, Janosch Frank wrote:
>> If a blob provides a reset PSW then we should use it instead of
>> branching to the PSW address and using our own mask.
>>
>> Signed-off-by: Janosch Frank 
>> ---
>>  pc-bios/s390-ccw/bootmap.c  |  3 ++-
>>  pc-bios/s390-ccw/jump2ipl.c | 22 +-
>>  pc-bios/s390-ccw/s390-ccw.h |  1 +
>>  3 files changed, 20 insertions(+), 6 deletions(-)
>>
>> diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
>> index 8747c4ea26..5a03b1eb8b 100644
>> --- a/pc-bios/s390-ccw/bootmap.c
>> +++ b/pc-bios/s390-ccw/bootmap.c
>> @@ -515,7 +515,8 @@ static void zipl_run(ScsiBlockPtr *pte)
>>  IPL_assert(entry->component_type == ZIPL_COMP_ENTRY_EXEC, "No EXEC 
>> entry");
>>  
>>  /* should not return */
>> -jump_to_IPL_code(entry->compdat.load_psw & PSW_MASK_SHORT_ADDR);
>> +write_reset_psw(entry->compdat.load_psw);
>> +jump_to_IPL_code(0);
>>  }
>>  
>>  static void ipl_scsi(void)
>> diff --git a/pc-bios/s390-ccw/jump2ipl.c b/pc-bios/s390-ccw/jump2ipl.c
>> index b6aad32def..5b8352d257 100644
>> --- a/pc-bios/s390-ccw/jump2ipl.c
>> +++ b/pc-bios/s390-ccw/jump2ipl.c
>> @@ -12,15 +12,21 @@
>>  
>>  #define KERN_IMAGE_START 0x01UL
>>  #define RESET_PSW_MASK (PSW_MASK_SHORTPSW | PSW_MASK_64)
>> +#define RESET_PSW ((uint64_t)_to_IPL_addr | RESET_PSW_MASK)
>>  
>>  static uint64_t *reset_psw = 0, save_psw, ipl_continue;
>>  
>> +void write_reset_psw(uint64_t psw)
>> +{
>> +*reset_psw = psw;
>> +}
>> +
>>  static void jump_to_IPL_addr(void)
>>  {
>>  __attribute__((noreturn)) void (*ipl)(void) = (void *)ipl_continue;
>>  
>>  /* Restore reset PSW */
>> -*reset_psw = save_psw;
>> +write_reset_psw(save_psw);
>>  
>>  ipl();
>>  /* should not return */
>> @@ -43,9 +49,10 @@ void jump_to_IPL_code(uint64_t address)
>>   * content of non-BIOS memory after we loaded the guest, so we
>>   * save the original content and restore it in jump_to_IPL_2.
>>   */
>> -save_psw = *reset_psw;
>> -*reset_psw = (uint64_t) _to_IPL_addr;
>> -*reset_psw |= RESET_PSW_MASK;
>> +if (address) {
>> +save_psw = *reset_psw;
>> +write_reset_psw(RESET_PSW);
>> +}
>>  ipl_continue = address;
>>  debug_print_int("set IPL addr to", ipl_continue);
> 
> In case you respin this series, I think I'd move the "ipl_continue =
> address" into the if-statement, too, and change the debug_print_int line
> to use address instead of ipl_continue.

Hmm, my intention was to always have something printed.
But I guess it would make more sense to print the reset psw addr in the
~address case.


> 
>> @@ -77,7 +84,12 @@ void jump_to_low_kernel(void)
>>  
>>  /* Trying to get PSW at zero address */
>>  if (*((uint64_t *)0) & RESET_PSW_MASK) {
>> -jump_to_IPL_code((*((uint64_t *)0)) & PSW_MASK_SHORT_ADDR);
>> +/*
>> + * Surely nobody will try running directly from lowcore, so
>> + * let's use 0 as an indication that we want to load the reset
>> + * psw at 0x0 and not jump to the entry.
>> + */
>> +jump_to_IPL_code(0);
>>  }
>>  
>>  /* No other option left, so use the Linux kernel start address */
>> diff --git a/pc-bios/s390-ccw/s390-ccw.h b/pc-bios/s390-ccw/s390-ccw.h
>> index 36b884cced..7090720422 100644
>> --- a/pc-bios/s390-ccw/s390-ccw.h
>> +++ b/pc-bios/s390-ccw/s390-ccw.h
>> @@ -78,6 +78,7 @@ int virtio_read(ulong sector, void *load_addr);
>>  void zipl_load(void);
>>  
>>  /* jump2ipl.c */
>> +void write_reset_psw(uint64_t psw);
>>  void jump_to_IPL_code(uint64_t address);
>>  void jump_to_low_kernel(void);
> 
> Looks sane to me:
> 
> Reviewed-by: Thomas Huth 
> 
> 




