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  3. [PATCH 00/11] hw/mips/loongson3: Remove uses of &first_cpu global
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[PATCH 02/11] hw/mips/loongson3_virt: Keep reference of vCPUs in machine_init()

Philippe Mathieu-Daudé posted 11 patches 1 year ago
There is a newer version of this series
[PATCH 02/11] hw/mips/loongson3_virt: Keep reference of vCPUs in machine_init()
Posted by Philippe Mathieu-Daudé 1 year ago 
Keep references of all vCPUs created. That allows
to directly access the first vCPU without using the
&first_cpu global.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 hw/mips/loongson3_virt.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/hw/mips/loongson3_virt.c b/hw/mips/loongson3_virt.c
index 47d112981a2..4b19941c1dc 100644
--- a/hw/mips/loongson3_virt.c
+++ b/hw/mips/loongson3_virt.c
@@ -492,9 +492,8 @@ static void mips_loongson3_virt_init(MachineState *machine)
 {
     int i;
     long bios_size;
-    MIPSCPU *cpu;
+    g_autofree MIPSCPU **cpus = NULL;
     Clock *cpuclk;
-    CPUMIPSState *env;
     DeviceState *liointc;
     DeviceState *ipi = NULL;
     char *filename;
@@ -569,13 +568,16 @@ static void mips_loongson3_virt_init(MachineState *machine)
     cpuclk = clock_new(OBJECT(machine), "cpu-refclk");
     clock_set_hz(cpuclk, DEF_LOONGSON3_FREQ);
 
+    cpus = g_new(MIPSCPU *, machine->smp.cpus);
     for (i = 0; i < machine->smp.cpus; i++) {
+        MIPSCPU *cpu;
         int node = i / LOONGSON3_CORE_PER_NODE;
         int core = i % LOONGSON3_CORE_PER_NODE;
         int ip;
 
         /* init CPUs */
         cpu = mips_cpu_create_with_clock(machine->cpu_type, cpuclk, false);
+        cpus[i] = cpu;
 
         /* Init internal devices */
         cpu_mips_irq_init_cpu(cpu);
@@ -609,7 +611,6 @@ static void mips_loongson3_virt_init(MachineState *machine)
                                pin, cpu->env.irq[ip + 2]);
         }
     }
-    env = &MIPS_CPU(first_cpu)->env;
 
     /* Allocate RAM/BIOS, 0x00000000~0x10000000 is alias of 0x80000000~0x90000000 */
     memory_region_init_rom(bios, NULL, "loongson3.bios",
@@ -640,7 +641,7 @@ static void mips_loongson3_virt_init(MachineState *machine)
         loaderparams.kernel_filename = kernel_filename;
         loaderparams.kernel_cmdline = kernel_cmdline;
         loaderparams.initrd_filename = initrd_filename;
-        loaderparams.kernel_entry = load_kernel(env);
+        loaderparams.kernel_entry = load_kernel(&cpus[0]->env);
 
