From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cornelia Huck Date: Fri, 20 Dec 2019 09:33:25 +0000 Subject: Re: [PATCH v2 30/45] KVM: Move vcpu alloc and init invocation to common code Message-Id: <20191220103325.34fc2bf0.cohuck@redhat.com> List-Id: References: <20191218215530.2280-1-sean.j.christopherson@intel.com> <20191218215530.2280-31-sean.j.christopherson@intel.com> In-Reply-To: <20191218215530.2280-31-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Sean Christopherson Cc: Marc Zyngier , James Hogan , Paul Mackerras , Christian Borntraeger , Janosch Frank , Paolo Bonzini , James Morse , Julien Thierry , Suzuki K Poulose , David Hildenbrand , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Greg Kurz On Wed, 18 Dec 2019 13:55:15 -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 > Signed-off-by: Sean Christopherson > --- > arch/mips/kvm/mips.c | 33 ++++++--------------------------- > arch/powerpc/kvm/powerpc.c | 27 ++++----------------------- > arch/s390/kvm/kvm-s390.c | 31 +++++-------------------------- > arch/x86/kvm/x86.c | 28 ++-------------------------- > include/linux/kvm_host.h | 2 +- > virt/kvm/arm/arm.c | 29 ++--------------------------- > virt/kvm/kvm_main.c | 21 ++++++++++++++++++--- > 7 files changed, 38 insertions(+), 133 deletions(-) (...) > 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 > @@ -2530,9 +2530,6 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) > if (vcpu->kvm->arch.use_cmma) > kvm_s390_vcpu_unsetup_cmma(vcpu); > free_page((unsigned long)(vcpu->arch.sie_block)); > - > - kvm_vcpu_uninit(vcpu); > - kmem_cache_free(kvm_vcpu_cache, vcpu); > } > > static void kvm_free_vcpus(struct kvm *kvm) > @@ -3014,29 +3011,15 @@ int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id) > return 0; > } > > -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); > > - return vcpu; > + return 0; > + > out_free_sie_block: > free_page((unsigned long)(vcpu->arch.sie_block)); > -out_uninit_vcpu: > - kvm_vcpu_uninit(vcpu); > -out_free_cpu: > - kmem_cache_free(kvm_vcpu_cache, vcpu); > -out: > - return ERR_PTR(rc); > + return rc; This is getting a bit hard to follow across the patches, but I think rc is now only set for ucontrol guests. So this looks correct right now, but feels a bit brittle... should we maybe init rc to 0 and always return rc instead? > } > > int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu) Otherwise, looks good.