Besides the fact that we did not have that for the current supported
boards, that makes sense for this new, virtualized mode, that is meant
to be run on top of full-fledged x86 64 CPUs.
By having xAPIC mode access only, Jailhouse has to intercept those MMIO
reads and writes, in order to examine what they do and arbitrate if it's
safe or not (e.g. not all values are accepted to ICR register). This
means that we can't run away from having a VM-exit event for each and
every access to APIC memory region and this impacts the latency the
guest OS observes over bare metal a lot.
When in x2APIC mode, Jailhouse does not require VM-exits for MSR
accesses other that writes to the ICR register, so the latency the guest
observes is reduced to almost zero.
Here are some outputs of the the command line
$ sudo ./tools/jailhouse cell stats tiny-demo
on a Jailhouse's root cell console, for one of the Zephyr demos using
LOAPIC timers, left for a couple of seconds:
Statistics for tiny-demo cell (x2APIC root, x2APIC inmate)
COUNTER SUM PER SEC
vmexits_total 7 0
vmexits_management 3 0
vmexits_cr 2 0
vmexits_cpuid 1 0
vmexits_msr 1 0
vmexits_exception 0 0
vmexits_hypercall 0 0
vmexits_mmio 0 0
vmexits_pio 0 0
vmexits_xapic 0 0
vmexits_xsetbv 0 0
Statistics for tiny-demo cell (xAPIC root, xAPIC inmate)
COUNTER SUM PER SEC
vmexits_total 4087 40
vmexits_xapic 4080 40
vmexits_management 3 0
vmexits_cr 2 0
vmexits_cpuid 1 0
vmexits_msr 1 0
vmexits_exception 0 0
vmexits_hypercall 0 0
vmexits_mmio 0 0
vmexits_pio 0 0
vmexits_xsetbv 0 0
Statistics for tiny-demo cell (xAPIC root, x2APIC inmate)
COUNTER SUM PER SEC
vmexits_total 4087 40
vmexits_msr 4080 40
vmexits_management 3 0
vmexits_cr 2 0
vmexits_cpuid 1 0
vmexits_exception 0 0
vmexits_hypercall 0 0
vmexits_mmio 0 0
vmexits_pio 0 0
vmexits_xapic 0 0
vmexits_xsetbv 0 0
See that under x2APIC mode on both Jailhouse/root-cell and guest, the
interruptions from the hypervisor are minimal. That is not the case when
Jailhouse is on xAPIC mode, though. Note also that, as a plus, x2APIC
accesses on the guest will map to xAPIC MMIO on the hypervisor just
fine.
Signed-off-by: Gustavo Lima Chaves <gustavo.lima.chaves@intel.com>
- _arch_user_mode_enter() implemented
- _arch_is_user_context() implemented
- _new_thread() will honor K_USER option if passed in
- System call triggering macros implemented
- _thread_entry_wrapper moved and now looks for the next function to
call in EDI
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Subsequent patches will set this guard page as unmapped,
triggering a page fault on access. If this is due to
stack overflow, a double fault will be triggered,
which we are now capable of handling with a switch to
a know good stack.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
None of this is currently necessary, the spurious interrupt
stubs and exception entry code is included in the binary just
fine. To make matters worse, some data referenced lives in the
.intList section which is completely stripped out of the binary.
If in the future we find certain essential functions are being
garbage collected when they should not be, the proper way to
mitigate this is with KEEP() directives in the linker script.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Convert code to use u{8,16,32,64}_t and s{8,16,32,64}_t instead of C99
integer types. There are few places we dont convert over to the new
types because of compatiability with ext/HALs or for ease of transition
at this point. Fixup a few of the PRI formatters so we build with newlib.
Jira: ZEP-2051
Change-Id: I7d2d3697cad04f20aaa8f6e77228f502cd9c8286
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Replace the existing Apache 2.0 boilerplate header with an SPDX tag
throughout the zephyr code tree. This patch was generated via a
script run over the master branch.
Also updated doc/porting/application.rst that had a dependency on
line numbers in a literal include.
Manually updated subsys/logging/sys_log.c that had a malformed
header in the original file. Also cleanup several cases that already
had a SPDX tag and we either got a duplicate or missed updating.
Jira: ZEP-1457
Change-Id: I6131a1d4ee0e58f5b938300c2d2fc77d2e69572c
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Also remove some old cflags referencing directories that do not exist
anymore.
Also replace references to legacy APIs in doxygen documentation of
various functions.
Change-Id: I8fce3d1fe0f4defc44e6eb0ae09a4863e33a39db
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
nano_cpu_idle/nano_cpu_atomic_idle were not ported to the unified
kernel, and only the old APIs were available. There was no real impact
since, in the unified kernel, only the idle thread should really be
doing power management. However, with a single-threaded kernel, these
functions can be useful again.
The kernel internals now make use of these APIs instead of the legacy
ones.
Change-Id: Ie8a6396ba378d3ddda27b8dd32fa4711bf53eb36
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
There was a lot of duplication between architectures for the definition
of threads and the "nanokernel" guts. These have been consolidated.
Now, a common file kernel/unified/include/kernel_structs.h holds the
common definitions. Architectures provide two files to complement it:
kernel_arch_data.h and kernel_arch_func.h. The first one contains at
least the struct _thread_arch and struct _kernel_arch data structures,
as well as the struct _callee_saved and struct _caller_saved register
layouts. The second file contains anything that needs what is provided
by the common stuff in kernel_structs.h. Those two files are only meant
to be included in kernel_structs.h in very specific locations.
The thread data structure has been separated into three major parts:
common struct _thread_base and struct k_thread, and arch-specific struct
_thread_arch. The first and third ones are included in the second.
The struct s_NANO data structure has been split into two: common struct
_kernel and arch-specific struct _kernel_arch. The latter is included in
the former.
Offsets files have also changed: nano_offsets.h has been renamed
kernel_offsets.h and is still included by the arch-specific offsets.c.
Also, since the thread and kernel data structures are now made of
sub-structures, offsets have to be added to make up the full offset.
Some of these additions have been consolidated in shorter symbols,
available from kernel/unified/include/offsets_short.h, which includes an
arch-specific offsets_arch_short.h. Most of the code include
offsets_short.h now instead of offsets.h.
Change-Id: I084645cb7e6db8db69aeaaf162963fe157045d5a
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Gustavo Lima Chaves