Add basic support for Pointer Authentication when running a KVM
guest and that the host supports it, loosely based on the SVE
support.
Although the feature is enabled by default when the host advertises
it, it is possible to disable it by setting the 'pauth=off' CPU
property. The 'pauth' comment is removed from cpu-features.rst,
as it is now common to both TCG and KVM.
Tested on an Apple M1 running 5.16-rc6.
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220107150154.2490308-1-maz@kernel.org
[PMM: fixed indentation]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
In rST markup, single backticks `like this` represent "interpreted
text", which can be handled as a bunch of different things if tagged
with a specific "role":
https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html#interpreted-text
(the most common one for us is "reference to a URL, which gets
hyperlinked").
The default "role" if none is specified is "title_reference",
intended for references to book or article titles, and it renders
into the HTML as <cite>...</cite> (usually comes out as italics).
To format a literal (generally rendered as fixed-width font),
double-backticks are required.
cpu-features.rst consistently uses single backticks when double backticks
are required; correct it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20210726142338.31872-8-peter.maydell@linaro.org
Mirror the behavour of /proc/sys/abi/sve_default_vector_length
under the real linux kernel. We have no way of passing along
a real default across exec like the kernel can, but this is a
decent way of adjusting the startup vector length of a process.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/482
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20210723203344.968563-4-richard.henderson@linaro.org
[PMM: tweaked docs formatting, document -1 special-case,
added fixup patch from RTH mentioning QEMU's maximum veclen.]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The crypto overhead of emulating pauth can be significant for
some workloads. Add two boolean properties that allows the
feature to be turned off, on with the architected algorithm,
or on with an implementation defined algorithm.
We need two intermediate booleans to control the state while
parsing properties lest we clobber ID_AA64ISAR1 into an invalid
intermediate state.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210111235740.462469-3-richard.henderson@linaro.org
[PMM: fixed docs typo, tweaked text to clarify that the impdef
algorithm is specific to QEMU]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We add the kvm-steal-time CPU property and implement it for machvirt.
A tiny bit of refactoring was also done to allow pmu and pvtime to
use the same vcpu device helper functions.
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Andrew Jones <drjones@redhat.com>
Message-id: 20201001061718.101915-7-drjones@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The company 'Arm' went through a rebranding some years back
involving a recapitalization from 'ARM' to 'Arm'. As a result
our documentation is a bit inconsistent between the two forms.
It's not worth trying to update everywhere in QEMU, but it's
easy enough to make docs/ consistent.
Note that "ARMv8" and similar architecture names, and
older CPU names like "ARM926" still retain all-caps.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Message-id: 20200309215818.2021-6-peter.maydell@linaro.org
Now we have somewhere to put arm-specific rst documentation,
we can move arm-cpu-features.rst from the docs/ top level
directory into docs/system/arm/.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Message-id: 20200309215818.2021-5-peter.maydell@linaro.org
