Beginning with its introduction, the virtio balloon has had an overflow error
that causes 'info balloon' to misreport the actual memory size when the balloon
itself becomes larger than 4G. Use a cast when converting dev->actual from
pages to kB to prevent overflows.
Before:
(qemu) info balloon
balloon: actual=5120
(qemu) balloon 1025
(qemu) info balloon
balloon: actual=1025
(qemu) balloon 1024
(qemu) info balloon
balloon: actual=5120
After:
(qemu) info balloon
balloon: actual=5120
(qemu) balloon 1025
(qemu) info balloon
balloon: actual=1025
(qemu) balloon 1024
(qemu) info balloon
balloon: actual=1024
Signed-off-by: Adam Litke <agl@us.ibm.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
When working with the VM state (for loadvm/savevm and migration), it is not
valid to load and store pointers since the validity of those pointers cannot be
assured in the new qemu address space. Therefore, virtio_balloon_save() and
virtio_balloon_load() must not handle the stats-related fields in struct
VirtIOBalloon.
If a memory stats request is in-flight at the time of a migration or savevm,
the request will not complete and should be resubmitted once migration or
loadvm completes. Note that this extremely small race window can only be
triggered using QMP so it is not possible to hang the user monitor.
Signed-off-by: Adam Litke <agl@us.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
When using ballooning to manage overcommitted memory on a host, a system for
guests to communicate their memory usage to the host can provide information
that will minimize the impact of ballooning on the guests. The current method
employs a daemon running in each guest that communicates memory statistics to a
host daemon at a specified time interval. The host daemon aggregates this
information and inflates and/or deflates balloons according to the level of
host memory pressure. This approach is effective but overly complex since a
daemon must be installed inside each guest and coordinated to communicate with
the host. A simpler approach is to collect memory statistics in the virtio
balloon driver and communicate them directly to the hypervisor.
Signed-off-by: Adam Litke <agl@us.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Add feature bits as properties to virtio. This makes it possible to e.g. define
machine without indirect buffer support, which is required for 0.10
compatibility, or without hardware checksum support, which is required for 0.11
compatibility. Since default values for optional features are now set by qdev,
get_features callback has been modified: it sets non-optional bits, and clears
bits not supported by host.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
In the very least, a change like this requires discussion on the list.
The naming convention is goofy and it causes a massive merge problem. Something
like this _must_ be presented on the list first so people can provide input
and cope with it.
This reverts commit 99a0949b72.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This patch adds and uses #defines for PCI device classes and subclases,
using a new pci_config_set_class() function, similar to the recently
added pci_config_set_vendor_id() and pci_config_set_device_id().
Change since v1: fixed compilation of hw/sun4u.c
Signed-off-by: Stuart Brady <stuart.brady@gmail.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6491 c046a42c-6fe2-441c-8c8c-71466251a162
A subsystem vendor ID of zero isn't allowed, so we use our
default ID.
Gerd points out that although the PCI subsystem vendor ID is
treated by the guest as the virtio vendor ID:
/* we use the subsystem vendor/device id as the virtio vendor/device
* id. this allows us to use the same PCI vendor/device id for all
* virtio devices and to identify the particular virtio driver by
* the subsytem ids */
vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
vp_dev->vdev.id.device = pci_dev->subsystem_device;
it looks like only the device ID is used right now:
# grep virtio modules.alias
alias virtio:d00000001v* virtio_net
alias virtio:d00000002v* virtio_blk
alias virtio:d00000003v* virtio_console
alias virtio:d00000004v* virtio-rng
alias virtio:d00000005v* virtio_balloon
alias pci:v00001AF4d*sv*sd*bc*sc*i* virtio_pci
alias virtio:d00000009v* 9pnet_virtio
so setting the subsystem vendor id to something != zero shouldn't cause
trouble.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6440 c046a42c-6fe2-441c-8c8c-71466251a162
Use the defines added by the previous patch in the virtio drivers.
Also remove the pointless vendor and device args from the
virtio_blk_init() function.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5987 c046a42c-6fe2-441c-8c8c-71466251a162
This adds a VirtIO based balloon driver. It uses madvise() to actually balloon
the memory when possible.
Until 2.6.27, KVM forced memory pinning so we must disable ballooning unless the
kernel actually supports it when using KVM. It's always safe when using TCG.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5874 c046a42c-6fe2-441c-8c8c-71466251a162
