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27 commits

Author SHA1 Message Date
Roger Pau Monné 399386f190 x86/xen: introduce non-hypercall based emergency print
The current xc_printf() function uses an hypercall in order to send character
buffers to the hypervisor for it to print on the hypervisor console (if the
hypervisor is configured to print such messages).

This requires the hypercall page to be initialized, which is extra work and can
go wrong.

On x86 instead of using the console IO hypercall use the debug console IO port,
also called "port E9 hack".  This allows sending characters to Xen using an
outb instruction, without any initialization required.

Keep the previous hypervisor based implementation by using the weak attribute,
which allows each architecture to provide an alternate (arch-specific)
implementation.

Sponsored by: Cloud Software Group
Reviewed by: markj
Differential revision: https://reviews.freebsd.org/D43929
2024-02-22 11:08:03 +01:00
Elliott Mitchell 4c9e6ad320 xen: add atomic #defines to accomodate differing xen_ulong_t sizes
Alas, ARM declared xen_ulong_t to be 64-bits long, unlike i386 where
it matches the word size.  As a result, compatibility wrappers are
needed for Xen atomic operations.

Reviewed by: royger
2023-12-15 14:59:26 +01:00
Elliott Mitchell c7368ccb68 xen: remove xen_domain_type enum/variable
The vm_guest variable readily covers all uses of xen_domain_type, so
merge them together.  Since support for PV domains has been removed
hard-core xen_pv_domain() to return false.

Reviewed by: royger
2023-11-28 13:40:19 +01:00
Warner Losh 95ee2897e9 sys: Remove $FreeBSD$: two-line .h pattern
Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/
2023-08-16 11:54:11 -06:00
Elliott Mitchell 20fc5bf7df xen: move vcpu_info to common, leave hook for setup
vcpu_info is crucial for the Xen event channel core.  Since both the
data and setup steps are identical between architectures, move them to
the common file.  Since there is no cross-architecture method to call
a function on every processor during bring-up, simply leave the setup
function.

The number of vcpu_info structures available on the shared information
page varies by architecture.  Instead of hard-coding the count use
nitems().  Add a warning message for this being used.

Switch to XEN_VCPUID() and use Xen's typedefs.

panic() on failure since >32 processors is no longer unusual.

royger: Specify 64-byte alignment for vcpu_info to try to defend
against vcpu_info crossing a page boundary.  Add detection for this
limit.

Reviewed by: royger
2023-07-21 10:59:12 +02:00
Roger Pau Monné 5489d7e93a xen: bump used interface version
This is required for a further change that will make use of a field
that was added in version 0x00040d00.

No functional change expected.

Sponsored by: Citrix Systems R&D
2023-03-09 17:13:17 +01:00
Elliott Mitchell ad7dd51499 xen: switch to use headers in contrib
These headers originate with the Xen project and shouldn't be mixed with
the main portion of the FreeBSD kernel. Notably they shouldn't be the
target of clean-up commits.

Switch to use the headers in sys/contrib/xen.

Reviewed by: royger
2022-02-07 10:11:56 +01:00
Julien Grall 69c6eee756 xen: introduce xen_pv_disks_disabled()
ARM guest is considered as HVM in Freebsd but they only support PV disk
(no emulation available).

Submitted by: Elliott Mitchell <ehem+freebsd@m5p.com>
Reviewed by: royger
Differential Revision: https://reviews.freebsd.org/D29403
2021-07-28 17:27:04 +02:00
Julien Grall 5f70008327 xen/netfront: introduce xen_pv_nics_disabled()
ARM guest is considered as HVM but it only supports PV nics (no
emulation available).

Submitted by: Elliott Mitchell <ehem+freebsd@m5p.com>
Reviewed by: royger
Differential Revision: https://reviews.freebsd.org/D29405
2021-07-28 17:27:04 +02:00
Elliott Mitchell c89f1f12b0 xen/xen-os: move inclusion of machine/xen-os.h later
Several of x86 enable/disable functions depend upon the xen*domain()
functions.  As such the xen*domain() functions need to be declared
before machine/xen-os.h.

