The current addition to the interrupt nesting level in
xen_arch_intr_handle_upcall() needs to be compensated in
xen_intr_handle_upcall(), otherwise interrupts dispatched by the upcall handler
end up seeing a td_intr_nesting_level of 2 or more, which makes them assume
there's been an interrupt nesting.
Such extra interrupt nesting count lead to statclock() reporting idle time as
interrupt, as the call from interrupt context will always be seen as a nested
one (td->td_intr_nesting_level >= 2) due to the nesting count increase done by
both xen_arch_intr_handle_upcall() and intr_execute_handlers().
Fix this by adjusting the nested interrupt count before dispatching interrupts
from xen_intr_handle_upcall().
PR: 277231
Reported by: Matthew Grooms <mgrooms@shrew.net>
Fixes: af610cabf1 ('xen/intr: adjust xen_intr_handle_upcall() to match driver filter')
Sponsored by: Cloud Software Group
Reviewed by: Elliott Mitchell <ehem+freebsd@m5p.com>
The event channel source code or equivalent is needed on all
architectures. Since much of this is viable to share, get this moved out
of x86-land. Each interrupt interface then needs a distinct back-end
implementation.
Reviewed by: royger
Submitted by: Elliott Mitchell <ehem+freebsd@m5p.com>
Original implementation: Julien Grall <julien@xen.org>, 2014-01-13 17:41:04
Differential Revision: https://reviews.freebsd.org/D30236
Simply moving the interrupt allocation and release functions into files
which belong to the architecture. Since x86 interrupt handling is quite
distinct from other architectures, this is a crucial necessary step.
Identifying the border between x86 and architecture-independent is
actually quite tricky. Similarly, getting the prototypes for the
border right is also quite tricky.
Inspired by the work of Julien Grall <julien@xen.org>,
2015-10-20 09:14:56, but heavily adjusted.
Reviewed by: royger
Differential Revision: https://reviews.freebsd.org/D30936
The x86 PIC interface is very much x86-specific and not used by other
architectures. Since most of xen_intr.c can be shared with other
architectures, the PIC interface needs to be broken off.
Introduce wrappers for calls into the architecture-dependent interrupt
layer. All architectures need roughly the same functionality, but the
interface is slightly different between architectures. Due to the
wrappers being so thin, all of them are implemented as inline in
arch-intr.h.
The original implementation was done by Julien Grall in 2015, but this
has required major updating.
Removal of PVHv1 meant substantial portions disappeared. The original
implementation took care of moving interrupt allocation to
xen_arch_intr.c, but this has required massive rework and was broken
off.
In the original implementation the wrappers were normal functions. Some
had empty stubs in xen_intr.c and were removed.
Reviewed by: royger
Submitted by: Elliott Mitchell <ehem+freebsd@m5p.com>
Original implementation: Julien Grall <julien@xen.org>, 2015-10-20 09:14:56
Differential Revision: https://reviews.freebsd.org/D30909
The evtchn_type enum is only touched by the Xen interrupt code. Other
event channel uses no longer need the value, so that has been moved to
restrict its use.
Copyright note. The current evtchn_type was introduced at 76acc41fb7
by Justin T. Gibbs. This in turn appears to have been heavily inspired
by 30d1eefe39 done by Kip Macy.
Reviewed by: royger
Move the xenisrc structure which needs to be shared between the core Xen
interrupt code and architecture-dependent code into a separate header. A
similar situation exists for the NR_EVENT_CHANNELS constant.
Turn xi_intsrc into a type definition named xi_arch to reflect the new
purpose of being an architectural variable for the interrupt source.
This was originally implemented by Julien Grall, but has been heavily
modified. The core side was renamed "intr-internal.h" and is #include'd
by "arch-intr.h" instead of the other way around. This allows the
architecture to add function definitions which use struct xenisrc.
The original version only moved xi_intsrc into xen_arch_isrc_t. Moving
xi_vector was done by the submitter.
The submitter had also moved xi_activehi and xi_edgetrigger into
xen_arch_isrc_t. Those disappeared with the removal of PVHv1 support.
Copyright note. The current xenisrc structure was introduced at
76acc41fb7 by Justin T. Gibbs. Traces remain, but the strength of
Copyright claims from before 2013 seem pretty weak.
Reviewed by: royger
Submitted by: Elliott Mitchell <ehem+freebsd@m5p.com>, 2021-03-17 19:09:01
Original implementation: Julien Grall <julien@xen.org>, 2015-10-20 09:14:56
Differential Revision: https://reviews.freebsd.org/D30648
[royger]
- Adjust some line lengths
- Fix comment about NR_EVENT_CHANNELS after movement.
- Use #include instead of symlinks.
This matches the return type of pmap_mapdev/bios.
Reviewed by: kib, markj
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D36548
While here, use driver->name instead of hardcoding the xenpv and
xen_et strings both for devclass_find() and BUS_ADD_CHILD().
Reviewed by: Elliott Mitchell <ehem+freebsd@m5p.com>, imp, royger
Differential Revision: https://reviews.freebsd.org/D35001
bus_activate_resource maps memory regions as uncacheable on x86, which
is more strict than required for regions allocated using xenmem_alloc,
so don't rely on bus_activate_resource and instead map the region
using pmap_mapdev_attr and VM_MEMATTR_XEN as the cache attribute.
Sponsored by: Citrix Systems R&D
For embedded devices reserved addresses will be known in advance. More
recently added devices will also likely be correctly updated. As a
result using any available address is reasonable on non-x86.
Reviewed by: royger
Differential Revision: https://reviews.freebsd.org/D29304
The requirements for pages shared with Xen/other VMs may vary from
architecture to architecture. As such create a macro which various
architectures can use.
Remove a use of PAT_WRITE_BACK in xenstore.c. This is a x86-ism which
shouldn't have been present in a common area.
Original idea: Julien Grall <julien@xen.org>, 2014-01-14 06:44:08
Approach suggested by: royger
Reviewed by: royger, mhorne
Differential Revision: https://reviews.freebsd.org/D29351
Minor changes are necessary to make this processor-independent, but
moving the file out of x86 and into common is the first step (so
others don't add /more/ x86-isms).
Submitted by: Elliott Mitchell <ehem+freebsd@m5p.com>
Reviewed by: royger
Differential Revision: https://reviews.freebsd.org/D29042
