memory: minor documentation fixes/enhancements

ram: ram@0x00000000-0xffffffff

The is a (simplified) PC memory map. The 4GB RAM block is mapped into the

This is a (simplified) PC memory map. The 4GB RAM block is mapped into the

system address space via two aliases: "lomem" is a 1:1 mapping of the first

3.5GB; "himem" maps the last 0.5GB at address 4GB.  This leaves 0.5GB for the

so-called PCI hole, that allows a 32-bit PCI bus to exist in a system with

 - .impl.min_access_size, .impl.max_access_size define the access sizes

   (in bytes) supported by the *implementation*; other access sizes will be

   emulated using the ones available.  For example a 4-byte write will be

   emulated using four 1-byte write, if .impl.max_access_size = 1.

   emulated using four 1-byte writes, if .impl.max_access_size = 1.

 - .impl.valid specifies that the *implementation* only supports unaligned

   accesses; unaligned accesses will be emulated by two aligned accesses.

 - .old_portio and .old_mmio can be used to ease porting from code using

/**

 * memory_region_init: Initialize a memory region

 *

 * The region typically acts as a container for other memory regions.  Us

 * The region typically acts as a container for other memory regions.  Use

 * memory_region_add_subregion() to add subregions.

 *

 * @mr: the #MemoryRegion to be initialized

/**

 * memory_region_init_io: Initialize an I/O memory region.

 *

 * Accesses into the region will be cause the callbacks in @ops to be called.

 * Accesses into the region will cause the callbacks in @ops to be called.

 * if @size is nonzero, subregions will be clipped to @size.

 *

 * @mr: the #MemoryRegion to be initialized.

/**

 * memory_region_init_ram:  Initialize RAM memory region.  Accesses into the

 *                          region will be modify memory directly.

 *                          region will modify memory directly.

 *

 * @mr: the #MemoryRegion to be initialized.

 * @dev: a device associated with the region; may be %NULL.

/**

 * memory_region_init_ram:  Initialize RAM memory region from a user-provided.

 *                          pointer.  Accesses into the region will be modify

 *                          pointer.  Accesses into the region will modify

 *                          memory directly.

 *

 * @mr: the #MemoryRegion to be initialized.

                                   uint64_t size);

/**

 * memory_region_destroy: Destroy a memory region and relaim all resources.

 * memory_region_destroy: Destroy a memory region and reclaim all resources.

 *

 * @mr: the region to be destroyed.  May not currently be a subregion

 *      (see memory_region_add_subregion()) or referenced in an alias

 *

 * Marks a word in an IO region (initialized with memory_region_init_io())

 * as a trigger for an eventfd event.  The I/O callback will not be called.

 * The caller must be prepared to handle failure (hat is, take the required

 * The caller must be prepared to handle failure (that is, take the required

 * action if the callback _is_ called).

 *

 * @mr: the memory region being updated.

                               int fd);

/**

 * memory_region_del_eventfd: Cancel and eventfd.

 * memory_region_del_eventfd: Cancel an eventfd.

 *

 * Cancels an eventfd trigger request by a previous memory_region_add_eventfd()

 * call.

 * Cancels an eventfd trigger requested by a previous

 * memory_region_add_eventfd() call.

 *

 * @mr: the memory region being updated.

 * @addr: the address within @mr that is to be monitored

                               uint64_t data,

                               int fd);

/**

 * memory_region_add_subregion: Add a sub-region to a container.

 * memory_region_add_subregion: Add a subregion to a container.

 *

 * Adds a sub-region at @offset.  The sub-region may not overlap with other

 * Adds a subregion at @offset.  The subregion may not overlap with other

 * subregions (except for those explicitly marked as overlapping).  A region

 * may only be added once as a subregion (unless removed with

 * memory_region_del_subregion()); use memory_region_init_alias() if you

                                 target_phys_addr_t offset,

                                 MemoryRegion *subregion);

/**

 * memory_region_add_subregion: Add a sub-region to a container, with overlap.

 * memory_region_add_subregion: Add a subregion to a container, with overlap.

 *

 * Adds a sub-region at @offset.  The sub-region may overlap with other

 * Adds a subregion at @offset.  The subregion may overlap with other

 * subregions.  Conflicts are resolved by having a higher @priority hide a

 * lower @priority. Subregions without priority are taken as @priority 0.

 * A region may only be added once as a subregion (unless removed with

void memory_region_del_subregion(MemoryRegion *mr,

                                 MemoryRegion *subregion);

/* Start a transaction; changes will be accumulated and made visible only

 * when the transaction ends.

/**

 * memory_region_transaction_begin: Start a transaction.

 *

 * During a transaction, changes will be accumulated and made visible

 * only when the transaction ends (is commited).

 */

void memory_region_transaction_begin(void);

/* Commit a transaction and make changes visible to the guest.

/**

 * memory_region_transaction_commit: Commit a transaction and make changes

 *                                   visible to the guest.

 */

void memory_region_transaction_commit(void);