The current Xen console driver is crashing very quickly when using it on
an ARM guest. This is because the console lock is recursive and it may
lead to recursion on the tty lock and/or corrupt the ring pointer.
Furthermore, the console lock is not always taken where it should be and has
to be released too early because of the way the console has been designed.
Over the years, code has been modified to support various new features but
the driver has not been reworked.
This new driver has been rewritten with the idea of only having a small set
of specific function to write either via the shared ring or the hypercall
interface.
Note that HVM support has been left aside for now because it requires
additional features which are not yet supported. A follow-up patch will be
sent with HVM guest support.
List of items that may be good to have but not mandatory:
- Avoid to flush for each character written when using the tty
- Support multiple consoles
Submitted by: Julien Grall <julien.grall@citrix.com>
Reviewed by: royger
Differential Revision: https://reviews.freebsd.org/D3698
Sponsored by: Citrix Systems R&D
Pull the latest headers for Xen which allow us to add support for ARM and
use new features in FreeBSD.
This is a verbatim copy of the xen/include/public so every headers which
don't exits anymore in the Xen repositories have been dropped.
Note the interface version hasn't been bumped, it will be done in a
follow-up. Although, it requires fix in the code to get it compiled:
- sys/xen/xen_intr.h: evtchn_port_t is already defined in the headers so
drop it.
- {amd64,i386}/include/intr_machdep.h: NR_EVENT_CHANNELS now depends on
xen/interface/event_channel.h, so include it.
- {amd64,i386}/{amd64,i386}/support.S: It's not neccessary to include
machine/intr_machdep.h. This is also fixing build compilation with the
new headers.
- dev/xen/blkfront/blkfront.c: The typedef for blkif_request_segmenthas
been dropped. So directly use struct blkif_request_segment
Finally, modify xen/interface/xen-compat.h to throw a preprocessing error if
__XEN_INTERFACE_VERSION__ is not set. This is allow us to catch any file
where xen/xen-os.h is not correctly included.
Submitted by: Julien Grall <julien.grall@citrix.com>
Reviewed by: royger
Differential Revision: https://reviews.freebsd.org/D3805
Sponsored by: Citrix Systems R&D
When the system has more than a single PCI domain, the bus numbers
are not unique, thus they cannot be used for "pci" device numbering.
Change bus numbers to -1 (i.e. to-be-determined automatically)
wherever the code did not care about domains.
Reviewed by: jhb
Obtained from: Semihalf
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3406
Introduce two new loader tunnables that can be used to disable PV disks and
PV nics at boot time. They default to 0 and should be set to 1 (or any
number different than 0) in order to disable the PV devices:
hw.xen.disable_pv_disks=1
hw.xen.disable_pv_nics=1
In /boot/loader.conf will disable both PV disks and nics.
Sponsored by: Citrix Systems R&D
Tested by: Karl Pielorz <kpielorz_lst@tdx.co.uk>
MFC after: 1 week
use vtophys() directly instead of vtomach() and retire the no-longer-used
headers <machine/xenfunc.h> and <machine/xenvar.h>.
Reported by: bde (stale bits in <machine/xenfunc.h>)
Reviewed by: royger (earlier version)
Differential Revision: https://reviews.freebsd.org/D3266
the blkfront driver to perform I/Os of up to 2 MB, subject to support from
the blkback to which it is connected and the initiation of such large I/Os
by the rest of the kernel. In practice, the I/O size is increased from 40 kB
to 128 kB.
The changes to xen/interface/io/blkif.h consist merely of merging updates
from the upstream Xen repository.
In dev/xen/blkfront/block.h we add some convenience macros and structure
fields used for indirect-page I/Os: The device records its negotiated limit
on the number of indirect pages used, while each I/O command structure gains
permanently allocated page(s) for indirect page references and the Xen grant
references for those pages.
In dev/xen/blkfront/blkfront.c we now check in xbd_queue_cb whether a request
is small enough to handle without an indirection page, and either follow the
previous behaviour or use new code for issuing an indirect segment I/O. In
xbd_connect we read the size of indirect segment I/Os supported by the backend
and select the maximum size we will use; then allocate the pages and Xen grant
references for each I/O command structure. In xbd_free those grants and pages
are released.
A new loader tunable, hw.xbd.xbd_enable_indirect, can be set to 0 in order to
disable this functionality; it works by pretending that the backend does not
support this feature. Some backends exhibit a loss of performance with large
I/Os, so users may wish to test with and without this functionality enabled.
Reviewed by: royger
MFC after: 3 days
Relnotes: yes
Previously several places were doing it on its own, partially
incorrectly (e.g. without the filedesc locked) or even actively harmful
by populating jdir or assigning rootvnode without vrefing it.
Reviewed by: kib
Try to preserve the xn configuration when migrating. This is not always
possible since the backend might not have the same set of options
available, in which case we will try to preserve as many as possible.
