Re: [PATCH v3 03/20] exec: Let qemu_ram_*() functions take a const pointer argument

[Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>]

On 2/20/20 2:21 PM, Paolo Bonzini wrote:
> On 20/02/20 14:05, Philippe Mathieu-Daudé wrote:
> > Signed-off-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>
> > ---
> >   include/exec/cpu-common.h     | 6 +++---
> >   include/sysemu/xen-mapcache.h | 4 ++--
> >   exec.c                        | 8 ++++----
> >   hw/i386/xen/xen-mapcache.c    | 2 +-
> >   4 files changed, 10 insertions(+), 10 deletions(-)
> >
> > diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
> > index 81753bbb34..05ac1a5d69 100644
> > --- a/include/exec/cpu-common.h
> > +++ b/include/exec/cpu-common.h
> > @@ -48,11 +48,11 @@ typedef uint32_t CPUReadMemoryFunc(void *opaque, hwaddr addr);
> >   
> >   void qemu_ram_remap(ram_addr_t addr, ram_addr_t length);
> >   /* This should not be used by devices.  */
> > -ram_addr_t qemu_ram_addr_from_host(void *ptr);
> > +ram_addr_t qemu_ram_addr_from_host(const void *ptr);
>
> This is a bit ugly, because the pointer _can_ be modified via
> qemu_map_ram_ptr.

OK.

> Is this needed for the rest of the series to apply?

No!

> Paolo
>
> >   RAMBlock *qemu_ram_block_by_name(const char *name);
> > -RAMBlock *qemu_ram_block_from_host(void *ptr, bool round_offset,
> > +RAMBlock *qemu_ram_block_from_host(const void *ptr, bool round_offset,
> >                                      ram_addr_t *offset);
> > -ram_addr_t qemu_ram_block_host_offset(RAMBlock *rb, void *host);
> > +ram_addr_t qemu_ram_block_host_offset(RAMBlock *rb, const void *host);
> >   void qemu_ram_set_idstr(RAMBlock *block, const char *name, DeviceState *dev);
> >   void qemu_ram_unset_idstr(RAMBlock *block);
> >   const char *qemu_ram_get_idstr(RAMBlock *rb);
> > diff --git a/include/sysemu/xen-mapcache.h b/include/sysemu/xen-mapcache.h
> > index c8e7c2f6cf..81e9aa2fa6 100644
> > --- a/include/sysemu/xen-mapcache.h
> > +++ b/include/sysemu/xen-mapcache.h
> > @@ -19,7 +19,7 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f,
> >                           void *opaque);
> >   uint8_t *xen_map_cache(hwaddr phys_addr, hwaddr size,
> >                          uint8_t lock, bool dma);
> > -ram_addr_t xen_ram_addr_from_mapcache(void *ptr);
> > +ram_addr_t xen_ram_addr_from_mapcache(const void *ptr);
> >   void xen_invalidate_map_cache_entry(uint8_t *buffer);
> >   void xen_invalidate_map_cache(void);
> >   uint8_t *xen_replace_cache_entry(hwaddr old_phys_addr,
> > @@ -40,7 +40,7 @@ static inline uint8_t *xen_map_cache(hwaddr phys_addr,
> >       abort();
> >   }
> >   
> > -static inline ram_addr_t xen_ram_addr_from_mapcache(void *ptr)
> > +static inline ram_addr_t xen_ram_addr_from_mapcache(const void *ptr)
> >   {
> >       abort();
> >   }
> > diff --git a/exec.c b/exec.c
> > index 8e9cc3b47c..02b4e6ea41 100644
> > --- a/exec.c
> > +++ b/exec.c
> > @@ -2614,7 +2614,7 @@ static void *qemu_ram_ptr_length(RAMBlock *ram_block, ram_addr_t addr,
> >   }
> >   
> >   /* Return the offset of a hostpointer within a ramblock */
> > -ram_addr_t qemu_ram_block_host_offset(RAMBlock *rb, void *host)
> > +ram_addr_t qemu_ram_block_host_offset(RAMBlock *rb, const void *host)
> >   {
> >       ram_addr_t res = (uint8_t *)host - (uint8_t *)rb->host;
> >       assert((uintptr_t)host >= (uintptr_t)rb->host);
> > @@ -2640,11 +2640,11 @@ ram_addr_t qemu_ram_block_host_offset(RAMBlock *rb, void *host)
> >    * pointer, such as a reference to the region that includes the incoming
> >    * ram_addr_t.
> >    */
> > -RAMBlock *qemu_ram_block_from_host(void *ptr, bool round_offset,
> > +RAMBlock *qemu_ram_block_from_host(const void *ptr, bool round_offset,
> >                                      ram_addr_t *offset)
> >   {
> >       RAMBlock *block;
> > -    uint8_t *host = ptr;
> > +    const uint8_t *host = ptr;
> >   
> >       if (xen_enabled()) {
> >           ram_addr_t ram_addr;
> > @@ -2705,7 +2705,7 @@ RAMBlock *qemu_ram_block_by_name(const char *name)
> >   
> >   /* Some of the softmmu routines need to translate from a host pointer
> >      (typically a TLB entry) back to a ram offset.  */
> > -ram_addr_t qemu_ram_addr_from_host(void *ptr)
> > +ram_addr_t qemu_ram_addr_from_host(const void *ptr)
> >   {
> >       RAMBlock *block;
> >       ram_addr_t offset;
> > diff --git a/hw/i386/xen/xen-mapcache.c b/hw/i386/xen/xen-mapcache.c
> > index 5b120ed44b..432ad3354d 100644
> > --- a/hw/i386/xen/xen-mapcache.c
> > +++ b/hw/i386/xen/xen-mapcache.c
> > @@ -363,7 +363,7 @@ uint8_t *xen_map_cache(hwaddr phys_addr, hwaddr size,
> >       return p;
> >   }
> >   
> > -ram_addr_t xen_ram_addr_from_mapcache(void *ptr)
> > +ram_addr_t xen_ram_addr_from_mapcache(const void *ptr)
> >   {
> >       MapCacheEntry *entry = NULL;
> >       MapCacheRev *reventry;