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authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2009-10-13 23:22:20 +0200
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2011-07-20 02:58:01 +0200
commit30edc14bf39afde24ef7db2de66c91805db80828 (patch)
tree1cf5b6f28a3ea4159a09bcef9d11be6d427e3558 /drivers/xen/Kconfig
parentLinux 3.0-rc4 (diff)
downloadlinux-30edc14bf39afde24ef7db2de66c91805db80828.tar.xz
linux-30edc14bf39afde24ef7db2de66c91805db80828.zip
xen/pciback: xen pci backend driver.
This is the host side counterpart to the frontend driver in drivers/pci/xen-pcifront.c. The PV protocol is also implemented by frontend drivers in other OSes too, such as the BSDs. The PV protocol is rather simple. There is page shared with the guest, which has the 'struct xen_pci_sharedinfo' embossed in it. The backend has a thread that is kicked every-time the structure is changed and based on the operation field it performs specific tasks: XEN_PCI_OP_conf_[read|write]: Read/Write 0xCF8/0xCFC filtered data. (conf_space*.c) Based on which field is probed, we either enable/disable the PCI device, change power state, read VPD, etc. The major goal of this call is to provide a Physical IRQ (PIRQ) to the guest. The PIRQ is Xen hypervisor global IRQ value irrespective of the IRQ is tied in to the IO-APIC, or is a vector. For GSI type interrupts, the PIRQ==GSI holds. For MSI/MSI-X the PIRQ value != Linux IRQ number (thought PIRQ==vector). Please note, that with Xen, all interrupts (except those level shared ones) are injected directly to the guest - there is no host interaction. XEN_PCI_OP_[enable|disable]_msi[|x] (pciback_ops.c) Enables/disables the MSI/MSI-X capability of the device. These operations setup the MSI/MSI-X vectors for the guest and pass them to the frontend. When the device is activated, the interrupts are directly injected in the guest without involving the host. XEN_PCI_OP_aer_[detected|resume|mmio|slotreset]: In case of failure, perform the appropriate AER commands on the guest. Right now that is a cop-out - we just kill the guest. Besides implementing those commands, it can also - hide a PCI device from the host. When booting up, the user can specify xen-pciback.hide=(1:0:0)(BDF..) so that host does not try to use the device. The driver was lifted from linux-2.6.18.hg tree and fixed up so that it could compile under v3.0. Per suggestion from Jesse Barnes moved the driver to drivers/xen/xen-pciback. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Diffstat (limited to 'drivers/xen/Kconfig')
-rw-r--r--drivers/xen/Kconfig43
1 files changed, 43 insertions, 0 deletions
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index a59638b37c1a..8af0792dfd67 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -105,4 +105,47 @@ config SWIOTLB_XEN
depends on PCI
select SWIOTLB
+config XEN_PCIDEV_BACKEND
+ tristate "Xen PCI-device backend driver"
+ depends on PCI && X86 && XEN
+ depends on XEN_BACKEND
+ help
+ The PCI device backend driver allows the kernel to export arbitrary
+ PCI devices to other guests. If you select this to be a module, you
+ will need to make sure no other driver has bound to the device(s)
+ you want to make visible to other guests.
+
+choice
+ prompt "PCI Backend Mode"
+ depends on XEN_PCIDEV_BACKEND
+
+config XEN_PCIDEV_BACKEND_VPCI
+ bool "Virtual PCI"
+ help
+ This PCI Backend hides the true PCI topology and makes the frontend
+ think there is a single PCI bus with only the exported devices on it.
+ For example, a device at 03:05.0 will be re-assigned to 00:00.0. A
+ second device at 02:1a.1 will be re-assigned to 00:01.1.
+
+config XEN_PCIDEV_BACKEND_PASS
+ bool "Passthrough"
+ help
+ This PCI Backend provides a real view of the PCI topology to the
+ frontend (for example, a device at 06:01.b will still appear at
+ 06:01.b to the frontend). This is similar to how Xen 2.0.x exposed
+ PCI devices to its driver domains. This may be required for drivers
+ which depend on finding their hardward in certain bus/slot
+ locations.
+
+endchoice
+
+config XEN_PCIDEV_BE_DEBUG
+ bool "Xen PCI Backend Debugging"
+ depends on XEN_PCIDEV_BACKEND
+ default n
+ help
+ Allows to observe all of the traffic from the frontend/backend
+ when reading and writting to the configuration registers.
+ If in doubt, say no.
+
endmenu