On Wed, Feb 10, 2016 at 07:09:09PM +0100, Thomas Huth wrote:
> This is a very simple hypercall that only sets up the SPRG0
> register for the guest (since writing to SPRG0 was only permitted
> to the hypervisor in older versions of the PowerISA).
>
> Signed-off-by: Thomas Huth <th...@redhat.com>
> ---
> hw/ppc/spapr_hcall.c | 15 +++++++++++++--
> 1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> index 12f8c33..58103ef 100644
> --- a/hw/ppc/spapr_hcall.c
> +++ b/hw/ppc/spapr_hcall.c
> @@ -332,6 +332,15 @@ static target_ulong h_read(PowerPCCPU *cpu,
> sPAPRMachineState *spapr,
> return H_SUCCESS;
> }
>
> +static target_ulong h_set_sprg0(PowerPCCPU *cpu, sPAPRMachineState *spapr,
> + target_ulong opcode, target_ulong *args)
> +{
> + CPUState *cs = CPU(cpu);
> +
> + set_spr(cs, SPR_SPRG0, args[0], -1L);
This looks correct, but I think set_spr() is serious overkill here.
It does some fancy synchronization designed for setting one cpu's SPR
from an hcall executed on a different CPU. In this case the calling
CPU is just setting its own SPRG0, so just
cpu_synchronize_state()
env->spr[SPR_SPRG0] = XXX
Should be sufficient.
> + return H_SUCCESS;
> +}
> +
> static target_ulong h_set_dabr(PowerPCCPU *cpu, sPAPRMachineState *spapr,
> target_ulong opcode, target_ulong *args)
> {
> @@ -997,6 +1006,10 @@ static void hypercall_register_types(void)
> spapr_register_hypercall(H_REGISTER_VPA, h_register_vpa);
> spapr_register_hypercall(H_CEDE, h_cede);
>
> + /* processor register resource access h-calls */
> + spapr_register_hypercall(H_SET_SPRG0, h_set_sprg0);
> + spapr_register_hypercall(H_SET_MODE, h_set_mode);
> +
> /* "debugger" hcalls (also used by SLOF). Note: We do -not- differenciate
> * here between the "CI" and the "CACHE" variants, they will use whatever
> * mapping attributes qemu is using. When using KVM, the kernel will
> @@ -1013,8 +1026,6 @@ static void hypercall_register_types(void)
> /* qemu/KVM-PPC specific hcalls */
> spapr_register_hypercall(KVMPPC_H_RTAS, h_rtas);
>
> - spapr_register_hypercall(H_SET_MODE, h_set_mode);
> -
> /* ibm,client-architecture-support support */
> spapr_register_hypercall(KVMPPC_H_CAS, h_client_architecture_support);
> }
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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