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memory-device: rewrite address assignment using ranges

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Let's rewrite it properly using ranges. This fixes certain overflows that
are right now possible. E.g.

qemu-system-x86_64 -m 4G,slots=20,maxmem=40G -M pc \
    -object memory-backend-file,id=mem1,share,mem-path=/dev/zero,size=2G
    -device pc-dimm,memdev=mem1,id=dimm1,addr=-0x40000000

Now properly errors out instead of succeeding. (Note that qapi
parsing of huge uint64_t values is broken and fixes are on the way)

"can't add memory device [0xffffffffa0000000:0x80000000], usable range for
memory devices [0x140000000:0xe00000000]"

Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181214131043.25071-3-david@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
This commit is contained in:
David Hildenbrand 2018-12-14 14:10:43 +01:00 committed by Eduardo Habkost
parent f3b0b626f6
commit e3213eb5ec
1 changed files with 26 additions and 25 deletions
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51
hw/mem/memory-device.c
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@ -100,9 +100,8 @@ static uint64_t memory_device_get_free_addr(MachineState *ms,
uint64_t align, uint64_t size, uint64_t align, uint64_t size,
Error **errp) Error **errp)
{ {
uint64_t address_space_start, address_space_end;
GSList *list = NULL, *item; GSList *list = NULL, *item;
uint64_t new_addr = 0; Range as, new = range_empty;
if (!ms->device_memory) { if (!ms->device_memory) {
error_setg(errp, "memory devices (e.g. for memory hotplug) are not " error_setg(errp, "memory devices (e.g. for memory hotplug) are not "
@ -115,13 +114,11 @@ static uint64_t memory_device_get_free_addr(MachineState *ms,
"enabled, please specify the maxmem option"); "enabled, please specify the maxmem option");
return 0; return 0;
} }
address_space_start = ms->device_memory->base; range_init_nofail(&as, ms->device_memory->base,
address_space_end = address_space_start + memory_region_size(&ms->device_memory->mr));
memory_region_size(&ms->device_memory->mr);
g_assert(address_space_end >= address_space_start);
/* address_space_start indicates the maximum alignment we expect */ /* start of address space indicates the maximum alignment we expect */
if (!QEMU_IS_ALIGNED(address_space_start, align)) { if (!QEMU_IS_ALIGNED(range_lob(&as), align)) {
error_setg(errp, "the alignment (0x%" PRIx64 ") is not supported", error_setg(errp, "the alignment (0x%" PRIx64 ") is not supported",
align); align);
return 0; return 0;
@ -145,20 +142,18 @@ static uint64_t memory_device_get_free_addr(MachineState *ms,
} }
if (hint) { if (hint) {
new_addr = *hint; if (range_init(&new, *hint, size) || !range_contains_range(&as, &new)) {
if (new_addr < address_space_start) {
error_setg(errp, "can't add memory device [0x%" PRIx64 ":0x%" PRIx64 error_setg(errp, "can't add memory device [0x%" PRIx64 ":0x%" PRIx64
"] before 0x%" PRIx64, new_addr, size, "], usable range for memory devices [0x%" PRIx64 ":0x%"
address_space_start); PRIx64 "]", *hint, size, range_lob(&as),
return 0; range_size(&as));
} else if ((new_addr + size) > address_space_end) {
error_setg(errp, "can't add memory device [0x%" PRIx64 ":0x%" PRIx64
"] beyond 0x%" PRIx64, new_addr, size,
address_space_end);
return 0; return 0;
} }
} else { } else {
new_addr = address_space_start; if (range_init(&new, range_lob(&as), size)) {
error_setg(errp, "can't add memory device, device too big");
return 0;
}
} }
/* find address range that will fit new memory device */ /* find address range that will fit new memory device */
@ -166,30 +161,36 @@ static uint64_t memory_device_get_free_addr(MachineState *ms,
for (item = list; item; item = g_slist_next(item)) { for (item = list; item; item = g_slist_next(item)) {
const MemoryDeviceState *md = item->data; const MemoryDeviceState *md = item->data;
const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(OBJECT(md)); const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(OBJECT(md));
uint64_t md_size, md_addr; uint64_t next_addr;
Range tmp;
md_addr = mdc->get_addr(md); range_init_nofail(&tmp, mdc->get_addr(md),
md_size = memory_device_get_region_size(md, &error_abort); memory_device_get_region_size(md, &error_abort));
if (ranges_overlap(md_addr, md_size, new_addr, size)) { if (range_overlaps_range(&tmp, &new)) {
if (hint) { if (hint) {
const DeviceState *d = DEVICE(md); const DeviceState *d = DEVICE(md);
error_setg(errp, "address range conflicts with memory device" error_setg(errp, "address range conflicts with memory device"
" id='%s'", d->id ? d->id : "(unnamed)"); " id='%s'", d->id ? d->id : "(unnamed)");
goto out; goto out;
} }
new_addr = QEMU_ALIGN_UP(md_addr + md_size, align);
next_addr = QEMU_ALIGN_UP(range_upb(&tmp) + 1, align);
if (!next_addr || range_init(&new, next_addr, range_size(&new))) {
range_make_empty(&new);
break;
}
} }
} }
if (new_addr + size > address_space_end) { if (!range_contains_range(&as, &new)) {
error_setg(errp, "could not find position in guest address space for " error_setg(errp, "could not find position in guest address space for "
"memory device - memory fragmented due to alignments"); "memory device - memory fragmented due to alignments");
goto out; goto out;
} }
out: out:
g_slist_free(list); g_slist_free(list);
return new_addr; return range_lob(&new);
} }
MemoryDeviceInfoList *qmp_memory_device_list(void) MemoryDeviceInfoList *qmp_memory_device_list(void)