diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/entry.S')
| -rw-r--r-- | arch/arm64/kvm/hyp/entry.S | 128 |
1 files changed, 80 insertions, 48 deletions
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S index ce9e5e5f28cf..12ee62d6d410 100644 --- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -55,79 +55,111 @@ */ ENTRY(__guest_enter) // x0: vcpu - // x1: host/guest context - // x2-x18: clobbered by macros + // x1: host context + // x2-x17: clobbered by macros + // x18: guest context // Store the host regs save_callee_saved_regs x1 - // Preserve vcpu & host_ctxt for use at exit time - stp x0, x1, [sp, #-16]! + // Store the host_ctxt for use at exit time + str x1, [sp, #-16]! - add x1, x0, #VCPU_CONTEXT + add x18, x0, #VCPU_CONTEXT - // Prepare x0-x1 for later restore by pushing them onto the stack - ldp x2, x3, [x1, #CPU_XREG_OFFSET(0)] - stp x2, x3, [sp, #-16]! + // Restore guest regs x0-x17 + ldp x0, x1, [x18, #CPU_XREG_OFFSET(0)] + ldp x2, x3, [x18, #CPU_XREG_OFFSET(2)] + ldp x4, x5, [x18, #CPU_XREG_OFFSET(4)] + ldp x6, x7, [x18, #CPU_XREG_OFFSET(6)] + ldp x8, x9, [x18, #CPU_XREG_OFFSET(8)] + ldp x10, x11, [x18, #CPU_XREG_OFFSET(10)] + ldp x12, x13, [x18, #CPU_XREG_OFFSET(12)] + ldp x14, x15, [x18, #CPU_XREG_OFFSET(14)] + ldp x16, x17, [x18, #CPU_XREG_OFFSET(16)] - // x2-x18 - ldp x2, x3, [x1, #CPU_XREG_OFFSET(2)] - ldp x4, x5, [x1, #CPU_XREG_OFFSET(4)] - ldp x6, x7, [x1, #CPU_XREG_OFFSET(6)] - ldp x8, x9, [x1, #CPU_XREG_OFFSET(8)] - ldp x10, x11, [x1, #CPU_XREG_OFFSET(10)] - ldp x12, x13, [x1, #CPU_XREG_OFFSET(12)] - ldp x14, x15, [x1, #CPU_XREG_OFFSET(14)] - ldp x16, x17, [x1, #CPU_XREG_OFFSET(16)] - ldr x18, [x1, #CPU_XREG_OFFSET(18)] - - // x19-x29, lr - restore_callee_saved_regs x1 - - // Last bits of the 64bit state - ldp x0, x1, [sp], #16 + // Restore guest regs x19-x29, lr + restore_callee_saved_regs x18 + + // Restore guest reg x18 + ldr x18, [x18, #CPU_XREG_OFFSET(18)] // Do not touch any register after this! eret ENDPROC(__guest_enter) ENTRY(__guest_exit) - // x0: vcpu - // x1: return code - // x2-x3: free - // x4-x29,lr: vcpu regs - // vcpu x0-x3 on the stack + // x0: return code + // x1: vcpu + // x2-x29,lr: vcpu regs + // vcpu x0-x1 on the stack - add x2, x0, #VCPU_CONTEXT + add x1, x1, #VCPU_CONTEXT - stp x4, x5, [x2, #CPU_XREG_OFFSET(4)] - stp x6, x7, [x2, #CPU_XREG_OFFSET(6)] - stp x8, x9, [x2, #CPU_XREG_OFFSET(8)] - stp x10, x11, [x2, #CPU_XREG_OFFSET(10)] - stp x12, x13, [x2, #CPU_XREG_OFFSET(12)] - stp x14, x15, [x2, #CPU_XREG_OFFSET(14)] - stp x16, x17, [x2, #CPU_XREG_OFFSET(16)] - str x18, [x2, #CPU_XREG_OFFSET(18)] + ALTERNATIVE(nop, SET_PSTATE_PAN(1), ARM64_HAS_PAN, CONFIG_ARM64_PAN) - ldp x6, x7, [sp], #16 // x2, x3 - ldp x4, x5, [sp], #16 // x0, x1 + // Store the guest regs x2 and x3 + stp x2, x3, [x1, #CPU_XREG_OFFSET(2)] - stp x4, x5, [x2, #CPU_XREG_OFFSET(0)] - stp x6, x7, [x2, #CPU_XREG_OFFSET(2)] + // Retrieve the guest regs x0-x1 from the stack + ldp x2, x3, [sp], #16 // x0, x1 + + // Store the guest regs x0-x1 and x4-x18 + stp x2, x3, [x1, #CPU_XREG_OFFSET(0)] + stp x4, x5, [x1, #CPU_XREG_OFFSET(4)] + stp x6, x7, [x1, #CPU_XREG_OFFSET(6)] + stp x8, x9, [x1, #CPU_XREG_OFFSET(8)] + stp x10, x11, [x1, #CPU_XREG_OFFSET(10)] + stp x12, x13, [x1, #CPU_XREG_OFFSET(12)] + stp x14, x15, [x1, #CPU_XREG_OFFSET(14)] + stp x16, x17, [x1, #CPU_XREG_OFFSET(16)] + str x18, [x1, #CPU_XREG_OFFSET(18)] + + // Store the guest regs x19-x29, lr + save_callee_saved_regs x1 - save_callee_saved_regs x2 + // Restore the host_ctxt from the stack + ldr x2, [sp], #16 - // Restore vcpu & host_ctxt from the stack - // (preserving return code in x1) - ldp x0, x2, [sp], #16 // Now restore the host regs restore_callee_saved_regs x2 - mov x0, x1 - ret + // If we have a pending asynchronous abort, now is the + // time to find out. From your VAXorcist book, page 666: + // "Threaten me not, oh Evil one! For I speak with + // the power of DEC, and I command thee to show thyself!" + mrs x2, elr_el2 + mrs x3, esr_el2 + mrs x4, spsr_el2 + mov x5, x0 + + dsb sy // Synchronize against in-flight ld/st + msr daifclr, #4 // Unmask aborts + + // This is our single instruction exception window. A pending + // SError is guaranteed to occur at the earliest when we unmask + // it, and at the latest just after the ISB. + .global abort_guest_exit_start +abort_guest_exit_start: + + isb + + .global abort_guest_exit_end +abort_guest_exit_end: + + // If the exception took place, restore the EL1 exception + // context so that we can report some information. + // Merge the exception code with the SError pending bit. + tbz x0, #ARM_EXIT_WITH_SERROR_BIT, 1f + msr elr_el2, x2 + msr esr_el2, x3 + msr spsr_el2, x4 + orr x0, x0, x5 +1: ret ENDPROC(__guest_exit) ENTRY(__fpsimd_guest_restore) + stp x2, x3, [sp, #-16]! stp x4, lr, [sp, #-16]! alternative_if_not ARM64_HAS_VIRT_HOST_EXTN |