MFC after: 2 weeks
PR: 183139
Reported by: mcdouga9@egr.msu.edu
Sponsored by: Citrix Systems R&D
xbd_initialize to xbd_connect. Both of these initialization steps need
to know what the maximum possible I/O size will be, and when we gain
support for indirect segment I/Os we won't know that value until we
reach xbd_connect. Since none of this data is used before xbd_connect
completes, moving the initialization is harmless.
This commit should not result in any functional changes.
into blkif segments, and moving it into a new function. This will be used
by upcoming support for indirect-segment blkif requests.
This commit should not result in any functional changes.
* nsegs must be at most BLKIF_MAX_SEGMENTS_PER_REQUEST (since we specify
that limit to bus_dma_tag_create), so KASSERT that rather than silently
adjusting the request.
* block_segs is now a synonym for nsegs, so garbage collect that variable.
* nsegs is never read during or after the while loop, so remove the dead
decrement from the loop.
These were all left behind from the pre-r284296 support for a "segment
block" extension.
The FreeBSD extension adds a new request type, called blkif_segment_block
which has a size of 112bytes for both i386 and amd64. This is fine on
amd64, since requests have a size of 112B there also. But this is not true
for i386, where requests have a size of 108B. So on i386 we basically
overrun the ring slot when queuing a request of type blkif_segment_block_t,
which is very bad.
Remove this extension (including a cleanup of the public blkif.h header
file) from blkfront and blkback.
Sponsored by: Citrix Systems R&D
Tested-by: cperciva
years for head. However, it is continuously misused as the mpsafe argument
for callout_init(9). Deprecate the flag and clean up callout_init() calls
to make them more consistent.
Differential Revision: https://reviews.freebsd.org/D2613
Reviewed by: jhb
MFC after: 2 weeks
Netfront has to wait for the backend to switch to state XenbusStateConnected
before sending the ARP request, or else the backend might not be connected
and thus the packet will be lost.
Sponsored by: Citrix Systems R&D
MFC after: 1 week
In order to map memory from other domains when running on Xen FreeBSD uses
unused physical memory regions. Until now this memory has been allocated
using bus_alloc_resource, but this is not completely safe as we can end up
using unreclaimed MMIO or ACPI regions.
Fix this by introducing a new newbus method that can be used by Xen drivers
to request for unused memory regions. On amd64 we make sure this memory
comes from regions above 4GB in order to prevent clashes with MMIO/ACPI
regions. On i386 there's nothing we can do, so just fall back to the
previous mechanism.
Sponsored by: Citrix Systems R&D
Tested by: Gustau Pérez <gperez@entel.upc.edu>
remains. Xen is planning to phase out support for PV upstream since it
is harder to maintain and has more overhead. Modern x86 CPUs include
virtualization extensions that support HVM guests instead of PV guests.
In addition, the PV code was i386 only and not as well maintained recently
as the HVM code.
- Remove the i386-only NATIVE option that was used to disable certain
components for PV kernels. These components are now standard as they
are on amd64.
- Remove !XENHVM bits from PV drivers.
- Remove various shims required for XEN (e.g. PT_UPDATES_FLUSH, LOAD_CR3,
etc.)
- Remove duplicate copy of <xen/features.h>.
- Remove unused, i386-only xenstored.h.
Differential Revision: https://reviews.freebsd.org/D2362
Reviewed by: royger
Tested by: royger (i386/amd64 HVM domU and amd64 PVH dom0)
Relnotes: yes
Handle the VIRQ_DEBUG signal and print a stack trace of each vCPU on the Xen
console. This is only used for debug purposes and is triggered by the
administrator of the Xen host.
Sponsored by: Citrix Systems R&D
MFC after: 1 week
The current GSO implementation in netback is broken and causes errors on the
guest tx path. While this is fixed disable GSO in order to have a working
netback.
Sponsored by: Citrix Systems R&D
Discussed with: gibbs
Xenstore user-space device has two problems currently:
- It does not correctly handle concurrent clients, because it's storing
each client data in dev->si_drv1.
- It does not correctly free this data when the client closes the device.
In order to solve both of this issues store the per-client data using
cdevpriv, which also comes with a hook in order to perform the necessary
cleanup on device close.
While there also make the device eternal.
Sponsored by: Citrix Systems R&D
Reported and Tested by: thompsa
MFC after: 2 weeks
KVM clock shares the same data structures between the guest and the host
as Xen so it makes sense to just have a single copy of this code.
Differential Revision: https://reviews.freebsd.org/D1429
Reviewed by: royger (eariler version)
MFC after: 1 month
Before this change, the current code handles SIOCGIFADDR the same
way with SIOCSIFADDR, which involves full arp_ifinit, et al. They
should be unnecessary for SIOCGIFADDR case.
