Aurelien Jarno <aurelien@xxxxxxxxxxx> writes: > Hi, > > I have noticed that virtio-rng only returns zero for kernels >= 2.6.33 > built with CONFIG_HW_RANDOM=m. This is a bit much too predictable for a > random generator ;-). Wow. Fortunately, all of SLES, RHEL, Ubuntu or Fedora set CONFIG_HW_RANDOM=y. What do they know that we don't? Oops, looks like Debian testing: config-3.2.0-4-amd64:CONFIG_HW_RANDOM=m > The reason for that is virtio expects guest real addresses, while > rng_core.ko (ie when built as a module) is passing a vmalloced buffer > to the virtio-rng read function, declared as such: > > static u8 rng_buffer[SMP_CACHE_BYTES < 32 ? 32 : SMP_CACHE_BYTES] > __cacheline_aligned; Yuck... It would be nice if this has oopsed. Jens, what about this patch? Cheers, Rusty. Subject: scatterlist: sg_set_buf() argument must be in linear mapping. Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx> diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index 4bd6c06..9365375 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -111,6 +111,9 @@ static inline struct page *sg_page(struct scatterlist *sg) static inline void sg_set_buf(struct scatterlist *sg, const void *buf, unsigned int buflen) { +#ifdef CONFIG_DEBUG_SG + BUG_ON(!virt_addr_valid(buf)); +#endif sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf)); } -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html