diff options
Diffstat (limited to 'arch/arm64/xen/hypercall.S')
| -rw-r--r-- | arch/arm64/xen/hypercall.S | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/arch/arm64/xen/hypercall.S b/arch/arm64/xen/hypercall.S index 9d01361696a1..ae551b857137 100644 --- a/arch/arm64/xen/hypercall.S +++ b/arch/arm64/xen/hypercall.S @@ -83,7 +83,26 @@ HYPERCALL3(vcpu_op); HYPERCALL1(platform_op_raw); HYPERCALL2(multicall); HYPERCALL2(vm_assist); -HYPERCALL3(dm_op); + +SYM_FUNC_START(HYPERVISOR_dm_op) + mov x16, #__HYPERVISOR_dm_op; \ + /* + * dm_op hypercalls are issued by the userspace. The kernel needs to + * enable access to TTBR0_EL1 as the hypervisor would issue stage 1 + * translations to user memory via AT instructions. Since AT + * instructions are not affected by the PAN bit (ARMv8.1), we only + * need the explicit uaccess_enable/disable if the TTBR0 PAN emulation + * is enabled (it implies that hardware UAO and PAN disabled). + */ + uaccess_ttbr0_enable x6, x7, x8 + hvc XEN_IMM + + /* + * Disable userspace access from kernel once the hyp call completed. + */ + uaccess_ttbr0_disable x6, x7 + ret +SYM_FUNC_END(HYPERVISOR_dm_op); SYM_FUNC_START(privcmd_call) mov x16, x0 |