8ae6efdde4
Currently, the SVE register ID macros are not all defined in the
same way, and advertise the fact that FFR maps onto the nonexistent
predicate register P16. This is really just for kernel
convenience, and may lead userspace into bad habits.
Instead, this patch masks the ID macro arguments so that
architecturally invalid register numbers will not be passed through
any more, and uses a literal KVM_REG_ARM64_SVE_FFR_BASE macro to
define KVM_REG_ARM64_SVE_FFR(), similarly to the way the _ZREG()
and _PREG() macros are defined.
Rather than plugging in magic numbers for the number of Z- and P-
registers and the maximum possible number of register slices, this
patch provides definitions for those too. Userspace is going to
need them in any case, and it makes sense for them to come from
<uapi/asm/kvm.h>.
sve_reg_to_region() uses convenience constants that are defined in
a different way, and also makes use of the fact that the FFR IDs
are really contiguous with the P15 IDs, so this patch retains the
existing convenience constants in guest.c, supplemented with a
couple of sanity checks to check for consistency with the UAPI
header.
Fixes: e1c9c98345b3 ("KVM: arm64/sve: Add SVE support to register access ioctl interface")
Suggested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.