Re: [PATCH v2 5/6] KVM: arm64: show writable masks for feature registers

From: Sebastian Ott
Date: Fri May 03 2024 - 07:03:39 EST


On Wed, 1 May 2024, Oliver Upton wrote:

On Fri, Apr 26, 2024 at 12:49:49PM +0200, Sebastian Ott wrote:
Instead of using ~0UL provide the actual writable mask for
non-id feature registers in the output of the
KVM_ARM_GET_REG_WRITABLE_MASKS ioctl.

Urgh, yeah in retrospect I think we should've constrained this to the
registers KVM considers "id regs" (the space occupied by known registers
or otherwise RAZ).

Explicitely set the mask for CLIDR_EL1 to make sure we present
the same value to userspace than before.

typo: explicitly

Also, we know the set of mutable bits for CLIDR_EL1 as it is handled in
set_clidr(). The mask really should match that, since the UAPI is
documented as "allowing userspace to know what fields can be changed for
the system register"

Done for the next revision.

Thanks,
Sebastian