Re: [PATCH v2] KVM: Clean up vm creation and release

[Jan Kiszka <jan.kiszka-kv7WeFo6aLtBDgjK7y7TUQ@public.gmane.org>]

Am 10.11.2010 10:45, Avi Kivity wrote:
> On 11/10/2010 11:30 AM, Jan Kiszka wrote:
>> Am 10.11.2010 10:17, Avi Kivity wrote:
>>>  On 11/09/2010 11:01 PM, Alexander Graf wrote:
>>>>  On 09.11.2010, at 17:02, Jan Kiszka wrote:
>>>>
>>>>>   IA64 support forces us to abstract the allocation of the kvm structure.
>>>>>   But instead of mixing this up with arch-specific initialization and
>>>>>   doing the same on destruction, split both steps. This allows to move
>>>>>   generic destruction calls into generic code.
>>>>>
>>>>>   It also fixes error clean-up on failures of kvm_create_vm for IA64.
>>>>>
>>>>>   Signed-off-by: Jan Kiszka<jan.kiszka-kv7WeFo6aLtBDgjK7y7TUQ@public.gmane.org>
>>>>>   ---
>>>>>
>>>>>   Changes in v2:
>>>>>   - Fixed s390 conversion and added linux/slab.h
>>>>>     as remarked by Christian (thanks!)
>>>>>
>>>>>   arch/ia64/include/asm/kvm_host.h |    4 ++++
>>>>>   arch/ia64/kvm/kvm-ia64.c         |   28 +++++++---------------------
>>>>>   arch/powerpc/kvm/powerpc.c       |   20 +++-----------------
>>>>>   arch/s390/kvm/kvm-s390.c         |   23 ++++++-----------------
>>>>>   arch/x86/kvm/x86.c               |   12 ++----------
>>>>>   include/linux/kvm_host.h         |   15 ++++++++++++++-
>>>>>   virt/kvm/kvm_main.c              |   19 +++++++++++++------
>>>>>   7 files changed, 49 insertions(+), 72 deletions(-)
>>>>>
>>>>>   diff --git a/arch/ia64/include/asm/kvm_host.h b/arch/ia64/include/asm/kvm_host.h
>>>>>   index 2f229e5..2689ee5 100644
>>>>>   --- a/arch/ia64/include/asm/kvm_host.h
>>>>>   +++ b/arch/ia64/include/asm/kvm_host.h
>>>>>   @@ -590,6 +590,10 @@ int kvm_emulate_halt(struct kvm_vcpu *vcpu);
>>>>>   int kvm_pal_emul(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run);
>>>>>   void kvm_sal_emul(struct kvm_vcpu *vcpu);
>>>>>
>>>>>   +#define __KVM_HAVE_ARCH_VM_ALLOC 1
>>>>>   +struct kvm *kvm_arch_alloc_vm(void);
>>>>>   +void kvm_arch_free_vm(struct kvm *kvm);
>>>>>   +
>>>>>   #endif /* __ASSEMBLY__*/
>>>>>
>>>>>   #endif
>>>>>   diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
>>>>>   index f56a631..48a48bd 100644
>>>>>   --- a/arch/ia64/kvm/kvm-ia64.c
>>>>>   +++ b/arch/ia64/kvm/kvm-ia64.c
>>>>>   @@ -749,7 +749,7 @@ out:
>>>>>   	return r;
>>>>>   }
>>>>>
>>>>>   -static struct kvm *kvm_alloc_kvm(void)
>>>>>   +struct kvm *kvm_arch_alloc_vm(void)
>>>>>   {
>>>>>
>>>>>   	struct kvm *kvm;
>>>>>   @@ -760,7 +760,7 @@ static struct kvm *kvm_alloc_kvm(void)
>>>>>   	vm_base = __get_free_pages(GFP_KERNEL, get_order(KVM_VM_DATA_SIZE));
>>>>>
>>>>>   	if (!vm_base)
>>>>>   -		return ERR_PTR(-ENOMEM);
>>>>>   +		return NULL;
>>>>>
