| Message ID | 20191218215530.2280-36-sean.j.christopherson@intel.com |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | KVM: Refactor vCPU creation | expand |
On Wed, 18 Dec 2019 13:55:20 -0800 Sean Christopherson <sean.j.christopherson@intel.com> wrote: > Rename kvm_arch_vcpu_setup() to kvm_s390_vcpu_setup() and manually call > the new function during kvm_arch_vcpu_create(). Define an empty > kvm_arch_vcpu_setup() as it's still required for compilation. This > is effectively a nop as kvm_arch_vcpu_create() and kvm_arch_vcpu_setup() > are called back-to-back by common KVM code. Obsoleting > kvm_arch_vcpu_setup() paves the way for its removal. > > Note, gmap_remove() is now called if setup fails, as s390 was previously > freeing it via kvm_arch_vcpu_destroy(), which is called by common KVM > code if kvm_arch_vcpu_setup() fails. Yes, this looks like the only thing that needs to be undone (sca_add_vcpu() is done later in the process.) Maybe mention that gmap_remove() is for ucontrol only? I was confused for a moment :) > > No functional change intended. > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > --- > arch/s390/kvm/kvm-s390.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) Reviewed-by: Cornelia Huck <cohuck@redhat.com>
On Fri, Dec 20, 2019 at 11:04:45AM +0100, Cornelia Huck wrote: > On Wed, 18 Dec 2019 13:55:20 -0800 > Sean Christopherson <sean.j.christopherson@intel.com> wrote: > > > Rename kvm_arch_vcpu_setup() to kvm_s390_vcpu_setup() and manually call > > the new function during kvm_arch_vcpu_create(). Define an empty > > kvm_arch_vcpu_setup() as it's still required for compilation. This > > is effectively a nop as kvm_arch_vcpu_create() and kvm_arch_vcpu_setup() > > are called back-to-back by common KVM code. Obsoleting > > kvm_arch_vcpu_setup() paves the way for its removal. > > > > Note, gmap_remove() is now called if setup fails, as s390 was previously > > freeing it via kvm_arch_vcpu_destroy(), which is called by common KVM > > code if kvm_arch_vcpu_setup() fails. > > Yes, this looks like the only thing that needs to be undone > (sca_add_vcpu() is done later in the process.) > > Maybe mention that gmap_remove() is for ucontrol only? I was confused > for a moment :) Will do. Would it also make sense to open code __kvm_ucontrol_vcpu_init() in a separate patch immediately preceding this change? That'd make it a little more obvious why gmap_remove() is called, and it would eliminate the "uninit" verbiage in the label, e.g.: if (kvm_is_ucontrol(vcpu->kvm)) { vcpu->arch.gmap = gmap_create(current->mm, -1UL); if (!vcpu->arch.gmap) { rc = -ENOMEM; goto out_free_sie_block; } vcpu->arch.gmap->private = vcpu->kvm; } VM_EVENT(kvm, 3, "create cpu %d at 0x%pK, sie block at 0x%pK", id, vcpu, vcpu->arch.sie_block); trace_kvm_s390_create_vcpu(id, vcpu, vcpu->arch.sie_block); rc = kvm_s390_vcpu_setup(vcpu); if (rc) goto out_free_ucontrol_gmap; return 0; out_free_ucontrol_gmap: if (kvm_is_ucontrol(vcpu->kvm)) gmap_remove(vcpu->arch.gmap); out_free_sie_block: free_page((unsigned long)(vcpu->arch.sie_block)); return rc; }
On Fri, 20 Dec 2019 07:56:07 -0800 Sean Christopherson <sean.j.christopherson@intel.com> wrote: > On Fri, Dec 20, 2019 at 11:04:45AM +0100, Cornelia Huck wrote: > > On Wed, 18 Dec 2019 13:55:20 -0800 > > Sean Christopherson <sean.j.christopherson@intel.com> wrote: > > > > > Rename kvm_arch_vcpu_setup() to kvm_s390_vcpu_setup() and manually call > > > the new function during kvm_arch_vcpu_create(). Define an empty > > > kvm_arch_vcpu_setup() as it's still required for compilation. This > > > is effectively a nop as kvm_arch_vcpu_create() and kvm_arch_vcpu_setup() > > > are called back-to-back by common KVM code. Obsoleting > > > kvm_arch_vcpu_setup() paves the way for its removal. > > > > > > Note, gmap_remove() is now called if setup fails, as s390 was previously > > > freeing it via kvm_arch_vcpu_destroy(), which is called by common KVM > > > code if kvm_arch_vcpu_setup() fails. > > > > Yes, this looks like the only thing that needs to be undone > > (sca_add_vcpu() is done later in the process.) > > > > Maybe mention that gmap_remove() is for ucontrol only? I was confused > > for a moment :) > > Will do. > > Would it also make sense to open code __kvm_ucontrol_vcpu_init() in a > separate patch immediately preceding this change? That'd make it a little > more obvious why gmap_remove() is called, and it would eliminate the > "uninit" verbiage in the label, e.g.: I'm a bit undecided here; especially as I'm not sure if there are any future plans with ucontrol. I'll leave that for Christian and Janosch to decide.
