From: Jing Zhang <jingzhangos@google.com> mainline inclusion from mainline-v6.7-rc1 commit d5a32b60dc184cc7309f83648a368b94d91c797f 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... ------------------------------------------------------------------------ Allow userspace to modify the guest-visible values of these ID registers. Prevent changes to any of the virtualization features until KVM picks up support for nested and we have a handle on managing NV features. Signed-off-by: Jing Zhang <jingzhangos@google.com> [oliver: prevent changes to EL2 features for now] Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231003230408.3405722-8-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev> --- arch/arm64/kvm/sys_regs.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index e797951a8a0d..4552c02f2f8c 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2210,9 +2210,23 @@ static const struct sys_reg_desc sys_reg_descs[] = { ID_UNALLOCATED(6,7), /* CRm=7 */ - ID_SANITISED(ID_AA64MMFR0_EL1), - ID_SANITISED(ID_AA64MMFR1_EL1), - ID_SANITISED(ID_AA64MMFR2_EL1), + ID_WRITABLE(ID_AA64MMFR0_EL1, ~(ID_AA64MMFR0_EL1_RES0 | + ID_AA64MMFR0_EL1_TGRAN4_2 | + ID_AA64MMFR0_EL1_TGRAN64_2 | + ID_AA64MMFR0_EL1_TGRAN16_2)), + ID_WRITABLE(ID_AA64MMFR1_EL1, ~(ID_AA64MMFR1_EL1_RES0 | + ID_AA64MMFR1_EL1_HCX | + ID_AA64MMFR1_EL1_XNX | + ID_AA64MMFR1_EL1_TWED | + ID_AA64MMFR1_EL1_XNX | + ID_AA64MMFR1_EL1_VH | + ID_AA64MMFR1_EL1_VMIDBits)), + ID_WRITABLE(ID_AA64MMFR2_EL1, ~(ID_AA64MMFR2_EL1_RES0 | + ID_AA64MMFR2_EL1_EVT | + ID_AA64MMFR2_EL1_FWB | + ID_AA64MMFR2_EL1_IDS | + ID_AA64MMFR2_EL1_NV | + ID_AA64MMFR2_EL1_CCIDX)), ID_SANITISED(ID_AA64MMFR3_EL1), ID_UNALLOCATED(7,4), ID_UNALLOCATED(7,5), -- 2.33.0