Officially declare direct inclusion of machine/xen/xen-os.h verboten as
such will break these functions/macros.  Remove one such soon to be
broken inclusion.

Reviewed by: royger
Differential Revision: https://reviews.freebsd.org/D29811
2021-07-28 17:27:04 +02:00
Julien Grall d561380eb3 xen/xen-os: don't let anyone else defining __XEN_INTERFACE_VERSION__
FreeBSD should always use the same version across the source. If not
it's a call for problem.

Submitted by: Elliott Mitchell <ehem+freebsd@m5p.com>
Reviewed by: royger
Differential Revision: https://reviews.freebsd.org/D29407
2021-07-28 17:27:02 +02:00
Mitchell Horne 2117a66af5 xen: remove hypervisor_info
This was a source of indirection needed to support PVHv1. Now that that
support has been removed, we can eliminate it.

Reviewed by: royger
2021-05-17 10:56:52 +02:00
Roger Pau Monné cfa0b7b82f xen: remove direct usage of HYPERVISOR_start_info
HYPERVISOR_start_info is only available to PV and PVHv1 guests, HVM
and PVHv2 guests get this data from HVM parameters that are fetched
using a hypercall.

Instead provide a set of helper functions that should be used to fetch
this data. The helper functions have different implementations
depending on whether FreeBSD is running as PVHv1 or HVM/PVHv2 guest
type.

This helps to cleanup generic Xen code by removing quite a lot of
xen_pv_domain and xen_hvm_domain macro usages.

Sponsored by:	Citrix Systems R&D
2018-07-19 07:54:45 +00:00
Roger Pau Monné 8dee0e9bd6 xen: add support for canceled suspend
When running on Xen, it's possible that a suspend request to the hypervisor
fails (return from HYPERVISOR_suspend different than 0). This means that the
suspend hasn't succeed, and the resume procedure needs to properly handle this
case.

First of all, when such situation happens there's no need to reset the vector
callback, hypercall page, shared info, event channels or grant table, because
it's state is preserved. Also, the PV drivers don't need to be reset to the
initial state, since the connection with the backed has not been interrupted.

Submitted by:		Liuyingdong <liuyingdong@huawei.com>
Reviewed by:		royger
MFC after:		2 weeks
Differential revision:	https://reviews.freebsd.org/D9635
2017-03-07 09:16:51 +00:00
Roger Pau Monné 89ee6cecbc xen: Correct typo in #undef for symbol NBPL
Submitted by:	Akshay Jaggi <akshay1994.leo@gmail.com>
Reviewed by:	royger
2016-06-06 14:55:46 +00:00
Roger Pau Monné f186ed526a xen/intr: fix the event channel enabled per-cpu mask
Fix two issues with the current event channel code, first ENABLED_SETSIZE is
not correctly defined and then using a BITSET to store the per-cpu masks is
not portable to other arches, since on arm32 the event channel arrays shared
with the hypervisor are of type uint64_t and not long. Partially restore the
previous code but switch the bit operations to use the recently introduced
xen_{set/clear/test}_bit versions.

Reviewed by:		Julien Grall <julien.grall@citrix.com>
Sponsored by:		Citrix Systems R&D
Differential Revision:	https://reviews.freebsd.org/D4080
2015-11-05 14:33:46 +00:00
Roger Pau Monné 2f9ec994bc xen: Code cleanup and small bug fixes
xen/hypervisor.h:
 - Remove unused helpers: MULTI_update_va_mapping, is_initial_xendomain,
   is_running_on_xen
 - Remove unused define CONFIG_X86_PAE
 - Remove unused variable xen_start_info: note that it's used inpcifront
   which is not built at all
 - Remove forward declaration of HYPERVISOR_crash

