diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/entry.S')
| -rw-r--r-- | arch/arm64/kvm/hyp/entry.S | 95 |
1 files changed, 40 insertions, 55 deletions
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S index 76e7eaf4675e..b0afad7a99c6 100644 --- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -7,7 +7,6 @@ #include <linux/linkage.h> #include <asm/alternative.h> -#include <asm/asm-offsets.h> #include <asm/assembler.h> #include <asm/fpsimdmacros.h> #include <asm/kvm.h> @@ -16,66 +15,28 @@ #include <asm/kvm_mmu.h> #include <asm/kvm_ptrauth.h> -#define CPU_XREG_OFFSET(x) (CPU_USER_PT_REGS + 8*x) -#define CPU_SP_EL0_OFFSET (CPU_XREG_OFFSET(30) + 8) - .text /* - * We treat x18 as callee-saved as the host may use it as a platform - * register (e.g. for shadow call stack). - */ -.macro save_callee_saved_regs ctxt - str x18, [\ctxt, #CPU_XREG_OFFSET(18)] - stp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)] - stp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)] - stp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)] - stp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)] - stp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)] - stp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)] -.endm - -.macro restore_callee_saved_regs ctxt - // We require \ctxt is not x18-x28 - ldr x18, [\ctxt, #CPU_XREG_OFFSET(18)] - ldp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)] - ldp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)] - ldp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)] - ldp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)] - ldp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)] - ldp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)] -.endm - -.macro save_sp_el0 ctxt, tmp - mrs \tmp, sp_el0 - str \tmp, [\ctxt, #CPU_SP_EL0_OFFSET] -.endm - -.macro restore_sp_el0 ctxt, tmp - ldr \tmp, [\ctxt, #CPU_SP_EL0_OFFSET] - msr sp_el0, \tmp -.endm - -/* - * u64 __guest_enter(struct kvm_vcpu *vcpu, - * struct kvm_cpu_context *host_ctxt); + * u64 __guest_enter(struct kvm_vcpu *vcpu); */ SYM_FUNC_START(__guest_enter) // x0: vcpu - // x1: host context - // x2-x17: clobbered by macros + // x1-x17: clobbered by macros // x29: guest context - // Store the host regs + adr_this_cpu x1, kvm_hyp_ctxt, x2 + + // Store the hyp regs save_callee_saved_regs x1 - // Save the host's sp_el0 + // Save hyp's sp_el0 save_sp_el0 x1, x2 - // Now the host state is stored if we have a pending RAS SError it must - // affect the host. If any asynchronous exception is pending we defer - // the guest entry. The DSB isn't necessary before v8.2 as any SError - // would be fatal. + // Now the hyp state is stored if we have a pending RAS SError it must + // affect the host or hyp. If any asynchronous exception is pending we + // defer the guest entry. The DSB isn't necessary before v8.2 as any + // SError would be fatal. alternative_if ARM64_HAS_RAS_EXTN dsb nshst isb @@ -86,6 +47,8 @@ alternative_else_nop_endif ret 1: + set_loaded_vcpu x0, x1, x2 + add x29, x0, #VCPU_CONTEXT // Macro ptrauth_switch_to_guest format: @@ -116,6 +79,26 @@ alternative_else_nop_endif eret sb +SYM_INNER_LABEL(__guest_exit_panic, SYM_L_GLOBAL) + // x2-x29,lr: vcpu regs + // vcpu x0-x1 on the stack + + // If the hyp context is loaded, go straight to hyp_panic + get_loaded_vcpu x0, x1 + cbz x0, hyp_panic + + // The hyp context is saved so make sure it is restored to allow + // hyp_panic to run at hyp and, subsequently, panic to run in the host. + // This makes use of __guest_exit to avoid duplication but sets the + // return address to tail call into hyp_panic. As a side effect, the + // current state is saved to the guest context but it will only be + // accurate if the guest had been completely restored. + adr_this_cpu x0, kvm_hyp_ctxt, x1 + adr x1, hyp_panic + str x1, [x0, #CPU_XREG_OFFSET(30)] + + get_vcpu_ptr x1, x0 + SYM_INNER_LABEL(__guest_exit, SYM_L_GLOBAL) // x0: return code // x1: vcpu @@ -148,21 +131,23 @@ SYM_INNER_LABEL(__guest_exit, SYM_L_GLOBAL) // Store the guest's sp_el0 save_sp_el0 x1, x2 - get_host_ctxt x2, x3 + adr_this_cpu x2, kvm_hyp_ctxt, x3 - // Macro ptrauth_switch_to_guest format: - // ptrauth_switch_to_host(guest cxt, host cxt, tmp1, tmp2, tmp3) + // Macro ptrauth_switch_to_hyp format: + // ptrauth_switch_to_hyp(guest cxt, host cxt, tmp1, tmp2, tmp3) // The below macro to save/restore keys is not implemented in C code // as it may cause Pointer Authentication key signing mismatch errors // when this feature is enabled for kernel code. - ptrauth_switch_to_host x1, x2, x3, x4, x5 + ptrauth_switch_to_hyp x1, x2, x3, x4, x5 - // Restore the hosts's sp_el0 + // Restore hyp's sp_el0 restore_sp_el0 x2, x3 - // Now restore the host regs + // Now restore the hyp regs restore_callee_saved_regs x2 + set_loaded_vcpu xzr, x1, x2 + alternative_if ARM64_HAS_RAS_EXTN // If we have the RAS extensions we can consume a pending error // without an unmask-SError and isb. The ESB-instruction consumed any |