KVM: arm64: Expose ID_AA64FPFR0_EL1 as a writable ID reg

ID_AA64FPFR0_EL1 contains all sort of bits that contain a description
of which FP8 subfeatures are implemented.

We don't really care about them, so let's just expose that register
and allow userspace to disable subfeatures at will.

Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240820131802.3547589-7-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 79d67f19130d129f8485c064f5c240e9d99deda5..4c2f7c0af537ca9d9a1f01fb85c061392d818c65 100644 (file)
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2386,7 +2386,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
        ID_WRITABLE(ID_AA64ZFR0_EL1, ~ID_AA64ZFR0_EL1_RES0),
        ID_HIDDEN(ID_AA64SMFR0_EL1),
        ID_UNALLOCATED(4,6),
-       ID_UNALLOCATED(4,7),
+       ID_WRITABLE(ID_AA64FPFR0_EL1, ~ID_AA64FPFR0_EL1_RES0),
 
        /* CRm=5 */
        { SYS_DESC(SYS_ID_AA64DFR0_EL1),