Device drivers that create and destroy SR-IOV virtual functions via
calls to pci_enable_sriov() and pci_disable_sriov can cause catastrophic
failures if they attempt to destroy VFs while they are assigned to
guest virtual machines. By adding a flag for use by the Xen PCI back
to indicate that a device is assigned a device driver can check that
flag and avoid destroying VFs while they are assigned and avoid system
failures.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Similar to the "xen/pciback: use mutex rather than spinlock in passthrough backend"
this patch converts the vpci backend to use a mutex instead of
a spinlock. Note that the code taking the lock won't ever get called
from non-sleepable context
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The caller that orchestrates the state changes is xenwatch_thread
and it takes a mutex. In our processing of Xenbus states we can take
the luxery of going to sleep on a mutex, so lets do that and
also fix this bug:
BUG: sleeping function called from invalid context at /linux/kernel/mutex.c:271
in_atomic(): 1, irqs_disabled(): 0, pid: 32, name: xenwatch
2 locks held by xenwatch/32:
#0: (xenwatch_mutex){......}, at: [<ffffffff813856ab>] xenwatch_thread+0x4b/0x180
#1: (&(&pdev->dev_lock)->rlock){......}, at: [<ffffffff8138f05b>] xen_pcibk_disconnect+0x1b/0x80
Pid: 32, comm: xenwatch Not tainted 3.1.0-rc6-00015-g3ce340d #2
Call Trace:
[<ffffffff810892b2>] __might_sleep+0x102/0x130
[<ffffffff8163b90f>] mutex_lock_nested+0x2f/0x50
[<ffffffff81382c1c>] unbind_from_irq+0x2c/0x1b0
[<ffffffff8110da66>] ? free_irq+0x56/0xb0
[<ffffffff81382dbc>] unbind_from_irqhandler+0x1c/0x30
[<ffffffff8138f06b>] xen_pcibk_disconnect+0x2b/0x80
[<ffffffff81390348>] xen_pcibk_frontend_changed+0xe8/0x140
[<ffffffff81387ac2>] xenbus_otherend_changed+0xd2/0x150
[<ffffffff810895c1>] ? get_parent_ip+0x11/0x50
[<ffffffff81387de0>] frontend_changed+0x10/0x20
[<ffffffff81385712>] xenwatch_thread+0xb2/0x180
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This is a minor bugfix and a set of small cleanups; as it is not clear
whether this needs splitting into pieces (and if so, at what
granularity), it is a single combined patch.
- add a missing return statement to an error path in
kill_domain_by_device()
- use pci_is_enabled() rather than raw atomic_read()
- remove a bogus attempt to zero-terminate an already zero-terminated
string
- #define DRV_NAME once uniformly in the shared local header
- make DRIVER_ATTR() variables static
- eliminate a pointless use of list_for_each_entry_safe()
- add MODULE_ALIAS()
- a little bit of constification
- adjust a few messages
- remove stray semicolons from inline function definitions
Signed-off-by: Jan Beulich <jbeulich@suse.com>
[v1: Dropped the resource_size fix, altered the description]
[v2: Fixed cleanpatch.pl comments]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To accommodate the call to the callback function from
__xen_pcibk_publish_pci_roots(), which so far dropped and the re-
acquired the lock without checking that the list didn't actually
change, convert the code to use a mutex instead (observing that the
code taking the lock won't ever get called from non-sleepable
context).
As a result, drop the bogus use of list_for_each_entry_safe() and
remove the inappropriate dropping of the lock.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Use resource_size function on resource object
instead of explicit computation.
The semantic patch that makes this output is available
in scripts/coccinelle/api/resource_size.cocci.
More information about semantic patching is available at
http://coccinelle.lip6.fr/
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
.. compile options. This way the user can decide during runtime whether they
want the default 'vpci' (virtual pci passthrough) or where the PCI devices
are passed in without any BDF renumbering. The option 'passthrough' allows
the user to toggle the it from 0 (vpci) to 1 (passthrough).
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The latter is easily fixed - by the developer compiling the
module with -DDEBUG. And during runtime - the loglvl provides
quite a lot of useful data.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
- Remove the slot and controller controller backend as they
are not used.
- Document the find pciback_[read|write]_config_[byte|word|dword]
to make it easier to find.
- Collapse the code from conf_space_capability_msi into pciback_ops.c
- Collapse conf_space_capability_[pm|vpd].c in conf_space_capability.c
[and remove the conf_space_capability.h file]
- Rename all visible functions from pciback to xen_pcibk.
- Rename all the printk/pr_info, etc that use the "pciback" to say
"xen-pciback".
- Convert functions that are not referenced outside the code to be
static to save on name space.
- Do the same thing for structures that are internal to the driver.
- Run checkpatch.pl after the renames and fixup its warnings and
fix any compile errors caused by the variable rename
- Cleanup any structs that checkpath.pl commented about or just
look odd.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
If the verbose_request is set (and loglevel high enough), print out
the MSI/MSI-X values that are sent to the guest. This should aid in
debugging issues.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
If we try to setup an fake IRQ handler for legacy interrupts
for devices that only have MSI-X (most if not all SR-IOV cards),
we will fail with this:
pciback[0000:01:10.0]: failed to install fake IRQ handler for IRQ 0! (rc:-38)
Since those cards don't have anything in dev->irq.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
pciback is rather generic for a modular distro style kernel.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
We were using coarse spinlocks that could end up with a deadlock.
This patch fixes that and makes the spinlocks much more fine-grained.
We also drop be->watchding state spinlocks as they are already
guarded by the xenwatch_thread against multiple customers. Without
that we would trigger the BUG: scheduling while atomic.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
If the device that is to be shared with a guest is a level device and
the IRQ is shared with the initial domain we need to take actions.
Mainly we install a dummy IRQ handler that will ACK on the interrupt
line so as to not have the initial domain disable the interrupt line.
This dummy IRQ handler is not enabled when the device MSI/MSI-X lines
are set, nor for edge interrupts. And also not for level interrupts
that are not shared amongst devices. Lastly, if the user passes
to the guest all of the PCI devices on the shared line the we won't
install the dummy handler either.
There is also SysFS instrumentation to check its state and turn
IRQ ACKing on/off if necessary.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
In cases where the guest is abruptly killed and has not disabled
MSI/MSI-X interrupts we want to do it for it.
Otherwise when the guest is started up and enables MSI, we would
get a WARN() that the device already had been enabled.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
These changes are for PV guest to use Virtual Function. Because the VF's
vendor, device registers in cfg space are 0xffff, which are invalid and
ignored by PCI device scan. Values in 'struct pci_dev' are fixed up by
SR-IOV code, and using these values will present correct VID and DID to
PV guest kernel.
And command registers in the cfg space are read only 0, which means we
have to emulate MMIO enable bit (VF only uses MMIO resource) so PV
kernel can work properly.
Acked-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
When the front-end and back-end start negotiating we register
the domain that will use the PCI device. Furthermore during shutdown
of guest or unbinding of the PCI device (and unloading of module)
from pciback we unregister the domain owner.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Checkpatch found some extra warnings and errors. This mega
patch fixes them all in one big swoop. We also spruce
up the pcistub_ids to use DEFINE_PCI_DEVICE_TABLE macro
(suggested by Jan Beulich).
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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>
