qemu/docs/specs
Markus Armbruster 5400c02b90 ivshmem: Split ivshmem-plain, ivshmem-doorbell off ivshmem
ivshmem can be configured with and without interrupt capability
(a.k.a. "doorbell").  The two configurations have largely disjoint
options, which makes for a confusing (and badly checked) user
interface.  Moreover, the device can't tell the guest whether its
doorbell is enabled.

Create two new device models ivshmem-plain and ivshmem-doorbell, and
deprecate the old one.

Changes from ivshmem:

* PCI revision is 1 instead of 0.  The new revision is fully backwards
  compatible for guests.  Guests may elect to require at least
  revision 1 to make sure they're not exposed to the funny "no shared
  memory, yet" state.

* Property "role" replaced by "master".  role=master becomes
  master=on, role=peer becomes master=off.  Default is off instead of
  auto.

* Property "use64" is gone.  The new devices always have 64 bit BARs.

Changes from ivshmem to ivshmem-plain:

* The Interrupt Pin register in PCI config space is zero (does not use
  an interrupt pin) instead of one (uses INTA).

* Property "x-memdev" is renamed to "memdev".

* Properties "shm" and "size" are gone.  Use property "memdev"
  instead.

* Property "msi" is gone.  The new device can't have MSI-X capability.
  It can't interrupt anyway.

* Properties "ioeventfd" and "vectors" are gone.  They're meaningless
  without interrupts anyway.

Changes from ivshmem to ivshmem-doorbell:

* Property "msi" is gone.  The new device always has MSI-X capability.

* Property "ioeventfd" defaults to on instead of off.

* Property "size" is gone.  The new device can only map all the shared
  memory received from the server.

Guests can easily find out whether the device is configured for
interrupts by checking for MSI-X capability.

Note: some code added in sub-optimal places to make the diff easier to
review.  The next commit will move it to more sensible places.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-37-git-send-email-armbru@redhat.com>
2016-03-21 21:29:03 +01:00
..
acpi_cpu_hotplug.txt acpi: ich9: add CPU hotplug handling to Q35 machine 2014-01-26 13:11:44 +02:00
acpi_mem_hotplug.txt acpi: add hardware implementation for memory hot unplug 2015-04-27 21:09:07 +02:00
acpi_pci_hotplug.txt acpi_piix4: Re-define PCI hotplug eject register read 2012-04-15 12:17:23 +03:00
edu.txt hw: misc, add educational driver 2015-01-26 12:26:55 +01:00
fw_cfg.txt fw_cfg: document ACPI device node information 2016-03-08 12:15:22 +01:00
ivshmem-spec.txt ivshmem: Split ivshmem-plain, ivshmem-doorbell off ivshmem 2016-03-21 21:29:03 +01:00
parallels.txt parallels: add format spec 2015-12-22 16:01:07 +08:00
pci-ids.txt pci-ids: add virtio 1.0 ids to spec 2016-03-11 16:59:11 +02:00
pci-serial.txt serial: add pci-serial documentation 2012-10-22 13:26:42 -05:00
pci-testdev.txt pci: add pci test device 2013-04-16 01:41:53 +03:00
ppc-spapr-hcalls.txt typofixes - v4 2015-09-11 10:45:43 +03:00
ppc-spapr-hotplug.txt spapr: Support ibm,dynamic-reconfiguration-memory 2015-09-23 10:51:10 +10:00
pvpanic.txt pvpanic: add document of pvpanic 2013-04-30 10:30:01 -05:00
qcow2.txt spec: add qcow2 bitmaps extension specification 2016-02-22 09:49:46 +01:00
qed_spec.txt docs: Describe zero data clusters in QED specification 2011-04-13 12:06:40 +02:00
rocker.txt maint: remove / fix many doubled words 2015-09-11 10:21:38 +03:00
standard-vga.txt vga-pci: add qext region to mmio 2014-10-15 11:08:35 +02:00
vhost-user.txt vhost-user: clarify start and enable 2015-11-25 13:42:38 +02:00
vmw_pvscsi-spec.txt scsi: VMWare PVSCSI paravirtual device implementation 2013-04-19 10:44:17 +02:00