diff options
author | David Hildenbrand <david@redhat.com> | 2023-06-22 12:18:23 +0200 |
---|---|---|
committer | Maciej S. Szmigiero <maciej.szmigiero@oracle.com> | 2023-11-03 20:26:59 +0100 |
commit | 6c1b28e9e405da8cfb7296b9efa2b85650086784 (patch) | |
tree | 082f57ac757c83839d79c900539ff6e225dfe10d /hw/mem | |
parent | d762bf97931b58839316b68a570eecc6143c9e3e (diff) | |
download | qemu-6c1b28e9e405da8cfb7296b9efa2b85650086784.zip qemu-6c1b28e9e405da8cfb7296b9efa2b85650086784.tar.gz qemu-6c1b28e9e405da8cfb7296b9efa2b85650086784.tar.bz2 |
memory-device: Support empty memory devices
Let's support empty memory devices -- memory devices that don't have a
memory device region in the current configuration. hv-balloon with an
optional memdev is the primary use case.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Diffstat (limited to 'hw/mem')
-rw-r--r-- | hw/mem/memory-device.c | 43 |
1 files changed, 40 insertions, 3 deletions
diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c index ae38f48..db702cc 100644 --- a/hw/mem/memory-device.c +++ b/hw/mem/memory-device.c @@ -20,6 +20,22 @@ #include "exec/address-spaces.h" #include "trace.h" +static bool memory_device_is_empty(const MemoryDeviceState *md) +{ + const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(md); + Error *local_err = NULL; + MemoryRegion *mr; + + /* dropping const here is fine as we don't touch the memory region */ + mr = mdc->get_memory_region((MemoryDeviceState *)md, &local_err); + if (local_err) { + /* Not empty, we'll report errors later when ontaining the MR again. */ + error_free(local_err); + return false; + } + return !mr; +} + static gint memory_device_addr_sort(gconstpointer a, gconstpointer b) { const MemoryDeviceState *md_a = MEMORY_DEVICE(a); @@ -249,6 +265,10 @@ static uint64_t memory_device_get_free_addr(MachineState *ms, uint64_t next_addr; Range tmp; + if (memory_device_is_empty(md)) { + continue; + } + range_init_nofail(&tmp, mdc->get_addr(md), memory_device_get_region_size(md, &error_abort)); @@ -292,6 +312,7 @@ MemoryDeviceInfoList *qmp_memory_device_list(void) const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(item->data); MemoryDeviceInfo *info = g_new0(MemoryDeviceInfo, 1); + /* Let's query infotmation even for empty memory devices. */ mdc->fill_device_info(md, info); QAPI_LIST_APPEND(tail, info); @@ -311,7 +332,7 @@ static int memory_device_plugged_size(Object *obj, void *opaque) const MemoryDeviceState *md = MEMORY_DEVICE(obj); const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(obj); - if (dev->realized) { + if (dev->realized && !memory_device_is_empty(md)) { *size += mdc->get_plugged_size(md, &error_abort); } } @@ -337,6 +358,11 @@ void memory_device_pre_plug(MemoryDeviceState *md, MachineState *ms, uint64_t addr, align = 0; MemoryRegion *mr; + /* We support empty memory devices even without device memory. */ + if (memory_device_is_empty(md)) { + return; + } + if (!ms->device_memory) { error_setg(errp, "the configuration is not prepared for memory devices" " (e.g., for memory hotplug), consider specifying the" @@ -380,10 +406,17 @@ out: void memory_device_plug(MemoryDeviceState *md, MachineState *ms) { const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(md); - const unsigned int memslots = memory_device_get_memslots(md); - const uint64_t addr = mdc->get_addr(md); + unsigned int memslots; + uint64_t addr; MemoryRegion *mr; + if (memory_device_is_empty(md)) { + return; + } + + memslots = memory_device_get_memslots(md); + addr = mdc->get_addr(md); + /* * We expect that a previous call to memory_device_pre_plug() succeeded, so * it can't fail at this point. @@ -408,6 +441,10 @@ void memory_device_unplug(MemoryDeviceState *md, MachineState *ms) const unsigned int memslots = memory_device_get_memslots(md); MemoryRegion *mr; + if (memory_device_is_empty(md)) { + return; + } + /* * We expect that a previous call to memory_device_pre_plug() succeeded, so * it can't fail at this point. |