xen/xen-os.h:
 - Remove unused define CONFIG_X86_PAE
 - Drop unused helpers: test_and_clear_bit, clear_bit,
   force_evtchn_callback
 - Implement a generic version (based on ofed/include/linux/bitops.h) of
   set_bit and test_bit and prefix them by xen_ to avoid any use by other
   code than Xen. Note that It would be worth to investigate a generic
   implementation in FreeBSD.
 - Replace barrier() by __compiler_membar()
 - Replace cpu_relax() by cpu_spinwait(): it's exactly the same as rep;nop
   = pause

xen/xen_intr.h:
 - Move the prototype of xen_intr_handle_upcall in it: Use by all the
   platform

x86/xen/xen_intr.c:
 - Use BITSET* for the enabledbits: Avoid to use custom helpers
 - test_bit/set_bit has been renamed to xen_test_bit/xen_set_bit
 - Don't export the variable xen_intr_pcpu

dev/xen/blkback/blkback.c:
 - Fix the string format when XBB_DEBUG is enabled: host_addr is typed
   uint64_t

dev/xen/balloon/balloon.c:
 - Remove set but not used variable
 - Use the correct type for frame_list: xen_pfn_t represents the frame
   number on any architecture

dev/xen/control/control.c:
 - Return BUS_PROBE_WILDCARD in xs_probe: Returning 0 in a probe callback
   means the driver can handle this device. If by any chance xenstore is the
   first driver, every new device with the driver is unset will use
   xenstore.

dev/xen/grant-table/grant_table.c:
 - Remove unused cmpxchg
 - Drop unused include opt_pmap.h: Doesn't exist on ARM64 and it doesn't
   contain anything required for the code on x86

dev/xen/netfront/netfront.c:
 - Use the correct type for rx_pfn_array: xen_pfn_t represents the frame
   number on any architecture

dev/xen/netback/netback.c:
 - Use the correct type for gmfn: xen_pfn_t represents the frame number on
   any architecture

dev/xen/xenstore/xenstore.c:
 - Return BUS_PROBE_WILDCARD in xctrl_probe: Returning 0 in a probe callback
   means the driver can handle this device. If by any chance xenstore is the
  first driver, every new device with the driver is unset will use xenstore.

Note that with the changes, x86/include/xen/xen-os.h doesn't contain anymore
arch-specific code. Although, a new series will add some helpers that differ
between x86 and ARM64, so I've kept the headers for now.

Submitted by:		Julien Grall <julien.grall@citrix.com>
Reviewed by:		royger
Differential Revision:	https://reviews.freebsd.org/D3921
Sponsored by:		Citrix Systems R&D
2015-10-21 10:44:07 +00:00
Roger Pau Monné f8f1bb83f7 xen: allow disabling PV disks and nics
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
2015-08-21 15:53:08 +00:00
Roger Pau Monné 0df8b29da3 xen: introduce a newbus function to allocate unused memory
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>
2015-05-08 14:48:40 +00:00
Warner Losh b7df74ee5a Make this compile with gcc.
Submitted by: royger@
2014-04-05 22:43:18 +00:00
Warner Losh e5d7b3ce52 Revert last change, it breaks other things. 2014-03-19 20:40:57 +00:00
Warner Losh 1afb8884a7 Remove redunant declaration. gcc complains while clang doesn't. 2014-03-19 17:53:09 +00:00
Roger Pau Monné c203fa6940 xen: add and enable Xen console for PVH guests
This adds and enables the PV console used on XEN kernels to
GENERIC/XENHVM kernels in order for it to be used on PVH.

Approved by: gibbs
Sponsored by: Citrix Systems R&D

dev/xen/console/console.c:
 - Define console_page.
 - Move xc_printf debug function from i386 XEN code to generic console
   code.
 - Rework xc_printf.
 - Use xen_initial_domain instead of open-coded checks for Dom0.
 - Gate the attach of the PV console to PV(H) guests.

dev/xen/console/xencons_ring.c:
 - Allow the PV Xen console to output earlier by directly signaling
   the event channel in start_info if the event channel is not yet
   initialized.
 - Use HYPERVISOR_start_info instead of xen_start_info.

