Re: [Qemu-devel] [kvm-unit-tests PATCH v3 03/10] arm/arm64: smp: support more than 8 cpus

[Auger Eric]

Hi Drew,

On 30/08/2016 16:28, Auger Eric wrote:
> Hi Drew,
> 
> Proper commit message?
> ... also selects the vgic model corresponding to the host
>> Reviewed-by: Alex Bennée <address@hidden>
>> Signed-off-by: Andrew Jones <address@hidden>
>> ---
>>  arm/run                   | 19 ++++++++++++-------
>>  arm/selftest.c            |  5 ++++-
>>  lib/arm/asm/processor.h   |  9 +++++++--
>>  lib/arm/asm/setup.h       |  4 ++--
>>  lib/arm/setup.c           | 12 +++++++++++-
>>  lib/arm64/asm/processor.h |  9 +++++++--
>>  6 files changed, 43 insertions(+), 15 deletions(-)
>>
>> diff --git a/arm/run b/arm/run
>> index a2f35ef6a7e63..2d0698619606e 100755
>> --- a/arm/run
>> +++ b/arm/run
>> @@ -31,13 +31,6 @@ if [ -z "$ACCEL" ]; then
>>      fi
>>  fi
>>  
>> -if [ "$HOST" = "aarch64" ] && [ "$ACCEL" = "kvm" ]; then
>> -    processor="host"
>> -    if [ "$ARCH" = "arm" ]; then
>> -            processor+=",aarch64=off"
>> -    fi
>> -fi
>> -
>>  qemu="${QEMU:-qemu-system-$ARCH_NAME}"
>>  qpath=$(which $qemu 2>/dev/null)
>>  
>> @@ -53,6 +46,18 @@ fi
>>  
>>  M='-machine virt'
>>  
>> +if [ "$ACCEL" = "kvm" ]; then
>> +    if $qemu $M,\? 2>&1 | grep gic-version > /dev/null; then
>> +            M+=',gic-version=host'
>> +    fi
>> +    if [ "$HOST" = "aarch64" ]; then
>> +            processor="host"
>> +            if [ "$ARCH" = "arm" ]; then
>> +                    processor+=",aarch64=off"
>> +            fi
>> +    fi
>> +fi
>> +
>>  if ! $qemu $M -device '?' 2>&1 | grep virtconsole > /dev/null; then
>>      echo "$qpath doesn't support virtio-console for chr-testdev. Exiting."
>>      exit 2
>> diff --git a/arm/selftest.c b/arm/selftest.c
>> index 196164f5313de..2f117f795d2dc 100644
>> --- a/arm/selftest.c
>> +++ b/arm/selftest.c
>> @@ -312,9 +312,10 @@ static bool psci_check(void)
>>  static cpumask_t smp_reported;
>>  static void cpu_report(void)
>>  {
>> +    unsigned long mpidr = get_mpidr();
>>      int cpu = smp_processor_id();
>>  
>> -    report("CPU%d online", true, cpu);
>> +    report("CPU(%3d) mpidr=%lx", mpidr_to_cpu(mpidr) == cpu, cpu, mpidr);
>>      cpumask_set_cpu(cpu, &smp_reported);
>>      halt();
>>  }
>> @@ -343,6 +344,7 @@ int main(int argc, char **argv)
>>  
>>      } else if (strcmp(argv[1], "smp") == 0) {
>>  
>> +            unsigned long mpidr = get_mpidr();
>>              int cpu;
>>  
>>              report("PSCI version", psci_check());
>> @@ -353,6 +355,7 @@ int main(int argc, char **argv)
>>                      smp_boot_secondary(cpu, cpu_report);
>>              }
>>  
>> +            report("CPU(%3d) mpidr=%lx", mpidr_to_cpu(mpidr) == 0, 0, 
>> mpidr);
>>              cpumask_set_cpu(0, &smp_reported);
>>              while (!cpumask_full(&smp_reported))
>>                      cpu_relax();
>> diff --git a/lib/arm/asm/processor.h b/lib/arm/asm/processor.h
>> index f25e7eee3666c..d2048f5f5f7e6 100644
>> --- a/lib/arm/asm/processor.h
>> +++ b/lib/arm/asm/processor.h
