RE: [PATCH 1/5] powerpc: define ePAPR hcall exit interface

Bhushan Bharat-R65777
2013-07-15T11:30:29Z

> -----Original Message-----
> From: Alexander Graf [mailto:agraf@suse.de]
> Sent: Monday, July 15, 2013 4:51 PM
> To: Bhushan Bharat-R65777
> Cc: kvm@vger.kernel.org; kvm-ppc@vger.kernel.org; Wood Scott-B07421; Yoder
> Stuart-B08248; Bhushan Bharat-R65777
> Subject: Re: [PATCH 1/5] powerpc: define ePAPR hcall exit interface
>
>
> On 15.07.2013, at 13:11, Bharat Bhushan wrote:
>
> > This patch defines the ePAPR hcall exit interface to guest user space.
>
> The subject line is misleading. This is a kvm patch. Same applies for most other
> patches.

Ok, will make this "kvm: powerpc: define ePAPR hcall exit interface"

>
> >
> > Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
> > ---
> > Documentation/virtual/kvm/api.txt | 20 ++++++++++++++++++++
> > include/uapi/linux/kvm.h | 7 +++++++
> > 2 files changed, 27 insertions(+), 0 deletions(-)
> >
> > diff --git a/Documentation/virtual/kvm/api.txt
> > b/Documentation/virtual/kvm/api.txt
> > index 66dd2aa..054f2f4 100644
> > --- a/Documentation/virtual/kvm/api.txt
> > +++ b/Documentation/virtual/kvm/api.txt
> > @@ -2597,6 +2597,26 @@ The possible hypercalls are defined in the
> > Power Architecture Platform Requirements (PAPR) document available
> > from www.power.org (free developer registration required to access it).
> >
> > + /* KVM_EXIT_EPAPR_HCALL */
> > + struct {
> > + __u64 nr;
> > + __u64 ret;
> > + __u64 args[8];
> > + } epapr_hcall;
> > +
> > +This is used on PowerPC platforms that support ePAPR hcalls.
> > +It occurs when a guest does a hypercall (as defined in the ePAPR 1.1)
> > +and the hcall is not handled by the kernel.
> > +
> > +The 'nr' field contains the hypercall number (from the guest R11),
> > +and 'args' contains the arguments (from the guest R3 - R10).
> > +Userspace should put the return code in 'ret' and any extra returned
> > +values in args[]. If the VM is not in 64-bit mode KVM zeros the
> > +upper half of each field in the struct.
> > +
> > +As per the ePAPR hcall ABI, the return value is returned to the guest
> > +in R3 and output return values in R4 - R10.
> > +
> > /* KVM_EXIT_S390_TSCH */
> > struct {
> > __u16 subchannel_id;
> > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index
> > acccd08..01ee50e 100644
> > --- a/include/uapi/linux/kvm.h
> > +++ b/include/uapi/linux/kvm.h
> > @@ -171,6 +171,7 @@ struct kvm_pit_config {
> > #define KVM_EXIT_WATCHDOG 21
> > #define KVM_EXIT_S390_TSCH 22
> > #define KVM_EXIT_EPR 23
> > +#define KVM_EXIT_EPAPR_HCALL 24
> >
> > /* For KVM_EXIT_INTERNAL_ERROR */
> > /* Emulate instruction failed. */
> > @@ -288,6 +289,12 @@ struct kvm_run {
> > __u64 ret;
> > __u64 args[9];
> > } papr_hcall;
> > + /* KVM_EXIT_EPAPR_HCALL */
> > + struct {
> > + __u64 nr;
> > + __u64 ret;
> > + __u64 args[8];
> > + } epapr_hcall;
>
> This should be at the end of the union.

Ok.

-Bharat

>
>
> Alex
>
> > /* KVM_EXIT_S390_TSCH */
> > struct {
> > __u16 subchannel_id;
> > --
> > 1.7.0.4
> >
> >
>