From 4d9392be6c1aada69ce86c0f6584128976985394 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Thu, 17 Sep 2015 10:49:41 +0200 Subject: ppc/spapr: Implement H_RANDOM hypercall in QEMU The PAPR interface defines a hypercall to pass high-quality hardware generated random numbers to guests. Recent kernels can already provide this hypercall to the guest if the right hardware random number generator is available. But in case the user wants to use another source like EGD, or QEMU is running with an older kernel, we should also have this call in QEMU, so that guests that do not support virtio-rng yet can get good random numbers, too. This patch now adds a new pseudo-device to QEMU that either directly provides this hypercall to the guest or is able to enable the in-kernel hypercall if available. The in-kernel hypercall can be enabled with the use-kvm property, e.g.: qemu-system-ppc64 -device spapr-rng,use-kvm=true For handling the hypercall in QEMU instead, a "RngBackend" is required since the hypercall should provide "good" random data instead of pseudo-random (like from a "simple" library function like rand() or g_random_int()). Since there are multiple RngBackends available, the user must select an appropriate back-end via the "rng" property of the device, e.g.: qemu-system-ppc64 -object rng-random,filename=/dev/hwrng,id=gid0 \ -device spapr-rng,rng=gid0 ... See http://wiki.qemu-project.org/Features-Done/VirtIORNG for other example of specifying RngBackends. Signed-off-by: Thomas Huth Signed-off-by: David Gibson --- include/hw/ppc/spapr.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/hw/ppc/spapr.h') diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h index ffb108d64c..56c5b0b2b8 100644 --- a/include/hw/ppc/spapr.h +++ b/include/hw/ppc/spapr.h @@ -334,6 +334,7 @@ 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 @@ -612,10 +613,13 @@ struct sPAPRConfigureConnectorState { void spapr_ccs_reset_hook(void *opaque); #define TYPE_SPAPR_RTC "spapr-rtc" +#define TYPE_SPAPR_RNG "spapr-rng" void spapr_rtc_read(DeviceState *dev, struct tm *tm, uint32_t *ns); int spapr_rtc_import_offset(DeviceState *dev, int64_t legacy_offset); +int spapr_rng_populate_dt(void *fdt); + #define SPAPR_MEMORY_BLOCK_SIZE (1 << 28) /* 256MB */ /* -- cgit v1.2.3-55-g7522