diff options
Diffstat (limited to 'hw/virtio/virtio-mem.c')
| -rw-r--r-- | hw/virtio/virtio-mem.c | 105 |
1 files changed, 100 insertions, 5 deletions
diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c index d5a578142b..04c223b0c9 100644 --- a/hw/virtio/virtio-mem.c +++ b/hw/virtio/virtio-mem.c @@ -33,6 +33,14 @@ #include "trace.h" /* + * We only had legacy x86 guests that did not support + * VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE. Other targets don't have legacy guests. + */ +#if defined(TARGET_X86_64) || defined(TARGET_I386) +#define VIRTIO_MEM_HAS_LEGACY_GUESTS +#endif + +/* * Let's not allow blocks smaller than 1 MiB, for example, to keep the tracking * bitmap small. */ @@ -110,6 +118,19 @@ static uint64_t virtio_mem_default_block_size(RAMBlock *rb) return MAX(page_size, VIRTIO_MEM_MIN_BLOCK_SIZE); } +#if defined(VIRTIO_MEM_HAS_LEGACY_GUESTS) +static bool virtio_mem_has_shared_zeropage(RAMBlock *rb) +{ + /* + * We only have a guaranteed shared zeropage on ordinary MAP_PRIVATE + * anonymous RAM. In any other case, reading unplugged *can* populate a + * fresh page, consuming actual memory. + */ + return !qemu_ram_is_shared(rb) && rb->fd < 0 && + qemu_ram_pagesize(rb) == qemu_real_host_page_size; +} +#endif /* VIRTIO_MEM_HAS_LEGACY_GUESTS */ + /* * Size the usable region bigger than the requested size if possible. Esp. * Linux guests will only add (aligned) memory blocks in case they fully @@ -429,10 +450,40 @@ static int virtio_mem_set_block_state(VirtIOMEM *vmem, uint64_t start_gpa, return -EBUSY; } virtio_mem_notify_unplug(vmem, offset, size); - } else if (virtio_mem_notify_plug(vmem, offset, size)) { - /* Could be a mapping attempt resulted in memory getting populated. */ - ram_block_discard_range(vmem->memdev->mr.ram_block, offset, size); - return -EBUSY; + } else { + int ret = 0; + + if (vmem->prealloc) { + void *area = memory_region_get_ram_ptr(&vmem->memdev->mr) + offset; + int fd = memory_region_get_fd(&vmem->memdev->mr); + Error *local_err = NULL; + + os_mem_prealloc(fd, area, size, 1, &local_err); + if (local_err) { + static bool warned; + + /* + * Warn only once, we don't want to fill the log with these + * warnings. + */ + if (!warned) { + warn_report_err(local_err); + warned = true; + } else { + error_free(local_err); + } + ret = -EBUSY; + } + } + if (!ret) { + ret = virtio_mem_notify_plug(vmem, offset, size); + } + + if (ret) { + /* Could be preallocation or a notifier populated memory. */ + ram_block_discard_range(vmem->memdev->mr.ram_block, offset, size); + return -EBUSY; + } } virtio_mem_set_bitmap(vmem, start_gpa, size, plug); return 0; @@ -653,15 +704,29 @@ static uint64_t virtio_mem_get_features(VirtIODevice *vdev, uint64_t features, Error **errp) { MachineState *ms = MACHINE(qdev_get_machine()); + VirtIOMEM *vmem = VIRTIO_MEM(vdev); if (ms->numa_state) { #if defined(CONFIG_ACPI) virtio_add_feature(&features, VIRTIO_MEM_F_ACPI_PXM); #endif } + assert(vmem->unplugged_inaccessible != ON_OFF_AUTO_AUTO); + if (vmem->unplugged_inaccessible == ON_OFF_AUTO_ON) { + virtio_add_feature(&features, VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE); + } return features; } +static int virtio_mem_validate_features(VirtIODevice *vdev) +{ + if (virtio_host_has_feature(vdev, VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE) && + !virtio_vdev_has_feature(vdev, VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE)) { + return -EFAULT; + } + return 0; +} + static void virtio_mem_system_reset(void *opaque) { VirtIOMEM *vmem = VIRTIO_MEM(opaque); @@ -716,6 +781,29 @@ static void virtio_mem_device_realize(DeviceState *dev, Error **errp) rb = vmem->memdev->mr.ram_block; page_size = qemu_ram_pagesize(rb); +#if defined(VIRTIO_MEM_HAS_LEGACY_GUESTS) + switch (vmem->unplugged_inaccessible) { + case ON_OFF_AUTO_AUTO: + if (virtio_mem_has_shared_zeropage(rb)) { + vmem->unplugged_inaccessible = ON_OFF_AUTO_OFF; + } else { + vmem->unplugged_inaccessible = ON_OFF_AUTO_ON; + } + break; + case ON_OFF_AUTO_OFF: + if (!virtio_mem_has_shared_zeropage(rb)) { + warn_report("'%s' property set to 'off' with a memdev that does" + " not support the shared zeropage.", + VIRTIO_MEM_UNPLUGGED_INACCESSIBLE_PROP); + } + break; + default: + break; + } +#else /* VIRTIO_MEM_HAS_LEGACY_GUESTS */ + vmem->unplugged_inaccessible = ON_OFF_AUTO_ON; +#endif /* VIRTIO_MEM_HAS_LEGACY_GUESTS */ + /* * If the block size wasn't configured by the user, use a sane default. This * allows using hugetlbfs backends of any page size without manual @@ -733,7 +821,8 @@ static void virtio_mem_device_realize(DeviceState *dev, Error **errp) warn_report("'%s' property is smaller than the default block size (%" PRIx64 " MiB)", VIRTIO_MEM_BLOCK_SIZE_PROP, virtio_mem_default_block_size(rb) / MiB); - } else if (!QEMU_IS_ALIGNED(vmem->requested_size, vmem->block_size)) { + } + if (!QEMU_IS_ALIGNED(vmem->requested_size, vmem->block_size)) { error_setg(errp, "'%s' property has to be multiples of '%s' (0x%" PRIx64 ")", VIRTIO_MEM_REQUESTED_SIZE_PROP, VIRTIO_MEM_BLOCK_SIZE_PROP, vmem->block_size); @@ -1107,8 +1196,13 @@ static void virtio_mem_instance_init(Object *obj) static Property virtio_mem_properties[] = { DEFINE_PROP_UINT64(VIRTIO_MEM_ADDR_PROP, VirtIOMEM, addr, 0), DEFINE_PROP_UINT32(VIRTIO_MEM_NODE_PROP, VirtIOMEM, node, 0), + DEFINE_PROP_BOOL(VIRTIO_MEM_PREALLOC_PROP, VirtIOMEM, prealloc, false), DEFINE_PROP_LINK(VIRTIO_MEM_MEMDEV_PROP, VirtIOMEM, memdev, TYPE_MEMORY_BACKEND, HostMemoryBackend *), +#if defined(VIRTIO_MEM_HAS_LEGACY_GUESTS) + DEFINE_PROP_ON_OFF_AUTO(VIRTIO_MEM_UNPLUGGED_INACCESSIBLE_PROP, VirtIOMEM, + unplugged_inaccessible, ON_OFF_AUTO_AUTO), +#endif DEFINE_PROP_END_OF_LIST(), }; @@ -1247,6 +1341,7 @@ static void virtio_mem_class_init(ObjectClass *klass, void *data) vdc->unrealize = virtio_mem_device_unrealize; vdc->get_config = virtio_mem_get_config; vdc->get_features = virtio_mem_get_features; + vdc->validate_features = virtio_mem_validate_features; vdc->vmsd = &vmstate_virtio_mem_device; vmc->fill_device_info = virtio_mem_fill_device_info; |