>>>>>   	memset((void *)vm_base, 0, KVM_VM_DATA_SIZE);
>>>>>   	kvm = (struct kvm *)(vm_base +
>>>>>   @@ -806,10 +806,12 @@ static void kvm_build_io_pmt(struct kvm *kvm)
>>>>>   #define GUEST_PHYSICAL_RR4	0x2739
>>>>>   #define VMM_INIT_RR		0x1660
>>>>>
>>>>>   -static void kvm_init_vm(struct kvm *kvm)
>>>>>   +int kvm_arch_init_vm(struct kvm *kvm)
>>>>>   {
>>>>>   	BUG_ON(!kvm);
>>>>>
>>>>>   +	kvm->arch.is_sn2 = ia64_platform_is("sn2");
>>>>>   +
>>>>>   	kvm->arch.metaphysical_rr0 = GUEST_PHYSICAL_RR0;
>>>>>   	kvm->arch.metaphysical_rr4 = GUEST_PHYSICAL_RR4;
>>>>>   	kvm->arch.vmm_init_rr = VMM_INIT_RR;
>>>>>   @@ -823,21 +825,8 @@ static void kvm_init_vm(struct kvm *kvm)
>>>>>
>>>>>   	/* Reserve bit 0 of irq_sources_bitmap for userspace irq source */
>>>>>   	set_bit(KVM_USERSPACE_IRQ_SOURCE_ID,&kvm->arch.irq_sources_bitmap);
>>>>>   -}
>>>>>   -
>>>>>   -struct  kvm *kvm_arch_create_vm(void)
>>>>>   -{
>>>>>   -	struct kvm *kvm = kvm_alloc_kvm();
>>>>>   -
>>>>>   -	if (IS_ERR(kvm))
>>>>>   -		return ERR_PTR(-ENOMEM);
>>>>>   -
>>>>>   -	kvm->arch.is_sn2 = ia64_platform_is("sn2");
>>>>>   -
>>>>>   -	kvm_init_vm(kvm);
>>>>>   -
>>>>>   -	return kvm;
>>>>>
>>>>>   +	return 0;
>>>>>   }
>>>>>
>>>>>   static int kvm_vm_ioctl_get_irqchip(struct kvm *kvm,
>>>>>   @@ -1357,7 +1346,7 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
>>>>>   	return -EINVAL;
>>>>>   }
>>>>>
>>>>>   -static void free_kvm(struct kvm *kvm)
>>>>>   +void kvm_arch_free_vm(struct kvm *kvm)
>>>>>   {
>>>>>   	unsigned long vm_base = kvm->arch.vm_base;
>>>>>
>>>>>   @@ -1399,9 +1388,6 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
>>>>>   #endif
>>>>>   	kfree(kvm->arch.vioapic);
>>>>>   	kvm_release_vm_pages(kvm);
>>>>>   -	kvm_free_physmem(kvm);
>>>>>   -	cleanup_srcu_struct(&kvm->srcu);
>>>>>   -	free_kvm(kvm);
>>>>>   }
>>>>>
>>>>>   void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
>>>>>   diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
>>>>>   index 38f756f..ce3dd65 100644
>>>>>   --- a/arch/powerpc/kvm/powerpc.c
>>>>>   +++ b/arch/powerpc/kvm/powerpc.c
>>>>>   @@ -145,18 +145,12 @@ void kvm_arch_check_processor_compat(void *rtn)
>>>>>   	*(int *)rtn = kvmppc_core_check_processor_compat();
>>>>>   }
>>>>>
>>>>>   -struct kvm *kvm_arch_create_vm(void)
>>>>>   +int kvm_arch_init_vm(struct kvm *)
>>>>
>>>>  Eh, no. This doesn't compile :).
>>>
>>>  What's the problem? lack of a formal argument?
>>
>> The unnamed argument is referenced as 'kvm' in this function.
> 
> It isn't referenced:
> 
>> int kvm_arch_init_vm(struct kvm *)
>> {
>>     return 0;
>> }
> 

Indeed. Anyway, this wasn't intended (even more if some compiler
versions/settings dislike it).

Jan

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