KVM: arm64: Make ID_AA64MMFR1_EL1.{HCX, TWED} writable from userspace

Allow userspace to downgrade {HCX, TWED} in ID_AA64MMFR1_EL1. Userspace can
only change the value from high to low.

Signed-off-by: Jinqian Yang <yangjinqian1@huawei.com>
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 b29f72478a50d594f3a37ab12bbb5ed9ea901d46..e6ec971eb9d12c37a5c4dd5aeee16310d3a45803 100644 (file)
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -3152,8 +3152,6 @@ static const struct sys_reg_desc sys_reg_descs[] = {
                                      ~(ID_AA64MMFR0_EL1_RES0 |
                                        ID_AA64MMFR0_EL1_ASIDBITS)),
        ID_WRITABLE(ID_AA64MMFR1_EL1, ~(ID_AA64MMFR1_EL1_RES0 |
-                                       ID_AA64MMFR1_EL1_HCX |
-                                       ID_AA64MMFR1_EL1_TWED |
                                        ID_AA64MMFR1_EL1_XNX |
                                        ID_AA64MMFR1_EL1_VH |
                                        ID_AA64MMFR1_EL1_VMIDBits)),