         init_boot_rom();
         init_boot_param();
-- 
2.47.1
Re: [PATCH 02/11] hw/mips/loongson3_virt: Keep reference of vCPUs in machine_init()
Posted by Richard Henderson 1 year ago 
On 1/12/25 13:58, Philippe Mathieu-Daudé wrote:
> Keep references of all vCPUs created. That allows
> to directly access the first vCPU without using the
> &first_cpu global.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>   hw/mips/loongson3_virt.c | 9 +++++----
>   1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/mips/loongson3_virt.c b/hw/mips/loongson3_virt.c
> index 47d112981a2..4b19941c1dc 100644
> --- a/hw/mips/loongson3_virt.c
> +++ b/hw/mips/loongson3_virt.c
> @@ -492,9 +492,8 @@ static void mips_loongson3_virt_init(MachineState *machine)
>   {
>       int i;
>       long bios_size;
> -    MIPSCPU *cpu;
> +    g_autofree MIPSCPU **cpus = NULL;
>       Clock *cpuclk;
> -    CPUMIPSState *env;
>       DeviceState *liointc;
>       DeviceState *ipi = NULL;
>       char *filename;
> @@ -569,13 +568,16 @@ static void mips_loongson3_virt_init(MachineState *machine)
>       cpuclk = clock_new(OBJECT(machine), "cpu-refclk");
>       clock_set_hz(cpuclk, DEF_LOONGSON3_FREQ);
>   
> +    cpus = g_new(MIPSCPU *, machine->smp.cpus);
>       for (i = 0; i < machine->smp.cpus; i++) {
> +        MIPSCPU *cpu;
>           int node = i / LOONGSON3_CORE_PER_NODE;
>           int core = i % LOONGSON3_CORE_PER_NODE;
>           int ip;
>   
>           /* init CPUs */
>           cpu = mips_cpu_create_with_clock(machine->cpu_type, cpuclk, false);
> +        cpus[i] = cpu;
>   
>           /* Init internal devices */
>           cpu_mips_irq_init_cpu(cpu);
> @@ -609,7 +611,6 @@ static void mips_loongson3_virt_init(MachineState *machine)
>                                  pin, cpu->env.irq[ip + 2]);
>           }
>       }
> -    env = &MIPS_CPU(first_cpu)->env;
>   
>       /* Allocate RAM/BIOS, 0x00000000~0x10000000 is alias of 0x80000000~0x90000000 */
>       memory_region_init_rom(bios, NULL, "loongson3.bios",
> @@ -640,7 +641,7 @@ static void mips_loongson3_virt_init(MachineState *machine)
>           loaderparams.kernel_filename = kernel_filename;
>           loaderparams.kernel_cmdline = kernel_cmdline;
>           loaderparams.initrd_filename = initrd_filename;
> -        loaderparams.kernel_entry = load_kernel(env);
> +        loaderparams.kernel_entry = load_kernel(&cpus[0]->env);
We only ever use cpu[0].  We don't really need the whole array.


r~
Re: [PATCH 02/11] hw/mips/loongson3_virt: Keep reference of vCPUs in machine_init()
Posted by Philippe Mathieu-Daudé 1 year ago 
On 15/1/25 06:18, Richard Henderson wrote:
> On 1/12/25 13:58, Philippe Mathieu-Daudé wrote:
>> Keep references of all vCPUs created. That allows
>> to directly access the first vCPU without using the
>> &first_cpu global.
>>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>> ---
>>   hw/mips/loongson3_virt.c | 9 +++++----
>>   1 file changed, 5 insertions(+), 4 deletions(-)
>>
>> diff --git a/hw/mips/loongson3_virt.c b/hw/mips/loongson3_virt.c
>> index 47d112981a2..4b19941c1dc 100644
>> --- a/hw/mips/loongson3_virt.c
>> +++ b/hw/mips/loongson3_virt.c
>> @@ -492,9 +492,8 @@ static void mips_loongson3_virt_init(MachineState 
>> *machine)
>>   {
>>       int i;
>>       long bios_size;
>> -    MIPSCPU *cpu;
>> +    g_autofree MIPSCPU **cpus = NULL;
>>       Clock *cpuclk;
>> -    CPUMIPSState *env;
>>       DeviceState *liointc;
>>       DeviceState *ipi = NULL;
>>       char *filename;
>> @@ -569,13 +568,16 @@ static void 
>> mips_loongson3_virt_init(MachineState *machine)
>>       cpuclk = clock_new(OBJECT(machine), "cpu-refclk");
>>       clock_set_hz(cpuclk, DEF_LOONGSON3_FREQ);
>> +    cpus = g_new(MIPSCPU *, machine->smp.cpus);
>>       for (i = 0; i < machine->smp.cpus; i++) {
>> +        MIPSCPU *cpu;
>>           int node = i / LOONGSON3_CORE_PER_NODE;
>>           int core = i % LOONGSON3_CORE_PER_NODE;
>>           int ip;
>>           /* init CPUs */
>>           cpu = mips_cpu_create_with_clock(machine->cpu_type, cpuclk, 
>> false);
>> +        cpus[i] = cpu;
>>           /* Init internal devices */
>>           cpu_mips_irq_init_cpu(cpu);
>> @@ -609,7 +611,6 @@ static void mips_loongson3_virt_init(MachineState 
>> *machine)
>>                                  pin, cpu->env.irq[ip + 2]);
>>           }
>>       }
>> -    env = &MIPS_CPU(first_cpu)->env;
>>       /* Allocate RAM/BIOS, 0x00000000~0x10000000 is alias of 
>> 0x80000000~0x90000000 */
>>       memory_region_init_rom(bios, NULL, "loongson3.bios",
>> @@ -640,7 +641,7 @@ static void mips_loongson3_virt_init(MachineState 
>> *machine)
>>           loaderparams.kernel_filename = kernel_filename;
>>           loaderparams.kernel_cmdline = kernel_cmdline;
>>           loaderparams.initrd_filename = initrd_filename;
>> -        loaderparams.kernel_entry = load_kernel(env);
>> +        loaderparams.kernel_entry = load_kernel(&cpus[0]->env);