Differential Revision: https://reviews.freebsd.org/D1508
Reviewed by: glebius
MFC after: 2 weeks
socket-buffer implementations, introduce a return value for MCLGET()
(and m_cljget() that underlies it) to allow the caller to avoid testing
M_EXT itself. Update all callers to use the return value.
With this change, very few network device drivers remain aware of
M_EXT; the primary exceptions lie in mbuf-chain pretty printers for
debugging, and in a few cases, custom mbuf and cluster allocation
implementations.
NB: This is a difficult-to-test change as it touches many drivers for
which I don't have physical devices. Instead we've gone for intensive
review, but further post-commit review would definitely be appreciated
to spot errors where changes could not easily be made mechanically,
but were largely mechanical in nature.
Differential Revision: https://reviews.freebsd.org/D1440
Reviewed by: adrian, bz, gnn
Sponsored by: EMC / Isilon Storage Division
This allows the Grant-table code to attach directly to the xenpv bus,
allowing us to remove the grant-table initialization done in xenpv.
Sponsored by: Citrix Systems R&D
Mave the grant table code into the dev/xen folder in preparation for turning
it into a device using the newbus interface. This is just code motion, no
functional changes.
Sponsored by: Citrix Systems R&D
When running as a Xen PVH Dom0 we need to add custom buses that override
some of the functionality present in the ACPI PCI Bus and the PCI Bus. We
currently override the ACPI PCI Bus, but not the PCI Bus, so add a new
override for the PCI Bus and share the generic functions between them.
Reported by: David P. Discher <dpd@dpdtech.com>
Sponsored by: Citrix Systems R&D
conf/files.amd64:
- Add the new files.
x86/xen/xen_pci_bus.c:
- Generic file that contains the PCI overrides so they can be used by the
several PCI specific buses.
xen/xen_pci.h:
- Prototypes for the generic overried functions.
dev/xen/pci/xen_pci.c:
- Xen specific override for the PCI bus.
dev/xen/pci/xen_acpi_pci.c:
- Xen specific override for the ACPI PCI bus.
Current FreeBSD netback names the interface with xnb<device unit>, but
this is not suitable for usage with the Xen toolstack, which expects
something similar to <prefix><domid><handle>. In order to solve this,
change the netback naming convention to use xnb<domid>.<handle>.
Sponsored by: Citrix Systems R&D
dev/xen/netback/netback.c:
- Change netback to use the nomenclature stated above.
This device is only attached to priviledged domains, and allows the
toolstack to interact with Xen. The two functions of the privcmd
interface is to allow the execution of hypercalls from user-space, and
the mapping of foreign domain memory.
Sponsored by: Citrix Systems R&D
i386/include/xen/hypercall.h:
amd64/include/xen/hypercall.h:
- Introduce a function to make generic hypercalls into Xen.
xen/interface/xen.h:
xen/interface/memory.h:
- Import the new hypercall XENMEM_add_to_physmap_range used by
auto-translated guests to map memory from foreign domains.
dev/xen/privcmd/privcmd.c:
- This device has the following functions:
- Allow user-space applications to make hypercalls into Xen.
- Allow user-space applications to map memory from foreign domains,
this is accomplished using the newly introduced hypercall
(XENMEM_add_to_physmap_range).
xen/privcmd.h:
- Public ioctl interface for the privcmd device.
x86/xen/hvm.c:
- Remove declaration of hypercall_page, now it's declared in
hypercall.h.
conf/files:
- Add the privcmd device to the build process.
The user-space event channel device is used by applications to receive
and send event channel interrupts. This device is based on the Linux
evtchn device.
Sponsored by: Citrix Systems R&D
xen/evtchn/evtchn_dev.c:
- Remove the old event channel device, which was already disabled in
the build system.
dev/xen/evtchn/evtchn_dev.c:
- Import a new event channel device based on the one present in
Linux.
- This device allows the following operations:
- Bind VIRQ event channels (ioctl).
- Bind regular event channels (ioctl).
- Create and bind new event channels (ioctl).
- Unbind event channels (ioctl).
- Send notifications to event channels (ioctl).
- Reset the device shared memory ring (ioctl).
- Unmask event channels (write).
- Receive event channel upcalls (read).
- The new code is MP safe, and can be used concurrently.
conf/files:
- Add the new device to the build system.
- Wrong integer type was specified.
- Wrong or missing "access" specifier. The "access" specifier
sometimes included the SYSCTL type, which it should not, except for
procedural SYSCTL nodes.
- Logical OR where binary OR was expected.
- Properly assert the "access" argument passed to all SYSCTL macros,
using the CTASSERT macro. This applies to both static- and dynamically
created SYSCTLs.
