On Wed, Dec 18, 2019 at 01:55:15PM -0800, Sean Christopherson wrote:
> Now that all architectures tightly couple vcpu allocation/free with the
> mandatory calls to kvm_{un}init_vcpu(), move the sequences verbatim to
> common KVM code.
>
> Move both allocation and initialization in a single patch to eliminate
> thrash in arch specific code. The bisection benefits of moving the two
> pieces in separate patches is marginal at best, whereas the odds of
> introducing a transient arch specific bug are non-zero.
>
> Acked-by: Christoffer Dall <christoffer.dall@xxxxxxx>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
[ ... ]
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 8543d338a06a..2ed76584ebd9 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
>
[ ... ]
> -struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
> - unsigned int id)
^^^^^^^^^^^^^^^
> +int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
> {
> - struct kvm_vcpu *vcpu;
> struct sie_page *sie_page;
> int rc;
>
> - rc = -ENOMEM;
> -
> - vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
> - if (!vcpu)
> - goto out;
> -
> - rc = kvm_vcpu_init(vcpu, kvm, id);
> - if (rc)
> - goto out_free_cpu;
> -
> - rc = -ENOMEM;
> -
> BUILD_BUG_ON(sizeof(struct sie_page) != 4096);
> sie_page = (struct sie_page *) get_zeroed_page(GFP_KERNEL);
> if (!sie_page)
> - goto out_uninit_vcpu;
> + return -ENOMEM;
>
> vcpu->arch.sie_block = &sie_page->sie_block;
> vcpu->arch.sie_block->itdba = (unsigned long) &sie_page->itdb;
> @@ -3087,15 +3070,11 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
> vcpu->arch.sie_block);
> trace_kvm_s390_create_vcpu(id, vcpu, vcpu->arch.sie_block);
^^^
For extensive changes like this, wouldn't it be desirable to at least
compile test it ?
Guenter