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Re: [PATCH v3 3/5] pc-bios: s390x: Use reset PSW if avaliable

2020-09-01 Thread Thomas Huth 
On 31/08/2020 17.09, Janosch Frank wrote:
> If a blob provides a reset PSW then we should use it instead of
> branching to the PSW address and using our own mask.
> 
> Signed-off-by: Janosch Frank 
> ---
>  pc-bios/s390-ccw/bootmap.c  |  3 ++-
>  pc-bios/s390-ccw/jump2ipl.c | 22 +-
>  pc-bios/s390-ccw/s390-ccw.h |  1 +
>  3 files changed, 20 insertions(+), 6 deletions(-)
> 
> diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
> index 8747c4ea26..5a03b1eb8b 100644
> --- a/pc-bios/s390-ccw/bootmap.c
> +++ b/pc-bios/s390-ccw/bootmap.c
> @@ -515,7 +515,8 @@ static void zipl_run(ScsiBlockPtr *pte)
>  IPL_assert(entry->component_type == ZIPL_COMP_ENTRY_EXEC, "No EXEC 
> entry");
>  
>  /* should not return */
> -jump_to_IPL_code(entry->compdat.load_psw & PSW_MASK_SHORT_ADDR);
> +write_reset_psw(entry->compdat.load_psw);
> +jump_to_IPL_code(0);
>  }
>  
>  static void ipl_scsi(void)
> diff --git a/pc-bios/s390-ccw/jump2ipl.c b/pc-bios/s390-ccw/jump2ipl.c
> index b6aad32def..5b8352d257 100644
> --- a/pc-bios/s390-ccw/jump2ipl.c
> +++ b/pc-bios/s390-ccw/jump2ipl.c
> @@ -12,15 +12,21 @@
>  
>  #define KERN_IMAGE_START 0x01UL
>  #define RESET_PSW_MASK (PSW_MASK_SHORTPSW | PSW_MASK_64)
> +#define RESET_PSW ((uint64_t)_to_IPL_addr | RESET_PSW_MASK)
>  
>  static uint64_t *reset_psw = 0, save_psw, ipl_continue;
>  
> +void write_reset_psw(uint64_t psw)
> +{
> +*reset_psw = psw;
> +}
> +
>  static void jump_to_IPL_addr(void)
>  {
>  __attribute__((noreturn)) void (*ipl)(void) = (void *)ipl_continue;
>  
>  /* Restore reset PSW */
> -*reset_psw = save_psw;
> +write_reset_psw(save_psw);
>  
>  ipl();
>  /* should not return */
> @@ -43,9 +49,10 @@ void jump_to_IPL_code(uint64_t address)
>   * content of non-BIOS memory after we loaded the guest, so we
>   * save the original content and restore it in jump_to_IPL_2.
>   */
> -save_psw = *reset_psw;
> -*reset_psw = (uint64_t) _to_IPL_addr;
> -*reset_psw |= RESET_PSW_MASK;
> +if (address) {
> +save_psw = *reset_psw;
> +write_reset_psw(RESET_PSW);
> +}
>  ipl_continue = address;
>  debug_print_int("set IPL addr to", ipl_continue);

In case you respin this series, I think I'd move the "ipl_continue =
address" into the if-statement, too, and change the debug_print_int line
to use address instead of ipl_continue.

> @@ -77,7 +84,12 @@ void jump_to_low_kernel(void)
>  
>  /* Trying to get PSW at zero address */
>  if (*((uint64_t *)0) & RESET_PSW_MASK) {
> -jump_to_IPL_code((*((uint64_t *)0)) & PSW_MASK_SHORT_ADDR);
> +/*
> + * Surely nobody will try running directly from lowcore, so
> + * let's use 0 as an indication that we want to load the reset
> + * psw at 0x0 and not jump to the entry.
> + */
> +jump_to_IPL_code(0);
>  }
>  
>  /* No other option left, so use the Linux kernel start address */
> diff --git a/pc-bios/s390-ccw/s390-ccw.h b/pc-bios/s390-ccw/s390-ccw.h
> index 36b884cced..7090720422 100644
> --- a/pc-bios/s390-ccw/s390-ccw.h
> +++ b/pc-bios/s390-ccw/s390-ccw.h
> @@ -78,6 +78,7 @@ int virtio_read(ulong sector, void *load_addr);
>  void zipl_load(void);
>  
>  /* jump2ipl.c */
> +void write_reset_psw(uint64_t psw);
>  void jump_to_IPL_code(uint64_t address);
>  void jump_to_low_kernel(void);

Looks sane to me:

Reviewed-by: Thomas Huth

[PATCH v3 3/5] pc-bios: s390x: Use reset PSW if avaliable

2020-08-31 Thread Janosch Frank 
If a blob provides a reset PSW then we should use it instead of
branching to the PSW address and using our own mask.

