#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
/********************************************************************
* Flush per-VMID TLBs
+ *
+ * void __kvm_tlb_flush_vmid(struct kvm *kvm);
+ *
+ * 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.
*/
ENTRY(__kvm_tlb_flush_vmid)
+ push {r2, r3}
+
+ add r0, r0, #KVM_VTTBR
+ ldrd r2, r3, [r0]
+ mcrr p15, 6, r2, r3, c2 @ Write VTTBR
+ isb
+ mcr p15, 0, r0, c8, c3, 0 @ TLBIALLIS (rt ignored)
+ dsb
+ 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)
/********************************************************************
- * Flush TLBs and instruction caches of current CPU for all VMIDs
+ * 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
+ 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)
- bx lr
+ @ Save the vcpu pointer
+ mcr p15, 4, vcpu, c13, c0, 2 @ HTPIDR
+
+ save_host_regs
+
+ @ 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, 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))
+
+#ifdef CONFIG_VFPv3
+ @ Save floating point registers we if let guest use them.
+ tst r2, #(HCPTR_TCP(10) | HCPTR_TCP(11))
+ bne after_vfp_restore
+
+ @ 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
+#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
+
+ restore_host_regs
+ clrex @ Clear exclusive monitor
+ mov r0, r1 @ Return the return code
+ mov r1, #0 @ Clear upper bits in return value
+ bx lr @ return to IOCTL
/********************************************************************
* Call function in Hyp mode
/********************************************************************
* 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 0x18 (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 0xc 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, =BSYM(panic)
+ msr ELR_hyp, r2
+ ldr r0, =\panic_str
+ eret
+.endm
+
+ .text
+
.align 5
__kvm_hyp_vector:
.globl __kvm_hyp_vector
- nop
+
+ @ 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
+#ifdef CONFIG_VFPv3
+ cmp r0, #HSR_EC_CP_0_13
+ beq switch_to_guest_vfp
+#endif
+ 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
+
+host_switch_to_hyp:
+ pop {r0, r1, r2}
+
+ 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}
+ 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
+ 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
+
+ /* 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
+
+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, r2} @ Failed translation, return to guest
+ 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:
+ load_vcpu @ Load VCPU pointer to r0
+ push {r3-r7}
+
+ @ NEON/VFP used. Turn on VFP access.
+ set_hcptr vmexit, (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}
+ 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"
+pabt_die_str:
+ .ascii "unexpected prefetch abort in Hyp mode at: %#08x"
+dabt_die_str:
+ .ascii "unexpected data abort in Hyp mode at: %#08x"
+svc_die_str:
+ .ascii "unexpected HVC/SVC trap in Hyp mode at: %#08x"
projects / firefly-linux-kernel-4.4.55.git / blobdiff