static void kvm_set_phys_mem(target_phys_addr_t start_addr, ram_addr_t size, ram_addr_t phys_offset) { KVMState *s = kvm_state; ram_addr_t flags = phys_offset & ~TARGET_PAGE_MASK; KVMSlot *mem, old; int err; /* kvm works in page size chunks, but the function may be called with sub-page size and unaligned start address. */ size = TARGET_PAGE_ALIGN(size); start_addr = TARGET_PAGE_ALIGN(start_addr); /* KVM does not support read-only slots */ phys_offset &= ~IO_MEM_ROM; while (1) { mem = kvm_lookup_overlapping_slot(s, start_addr, start_addr + size); if (!mem) { break; } if (flags < IO_MEM_UNASSIGNED && start_addr >= mem->start_addr && (start_addr + size <= mem->start_addr + mem->memory_size) && (phys_offset - start_addr == mem->phys_offset - mem->start_addr)) { /* The new slot fits into the existing one and comes with * identical parameters - nothing to be done. */ return; } old = *mem; /* unregister the overlapping slot */ mem->memory_size = 0; err = kvm_set_user_memory_region(s, mem); if (err) { fprintf(stderr, "%s: error unregistering overlapping slot: %s\n", __func__, strerror(-err)); abort(); } /* Workaround for older KVM versions: we can't join slots, even not by * unregistering the previous ones and then registering the larger * slot. We have to maintain the existing fragmentation. Sigh. * * This workaround assumes that the new slot starts at the same * address as the first existing one. If not or if some overlapping * slot comes around later, we will fail (not seen in practice so far) * - and actually require a recent KVM version. */ if (s->broken_set_mem_region && old.start_addr == start_addr && old.memory_size < size && flags < IO_MEM_UNASSIGNED) { mem = kvm_alloc_slot(s); mem->memory_size = old.memory_size; mem->start_addr = old.start_addr; mem->phys_offset = old.phys_offset; mem->flags = 0; err = kvm_set_user_memory_region(s, mem); if (err) { fprintf(stderr, "%s: error updating slot: %s\n", __func__, strerror(-err)); abort(); } start_addr += old.memory_size; phys_offset += old.memory_size; size -= old.memory_size; continue; } /* register prefix slot */ if (old.start_addr < start_addr) { mem = kvm_alloc_slot(s); mem->memory_size = start_addr - old.start_addr; mem->start_addr = old.start_addr; mem->phys_offset = old.phys_offset; mem->flags = 0; err = kvm_set_user_memory_region(s, mem); if (err) { fprintf(stderr, "%s: error registering prefix slot: %s\n", __func__, strerror(-err)); abort(); } } /* register suffix slot */ if (old.start_addr + old.memory_size > start_addr + size) { ram_addr_t size_delta; mem = kvm_alloc_slot(s); mem->start_addr = start_addr + size; size_delta = mem->start_addr - old.start_addr; mem->memory_size = old.memory_size - size_delta; mem->phys_offset = old.phys_offset + size_delta; mem->flags = 0; err = kvm_set_user_memory_region(s, mem); if (err) { fprintf(stderr, "%s: error registering suffix slot: %s\n", __func__, strerror(-err)); abort(); } } } /* in case the KVM bug workaround already "consumed" the new slot */ if (!size) return; /* KVM does not need to know about this memory */ if (flags >= IO_MEM_UNASSIGNED) return; mem = kvm_alloc_slot(s); mem->memory_size = size; mem->start_addr = start_addr; mem->phys_offset = phys_offset; mem->flags = 0; err = kvm_set_user_memory_region(s, mem); if (err) { fprintf(stderr, "%s: error registering slot: %s\n", __func__, strerror(-err)); abort(); } }