diff mbox series

[v2,35/45] KVM: s390: Manually invoke vcpu setup during kvm_arch_vcpu_create()

Message ID 20191218215530.2280-36-sean.j.christopherson@intel.com (mailing list archive)
State New, archived
Headers show
Series KVM: Refactor vCPU creation | expand

Commit Message

Sean Christopherson Dec. 18, 2019, 9:55 p.m. UTC
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(+)

Comments

Cornelia Huck Dec. 20, 2019, 10:04 a.m. UTC | #1
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>
Sean Christopherson Dec. 20, 2019, 3:56 p.m. UTC | #2
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;
}
Cornelia Huck Dec. 20, 2019, 4:02 p.m. UTC | #3
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.
Sean Christopherson Dec. 20, 2019, 4:22 p.m. UTC | #4
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 mbox series

Patch

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;