/* If current_page is non-NULL, pc must have been increased exactly by 1. */
static u8 *map_code_page(const struct guest_paging_structures *pg_structs,
unsigned long pc, u8 *current_page)
{
/* If page offset is 0, previous pc was pointing to a different page,
* and we have to map a new one now. */
if (current_page && ((pc & ~PAGE_MASK) != 0))
return current_page;
return paging_get_guest_pages(pg_structs, pc, 1, PAGE_READONLY_FLAGS);
}
const u8 *vcpu_map_inst(const struct guest_paging_structures *pg_structs,
unsigned long pc, unsigned int *size)
{
unsigned short bytes_avail;
u8 *page = NULL;
if (!*size)
goto out_err;
page = paging_get_guest_pages(pg_structs, pc,
1, PAGE_READONLY_FLAGS);
if (!page)
goto out_err;
/* Number of bytes available before page boundary */
bytes_avail = PAGE_SIZE - (pc & PAGE_OFFS_MASK);
if (*size > bytes_avail)
*size = bytes_avail;
return &page[pc & PAGE_OFFS_MASK];
out_err:
return NULL;
}