- Properly assert the the data type for both static and dynamic
SYSCTLs. In the case of static SYSCTLs we only assert that the data
pointed to by the SYSCTL data pointer has the correct size, hence
there is no easy way to assert types in the C language outside a
C-function.
- Rewrote some code which doesn't pass a constant "access" specifier
when creating dynamic SYSCTL nodes, which is now a requirement.
- Updated "EXAMPLES" section in SYSCTL manual page.
MFC after: 3 days
Sponsored by: Mellanox Technologies
Fix a problem where the blockback driver could run out of requests,
despite the fact that we allocate enough request and reqlist
structures to satisfy the maximum possible number of requests.
The problem was that we were sending responses back to the other
end (blockfront) before freeing resources. The Citrix Windows
driver is pretty agressive about queueing, and would queue more I/O
to us immediately after we sent responses to it. We would run into
a resource shortage and stall out I/O until we freed resources.
It isn't clear whether the request shortage condition was an
indirect cause of the I/O hangs we've been seeing between Windows
with the Citrix PV drivers and FreeBSD's blockback, but the above
problem is certainly a bug.
Sponsored by: Spectra Logic
Submitted by: ken
Reviewed by: royger
dev/xen/blkback/blkback.c:
- Break xbb_send_response() into two sub-functions,
xbb_queue_response() and xbb_push_responses().
Remove xbb_send_response(), because it is no longer
used.
- Adjust xbb_complete_reqlist() so that it calls the
two new functions, and holds the mutex around both
calls. The mutex insures that another context
can't come along and push responses before we've
freed our resources.
- Change xbb_release_reqlist() so that it requires
the mutex to be held instead of acquiring the mutex
itself. Both callers could easily hold the mutex
while calling it, and one really needs to hold the
mutex during the call.
- Add two new counters, accessible via sysctl
variables. The first one counts the number of
I/Os that are queued and waiting to be pushed
(reqs_queued_for_completion). The second one
(reqs_completed_with_error) counts the number of
requests we've completed with an error status.
Using realmem on PVH is not realiable, since in this case the realmem value
is computed from Maxmem, which contains the higher memory address found. Use
HYPERVISOR_start_info->nr_pages instead, which is set by the hypervisor and
contains the exact number of memory pages assigned to the domain.
Sponsored by: Citrix Systems R&D
This device is used by the user-space daemon that runs xenstore
(xenstored). It allows xenstored to map the xenstore memory page, and
reports the event channel xenstore is using.
Sponsored by: Citrix Systems R&D
dev/xen/xenstore/xenstored_dev.c:
- Add the xenstored character device that's used to map the xenstore
memory into user-space, and to report the event channel used by
xenstore.
conf/files:
- Add the device to the build process.
Convert the xenstore user-space device (/dev/xen/xenstore) to a device
using the newbus interface. This allows us to make the device
initialization dependant on the initialization of xenstore itself in
the kernel.
Sponsored by: Citrix Systems R&D
dev/xen/xenstore/xenstore.c:
- Convert to a newbus device, this removes the xs_dev_init function.
xen/xenstore/xenstore_internal.h:
- Remove xs_dev_init prototype.
dev/xen/xenstore/xenstore.c:
- Don't call xs_dev_init anymore, the device will attach itself when
xenstore is started.
The xenstore related devices in the kernel cannot be started until
xenstored is running, which will happen later in the Dom0 case. If
start_info_t doesn't contain a valid xenstore event channel, defer all
xenstore related devices attachment to later.
Sponsored by: Citrix Systems R&D
dev/xen/xenstore/xenstore.c:
- Prevent xenstore from trying to attach it's descendant devices if
xenstore is not initialized.
- Add a callback in the xenstore interrupt filter that will trigger
the plug of xenstore descendant devices on the first received
interrupt. This interrupt is generated when xenstored attaches to
the event channel, and serves as a notification that xenstored is
running.
Move xenstore related devices (xenstore.c and xenstore_dev.c) from
xen/xenstore to dev/xen/xenstore. This is just code motion, no
functional changes.
Sponsored by: Citrix Systems R&D
This is done so we can prevent the Xen Balloon driver from attaching
before xenstore is setup.
Sponsored by: Citrix Systems R&D
dev/xen/balloon/balloon.c:
- Make xen balloon a driver that depends on xenstore.
The current TSO limitation feature only takes the total number of
bytes in an mbuf chain into account and does not limit by the number
of mbufs in a chain. Some kinds of hardware is limited by two
factors. One is the fragment length and the second is the fragment
count. Both of these limits need to be taken into account when doing
TSO. Else some kinds of hardware might have to drop completely valid
mbuf chains because they cannot loaded into the given hardware's DMA
engine. The new way of doing TSO limitation has been made backwards
compatible as input from other FreeBSD developers and will use
defaults for values not set.
Reviewed by: adrian, rmacklem
Sponsored by: Mellanox Technologies
MFC after: 1 week
