ChangeLog/1.1: Difference between revisions

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* QEMU's NBD client implementation and the qemu-nbd server both fully support asynchronous I/O.
* QEMU's NBD client implementation and the qemu-nbd server both fully support asynchronous I/O.
* [group snapshots]
* The new QMP command ''transaction'' can be used to perform a set of multiple snapshots atomically, rolling back to the original images if there is a problem along the way. See [[Features/SnapshotsMultipleDevices]] for more information.
* [streaming]
* The new monitor command ''block_stream'' lets guest copy data from the backing file to the current image while the guest is running.  This lets users enables quick provisioning of new virtual machines using shared remote storage, and lets the guest transition incrementally to fast local storage.  An alternative to streaming is the ''copy-on-read'' option of the -drive command-line option, which only transfers data when the guest needs it.


=== Live Migration, Save/Restore ===
=== Live Migration, Save/Restore ===

Revision as of 12:16, 13 March 2012

System emulation

All targets

  • qdev properties of type hex8 and hex32 used to accept hexadecimal values not prefixed with "0x"; the prefix is mandatory starting with this version. These properties are: iobase, membase, io_base for all devices that support the properties; vram_size for sysbus-g364 and SUNW,tcx; version for sb16 and iommu; ctl_iobase and data_iobase for fw_cfg; readback for debugcon; elcr_addr and elcr_mask for i8259.
    PCI addresses can still be addressed with a pair of hexadecimal device and function without a "0x" prefix.
  • -kernel, -initrd and -append are now aliases for suboptions of -machine (for example -machine kernel=foo), and as such they are also available with -readconfig.

ARM

  • The syborg machine type has been removed since the Symbian Virtual Platform is no longer relevant with the disbanding of Symbian.
  • A device tree can be passed to the kernel using -dtb option (or alternatively -machine dtb=...).
  • [new machine types]

PowerPC

  • Bamboo now works with TCG
  • Pseries handles PCI
  • Pseries works with PR KVM

S/390

  • -kernel now also supports ELF binaries
  • -kernel can boot new guest kernels
  • Devices can now be hotplug add'ed (remove is not there yet)

x86

  • NMIs are correctly injected through the LAPIC (rather than sent directly to the guest CPU) and respect the LINT1 mask, thus fixing kdump.
  • The -rtc-td-hack option is now available as a qdev property (-global mc146818rtc.lost_tick_policy=slew) and as such can be specified in a -readconfig configuration file.
  • [S3 support]
  • KVM can optionally use kernel-based emulation of the local APIC, IOAPIC and i8259 PIC. This is supported with the -machine ...,kernel_irqchip=on command-line option. MSI is not supported yet when using the kernel_irqchip option.
  • [pflash stuff]?

Device emulation

  • The virtio-scsi device is now supported by QEMU. The guest driver will be supported in Linux starting at version 3.4.
  • QEMU now includes experimental support for USB 3.0 (xHCI).

Block devices

  • QEMU's NBD client implementation and the qemu-nbd server both fully support asynchronous I/O.
  • The new QMP command transaction can be used to perform a set of multiple snapshots atomically, rolling back to the original images if there is a problem along the way. See Features/SnapshotsMultipleDevices for more information.
  • The new monitor command block_stream lets guest copy data from the backing file to the current image while the guest is running. This lets users enables quick provisioning of new virtual machines using shared remote storage, and lets the guest transition incrementally to fast local storage. An alternative to streaming is the copy-on-read option of the -drive command-line option, which only transfers data when the guest needs it.

Live Migration, Save/Restore

  • Live migration (or save/restore) from QEMU releases prior to 0.13 to QEMU 1.1 is not supported

Guest agent

  • qemu-ga has been ported to Windows.

Host support

  • System emulation on ARM hosts was broken in 1.0 and works again

User-mode emulation

  • User-mode emulation can provide some information from the /proc filesystem.