From: Sebastian Ott <sebott@redhat.com> mainline inclusion from mainline-v6.11-rc1 commit bb4fa769dcdd0b6e47ecbf0363489be510498b1d category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IBN3WI CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------------------------------------ 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. This changes the mask for the CTR_EL0 and CLIDR_EL1 registers. Signed-off-by: Sebastian Ott <sebott@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Link: https://lore.kernel.org/r/20240619174036.483943-9-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com> --- arch/arm64/kvm/sys_regs.c | 19 +++++-------------- 1 file changed, 5 insertions(+), 14 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 74fb43c8a1a0..f4884776456b 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2514,7 +2514,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { { SYS_DESC(SYS_CCSIDR_EL1), access_ccsidr }, { SYS_DESC(SYS_CLIDR_EL1), access_clidr, reset_clidr, CLIDR_EL1, - .set_user = set_clidr }, + .set_user = set_clidr, .val = ~CLIDR_EL1_RES0 }, { SYS_DESC(SYS_CCSIDR2_EL1), undef_access }, { SYS_DESC(SYS_SMIDR_EL1), undef_access }, { SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 }, @@ -3997,20 +3997,11 @@ int kvm_vm_ioctl_get_reg_writable_masks(struct kvm *kvm, struct reg_mask_range * if (!is_feature_id_reg(encoding) || !reg->set_user) continue; - /* - * For ID registers, we return the writable mask. Other feature - * registers return a full 64bit mask. That's not necessary - * compliant with a given revision of the architecture, but the - * RES0/RES1 definitions allow us to do that. - */ - if (is_vm_ftr_id_reg(encoding)) { - if (!reg->val || - (is_aa32_id_reg(encoding) && !kvm_supports_32bit_el0())) - continue; - val = reg->val; - } else { - val = ~0UL; + if (!reg->val || + (is_aa32_id_reg(encoding) && !kvm_supports_32bit_el0())) { + continue; } + val = reg->val; if (put_user(val, (masks + KVM_ARM_FEATURE_ID_RANGE_INDEX(encoding)))) return -EFAULT; -- 2.33.0