> We only ever use cpu[0].  We don't really need the whole array.

Yes. What about:

-- >8 --
commit ffc8c8873c0c102457f0e660437874555b022cc2
Author: Philippe Mathieu-Daudé <philmd@linaro.org>
Date:   Sun Jan 12 21:01:24 2025 +0100

     hw/mips/loongson3_virt: Invert vCPU creation order to remove &first_cpu

     Create vCPUs from the last one to the first one.
     No need to use the &first_cpu global since we already
     have it referenced.

     Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

diff --git a/hw/mips/loongson3_virt.c b/hw/mips/loongson3_virt.c
index 47d112981a2..488eba495cd 100644
--- a/hw/mips/loongson3_virt.c
+++ b/hw/mips/loongson3_virt.c
@@ -496,3 +496,2 @@ static void mips_loongson3_virt_init(MachineState 
*machine)
      Clock *cpuclk;
-    CPUMIPSState *env;
      DeviceState *liointc;
@@ -571,3 +570,3 @@ static void mips_loongson3_virt_init(MachineState 
*machine)

-    for (i = 0; i < machine->smp.cpus; i++) {
+    for (i = machine->smp.cpus - 1; i >= 0; --i) {
          int node = i / LOONGSON3_CORE_PER_NODE;
@@ -611,3 +610,2 @@ static void mips_loongson3_virt_init(MachineState 
*machine)
      }
-    env = &MIPS_CPU(first_cpu)->env;

@@ -642,3 +640,3 @@ static void mips_loongson3_virt_init(MachineState 
*machine)
          loaderparams.initrd_filename = initrd_filename;
-        loaderparams.kernel_entry = load_kernel(env);
+        loaderparams.kernel_entry = load_kernel(&cpu->env);

