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

Alexander Graf
2010-11-10T12:57:57Z

On 10.11.2010, at 11:21, Avi Kivity wrote:

> On 11/10/2010 12:18 PM, Jan Kiszka wrote:
>> 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).
>
> Ok. I'll add the name and hope that this was the problem.

Yes, that was the problem. Sorry for not being clear about it, I thought it was obvious :).

Alex