On Mon, Aug 31, 2015 at 08:46:01PM +0200, Thomas Huth wrote: > From: Michael Ellerman <mich...@ellerman.id.au> > > Some powerpc systems have support for a hardware random number generator > (hwrng). If such a hwrng is present the host kernel can provide access > to it via the H_RANDOM hcall. > > The kernel advertises the presence of a hwrng with the KVM_CAP_PPC_HWRNG > capability. If this is detected we add the appropriate device tree bits > to advertise the presence of the hwrng to the guest kernel. > > Signed-off-by: Michael Ellerman <mich...@ellerman.id.au> > [thuth: Refreshed patch so it applies to QEMU master branch] > Signed-off-by: Thomas Huth <th...@redhat.com>
So, I'm confused by one thing.
I thought new kernel handled hcalls were supposed to be disabled by
default, but I don't see any calls to kvmppc_enable_hcall() to turn on
H_RANDOM.
> ---
> hw/ppc/spapr.c | 16 ++++++++++++++++
> include/hw/ppc/spapr.h | 1 +
> target-ppc/kvm.c | 5 +++++
> target-ppc/kvm_ppc.h | 5 +++++
> 4 files changed, 27 insertions(+)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index bf0c64f..bc3a112 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -466,6 +466,22 @@ static void *spapr_create_fdt_skel(hwaddr initrd_base,
>
> _FDT((fdt_end_node(fdt)));
>
> + if (kvmppc_hwrng_present()) {
> + _FDT(fdt_begin_node(fdt, "ibm,platform-facilities"));
> +
> + _FDT(fdt_property_string(fdt, "name", "ibm,platform-facilities"));
Also, "name" properties don't need to be set in flattened trees -
that's implicit in the node name itself.
> + _FDT(fdt_property_string(fdt, "device_type",
> + "ibm,platform-facilities"));
> + _FDT(fdt_property_cell(fdt, "#address-cells", 0x1));
> + _FDT(fdt_property_cell(fdt, "#size-cells", 0x0));
> + _FDT(fdt_begin_node(fdt, "ibm,random-v1"));
> + _FDT(fdt_property_string(fdt, "name", "ibm,random-v1"));
> + _FDT(fdt_property_string(fdt, "compatible", "ibm,random"));
> + _FDT((fdt_end_node(fdt)));
> + }
> +
> + _FDT((fdt_end_node(fdt)));
> +
> /* event-sources */
> spapr_events_fdt_skel(fdt, epow_irq);
>
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index 91a61ab..ab8906f 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -331,6 +331,7 @@ struct sPAPRMachineState {
> #define H_SET_MPP 0x2D0
> #define H_GET_MPP 0x2D4
> #define H_XIRR_X 0x2FC
> +#define H_RANDOM 0x300
> #define H_SET_MODE 0x31C
> #define MAX_HCALL_OPCODE H_SET_MODE
>
> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> index 110436d..7317f8f 100644
> --- a/target-ppc/kvm.c
> +++ b/target-ppc/kvm.c
> @@ -2484,3 +2484,8 @@ int kvm_arch_msi_data_to_gsi(uint32_t data)
> {
> return data & 0xffff;
> }
> +
> +bool kvmppc_hwrng_present(void)
> +{
> + return kvm_enabled() && kvm_check_extension(kvm_state,
> KVM_CAP_PPC_HWRNG);
> +}
> diff --git a/target-ppc/kvm_ppc.h b/target-ppc/kvm_ppc.h
> index 4d30e27..62ff601 100644
> --- a/target-ppc/kvm_ppc.h
> +++ b/target-ppc/kvm_ppc.h
> @@ -55,6 +55,7 @@ void kvmppc_hash64_free_pteg(uint64_t token);
> void kvmppc_hash64_write_pte(CPUPPCState *env, target_ulong pte_index,
> target_ulong pte0, target_ulong pte1);
> bool kvmppc_has_cap_fixup_hcalls(void);
> +bool kvmppc_hwrng_present(void);
>
> #else
>
> @@ -248,6 +249,10 @@ static inline bool kvmppc_has_cap_fixup_hcalls(void)
> abort();
> }
>
> +static inline bool kvmppc_hwrng_present(void)
> +{
> + return false;
> +}
> #endif
>
> #ifndef CONFIG_KVM
--
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
pgpt4KY1bcxmj.pgp
Description: PGP signature
