On Thu, Sep 17, 2015 at 10:49:41AM +0200, Thomas Huth wrote: > 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 <thuth@xxxxxxxxxx> Thanks, applied to spapr-next. -- 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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