>> @@ -40,8 +40,13 @@ static inline unsigned int get_mpidr(void)
>>      return mpidr;
>>  }
>>  
>> -/* Only support Aff0 for now, up to 4 cpus */
>> -#define mpidr_to_cpu(mpidr) ((int)((mpidr) & 0xff))
>> +#define MPIDR_HWID_BITMASK 0xffffff
>> +extern int mpidr_to_cpu(unsigned long mpidr);
>> +
>> +#define MPIDR_LEVEL_SHIFT(level) \
>> +    (((1 << level) >> 1) << 3)
> can't we have level << 3?
Forget this, see below
>> +#define MPIDR_AFFINITY_LEVEL(mpidr, level) \
>> +    ((mpidr >> MPIDR_LEVEL_SHIFT(level)) & 0xff)
>>  
>>  extern void start_usr(void (*func)(void *arg), void *arg, unsigned long 
>> sp_usr);
>>  extern bool is_user(void);
>> diff --git a/lib/arm/asm/setup.h b/lib/arm/asm/setup.h
>> index cb8fdbd38dd5d..c501c6ddd8657 100644
>> --- a/lib/arm/asm/setup.h
>> +++ b/lib/arm/asm/setup.h
>> @@ -10,8 +10,8 @@
>>  #include <asm/page.h>
>>  #include <asm/pgtable-hwdef.h>
>>  
>> -#define NR_CPUS                     8
>> -extern u32 cpus[NR_CPUS];
>> +#define NR_CPUS                     255
> 256?
>> +extern u64 cpus[NR_CPUS];
> maybe worth commenting the semantic of cpus[i]?
>>  extern int nr_cpus;
> what about MAX_CPUS instead of NR_CPUS?
>>  
>>  #define NR_MEM_REGIONS              8
>> diff --git a/lib/arm/setup.c b/lib/arm/setup.c
>> index 7e7b39f11dde1..b6e2d5815e723 100644
>> --- a/lib/arm/setup.c
>> +++ b/lib/arm/setup.c
>> @@ -24,12 +24,22 @@ extern unsigned long stacktop;
>>  extern void io_init(void);
>>  extern void setup_args_progname(const char *args);
>>  
>> -u32 cpus[NR_CPUS] = { [0 ... NR_CPUS-1] = (~0U) };
>> +u64 cpus[NR_CPUS] = { [0 ... NR_CPUS-1] = (~0U) };
>>  int nr_cpus;
>>  
>>  struct mem_region mem_regions[NR_MEM_REGIONS];
>>  phys_addr_t __phys_offset, __phys_end;
>>  
>> +int mpidr_to_cpu(unsigned long mpidr)
>> +{
>> +    int i;
>> +
>> +    for (i = 0; i < nr_cpus; ++i)
>> +            if (cpus[i] == (mpidr & MPIDR_HWID_BITMASK))
>> +                    return i;
>> +    return -1;
>> +}
>> +
>>  static void cpu_set(int fdtnode __unused, u32 regval, void *info __unused)
>>  {
>>      int cpu = nr_cpus++;
>> diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h
>> index 9a208ff729b7e..7e448dc81a6aa 100644
>> --- a/lib/arm64/asm/processor.h
>> +++ b/lib/arm64/asm/processor.h
>> @@ -78,8 +78,13 @@ static inline type get_##reg(void)                        
>>         \
>>  
>>  DEFINE_GET_SYSREG64(mpidr)
>>  
>> -/* Only support Aff0 for now, gicv2 only */
>> -#define mpidr_to_cpu(mpidr) ((int)((mpidr) & 0xff))
>> +#define MPIDR_HWID_BITMASK 0xff00ffffff
>> +extern int mpidr_to_cpu(unsigned long mpidr);
>> +
>> +#define MPIDR_LEVEL_SHIFT(level) \
>> +    (((1 << level) >> 1) << 3)
> what about level 3? the macro would fail fetching affinity level 3.
Forget that remark too. I read the magic behind in the patch's history.
Sorry for the noise.

Thanks

Eric
> 
> Thanks
> 
> Eric
>> +#define MPIDR_AFFINITY_LEVEL(mpidr, level) \
>> +    ((mpidr >> MPIDR_LEVEL_SHIFT(level)) & 0xff)
>>  
>>  extern void start_usr(void (*func)(void *arg), void *arg, unsigned long 
>> sp_usr);
>>  extern bool is_user(void);
>>