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>
---
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"));
+ _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
--
1.8.3.1
