Re: [PATCH kvmtool 02/16] kvm__arch_init: Don't pass hugetlbfs_path and ram_size in parameter

[Alexandru Elisei <alexandru.elisei@arm.com>]

Hi,

On 11/6/19 4:47 PM, Andre Przywara wrote:
> On Mon, 23 Sep 2019 14:35:08 +0100
> Alexandru Elisei <alexandru.elisei@arm.com> wrote:
>
> Hi,
>
>> From: Julien Grall <julien.grall@arm.com>
>>
>> The structure KVM already contains a pointer to the configuration. Both
>> hugetlbfs_path and ram_size are part of the configuration, so is it not
>> necessary to path them again in parameter.
>>
>> Signed-off-by: Julien Grall <julien.grall@arm.com>
>> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
>> ---
>>  arm/kvm.c         | 5 ++++-
>>  include/kvm/kvm.h | 2 +-
>>  kvm.c             | 2 +-
>>  mips/kvm.c        | 5 ++++-
>>  powerpc/kvm.c     | 5 ++++-
>>  x86/kvm.c         | 5 ++++-
>>  6 files changed, 18 insertions(+), 6 deletions(-)
>>
>> diff --git a/arm/kvm.c b/arm/kvm.c
>> index 1c5bdb8026bf..198cee5c0997 100644
>> --- a/arm/kvm.c
>> +++ b/arm/kvm.c
>> @@ -57,9 +57,12 @@ void kvm__arch_set_cmdline(char *cmdline, bool video)
>>  {
>>  }
>>  
>> -void kvm__arch_init(struct kvm *kvm, const char *hugetlbfs_path, u64 ram_size)
>> +void kvm__arch_init(struct kvm *kvm)
>>  {
>>  	unsigned long alignment;
>> +	/* Convenience aliases */
>> +	u64 ram_size = kvm->cfg.ram_size;
>> +	const char *hugetlbfs_path = kvm->cfg.hugetlbfs_path;
> Do we really need these aliases?
> Definitely we should lose the comment ...

I agree, they need to go.

Thanks,
Alex
>
>>  	/*
>>  	 * Allocate guest memory. If the user wants to use hugetlbfs, then the
>> diff --git a/include/kvm/kvm.h b/include/kvm/kvm.h
>> index 7a738183d67a..635ce0f40b1e 100644
>> --- a/include/kvm/kvm.h
>> +++ b/include/kvm/kvm.h
>> @@ -140,7 +140,7 @@ int kvm__enumerate_instances(int (*callback)(const char *name, int pid));
>>  void kvm__remove_socket(const char *name);
>>  
>>  void kvm__arch_set_cmdline(char *cmdline, bool video);
>> -void kvm__arch_init(struct kvm *kvm, const char *hugetlbfs_path, u64 ram_size);
>> +void kvm__arch_init(struct kvm *kvm);
>>  void kvm__arch_delete_ram(struct kvm *kvm);
>>  int kvm__arch_setup_firmware(struct kvm *kvm);
>>  int kvm__arch_free_firmware(struct kvm *kvm);
>> diff --git a/kvm.c b/kvm.c
>> index 57c4ff98ec4c..36b238791fc1 100644
>> --- a/kvm.c
>> +++ b/kvm.c
>> @@ -392,7 +392,7 @@ int kvm__init(struct kvm *kvm)
>>  		goto err_vm_fd;
>>  	}
>>  
>> -	kvm__arch_init(kvm, kvm->cfg.hugetlbfs_path, kvm->cfg.ram_size);
>> +	kvm__arch_init(kvm);
>>  
>>  	INIT_LIST_HEAD(&kvm->mem_banks);
>>  	kvm__init_ram(kvm);
>> diff --git a/mips/kvm.c b/mips/kvm.c
>> index 211770da0d85..e2a0c63b14b8 100644
>> --- a/mips/kvm.c
>> +++ b/mips/kvm.c
>> @@ -57,9 +57,12 @@ void kvm__arch_set_cmdline(char *cmdline, bool video)
>>  }
>>  
>>  /* Architecture-specific KVM init */
>> -void kvm__arch_init(struct kvm *kvm, const char *hugetlbfs_path, u64 ram_size)
>> +void kvm__arch_init(struct kvm *kvm)
>>  {
>>  	int ret;
>> +	/* Convenience aliases */
>> +	u64 ram_size = kvm->cfg.ram_size;
>> +	const char *hugetlbfs_path = kvm->cfg.hugetlbfs_path;
> Same here, there is only one user of hugetlbfs_path.
>
>>  	kvm->ram_start = mmap_anon_or_hugetlbfs(kvm, hugetlbfs_path, ram_size);
>>  	kvm->ram_size = ram_size;
>> diff --git a/powerpc/kvm.c b/powerpc/kvm.c
>> index 702d67dca614..034bc4608ad9 100644
>> --- a/powerpc/kvm.c
>> +++ b/powerpc/kvm.c
>> @@ -88,10 +88,13 @@ void kvm__arch_set_cmdline(char *cmdline, bool video)
>>  }
>>  
>>  /* Architecture-specific KVM init */
>> -void kvm__arch_init(struct kvm *kvm, const char *hugetlbfs_path, u64 ram_size)
>> +void kvm__arch_init(struct kvm *kvm)
>>  {
>>  	int cap_ppc_rma;
>>  	unsigned long hpt;
>> +	/* Convenience aliases */
> Not needed and not even true for hugetlbfs_path.
>
>> +	u64 ram_size = kvm->cfg.ram_size;
> This is somewhat pointless, the only user is right below the next line ...
>
>> +	const char *hugetlbfs_path = kvm->cfg.hugetlbfs_path;
> We need to keep that, though, as the code modifies it.
>
>>  
>>  	kvm->ram_size		= ram_size;
>>  
>> diff --git a/x86/kvm.c b/x86/kvm.c
>> index 3e0f0b743f8c..5abb41e370bb 100644
>> --- a/x86/kvm.c
>> +++ b/x86/kvm.c
>> @@ -130,10 +130,13 @@ void kvm__arch_set_cmdline(char *cmdline, bool video)
>>  }
>>  
>>  /* Architecture-specific KVM init */
>> -void kvm__arch_init(struct kvm *kvm, const char *hugetlbfs_path, u64 ram_size)
>> +void kvm__arch_init(struct kvm *kvm)
>>  {
>>  	struct kvm_pit_config pit_config = { .flags = 0, };
>>  	int ret;
>> +	/* Convenience aliases */
> I don't think the comment is needed.
>
> Otherwise it's a nice cleanup.
>
> Cheers,
> Andre
>
>> +	u64 ram_size = kvm->cfg.ram_size;
>> +	const char *hugetlbfs_path = kvm->cfg.hugetlbfs_path;
>>  
>>  	ret = ioctl(kvm->vm_fd, KVM_SET_TSS_ADDR, 0xfffbd000);
>>  	if (ret < 0)