i386/include/xen/xen-os.h:
 - Remove prototype for xc_printf since it's now declared in global
   xen-os.h

i386/xen/xen_machdep.c:
 - Remove previous version of xc_printf.
 - Remove definition of console_page (now it's defined in the console
   itself).
 - Fix some printf formatting errors.

x86/xen/pv.c:
 - Add some early boot debug messages using xc_printf.
 - Set console_page based on the value passed in start_info.

xen/xen-os.h:
 - Declare console_page and add prototype for xc_printf.
2014-03-11 10:09:23 +00:00
Roger Pau Monné 6f4246bce1 xen: add macro to detect if running as Dom0
Approved by: gibbs
Sponsored by: Citrix Systems R&D

xen/xen-os.h:
 - Add macro to detect if running as Dom0.
2014-03-11 10:07:55 +00:00
Roger Pau Monné 1a9cdd373a xen: add PV/PVH kernel entry point
Add the PV/PVH entry point and the low level functions for PVH
early initialization.

Approved by: gibbs
Sponsored by: Citrix Systems R&D

amd64/amd64/genassym.c:
 - Add __FreeBSD_version define to assym.s so it can be used for the
   Xen notes.

amd64/amd64/locore.S:
 - Make bootstack global so it can be used from Xen kernel entry
   point.

amd64/amd64/xen-locore.S:
 - Add Xen notes to the kernel.
 - Add the Xen PV entry point, that is going to call hammer_time_xen.

amd64/include/asmacros.h:
 - Add ELFNOTE macros.

i386/xen/xen_machdep.c:
 - Define HYPERVISOR_start_info for the XEN i386 PV port, which is
   going to be used in some shared code between PV and PVH.

x86/xen/hvm.c:
 - Define HYPERVISOR_start_info for the PVH port.

x86/xen/pv.c:
 - Introduce hammer_time_xen which is going to perform early setup for
   Xen PVH:
    - Setup shared Xen variables start_info, shared_info and
      xen_store.
    - Set guest type.
    - Create initial page tables as FreeBSD expects to find them.
    - Call into native init function (hammer_time).

xen/xen-os.h:
 - Declare HYPERVISOR_start_info.

conf/files.amd64:
 - Add amd64/amd64/locore.S and x86/xen/pv.c to the list of files.
2014-03-11 10:07:01 +00:00
Dimitry Andric ede491c085 Remove redundant redeclaration of gdtset in sys/xen/xen-os.h, to silence
a gcc warning.

Approved by:	re (glebius)
2013-10-18 17:06:13 +00:00
Justin T. Gibbs 76acc41fb7 Implement vector callback for PVHVM and unify event channel implementations
Re-structure Xen HVM support so that:
	- Xen is detected and hypercalls can be performed very
	  early in system startup.
	- Xen interrupt services are implemented using FreeBSD's native
	  interrupt delivery infrastructure.
	- the Xen interrupt service implementation is shared between PV
	  and HVM guests.
	- Xen interrupt handlers can optionally use a filter handler
	  in order to avoid the overhead of dispatch to an interrupt
	  thread.
	- interrupt load can be distributed among all available CPUs.
	- the overhead of accessing the emulated local and I/O apics
	  on HVM is removed for event channel port events.
	- a similar optimization can eventually, and fairly easily,
	  be used to optimize MSI.

Early Xen detection, HVM refactoring, PVHVM interrupt infrastructure,
and misc Xen cleanups:

Sponsored by: Spectra Logic Corporation

Unification of PV & HVM interrupt infrastructure, bug fixes,
and misc Xen cleanups:

