diff options
Diffstat (limited to 'arch/arm/kvm/interrupts.S')
| -rw-r--r-- | arch/arm/kvm/interrupts.S | 480 |
1 files changed, 3 insertions, 477 deletions
diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S index 900ef6dd8f72..b1bd316f14c0 100644 --- a/arch/arm/kvm/interrupts.S +++ b/arch/arm/kvm/interrupts.S @@ -17,211 +17,14 @@ */ #include <linux/linkage.h> -#include <linux/const.h> -#include <asm/unified.h> -#include <asm/page.h> -#include <asm/ptrace.h> -#include <asm/asm-offsets.h> -#include <asm/kvm_asm.h> -#include <asm/kvm_arm.h> -#include <asm/vfpmacros.h> -#include "interrupts_head.S" .text -__kvm_hyp_code_start: - .globl __kvm_hyp_code_start - -/******************************************************************** - * Flush per-VMID TLBs - * - * void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa); - * - * We rely on the hardware to broadcast the TLB invalidation to all CPUs - * inside the inner-shareable domain (which is the case for all v7 - * implementations). If we come across a non-IS SMP implementation, we'll - * have to use an IPI based mechanism. Until then, we stick to the simple - * hardware assisted version. - * - * As v7 does not support flushing per IPA, just nuke the whole TLB - * instead, ignoring the ipa value. - */ -ENTRY(__kvm_tlb_flush_vmid_ipa) - push {r2, r3} - - dsb ishst - add r0, r0, #KVM_VTTBR - ldrd r2, r3, [r0] - mcrr p15, 6, rr_lo_hi(r2, r3), c2 @ Write VTTBR - isb - mcr p15, 0, r0, c8, c3, 0 @ TLBIALLIS (rt ignored) - dsb ish - isb - mov r2, #0 - mov r3, #0 - mcrr p15, 6, r2, r3, c2 @ Back to VMID #0 - isb @ Not necessary if followed by eret - - pop {r2, r3} - bx lr -ENDPROC(__kvm_tlb_flush_vmid_ipa) - -/** - * void __kvm_tlb_flush_vmid(struct kvm *kvm) - Flush per-VMID TLBs - * - * Reuses __kvm_tlb_flush_vmid_ipa() for ARMv7, without passing address - * parameter - */ - -ENTRY(__kvm_tlb_flush_vmid) - b __kvm_tlb_flush_vmid_ipa -ENDPROC(__kvm_tlb_flush_vmid) - -/******************************************************************** - * Flush TLBs and instruction caches of all CPUs inside the inner-shareable - * domain, for all VMIDs - * - * void __kvm_flush_vm_context(void); - */ -ENTRY(__kvm_flush_vm_context) - mov r0, #0 @ rn parameter for c15 flushes is SBZ - - /* Invalidate NS Non-Hyp TLB Inner Shareable (TLBIALLNSNHIS) */ - mcr p15, 4, r0, c8, c3, 4 - /* Invalidate instruction caches Inner Shareable (ICIALLUIS) */ - mcr p15, 0, r0, c7, c1, 0 - dsb ish - isb @ Not necessary if followed by eret - - bx lr -ENDPROC(__kvm_flush_vm_context) - - -/******************************************************************** - * Hypervisor world-switch code - * - * - * int __kvm_vcpu_run(struct kvm_vcpu *vcpu) - */ -ENTRY(__kvm_vcpu_run) - @ Save the vcpu pointer - mcr p15, 4, vcpu, c13, c0, 2 @ HTPIDR - - save_host_regs - - restore_vgic_state - restore_timer_state - - @ Store hardware CP15 state and load guest state - read_cp15_state store_to_vcpu = 0 - write_cp15_state read_from_vcpu = 1 - - @ If the host kernel has not been configured with VFPv3 support, - @ then it is safer if we deny guests from using it as well. -#ifdef CONFIG_VFPv3 - @ Set FPEXC_EN so the guest doesn't trap floating point instructions - VFPFMRX r2, FPEXC @ VMRS - push {r2} - orr r2, r2, #FPEXC_EN - VFPFMXR FPEXC, r2 @ VMSR -#endif - - @ Configure Hyp-role - configure_hyp_role vmentry - - @ Trap coprocessor CRx accesses - set_hstr vmentry - set_hcptr vmentry, (HCPTR_TTA | HCPTR_TCP(10) | HCPTR_TCP(11)) - set_hdcr vmentry - - @ Write configured ID register into MIDR alias - ldr r1, [vcpu, #VCPU_MIDR] - mcr p15, 4, r1, c0, c0, 0 - - @ Write guest view of MPIDR into VMPIDR - ldr r1, [vcpu, #CP15_OFFSET(c0_MPIDR)] - mcr p15, 4, r1, c0, c0, 5 - - @ Set up guest memory translation - ldr r1, [vcpu, #VCPU_KVM] - add r1, r1, #KVM_VTTBR - ldrd r2, r3, [r1] - mcrr p15, 6, rr_lo_hi(r2, r3), c2 @ Write VTTBR - - @ We're all done, just restore the GPRs and go to the guest - restore_guest_regs - clrex @ Clear exclusive monitor - eret - -__kvm_vcpu_return: - /* - * return convention: - * guest r0, r1, r2 saved on the stack - * r0: vcpu pointer - * r1: exception code - */ - save_guest_regs - - @ Set VMID == 0 - mov r2, #0 - mov r3, #0 - mcrr p15, 6, r2, r3, c2 @ Write VTTBR - - @ Don't trap coprocessor accesses for host kernel - set_hstr vmexit - set_hdcr vmexit - set_hcptr vmexit, (HCPTR_TTA | HCPTR_TCP(10) | HCPTR_TCP(11)), after_vfp_restore - -#ifdef CONFIG_VFPv3 - @ Switch VFP/NEON hardware state to the host's - add r7, vcpu, #VCPU_VFP_GUEST - store_vfp_state r7 - add r7, vcpu, #VCPU_VFP_HOST - ldr r7, [r7] - restore_vfp_state r7 - -after_vfp_restore: - @ Restore FPEXC_EN which we clobbered on entry - pop {r2} - VFPFMXR FPEXC, r2 -#else -after_vfp_restore: -#endif - - @ Reset Hyp-role - configure_hyp_role vmexit - - @ Let host read hardware MIDR - mrc p15, 0, r2, c0, c0, 0 - mcr p15, 4, r2, c0, c0, 0 - - @ Back to hardware MPIDR - mrc p15, 0, r2, c0, c0, 5 - mcr p15, 4, r2, c0, c0, 5 - - @ Store guest CP15 state and restore host state - read_cp15_state store_to_vcpu = 1 - write_cp15_state read_from_vcpu = 0 - - save_timer_state - save_vgic_state - - restore_host_regs - clrex @ Clear exclusive monitor -#ifndef CONFIG_CPU_ENDIAN_BE8 - mov r0, r1 @ Return the return code - mov r1, #0 @ Clear upper bits in return value -#else - @ r1 already has return code - mov r0, #0 @ Clear upper bits in return value -#endif /* CONFIG_CPU_ENDIAN_BE8 */ - bx lr @ return to IOCTL - /******************************************************************** * Call function in Hyp mode * * - * u64 kvm_call_hyp(void *hypfn, ...); + * unsigned long kvm_call_hyp(void *hypfn, ...); * * This is not really a variadic function in the classic C-way and care must * be taken when calling this to ensure parameters are passed in registers @@ -232,7 +35,7 @@ after_vfp_restore: * passed as r0, r1, and r2 (a maximum of 3 arguments in addition to the * function pointer can be passed). The function being called must be mapped * in Hyp mode (see init_hyp_mode in arch/arm/kvm/arm.c). Return values are - * passed in r0 and r1. + * passed in r0 (strictly 32bit). * * A function pointer with a value of 0xffffffff has a special meaning, * and is used to implement __hyp_get_vectors in the same way as in @@ -246,281 +49,4 @@ after_vfp_restore: ENTRY(kvm_call_hyp) hvc #0 bx lr - -/******************************************************************** - * Hypervisor exception vector and handlers - * - * - * The KVM/ARM Hypervisor ABI is defined as follows: - * - * Entry to Hyp mode from the host kernel will happen _only_ when an HVC - * instruction is