diff options
| author | Stefan Hajnoczi <stefanha@redhat.com> | 2019-07-10 16:14:40 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2019-07-12 10:56:26 -0400 |
| commit | 2bbadb08ce272d65e1f78621002008b07d1e0f03 (patch) | |
| tree | e1820bab0f491b4bd98b33b14a8901110610f211 /hw/core/machine.c | |
| parent | 4d90b7a0e4aa8051d4a059d49e458e3378aa39ff (diff) | |
virtio-balloon: fix QEMU 4.0 config size migration incompatibility
The virtio-balloon config size changed in QEMU 4.0 even for existing
machine types. Migration from QEMU 3.1 to 4.0 can fail in some
circumstances with the following error:
qemu-system-x86_64: get_pci_config_device: Bad config data: i=0x10 read: a1 device: 1 cmask: ff wmask: c0 w1cmask:0
This happens because the virtio-balloon config size affects the VIRTIO
Legacy I/O Memory PCI BAR size.
Introduce a qdev property called "qemu-4-0-config-size" and enable it
only for the QEMU 4.0 machine types. This way <4.0 machine types use
the old size, 4.0 uses the larger size, and >4.0 machine types use the
appropriate size depending on enabled virtio-balloon features.
Live migration to and from old QEMUs to QEMU 4.1 works again as long as
a versioned machine type is specified (do not use just "pc"!).
Originally-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20190710141440.27635-1-stefanha@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Tested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Tested-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/core/machine.c')
| -rw-r--r-- | hw/core/machine.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/hw/core/machine.c b/hw/core/machine.c index 2be19ec0cd..c4ead16010 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -34,6 +34,7 @@ GlobalProperty hw_compat_4_0[] = { { "virtio-vga", "edid", "false" }, { "virtio-gpu-pci", "edid", "false" }, { "virtio-device", "use-started", "false" }, + { "virtio-balloon-device", "qemu-4-0-config-size", "true" }, }; const size_t hw_compat_4_0_len = G_N_ELEMENTS(hw_compat_4_0); @@ -49,6 +50,7 @@ GlobalProperty hw_compat_3_1[] = { { "usb-tablet", "serial", "42" }, { "virtio-blk-device", "discard", "false" }, { "virtio-blk-device", "write-zeroes", "false" }, + { "virtio-balloon-device", "qemu-4-0-config-size", "false" }, }; const size_t hw_compat_3_1_len = G_N_ELEMENTS(hw_compat_3_1); |