diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/sysreg-sr.c')
| -rw-r--r-- | arch/arm64/kvm/hyp/sysreg-sr.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c index 9ce223944983..8dc285318204 100644 --- a/arch/arm64/kvm/hyp/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/sysreg-sr.c @@ -152,8 +152,25 @@ static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt) static void __hyp_text __sysreg_restore_el2_return_state(struct kvm_cpu_context *ctxt) { + u64 pstate = ctxt->gp_regs.regs.pstate; + u64 mode = pstate & PSR_AA32_MODE_MASK; + + /* + * Safety check to ensure we're setting the CPU up to enter the guest + * in a less privileged mode. + * + * If we are attempting a return to EL2 or higher in AArch64 state, + * program SPSR_EL2 with M=EL2h and the IL bit set which ensures that + * we'll take an illegal exception state exception immediately after + * the ERET to the guest. Attempts to return to AArch32 Hyp will + * result in an illegal exception return because EL2's execution state + * is determined by SCR_EL3.RW. + */ + if (!(mode & PSR_MODE32_BIT) && mode >= PSR_MODE_EL2t) + pstate = PSR_MODE_EL2h | PSR_IL_BIT; + write_sysreg_el2(ctxt->gp_regs.regs.pc, elr); - write_sysreg_el2(ctxt->gp_regs.regs.pstate, spsr); + write_sysreg_el2(pstate, spsr); if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN)) write_sysreg_s(ctxt->sys_regs[DISR_EL1], SYS_VDISR_EL2); |