issued since all traps are disabled when running the host - * kernel as per the Hyp-mode initialization at boot time. - * - * HVC instructions cause a trap to the vector page + offset 0x14 (see hyp_hvc - * below) when the HVC instruction is called from SVC mode (i.e. a guest or the - * host kernel) and they cause a trap to the vector page + offset 0x8 when HVC - * instructions are called from within Hyp-mode. - * - * Hyp-ABI: Calling HYP-mode functions from host (in SVC mode): - * Switching to Hyp mode is done through a simple HVC #0 instruction. The - * exception vector code will check that the HVC comes from VMID==0 and if - * so will push the necessary state (SPSR, lr_usr) on the Hyp stack. - * - r0 contains a pointer to a HYP function - * - r1, r2, and r3 contain arguments to the above function. - * - The HYP function will be called with its arguments in r0, r1 and r2. - * On HYP function return, we return directly to SVC. - * - * Note that the above is used to execute code in Hyp-mode from a host-kernel - * point of view, and is a different concept from performing a world-switch and - * executing guest code SVC mode (with a VMID != 0). - */ - -/* Handle undef, svc, pabt, or dabt by crashing with a user notice */ -.macro bad_exception exception_code, panic_str - push {r0-r2} - mrrc p15, 6, r0, r1, c2 @ Read VTTBR - lsr r1, r1, #16 - ands r1, r1, #0xff - beq 99f - - load_vcpu @ Load VCPU pointer - .if \exception_code == ARM_EXCEPTION_DATA_ABORT - mrc p15, 4, r2, c5, c2, 0 @ HSR - mrc p15, 4, r1, c6, c0, 0 @ HDFAR - str r2, [vcpu, #VCPU_HSR] - str r1, [vcpu, #VCPU_HxFAR] - .endif - .if \exception_code == ARM_EXCEPTION_PREF_ABORT - mrc p15, 4, r2, c5, c2, 0 @ HSR - mrc p15, 4, r1, c6, c0, 2 @ HIFAR - str r2, [vcpu, #VCPU_HSR] - str r1, [vcpu, #VCPU_HxFAR] - .endif - mov r1, #\exception_code - b __kvm_vcpu_return - - @ We were in the host already. Let's craft a panic-ing return to SVC. -99: mrs r2, cpsr - bic r2, r2, #MODE_MASK - orr r2, r2, #SVC_MODE -THUMB( orr r2, r2, #PSR_T_BIT ) - msr spsr_cxsf, r2 - mrs r1, ELR_hyp - ldr r2, =panic - msr ELR_hyp, r2 - ldr r0, =\panic_str - clrex @ Clear exclusive monitor - eret -.endm - - .text - - .align 5 -__kvm_hyp_vector: - .globl __kvm_hyp_vector - - @ Hyp-mode exception vector - W(b) hyp_reset - W(b) hyp_undef - W(b) hyp_svc - W(b) hyp_pabt - W(b) hyp_dabt - W(b) hyp_hvc - W(b) hyp_irq - W(b) hyp_fiq - - .align -hyp_reset: - b hyp_reset - - .align -hyp_undef: - bad_exception ARM_EXCEPTION_UNDEFINED, und_die_str - - .align -hyp_svc: - bad_exception ARM_EXCEPTION_HVC, svc_die_str - - .align -hyp_pabt: - bad_exception ARM_EXCEPTION_PREF_ABORT, pabt_die_str - - .align -hyp_dabt: - bad_exception ARM_EXCEPTION_DATA_ABORT, dabt_die_str - - .align -hyp_hvc: - /* - * Getting here is either becuase of a trap from a guest or from calling - * HVC from the host kernel, which means "switch to Hyp mode". - */ - push {r0, r1, r2} - - @ Check syndrome register - mrc p15, 4, r1, c5, c2, 0 @ HSR - lsr r0, r1, #HSR_EC_SHIFT - cmp r0, #HSR_EC_HVC - bne guest_trap @ Not HVC instr. - - /* - * Let's check if the HVC came from VMID 0 and allow simple - * switch to Hyp mode - */ - mrrc p15, 6, r0, r2, c2 - lsr r2, r2, #16 - and r2, r2, #0xff - cmp r2, #0 - bne guest_trap @ Guest called HVC - - /* - * Getting here means host called