On Fri, Dec 20, 2019 at 05:02:46PM +0100, Cornelia Huck wrote: > On Fri, 20 Dec 2019 07:56:07 -0800 > Sean Christopherson <sean.j.christopherson@intel.com> wrote: > > > On Fri, Dec 20, 2019 at 11:04:45AM +0100, Cornelia Huck wrote: > > > On Wed, 18 Dec 2019 13:55:20 -0800 > > > Sean Christopherson <sean.j.christopherson@intel.com> wrote: > > > > > > > Rename kvm_arch_vcpu_setup() to kvm_s390_vcpu_setup() and manually call > > > > the new function during kvm_arch_vcpu_create(). Define an empty > > > > kvm_arch_vcpu_setup() as it's still required for compilation. This > > > > is effectively a nop as kvm_arch_vcpu_create() and kvm_arch_vcpu_setup() > > > > are called back-to-back by common KVM code. Obsoleting > > > > kvm_arch_vcpu_setup() paves the way for its removal. > > > > > > > > Note, gmap_remove() is now called if setup fails, as s390 was previously > > > > freeing it via kvm_arch_vcpu_destroy(), which is called by common KVM > > > > code if kvm_arch_vcpu_setup() fails. > > > > > > Yes, this looks like the only thing that needs to be undone > > > (sca_add_vcpu() is done later in the process.) > > > > > > Maybe mention that gmap_remove() is for ucontrol only? I was confused > > > for a moment :) > > > > Will do. > > > > Would it also make sense to open code __kvm_ucontrol_vcpu_init() in a > > separate patch immediately preceding this change? That'd make it a little > > more obvious why gmap_remove() is called, and it would eliminate the > > "uninit" verbiage in the label, e.g.: > > I'm a bit undecided here; especially as I'm not sure if there are any > future plans with ucontrol. I'll leave that for Christian and Janosch > to decide. Sounds good. Thanks for the reviews!
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 2ed76584ebd9..5cd92c9fc050 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2932,6 +2932,11 @@ static void kvm_s390_vcpu_setup_model(struct kvm_vcpu *vcpu) } int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) +{ + return 0; +} + +static int kvm_s390_vcpu_setup(struct kvm_vcpu *vcpu) { int rc = 0; @@ -3070,8 +3075,14 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) vcpu->arch.sie_block); trace_kvm_s390_create_vcpu(id, vcpu, vcpu->arch.sie_block); + rc = kvm_s390_vcpu_setup(vcpu); + if (rc) + goto out_ucontrol_uninit; return 0; +out_ucontrol_uninit: + if (kvm_is_ucontrol(vcpu->kvm)) + gmap_remove(vcpu->arch.gmap); out_free_sie_block: free_page((unsigned long)(vcpu->arch.sie_block)); return rc;
Rename kvm_arch_vcpu_setup() to kvm_s390_vcpu_setup() and manually call the new function during kvm_arch_vcpu_create(). Define an empty kvm_arch_vcpu_setup() as it's still required for compilation. This is effectively a nop as kvm_arch_vcpu_create() and kvm_arch_vcpu_setup() are called back-to-back by common KVM code. Obsoleting kvm_arch_vcpu_setup() paves the way for its removal. Note, gmap_remove() is now called if setup fails, as s390 was previously freeing it via kvm_arch_vcpu_destroy(), which is called by common KVM code if kvm_arch_vcpu_setup() fails. No functional change intended. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- arch/s390/kvm/kvm-s390.c | 11 +++++++++++ 1 file changed, 11 insertions(+)