Signed-off-by: Janosch Frank 
---
 pc-bios/s390-ccw/bootmap.c  |  3 ++-
 pc-bios/s390-ccw/jump2ipl.c | 22 +-
 pc-bios/s390-ccw/s390-ccw.h |  1 +
 3 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
index 8747c4ea26..5a03b1eb8b 100644
--- a/pc-bios/s390-ccw/bootmap.c
+++ b/pc-bios/s390-ccw/bootmap.c
@@ -515,7 +515,8 @@ static void zipl_run(ScsiBlockPtr *pte)
 IPL_assert(entry->component_type == ZIPL_COMP_ENTRY_EXEC, "No EXEC entry");
 
 /* should not return */
-jump_to_IPL_code(entry->compdat.load_psw & PSW_MASK_SHORT_ADDR);
+write_reset_psw(entry->compdat.load_psw);
+jump_to_IPL_code(0);
 }
 
 static void ipl_scsi(void)
diff --git a/pc-bios/s390-ccw/jump2ipl.c b/pc-bios/s390-ccw/jump2ipl.c
index b6aad32def..5b8352d257 100644
--- a/pc-bios/s390-ccw/jump2ipl.c
+++ b/pc-bios/s390-ccw/jump2ipl.c
@@ -12,15 +12,21 @@
 
 #define KERN_IMAGE_START 0x01UL
 #define RESET_PSW_MASK (PSW_MASK_SHORTPSW | PSW_MASK_64)
+#define RESET_PSW ((uint64_t)_to_IPL_addr | RESET_PSW_MASK)
 
 static uint64_t *reset_psw = 0, save_psw, ipl_continue;
 
+void write_reset_psw(uint64_t psw)
+{
+*reset_psw = psw;
+}
+
 static void jump_to_IPL_addr(void)
 {
 __attribute__((noreturn)) void (*ipl)(void) = (void *)ipl_continue;
 
 /* Restore reset PSW */
-*reset_psw = save_psw;
+write_reset_psw(save_psw);
 
 ipl();
 /* should not return */
@@ -43,9 +49,10 @@ void jump_to_IPL_code(uint64_t address)
  * content of non-BIOS memory after we loaded the guest, so we
  * save the original content and restore it in jump_to_IPL_2.
  */
-save_psw = *reset_psw;
-*reset_psw = (uint64_t) _to_IPL_addr;
-*reset_psw |= RESET_PSW_MASK;
+if (address) {
+save_psw = *reset_psw;
+write_reset_psw(RESET_PSW);
+}
 ipl_continue = address;
 debug_print_int("set IPL addr to", ipl_continue);
 
@@ -77,7 +84,12 @@ void jump_to_low_kernel(void)
 
 /* Trying to get PSW at zero address */
 if (*((uint64_t *)0) & RESET_PSW_MASK) {
-jump_to_IPL_code((*((uint64_t *)0)) & PSW_MASK_SHORT_ADDR);
+/*
+ * Surely nobody will try running directly from lowcore, so
+ * let's use 0 as an indication that we want to load the reset
+ * psw at 0x0 and not jump to the entry.
+ */
+jump_to_IPL_code(0);
 }
 
 /* No other option left, so use the Linux kernel start address */
diff --git a/pc-bios/s390-ccw/s390-ccw.h b/pc-bios/s390-ccw/s390-ccw.h
index 36b884cced..7090720422 100644
--- a/pc-bios/s390-ccw/s390-ccw.h
+++ b/pc-bios/s390-ccw/s390-ccw.h
@@ -78,6 +78,7 @@ int virtio_read(ulong sector, void *load_addr);
 void zipl_load(void);
 
 /* jump2ipl.c */
+void write_reset_psw(uint64_t psw);
 void jump_to_IPL_code(uint64_t address);
 void jump_to_low_kernel(void);
 
-- 
2.25.1