diff options
Diffstat (limited to 'hw')
| -rw-r--r-- | hw/mem/memory-device.c | 29 | ||||
| -rw-r--r-- | hw/virtio/vhost.c | 18 |
2 files changed, 41 insertions, 6 deletions
diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c index d37cfbd65d..1b14ba5661 100644 --- a/hw/mem/memory-device.c +++ b/hw/mem/memory-device.c @@ -62,19 +62,44 @@ static unsigned int memory_device_get_memslots(MemoryDeviceState *md) return 1; } +/* + * Memslots that are reserved by memory devices (required but still reported + * as free from KVM / vhost). + */ +static unsigned int get_reserved_memslots(MachineState *ms) +{ + if (ms->device_memory->used_memslots > + ms->device_memory->required_memslots) { + /* This is unexpected, and we warned already in the memory notifier. */ + return 0; + } + return ms->device_memory->required_memslots - + ms->device_memory->used_memslots; +} + +unsigned int memory_devices_get_reserved_memslots(void) +{ + if (!current_machine->device_memory) { + return 0; + } + return get_reserved_memslots(current_machine); +} + static void memory_device_check_addable(MachineState *ms, MemoryDeviceState *md, MemoryRegion *mr, Error **errp) { const uint64_t used_region_size = ms->device_memory->used_region_size; const uint64_t size = memory_region_size(mr); const unsigned int required_memslots = memory_device_get_memslots(md); + const unsigned int reserved_memslots = get_reserved_memslots(ms); /* we will need memory slots for kvm and vhost */ - if (kvm_enabled() && kvm_get_free_memslots() < required_memslots) { + if (kvm_enabled() && + kvm_get_free_memslots() < required_memslots + reserved_memslots) { error_setg(errp, "hypervisor has not enough free memory slots left"); return; } - if (vhost_get_free_memslots() < required_memslots) { + if (vhost_get_free_memslots() < required_memslots + reserved_memslots) { error_setg(errp, "a used vhost backend has not enough free memory slots left"); return; } diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 82c3d20521..041a05d5f1 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -23,6 +23,7 @@ #include "qemu/log.h" #include "standard-headers/linux/vhost_types.h" #include "hw/virtio/virtio-bus.h" +#include "hw/mem/memory-device.h" #include "migration/blocker.h" #include "migration/qemu-file-types.h" #include "sysemu/dma.h" @@ -1423,7 +1424,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque, VhostBackendType backend_type, uint32_t busyloop_timeout, Error **errp) { - unsigned int used; + unsigned int used, reserved, limit; uint64_t features; int i, r, n_initialized_vqs = 0; @@ -1529,9 +1530,18 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque, } else { used = used_memslots; } - if (used > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) { - error_setg(errp, "vhost backend memory slots limit is less" - " than current number of present memory slots"); + /* + * We assume that all reserved memslots actually require a real memslot + * in our vhost backend. This might not be true, for example, if the + * memslot would be ROM. If ever relevant, we can optimize for that -- + * but we'll need additional information about the reservations. + */ + reserved = memory_devices_get_reserved_memslots(); + limit = hdev->vhost_ops->vhost_backend_memslots_limit(hdev); + if (used + reserved > limit) { + error_setg(errp, "vhost backend memory slots limit (%d) is less" + " than current number of used (%d) and reserved (%d)" + " memory slots for memory devices.", limit, used, reserved); r = -EINVAL; goto fail_busyloop; } |