Submitted by: Roger Pau Monné
Sponsored by: Citrix Systems R&D

sys/x86/x86/local_apic.c:
sys/amd64/include/apicvar.h:
sys/i386/include/apicvar.h:
sys/amd64/amd64/apic_vector.S:
sys/i386/i386/apic_vector.s:
sys/amd64/amd64/machdep.c:
sys/i386/i386/machdep.c:
sys/i386/xen/exception.s:
sys/x86/include/segments.h:
	Reserve IDT vector 0x93 for the Xen event channel upcall
	interrupt handler.  On Hypervisors that support the direct
	vector callback feature, we can request that this vector be
	called directly by an injected HVM interrupt event, instead
	of a simulated PCI interrupt on the Xen platform PCI device.
	This avoids all of the overhead of dealing with the emulated
	I/O APIC and local APIC.  It also means that the Hypervisor
	can inject these events on any CPU, allowing upcalls for
	different ports to be handled in parallel.

sys/amd64/amd64/mp_machdep.c:
sys/i386/i386/mp_machdep.c:
	Map Xen per-vcpu area during AP startup.

sys/amd64/include/intr_machdep.h:
sys/i386/include/intr_machdep.h:
	Increase the FreeBSD IRQ vector table to include space
	for event channel interrupt sources.

sys/amd64/include/pcpu.h:
sys/i386/include/pcpu.h:
	Remove Xen HVM per-cpu variable data.  These fields are now
	allocated via the dynamic per-cpu scheme.  See xen_intr.c
	for details.

sys/amd64/include/xen/hypercall.h:
sys/dev/xen/blkback/blkback.c:
sys/i386/include/xen/xenvar.h:
sys/i386/xen/clock.c:
sys/i386/xen/xen_machdep.c:
sys/xen/gnttab.c:
	Prefer FreeBSD primatives to Linux ones in Xen support code.

sys/amd64/include/xen/xen-os.h:
sys/i386/include/xen/xen-os.h:
sys/xen/xen-os.h:
sys/dev/xen/balloon/balloon.c:
sys/dev/xen/blkback/blkback.c:
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/console/xencons_ring.c:
sys/dev/xen/control/control.c:
sys/dev/xen/netback/netback.c:
sys/dev/xen/netfront/netfront.c:
sys/dev/xen/xenpci/xenpci.c:
sys/i386/i386/machdep.c:
sys/i386/include/pmap.h:
sys/i386/include/xen/xenfunc.h:
sys/i386/isa/npx.c:
sys/i386/xen/clock.c:
sys/i386/xen/mp_machdep.c:
sys/i386/xen/mptable.c:
sys/i386/xen/xen_clock_util.c:
sys/i386/xen/xen_machdep.c:
sys/i386/xen/xen_rtc.c:
sys/xen/evtchn/evtchn_dev.c:
sys/xen/features.c:
sys/xen/gnttab.c:
sys/xen/gnttab.h:
sys/xen/hvm.h:
sys/xen/xenbus/xenbus.c:
sys/xen/xenbus/xenbus_if.m:
sys/xen/xenbus/xenbusb_front.c:
sys/xen/xenbus/xenbusvar.h:
sys/xen/xenstore/xenstore.c:
sys/xen/xenstore/xenstore_dev.c:
sys/xen/xenstore/xenstorevar.h:
	Pull common Xen OS support functions/settings into xen/xen-os.h.

sys/amd64/include/xen/xen-os.h:
sys/i386/include/xen/xen-os.h:
sys/xen/xen-os.h:
	Remove constants, macros, and functions unused in FreeBSD's Xen
	support.

sys/xen/xen-os.h:
sys/i386/xen/xen_machdep.c:
sys/x86/xen/hvm.c:
	Introduce new functions xen_domain(), xen_pv_domain(), and
	xen_hvm_domain().  These are used in favor of #ifdefs so that
	FreeBSD can dynamically detect and adapt to the presence of
	a hypervisor.  The goal is to have an HVM optimized GENERIC,
	but more is necessary before this is possible.

sys/amd64/amd64/machdep.c:
sys/dev/xen/xenpci/xenpcivar.h:
sys/dev/xen/xenpci/xenpci.c:
sys/x86/xen/hvm.c:
sys/sys/kernel.h:
	Refactor magic ioport, Hypercall table and Hypervisor shared
	information page setup, and move it to a dedicated HVM support
	module.