---
Re: [PATCH 02/11] hw/mips/loongson3_virt: Keep reference of vCPUs in machine_init()
Posted by Richard Henderson 1 year ago 
On 1/15/25 12:32, Philippe Mathieu-Daudé wrote:
> On 15/1/25 06:18, Richard Henderson wrote:
>> On 1/12/25 13:58, Philippe Mathieu-Daudé wrote:
>>> Keep references of all vCPUs created. That allows
>>> to directly access the first vCPU without using the
>>> &first_cpu global.
>>>
>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>>> ---
>>>   hw/mips/loongson3_virt.c | 9 +++++----
>>>   1 file changed, 5 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/hw/mips/loongson3_virt.c b/hw/mips/loongson3_virt.c
>>> index 47d112981a2..4b19941c1dc 100644
>>> --- a/hw/mips/loongson3_virt.c
>>> +++ b/hw/mips/loongson3_virt.c
>>> @@ -492,9 +492,8 @@ static void mips_loongson3_virt_init(MachineState *machine)
>>>   {
>>>       int i;
>>>       long bios_size;
>>> -    MIPSCPU *cpu;
>>> +    g_autofree MIPSCPU **cpus = NULL;
>>>       Clock *cpuclk;
>>> -    CPUMIPSState *env;
>>>       DeviceState *liointc;
>>>       DeviceState *ipi = NULL;
>>>       char *filename;
>>> @@ -569,13 +568,16 @@ static void mips_loongson3_virt_init(MachineState *machine)
>>>       cpuclk = clock_new(OBJECT(machine), "cpu-refclk");
>>>       clock_set_hz(cpuclk, DEF_LOONGSON3_FREQ);
>>> +    cpus = g_new(MIPSCPU *, machine->smp.cpus);
>>>       for (i = 0; i < machine->smp.cpus; i++) {
>>> +        MIPSCPU *cpu;
>>>           int node = i / LOONGSON3_CORE_PER_NODE;
>>>           int core = i % LOONGSON3_CORE_PER_NODE;
>>>           int ip;
>>>           /* init CPUs */
>>>           cpu = mips_cpu_create_with_clock(machine->cpu_type, cpuclk, false);
>>> +        cpus[i] = cpu;
>>>           /* Init internal devices */
>>>           cpu_mips_irq_init_cpu(cpu);
>>> @@ -609,7 +611,6 @@ static void mips_loongson3_virt_init(MachineState *machine)
>>>                                  pin, cpu->env.irq[ip + 2]);
>>>           }
>>>       }
>>> -    env = &MIPS_CPU(first_cpu)->env;
>>>       /* Allocate RAM/BIOS, 0x00000000~0x10000000 is alias of 0x80000000~0x90000000 */
>>>       memory_region_init_rom(bios, NULL, "loongson3.bios",
>>> @@ -640,7 +641,7 @@ static void mips_loongson3_virt_init(MachineState *machine)
>>>           loaderparams.kernel_filename = kernel_filename;
>>>           loaderparams.kernel_cmdline = kernel_cmdline;
>>>           loaderparams.initrd_filename = initrd_filename;
>>> -        loaderparams.kernel_entry = load_kernel(env);
>>> +        loaderparams.kernel_entry = load_kernel(&cpus[0]->env);
> 
>> We only ever use cpu[0].  We don't really need the whole array.
> 
> Yes. What about:
> 
> -- >8 --
> commit ffc8c8873c0c102457f0e660437874555b022cc2
> Author: Philippe Mathieu-Daudé <philmd@linaro.org>
> Date:   Sun Jan 12 21:01:24 2025 +0100
> 
>      hw/mips/loongson3_virt: Invert vCPU creation order to remove &first_cpu
> 
>      Create vCPUs from the last one to the first one.
>      No need to use the &first_cpu global since we already
>      have it referenced.
> 
>      Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> 
> diff --git a/hw/mips/loongson3_virt.c b/hw/mips/loongson3_virt.c
> index 47d112981a2..488eba495cd 100644
> --- a/hw/mips/loongson3_virt.c
> +++ b/hw/mips/loongson3_virt.c
> @@ -496,3 +496,2 @@ static void mips_loongson3_virt_init(MachineState *machine)
>       Clock *cpuclk;
> -    CPUMIPSState *env;
>       DeviceState *liointc;
> @@ -571,3 +570,3 @@ static void mips_loongson3_virt_init(MachineState *machine)
> 
> -    for (i = 0; i < machine->smp.cpus; i++) {
> +    for (i = machine->smp.cpus - 1; i >= 0; --i) {
>           int node = i / LOONGSON3_CORE_PER_NODE;
> @@ -611,3 +610,2 @@ static void mips_loongson3_virt_init(MachineState *machine)
>       }
> -    env = &MIPS_CPU(first_cpu)->env;
> 
> @@ -642,3 +640,3 @@ static void mips_loongson3_virt_init(MachineState *machine)
>           loaderparams.initrd_filename = initrd_filename;
> -        loaderparams.kernel_entry = load_kernel(env);
> +        loaderparams.kernel_entry = load_kernel(&cpu->env);
> 
> ---

Looks good, thanks.


r~

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