Re: [RFC PATCH v1 3/4] kvmppc: H_SVM_INIT_START and H_SVM_INIT_DONE hcalls

[Bharata B Rao <bharata@linux.ibm.com>]

On Thu, Nov 01, 2018 at 09:49:26PM +1100, Balbir Singh wrote:
> On Mon, Oct 22, 2018 at 10:48:36AM +0530, Bharata B Rao wrote:
> > H_SVM_INIT_START: Initiate securing a VM
> > H_SVM_INIT_DONE: Conclude securing a VM
> > 
> > During early guest init, these hcalls will be issued by UV.
> > As part of these hcalls, [un]register memslots with UV.
> > 
> > Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
> > ---
> >  arch/powerpc/include/asm/hvcall.h    |  4 ++-
> >  arch/powerpc/include/asm/kvm_host.h  |  1 +
> >  arch/powerpc/include/asm/ucall-api.h |  6 ++++
> >  arch/powerpc/kvm/book3s_hv.c         | 54 ++++++++++++++++++++++++++++
> >  4 files changed, 64 insertions(+), 1 deletion(-)
> > 
> > diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
> > index 89e6b70c1857..6091276fef07 100644
> > --- a/arch/powerpc/include/asm/hvcall.h
> > +++ b/arch/powerpc/include/asm/hvcall.h
> > @@ -300,7 +300,9 @@
> >  #define H_INT_RESET             0x3D0
> >  #define H_SVM_PAGE_IN		0x3D4
> >  #define H_SVM_PAGE_OUT		0x3D8
> > -#define MAX_HCALL_OPCODE	H_SVM_PAGE_OUT
> > +#define H_SVM_INIT_START	0x3DC
> > +#define H_SVM_INIT_DONE		0x3E0
> > +#define MAX_HCALL_OPCODE	H_SVM_INIT_DONE
> >  
> >  /* H_VIOCTL functions */
> >  #define H_GET_VIOA_DUMP_SIZE	0x01
> > diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
> > index 194e6e0ff239..267f8c568bc3 100644
> > --- a/arch/powerpc/include/asm/kvm_host.h
> > +++ b/arch/powerpc/include/asm/kvm_host.h
> > @@ -292,6 +292,7 @@ struct kvm_arch {
> >  	struct dentry *debugfs_dir;
> >  	struct dentry *htab_dentry;
> >  	struct kvm_resize_hpt *resize_hpt; /* protected by kvm->lock */
> > +	bool svm_init_start; /* Indicates H_SVM_INIT_START has been called */
> >  #endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
> >  #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
> >  	struct mutex hpt_mutex;
> > diff --git a/arch/powerpc/include/asm/ucall-api.h b/arch/powerpc/include/asm/ucall-api.h
> > index 2c12f514f8ab..9ddfcf541211 100644
> > --- a/arch/powerpc/include/asm/ucall-api.h
> > +++ b/arch/powerpc/include/asm/ucall-api.h
> > @@ -17,4 +17,10 @@ static inline int uv_page_out(u64 lpid, u64 dw0, u64 dw1, u64 dw2, u64 dw3)
> >  	return U_SUCCESS;
> >  }
> >  
> > +static inline int uv_register_mem_slot(u64 lpid, u64 dw0, u64 dw1, u64 dw2,
> > +				       u64 dw3)
> > +{
> > +	return 0;
> > +}
> > +
> >  #endif	/* _ASM_POWERPC_UCALL_API_H */
> > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> > index 05084eb8aadd..47f366f634fd 100644
> > --- a/arch/powerpc/kvm/book3s_hv.c
> > +++ b/arch/powerpc/kvm/book3s_hv.c
> > @@ -819,6 +819,50 @@ static int kvmppc_get_yield_count(struct kvm_vcpu *vcpu)
> >  	return yield_count;
> >  }
> >  
> > +#ifdef CONFIG_PPC_SVM
> > +#include <asm/ucall-api.h>
> > +/*
> > + * TODO: Check if memslots related calls here need to be called
> > + * under any lock.
> > + */
> > +static unsigned long kvmppc_h_svm_init_start(struct kvm *kvm)
> > +{
> > +	struct kvm_memslots *slots;
> > +	struct kvm_memory_slot *memslot;
> > +	int ret;
> > +
> > +	slots = kvm_memslots(kvm);
> > +	kvm_for_each_memslot(memslot, slots) {
> > +		ret = uv_register_mem_slot(kvm->arch.lpid,
> > +					   memslot->base_gfn << PAGE_SHIFT,
> > +					   memslot->npages * PAGE_SIZE,
> > +					   0, memslot->id);
> 
> For every memslot their is a corresponding registration in the ultravisor?
> Is there a corresponding teardown?

Yes, uv_unregister_mem_slot(), called during memory unplug time.

Regards,
Bharata.