On 8 April 2015 at 12:03, Paolo Bonzini <pbonz...@redhat.com> wrote: > > > On 07/04/2015 22:09, Peter Maydell wrote: >> +#ifdef NEED_CPU_H >> +uint32_t address_space_lduw(AddressSpace *as, hwaddr addr, >> + MemTxAttrs attrs, MemTxResult *result); >> +uint32_t address_space_ldl(AddressSpace *as, hwaddr addr, >> + MemTxAttrs attrs, MemTxResult *result); >> +uint64_t address_space_ldq(AddressSpace *as, hwaddr addr, >> + MemTxAttrs attrs, MemTxResult *result); >> +void address_space_stl_notdirty(AddressSpace *as, hwaddr addr, uint32_t val, >> + MemTxAttrs attrs, MemTxResult *result); >> +void address_space_stw(AddressSpace *as, hwaddr addr, uint32_t val, >> + MemTxAttrs attrs, MemTxResult *result); >> +void address_space_stl(AddressSpace *as, hwaddr addr, uint32_t val, >> + MemTxAttrs attrs, MemTxResult *result); >> +void address_space_stq(AddressSpace *as, hwaddr addr, uint64_t val, >> + MemTxAttrs attrs, MemTxResult *result); >> +#endif > > I think we do not want to expose these at all (or at least, all users > should really be CPUs and hence use *_phys functions). > > S390 is always big-endian, and watch_mem_read/write can use the same > buffer trick as subpages (and in fact should probably use memattrs as well). > > So, please at least add a comment that these functions are deprecated, > and check if watch_mem_read/write should be handled like subpages.
I looked at the subpages code, and it seems to me that it's the other way around -- the subpages code should use these new functions. At the moment the subpage handlers use address_space_read/write to pull the data into a buffer, and then use the ldl_p/stl_p functions to do "read data from target-CPU order buffer into host variable". It would be better for them to just directly be able to say "do a ld/st in target-CPU order into this host variable", which is the purpose of these new functions. Indirecting via a buffer seems like an ugly workaround for not having the direct operation. -- PMM
