Re: [Qemu-ppc] [PATCH qemu] spapr: Enable in-kernel H_SET_MODE handling

[Alexey Kardashevskiy]

On 09/03/2015 09:18 AM, David Gibson wrote:
> On Wed, Sep 02, 2015 at 07:29:58PM +1000, Alexey Kardashevskiy wrote:
> > For setting debug watchpoints, sPAPR guests use H_SET_MODE hypercall.
> > The existing QEMU H_SET_MODE handler does not support this but
> > the KVM handler in HV KVM does. However it is not enabled.
> >
> > This enables the in-kernel H_SET_MODE handler which handles:
> > - Completed Instruction Address Breakpoint Register
> > - Watch point 0 registers.
> >
> > The rest is still handled in QEMU.
> >
> > Reported-by: Anton Blanchard <address@hidden>
> > Signed-off-by: Alexey Kardashevskiy <address@hidden>
>
> Won't this break auto-switching of VGA endianness, since that is
> triggered from the qemu implementation of H_SET_MODE?

Only breakpoints are handled in the kernel, at least in upstream and 
powerkvm, for the rest it is H_TOO_HARD and then handled in QEMU so it 
won't break endianness.


> > ---
> >   hw/ppc/spapr.c       | 1 +
> >   target-ppc/kvm.c     | 5 +++++
> >   target-ppc/kvm_ppc.h | 5 +++++
> >   3 files changed, 11 insertions(+)
> >
> > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > index ae82565..7df0e15 100644
> > --- a/hw/ppc/spapr.c
> > +++ b/hw/ppc/spapr.c
> > @@ -1728,6 +1728,7 @@ static void ppc_spapr_init(MachineState *machine)
> >       if (kvm_enabled()) {
> >           /* Enable H_LOGICAL_CI_* so SLOF can talk to in-kernel devices */
> >           kvmppc_enable_logical_ci_hcalls();
> > +        kvmppc_enable_set_mode_hcall();
> >       }
> >
> >       /* allocate RAM */
> > diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> > index 110436d..9cf5308 100644
> > --- a/target-ppc/kvm.c
> > +++ b/target-ppc/kvm.c
> > @@ -1953,6 +1953,11 @@ void kvmppc_enable_logical_ci_hcalls(void)
> >       kvmppc_enable_hcall(kvm_state, H_LOGICAL_CI_STORE);
> >   }
> >
> > +void kvmppc_enable_set_mode_hcall(void)
> > +{
> > +    kvmppc_enable_hcall(kvm_state, H_SET_MODE);
> > +}
> > +
> >   void kvmppc_set_papr(PowerPCCPU *cpu)
> >   {
> >       CPUState *cs = CPU(cpu);
> > diff --git a/target-ppc/kvm_ppc.h b/target-ppc/kvm_ppc.h
> > index 4d30e27..0714ba0 100644
> > --- a/target-ppc/kvm_ppc.h
> > +++ b/target-ppc/kvm_ppc.h
> > @@ -25,6 +25,7 @@ int kvmppc_get_hasidle(CPUPPCState *env);
> >   int kvmppc_get_hypercall(CPUPPCState *env, uint8_t *buf, int buf_len);
> >   int kvmppc_set_interrupt(PowerPCCPU *cpu, int irq, int level);
> >   void kvmppc_enable_logical_ci_hcalls(void);
> > +void kvmppc_enable_set_mode_hcall(void);
> >   void kvmppc_set_papr(PowerPCCPU *cpu);
> >   int kvmppc_set_compat(PowerPCCPU *cpu, uint32_t cpu_version);
> >   void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy);
> > @@ -112,6 +113,10 @@ static inline void kvmppc_enable_logical_ci_hcalls(void)
> >   {
> >   }
> >
> > +static inline void kvmppc_enable_set_mode_hcall(void)
> > +{
> > +}
> > +
> >   static inline void kvmppc_set_papr(PowerPCCPU *cpu)
> >   {
> >   }


--
Alexey