On Tue, Jan 16, 2018 at 09:25:12PM +0100, David Hildenbrand wrote: > > > +struct kvm_s390_gisa { > > + u32 next_alert; > > + u8 ipm; > > + u8 reserved01; > > + u8:6; > > + u8 g:1; > > + u8 c:1; > > + u8 iam; > > + u8 reserved02[4]; > > + u32 airq_count; > > +}; > > + > > /* > > - * sie_page2 has to be allocated as DMA because fac_list and crycb need > > - * 31bit addresses in the sie control block. > > + * sie_page2 has to be allocated as DMA because fac_list, crycb and > > + * gisa need 31bit addresses in the sie control block. > > */ > > struct sie_page2 { > > __u64 fac_list[S390_ARCH_FAC_LIST_SIZE_U64]; /* 0x0000 */ > > struct kvm_s390_crypto_cb crycb; /* 0x0800 */ > > - u8 reserved900[0x1000 - 0x900]; /* 0x0900 */ > > + struct kvm_s390_gisa gisa __aligned(sizeof(struct kvm_s390_gisa)); /* 0x0900 */ > > can we instead specify sie_page2 as packed if really needed? (I can see > that we have a BUILD_BUG_ON below, which is nice) > > (alignment within well defined data structures looks strange) The alignment, if needed, should go to the definition of struct kvm_s390_gisa above. The structure needs at least an alignment of eight bytes since bitops are used to modify ipm (in a later patch), by using a (long *) cast to this structure. But of course it is all naturally aligned anyway... ;) -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html