	HVM mode initialization is now triggered during the
	SI_SUB_HYPERVISOR phase of system startup.  This currently
	occurs just after the kernel VM is fully setup which is
	just enough infrastructure to allow the hypercall table
	and shared info page to be properly mapped.

sys/xen/hvm.h:
sys/x86/xen/hvm.c:
	Add definitions and a method for configuring Hypervisor event
	delievery via a direct vector callback.

sys/amd64/include/xen/xen-os.h:
sys/x86/xen/hvm.c:

sys/conf/files:
sys/conf/files.amd64:
sys/conf/files.i386:
	Adjust kernel build to reflect the refactoring of early
	Xen startup code and Xen interrupt services.

sys/dev/xen/blkback/blkback.c:
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/blkfront/block.h:
sys/dev/xen/control/control.c:
sys/dev/xen/evtchn/evtchn_dev.c:
sys/dev/xen/netback/netback.c:
sys/dev/xen/netfront/netfront.c:
sys/xen/xenstore/xenstore.c:
sys/xen/evtchn/evtchn_dev.c:
sys/dev/xen/console/console.c:
sys/dev/xen/console/xencons_ring.c
	Adjust drivers to use new xen_intr_*() API.

sys/dev/xen/blkback/blkback.c:
	Since blkback defers all event handling to a taskqueue,
	convert this task queue to a "fast" taskqueue, and schedule
	it via an interrupt filter.  This avoids an unnecessary
	ithread context switch.

sys/xen/xenstore/xenstore.c:
	The xenstore driver is MPSAFE.  Indicate as much when
	registering its interrupt handler.

sys/xen/xenbus/xenbus.c:
sys/xen/xenbus/xenbusvar.h:
	Remove unused event channel APIs.

sys/xen/evtchn.h:
	Remove all kernel Xen interrupt service API definitions
	from this file.  It is now only used for structure and
	ioctl definitions related to the event channel userland
	device driver.

	Update the definitions in this file to match those from
	NetBSD.  Implementing this interface will be necessary for
	Dom0 support.

sys/xen/evtchn/evtchnvar.h:
	Add a header file for implemenation internal APIs related
	to managing event channels event delivery.  This is used
	to allow, for example, the event channel userland device
	driver to access low-level routines that typical kernel
	consumers of event channel services should never access.

sys/xen/interface/event_channel.h:
sys/xen/xen_intr.h:
	Standardize on the evtchn_port_t type for referring to
	an event channel port id.  In order to prevent low-level
	event channel APIs from leaking to kernel consumers who
	should not have access to this data, the type is defined
	twice: Once in the Xen provided event_channel.h, and again
	in xen/xen_intr.h.  The double declaration is protected by
	__XEN_EVTCHN_PORT_DEFINED__ to ensure it is never declared
	twice within a given compilation unit.

sys/xen/xen_intr.h:
sys/xen/evtchn/evtchn.c:
sys/x86/xen/xen_intr.c:
sys/dev/xen/xenpci/evtchn.c:
sys/dev/xen/xenpci/xenpcivar.h:
	New implementation of Xen interrupt services.  This is
	similar in many respects to the i386 PV implementation with
	the exception that events for bound to event channel ports
	(i.e. not IPI, virtual IRQ, or physical IRQ) are further
	optimized to avoid mask/unmask operations that aren't
	necessary for these edge triggered events.

	Stubs exist for supporting physical IRQ binding, but will
	need additional work before this implementation can be
	fully shared between PV and HVM.

sys/amd64/amd64/mp_machdep.c:
sys/i386/i386/mp_machdep.c:
sys/i386/xen/mp_machdep.c
sys/x86/xen/hvm.c:
	Add support for placing vcpu_info into an arbritary memory
	page instead of using HYPERVISOR_shared_info->vcpu_info.
	This allows the creation of domains with more than 32 vcpus.

sys/i386/i386/machdep.c:
sys/i386/xen/clock.c:
sys/i386/xen/xen_machdep.c:
sys/i386/xen/exception.s:
	Add support for new event channle implementation.
2013-08-29 19:52:18 +00:00