diff options
| author | Christoffer Dall <christoffer.dall@arm.com> | 2018-10-17 20:21:16 +0200 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2018-10-19 11:13:03 +0100 |
| commit | e4e11cc0f81ee7be17d6f6fb96128a6d51c0e838 (patch) | |
| tree | 16a1070795b753152fff3b97c20f7bdc18123a0c /arch/arm64/kvm/hyp/hyp-entry.S | |
| parent | 58bf437ff64eac8aca606e42d7e4623e40b61fa1 (diff) | |
KVM: arm64: Safety check PSTATE when entering guest and handle IL
This commit adds a paranoid check when entering the guest to make sure
we don't attempt running guest code in an equally or more privilged mode
than the hypervisor. We also catch other accidental programming of the
SPSR_EL2 which results in an illegal exception return and report this
safely back to the user.
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm64/kvm/hyp/hyp-entry.S')
| -rw-r--r-- | arch/arm64/kvm/hyp/hyp-entry.S | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S index 24b4fbafe3e4..b1f14f736962 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -162,6 +162,20 @@ el1_error: mov x0, #ARM_EXCEPTION_EL1_SERROR b __guest_exit +el2_sync: + /* Check for illegal exception return, otherwise panic */ + mrs x0, spsr_el2 + + /* if this was something else, then panic! */ + tst x0, #PSR_IL_BIT + b.eq __hyp_panic + + /* Let's attempt a recovery from the illegal exception return */ + get_vcpu_ptr x1, x0 + mov x0, #ARM_EXCEPTION_IL + b __guest_exit + + el2_error: ldp x0, x1, [sp], #16 @@ -240,7 +254,7 @@ ENTRY(__kvm_hyp_vector) invalid_vect el2t_fiq_invalid // FIQ EL2t invalid_vect el2t_error_invalid // Error EL2t - invalid_vect el2h_sync_invalid // Synchronous EL2h + valid_vect el2_sync // Synchronous EL2h invalid_vect el2h_irq_invalid // IRQ EL2h invalid_vect el2h_fiq_invalid // FIQ EL2h valid_vect el2_error // Error EL2h |