diff options
| -rw-r--r-- | kvm-all.c | 166 |
1 files changed, 114 insertions, 52 deletions
@@ -98,19 +98,31 @@ static KVMSlot *kvm_lookup_matching_slot(KVMState *s, return NULL; } -static KVMSlot *kvm_lookup_slot(KVMState *s, target_phys_addr_t start_addr) +/* + * Find overlapping slot with lowest start address + */ +static KVMSlot *kvm_lookup_overlapping_slot(KVMState *s, + target_phys_addr_t start_addr, + target_phys_addr_t end_addr) { + KVMSlot *found = NULL; int i; for (i = 0; i < ARRAY_SIZE(s->slots); i++) { KVMSlot *mem = &s->slots[i]; - if (start_addr >= mem->start_addr && - start_addr < (mem->start_addr + mem->memory_size)) - return mem; + if (mem->memory_size == 0 || + (found && found->start_addr < mem->start_addr)) { + continue; + } + + if (end_addr > mem->start_addr && + start_addr < mem->start_addr + mem->memory_size) { + found = mem; + } } - return NULL; + return found; } static int kvm_set_user_memory_region(KVMState *s, KVMSlot *slot) @@ -567,7 +579,8 @@ void kvm_set_phys_mem(target_phys_addr_t start_addr, { KVMState *s = kvm_state; ram_addr_t flags = phys_offset & ~TARGET_PAGE_MASK; - KVMSlot *mem; + KVMSlot *mem, old; + int err; if (start_addr & ~TARGET_PAGE_MASK) { fprintf(stderr, "Only page-aligned memory slots supported\n"); @@ -577,55 +590,100 @@ void kvm_set_phys_mem(target_phys_addr_t start_addr, /* KVM does not support read-only slots */ phys_offset &= ~IO_MEM_ROM; - mem = kvm_lookup_slot(s, start_addr); - if (mem) { - if (flags >= IO_MEM_UNASSIGNED) { - mem->memory_size = 0; - mem->start_addr = start_addr; - mem->phys_offset = 0; - mem->flags = 0; - - kvm_set_user_memory_region(s, mem); - } else if (start_addr >= mem->start_addr && - (start_addr + size) <= (mem->start_addr + - mem->memory_size)) { - KVMSlot slot; - target_phys_addr_t mem_start; - ram_addr_t mem_size, mem_offset; - - /* Not splitting */ - if ((phys_offset - (start_addr - mem->start_addr)) == - mem->phys_offset) - return; - - /* unregister whole slot */ - memcpy(&slot, mem, sizeof(slot)); - mem->memory_size = 0; - kvm_set_user_memory_region(s, mem); - - /* register prefix slot */ - mem_start = slot.start_addr; - mem_size = start_addr - slot.start_addr; - mem_offset = slot.phys_offset; - if (mem_size) - kvm_set_phys_mem(mem_start, mem_size, mem_offset); - - /* register new slot */ - kvm_set_phys_mem(start_addr, size, phys_offset); - - /* register suffix slot */ - mem_start = start_addr + size; - mem_offset += mem_size + size; - mem_size = slot.memory_size - mem_size - size; - if (mem_size) - kvm_set_phys_mem(mem_start, mem_size, mem_offset); + 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; - } else { - printf("Registering overlapping slot\n"); + } + + 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 (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; @@ -636,8 +694,12 @@ void kvm_set_phys_mem(target_phys_addr_t start_addr, mem->phys_offset = phys_offset; mem->flags = 0; - kvm_set_user_memory_region(s, mem); - /* FIXME deal with errors */ + err = kvm_set_user_memory_region(s, mem); + if (err) { + fprintf(stderr, "%s: error registering slot: %s\n", __func__, + strerror(-err)); + abort(); + } } int kvm_ioctl(KVMState *s, int type, ...) |
