From: Marc Zyngier <maz@kernel.org> mainline inclusion from mainline-6.15 commit ffea7c73d181db273be8b306be6bc573dfe2257b category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/8904 CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ---------------------------------------------------------------------- Rather than restoring HCRX_EL2 to a fixed value on vcpu exit, perform a full save/restore of the register, ensuring that we don't lose bits that would have been set at some point in the host kernel lifetime, such as the GCSEn bit. Fixes: ff5181d8a2a82 ("arm64/gcs: Provide basic EL2 setup to allow GCS usage at EL0 and EL1") Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250430105916.3815157-2-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com> Signed-off-by: Hongye Lin <linhongye@h-partners.com> --- arch/arm64/kvm/hyp/include/hyp/switch.h | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index 04d38432a1b9..a28d79608d06 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -204,6 +204,8 @@ static inline void __deactivate_traps_mpam(void) static inline void __activate_traps_common(struct kvm_vcpu *vcpu) { + struct kvm_cpu_context *hctxt = host_data_ptr(host_ctxt); + /* Trap on AArch32 cp15 c15 (impdef sysregs) accesses (EL1 or EL0) */ write_sysreg(1 << 15, hstr_el2); @@ -214,11 +216,8 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu) * EL1 instead of being trapped to EL2. */ if (kvm_arm_support_pmu_v3()) { - struct kvm_cpu_context *hctxt; - write_sysreg(0, pmselr_el0); - hctxt = host_data_ptr(host_ctxt); ctxt_sys_reg(hctxt, PMUSERENR_EL0) = read_sysreg(pmuserenr_el0); write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0); vcpu_set_flag(vcpu, PMUSERENR_ON_CPU); @@ -248,6 +247,7 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu) if (cpus_have_final_cap(ARM64_HAS_LS64_V)) hcrx |= HCRX_EL2_EnASR; + ctxt_sys_reg(hctxt, HCRX_EL2) = read_sysreg_s(SYS_HCRX_EL2); write_sysreg_s(hcrx, SYS_HCRX_EL2); } @@ -257,6 +257,8 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu) static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu) { + struct kvm_cpu_context *hctxt = host_data_ptr(host_ctxt); + write_sysreg(*host_data_ptr(host_debug_state.mdcr_el2), mdcr_el2); if (cpus_have_final_cap(ARM64_HAS_NMI) && @@ -265,15 +267,12 @@ static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu) write_sysreg(0, hstr_el2); if (kvm_arm_support_pmu_v3()) { - struct kvm_cpu_context *hctxt; - - hctxt = host_data_ptr(host_ctxt); write_sysreg(ctxt_sys_reg(hctxt, PMUSERENR_EL0), pmuserenr_el0); vcpu_clear_flag(vcpu, PMUSERENR_ON_CPU); } if (cpus_have_final_cap(ARM64_HAS_HCX)) - write_sysreg_s(HCRX_HOST_FLAGS, SYS_HCRX_EL2); + write_sysreg_s(ctxt_sys_reg(hctxt, HCRX_EL2), SYS_HCRX_EL2); __deactivate_traps_hfgxtr(vcpu); __deactivate_traps_mpam(); -- 2.33.0