HVC, we shift parameters and branch - * to Hyp function. - */ - pop {r0, r1, r2} - - /* Check for __hyp_get_vectors */ - cmp r0, #-1 - mrceq p15, 4, r0, c12, c0, 0 @ get HVBAR - beq 1f - - push {lr} - mrs lr, SPSR - push {lr} - - mov lr, r0 - mov r0, r1 - mov r1, r2 - mov r2, r3 - -THUMB( orr lr, #1) - blx lr @ Call the HYP function - - pop {lr} - msr SPSR_csxf, lr - pop {lr} -1: eret - -guest_trap: - load_vcpu @ Load VCPU pointer to r0 - str r1, [vcpu, #VCPU_HSR] - - @ Check if we need the fault information - lsr r1, r1, #HSR_EC_SHIFT -#ifdef CONFIG_VFPv3 - cmp r1, #HSR_EC_CP_0_13 - beq switch_to_guest_vfp -#endif - cmp r1, #HSR_EC_IABT - mrceq p15, 4, r2, c6, c0, 2 @ HIFAR - beq 2f - cmp r1, #HSR_EC_DABT - bne 1f - mrc p15, 4, r2, c6, c0, 0 @ HDFAR - -2: str r2, [vcpu, #VCPU_HxFAR] - - /* - * B3.13.5 Reporting exceptions taken to the Non-secure PL2 mode: - * - * Abort on the stage 2 translation for a memory access from a - * Non-secure PL1 or PL0 mode: - * - * For any Access flag fault or Translation fault, and also for any - * Permission fault on the stage 2 translation of a memory access - * made as part of a translation table walk for a stage 1 translation, - * the HPFAR holds the IPA that caused the fault. Otherwise, the HPFAR - * is UNKNOWN. - */ - - /* Check for permission fault, and S1PTW */ - mrc p15, 4, r1, c5, c2, 0 @ HSR - and r0, r1, #HSR_FSC_TYPE - cmp r0, #FSC_PERM - tsteq r1, #(1 << 7) @ S1PTW - mrcne p15, 4, r2, c6, c0, 4 @ HPFAR - bne 3f - - /* Preserve PAR */ - mrrc p15, 0, r0, r1, c7 @ PAR - push {r0, r1} - - /* Resolve IPA using the xFAR */ - mcr p15, 0, r2, c7, c8, 0 @ ATS1CPR - isb - mrrc p15, 0, r0, r1, c7 @ PAR - tst r0, #1 - bne 4f @ Failed translation - ubfx r2, r0, #12, #20 - lsl r2, r2, #4 - orr r2, r2, r1, lsl #24 - - /* Restore PAR */ - pop {r0, r1} - mcrr p15, 0, r0, r1, c7 @ PAR - -3: load_vcpu @ Load VCPU pointer to r0 - str r2, [r0, #VCPU_HPFAR] - -1: mov r1, #ARM_EXCEPTION_HVC - b __kvm_vcpu_return - -4: pop {r0, r1} @ Failed translation, return to guest - mcrr p15, 0, r0, r1, c7 @ PAR - clrex - pop {r0, r1, r2} - eret - -/* - * If VFPv3 support is not available, then we will not switch the VFP - * registers; however cp10 and cp11 accesses will still trap and fallback - * to the regular coprocessor emulation code, which currently will - * inject an undefined exception to the guest. - */ -#ifdef CONFIG_VFPv3 -switch_to_guest_vfp: - push {r3-r7} - - @ NEON/VFP used. Turn on VFP access. - set_hcptr vmtrap, (HCPTR_TCP(10) | HCPTR_TCP(11)) - - @ Switch VFP/NEON hardware state to the guest's - add r7, r0, #VCPU_VFP_HOST - ldr r7, [r7] - store_vfp_state r7 - add r7, r0, #VCPU_VFP_GUEST - restore_vfp_state r7 - - pop {r3-r7} - pop {r0-r2} - clrex - eret -#endif - - .align -hyp_irq: - push {r0, r1, r2} - mov r1, #ARM_EXCEPTION_IRQ - load_vcpu @ Load VCPU pointer to r0 - b __kvm_vcpu_return - - .align -hyp_fiq: - b hyp_fiq - - .ltorg - -__kvm_hyp_code_end: - .globl __kvm_hyp_code_end - - .section ".rodata" - -und_die_str: - .ascii "unexpected undefined exception in Hyp mode at: %#08x\n" -pabt_die_str: - .ascii "unexpected prefetch abort in Hyp mode at: %#08x\n" -dabt_die_str: - .ascii "unexpected data abort in Hyp mode at: %#08x\n" -svc_die_str: - .ascii "unexpected HVC/SVC trap in Hyp mode at: %#08x\n" +ENDPROC(kvm_call_hyp) |