/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Main entry point for the guest, exception handling. * * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved. * Authors: Sanjay Lal */ #include #include #include #include #include #include #define _C_LABEL(x) x #define MIPSX(name) mips32_ ## name #define CALLFRAME_SIZ 32 /* * VECTOR * exception vector entrypoint */ #define VECTOR(x, regmask) \ .ent _C_LABEL(x),0; \ EXPORT(x); #define VECTOR_END(x) \ EXPORT(x); /* Overload, Danger Will Robinson!! */ #define PT_HOST_ASID PT_BVADDR #define PT_HOST_USERLOCAL PT_EPC #define CP0_DDATA_LO $28,3 #define CP0_CONFIG3 $16,3 #define CP0_CONFIG5 $16,5 #define CP0_EBASE $15,1 #define CP0_INTCTL $12,1 #define CP0_SRSCTL $12,2 #define CP0_SRSMAP $12,3 #define CP0_HWRENA $7,0 /* Resume Flags */ #define RESUME_FLAG_HOST (1<<1) /* Resume host? */ #define RESUME_GUEST 0 #define RESUME_HOST RESUME_FLAG_HOST /* * __kvm_mips_vcpu_run: entry point to the guest * a0: run * a1: vcpu */ .set noreorder .set noat FEXPORT(__kvm_mips_vcpu_run) /* k0/k1 not being used in host kernel context */ INT_ADDIU k1, sp, -PT_SIZE LONG_S $0, PT_R0(k1) LONG_S $1, PT_R1(k1) LONG_S $2, PT_R2(k1) LONG_S $3, PT_R3(k1) LONG_S $4, PT_R4(k1) LONG_S $5, PT_R5(k1) LONG_S $6, PT_R6(k1) LONG_S $7, PT_R7(k1) LONG_S $8, PT_R8(k1) LONG_S $9, PT_R9(k1) LONG_S $10, PT_R10(k1) LONG_S $11, PT_R11(k1) LONG_S $12, PT_R12(k1) LONG_S $13, PT_R13(k1) LONG_S $14, PT_R14(k1) LONG_S $15, PT_R15(k1) LONG_S $16, PT_R16(k1) LONG_S $17, PT_R17(k1) LONG_S $18, PT_R18(k1) LONG_S $19, PT_R19(k1) LONG_S $20, PT_R20(k1) LONG_S $21, PT_R21(k1) LONG_S $22, PT_R22(k1) LONG_S $23, PT_R23(k1) LONG_S $24, PT_R24(k1) LONG_S $25, PT_R25(k1) /* * XXXKYMA k0/k1 not saved, not being used if we got here through * an ioctl() */ LONG_S $28, PT_R28(k1) LONG_S $29, PT_R29(k1) LONG_S $30, PT_R30(k1) LONG_S $31, PT_R31(k1) /* Save hi/lo */ mflo v0 LONG_S v0, PT_LO(k1) mfhi v1 LONG_S v1, PT_HI(k1) /* Save host status */ mfc0 v0, CP0_STATUS LONG_S v0, PT_STATUS(k1) /* Save host ASID, shove it into the BVADDR location */ mfc0 v1, CP0_ENTRYHI andi v1, 0xff LONG_S v1, PT_HOST_ASID(k1) /* Save DDATA_LO, will be used to store pointer to vcpu */ mfc0 v1, CP0_DDATA_LO LONG_S v1, PT_HOST_USERLOCAL(k1) /* DDATA_LO has pointer to vcpu */ mtc0 a1, CP0_DDATA_LO /* Offset into vcpu->arch */ INT_ADDIU k1, a1, VCPU_HOST_ARCH /* * Save the host stack to VCPU, used for exception processing * when we exit from the Guest */ LONG_S sp, VCPU_HOST_STACK(k1) /* Save the kernel gp as well */ LONG_S gp, VCPU_HOST_GP(k1) /* * Setup status register for running the guest in UM, interrupts * are disabled */ li k0, (ST0_EXL | KSU_USER | ST0_BEV) mtc0 k0, CP0_STATUS ehb /* load up the new EBASE */ LONG_L k0, VCPU_GUEST_EBASE(k1) mtc0 k0, CP0_EBASE /* * Now that the new EBASE has been loaded, unset BEV, set * interrupt mask as it was but make sure that timer interrupts * are enabled */ li k0, (ST0_EXL | KSU_USER | ST0_IE) andi v0, v0, ST0_IM or k0, k0, v0 mtc0 k0, CP0_STATUS ehb /* Set Guest EPC */ LONG_L t0, VCPU_PC(k1) mtc0 t0, CP0_EPC FEXPORT(__kvm_mips_load_asid) /* Set the ASID for the Guest Kernel */ PTR_L t0, VCPU_COP0(k1) LONG_L t0, COP0_STATUS(t0) andi t0, KSU_USER | ST0_ERL | ST0_EXL xori t0, KSU_USER bnez t0, 1f /* If kernel */ INT_ADDIU t1, k1, VCPU_GUEST_KERNEL_ASID /* (BD) */ INT_ADDIU t1, k1, VCPU_GUEST_USER_ASID /* else user */ 1: /* t1: contains the base of the ASID array, need to get the cpu id */ LONG_L t2, TI_CPU($28) /* smp_processor_id */ INT_SLL t2, t2, 2 /* x4 */ REG_ADDU t3, t1, t2 LONG_L k0, (t3) andi k0, k0, 0xff mtc0 k0, CP0_ENTRYHI ehb /* Disable RDHWR access */ mtc0 zero, CP0_HWRENA /* Now load up the Guest Context from VCPU */ LONG_L $1, VCPU_R1(k1) LONG_L $2, VCPU_R2(k1) LONG_L $3, VCPU_R3(k1) LONG_L $4, VCPU_R4(k1) LONG_L $5, VCPU_R5(k1) LONG_L $6, VCPU_R6(k1) LONG_L $7, VCPU_R7(k1) LONG_L $8, VCPU_R8(k1) LONG_L $9, VCPU_R9(k1) LONG_L $10, VCPU_R10(k1) LONG_L $11, VCPU_R11(k1) LONG_L $12, VCPU_R12(k1) LONG_L $13, VCPU_R13(k1) LONG_L $14, VCPU_R14(k1) LONG_L $15, VCPU_R15(k1) LONG_L $16, VCPU_R16(k1) LONG_L $17, VCPU_R17(k1) LONG_L $18, VCPU_R18(k1) LONG_L $19, VCPU_R19(k1) LONG_L $20, VCPU_R20(k1) LONG_L $21, VCPU_R21(k1) LONG_L $22, VCPU_R22(k1) LONG_L $23, VCPU_R23(k1) LONG_L $24, VCPU_R24(k1) LONG_L $25, VCPU_R25(k1) /* k0/k1 loaded up later */ LONG_L $28, VCPU_R28(k1) LONG_L $29, VCPU_R29(k1) LONG_L $30, VCPU_R30(k1) LONG_L $31, VCPU_R31(k1) /* Restore hi/lo */ LONG_L k0, VCPU_LO(k1) mtlo k0 LONG_L k0, VCPU_HI(k1) mthi k0 FEXPORT(__kvm_mips_load_k0k1) /* Restore the guest's k0/k1 registers */ LONG_L k0, VCPU_R26(k1) LONG_L k1, VCPU_R27(k1) /* Jump to guest */ eret VECTOR(MIPSX(exception), unknown) /* Find out what mode we came from and jump to the proper handler. */ mtc0 k0, CP0_ERROREPC #01: Save guest k0 ehb #02: mfc0 k0, CP0_EBASE #02: Get EBASE INT_SRL k0, k0, 10 #03: Get rid of CPUNum INT_SLL k0, k0, 10 #04 LONG_S k1, 0x3000(k0) #05: Save k1 @ offset 0x3000 INT_ADDIU k0, k0, 0x2000 #06: Exception handler is # installed @ offset 0x2000 j k0 #07: jump to the function nop #08: branch delay slot VECTOR_END(MIPSX(exceptionEnd)) .end MIPSX(exception) /* * Generic Guest exception handler. We end up here when the guest * does something that causes a trap to kernel mode. */ NESTED (MIPSX(GuestException), CALLFRAME_SIZ, ra) /* Get the VCPU pointer from DDTATA_LO */ mfc0 k1, CP0_DDATA_LO INT_ADDIU k1, k1, VCPU_HOST_ARCH /* Start saving Guest context to VCPU */ LONG_S $0, VCPU_R0(k1) LONG_S $1, VCPU_R1(k1) LONG_S $2, VCPU_R2(k1) LONG_S $3, VCPU_R3(k1) LONG_S $4, VCPU_R4(k1) LONG_S $5, VCPU_R5(k1) LONG_S $6, VCPU_R6(k1) LONG_S $7, VCPU_R7(k1) LONG_S $8, VCPU_R8(k1) LONG_S $9, VCPU_R9(k1) LONG_S $10, VCPU_R10(k1) LONG_S $11, VCPU_R11(k1) LONG_S $12, VCPU_R12(k1) LONG_S $13, VCPU_R13(k1) LONG_S $14, VCPU_R14(k1) LONG_S $15, VCPU_R15(k1) LONG_S $16, VCPU_R16(k1) LONG_S $17, VCPU_R17(k1) LONG_S $18, VCPU_R18(k1) LONG_S $19, VCPU_R19(k1) LONG_S $20, VCPU_R20(k1) LONG_S $21, VCPU_R21(k1) LONG_S $22, VCPU_R22(k1) LONG_S $23, VCPU_R23(k1) LONG_S $24, VCPU_R24(k1) LONG_S $25, VCPU_R25(k1) /* Guest k0/k1 saved later */ LONG_S $28, VCPU_R28(k1) LONG_S $29, VCPU_R29(k1) LONG_S $30, VCPU_R30(k1) LONG_S $31, VCPU_R31(k1) /* We need to save hi/lo and restore them on the way out */ mfhi t0 LONG_S t0, VCPU_HI(k1) mflo t0 LONG_S t0, VCPU_LO(k1) /* Finally save guest k0/k1 to VCPU */ mfc0 t0, CP0_ERROREPC LONG_S t0, VCPU_R26(k1) /* Get GUEST k1 and save it in VCPU */ PTR_LI t1, ~0x2ff mfc0 t0, CP0_EBASE and t0, t0, t1 LONG_L t0, 0x3000(t0) LONG_S t0, VCPU_R27(k1) /* Now that context has been saved, we can use other registers */ /* Restore vcpu */ mfc0 a1, CP0_DDATA_LO move s1, a1 /* Restore run (vcpu->run) */ LONG_L a0, VCPU_RUN(a1) /* Save pointer to run in s0, will be saved by the compiler */ move s0, a0 /* * Save Host level EPC, BadVaddr and Cause to VCPU, useful to * process the exception */ mfc0 k0,CP0_EPC LONG_S k0, VCPU_PC(k1) mfc0 k0, CP0_BADVADDR LONG_S k0, VCPU_HOST_CP0_BADVADDR(k1) mfc0 k0, CP0_CAUSE LONG_S k0, VCPU_HOST_CP0_CAUSE(k1) mfc0 k0, CP0_ENTRYHI LONG_S k0, VCPU_HOST_ENTRYHI(k1) /* Now restore the host state just enough to run the handlers */ /* Swtich EBASE to the one used by Linux */ /* load up the host EBASE */ mfc0 v0, CP0_STATUS .set at or k0, v0, ST0_BEV .set noat mtc0 k0, CP0_STATUS ehb LONG_L k0, VCPU_HOST_EBASE(k1) mtc0 k0,CP0_EBASE /* * If FPU is enabled, save FCR31 and clear it so that later ctc1's don't * trigger FPE for pending exceptions. */ .set at and v1, v0, ST0_CU1 beqz v1, 1f nop .set push SET_HARDFLOAT cfc1 t0, fcr31 sw t0, VCPU_FCR31(k1) ctc1 zero,fcr31 .set pop .set noat 1: #ifdef CONFIG_CPU_HAS_MSA /* * If MSA is enabled, save MSACSR and clear it so that later * instructions don't trigger MSAFPE for pending exceptions. */ mfc0 t0, CP0_CONFIG3 ext t0, t0, 28, 1 /* MIPS_CONF3_MSAP */ beqz t0, 1f nop mfc0 t0, CP0_CONFIG5 ext t0, t0, 27, 1 /* MIPS_CONF5_MSAEN */ beqz t0, 1f nop _cfcmsa t0, MSA_CSR sw t0, VCPU_MSA_CSR(k1) _ctcmsa MSA_CSR, zero 1: #endif /* Now that the new EBASE has been loaded, unset BEV and KSU_USER */ .set at and v0, v0, ~(ST0_EXL | KSU_USER | ST0_IE) or v0, v0, ST0_CU0 .set noat mtc0 v0, CP0_STATUS ehb /* Load up host GP */ LONG_L gp, VCPU_HOST_GP(k1) /* Need a stack before we can jump to "C" */ LONG_L sp, VCPU_HOST_STACK(k1) /* Saved host state */ INT_ADDIU sp, sp, -PT_SIZE /* * XXXKYMA do we need to load the host ASID, maybe not because the * kernel entries are marked GLOBAL, need to verify */ /* Restore host DDATA_LO */ LONG_L k0, PT_HOST_USERLOCAL(sp) mtc0 k0, CP0_DDATA_LO /* Restore RDHWR access */ PTR_LI k0, 0x2000000F mtc0 k0, CP0_HWRENA /* Jump to handler */ FEXPORT(__kvm_mips_jump_to_handler) /* * XXXKYMA: not sure if this is safe, how large is the stack?? * Now jump to the kvm_mips_handle_exit() to see if we can deal * with this in the kernel */ PTR_LA t9, kvm_mips_handle_exit jalr.hb t9 INT_ADDIU sp, sp, -CALLFRAME_SIZ /* BD Slot */ /* Return from handler Make sure interrupts are disabled */ di ehb /* * XXXKYMA: k0/k1 could have been blown away if we processed * an exception while we were handling the exception from the * guest, reload k1 */ move k1, s1 INT_ADDIU k1, k1, VCPU_HOST_ARCH /* * Check return value, should tell us if we are returning to the * host (handle I/O etc)or resuming the guest */ andi t0, v0, RESUME_HOST bnez t0, __kvm_mips_return_to_host nop __kvm_mips_return_to_guest: /* Put the saved pointer to vcpu (s1) back into the DDATA_LO Register */ mtc0 s1, CP0_DDATA_LO /* Load up the Guest EBASE to minimize the window where BEV is set */ LONG_L t0, VCPU_GUEST_EBASE(k1) /* Switch EBASE back to the one used by KVM */ mfc0 v1, CP0_STATUS .set at or k0, v1, ST0_BEV .set noat mtc0 k0, CP0_STATUS ehb mtc0 t0, CP0_EBASE /* Setup status register for running guest in UM */ .set at or v1, v1, (ST0_EXL | KSU_USER | ST0_IE) and v1, v1, ~(ST0_CU0 | ST0_MX) .set noat mtc0 v1, CP0_STATUS ehb /* Set Guest EPC */ LONG_L t0, VCPU_PC(k1) mtc0 t0, CP0_EPC /* Set the ASID for the Guest Kernel */ PTR_L t0, VCPU_COP0(k1) LONG_L t0, COP0_STATUS(t0) andi t0, KSU_USER | ST0_ERL | ST0_EXL xori t0, KSU_USER bnez t0, 1f /* If kernel */ INT_ADDIU t1, k1, VCPU_GUEST_KERNEL_ASID /* (BD) */ INT_ADDIU t1, k1, VCPU_GUEST_USER_ASID /* else user */ 1: /* t1: contains the base of the ASID array, need to get the cpu id */ LONG_L t2, TI_CPU($28) /* smp_processor_id */ INT_SLL t2, t2, 2 /* x4 */ REG_ADDU t3, t1, t2 LONG_L k0, (t3) andi k0, k0, 0xff mtc0 k0,CP0_ENTRYHI ehb /* Disable RDHWR access */ mtc0 zero, CP0_HWRENA /* load the guest context from VCPU and return */ LONG_L $0, VCPU_R0(k1) LONG_L $1, VCPU_R1(k1) LONG_L $2, VCPU_R2(k1) LONG_L $3, VCPU_R3(k1) LONG_L $4, VCPU_R4(k1) LONG_L $5, VCPU_R5(k1) LONG_L $6, VCPU_R6(k1) LONG_L $7, VCPU_R7(k1) LONG_L $8, VCPU_R8(k1) LONG_L $9, VCPU_R9(k1) LONG_L $10, VCPU_R10(k1) LONG_L $11, VCPU_R11(k1) LONG_L $12, VCPU_R12(k1) LONG_L $13, VCPU_R13(k1) LONG_L $14, VCPU_R14(k1) LONG_L $15, VCPU_R15(k1) LONG_L $16, VCPU_R16(k1) LONG_L $17, VCPU_R17(k1) LONG_L $18, VCPU_R18(k1) LONG_L $19, VCPU_R19(k1) LONG_L $20, VCPU_R20(k1) LONG_L $21, VCPU_R21(k1) LONG_L $22, VCPU_R22(k1) LONG_L $23, VCPU_R23(k1) LONG_L $24, VCPU_R24(k1) LONG_L $25, VCPU_R25(k1) /* $/k1 loaded later */ LONG_L $28, VCPU_R28(k1) LONG_L $29, VCPU_R29(k1) LONG_L $30, VCPU_R30(k1) LONG_L $31, VCPU_R31(k1) FEXPORT(__kvm_mips_skip_guest_restore) LONG_L k0, VCPU_HI(k1) mthi k0 LONG_L k0, VCPU_LO(k1) mtlo k0 LONG_L k0, VCPU_R26(k1) LONG_L k1, VCPU_R27(k1) eret __kvm_mips_return_to_host: /* EBASE is already pointing to Linux */ LONG_L k1, VCPU_HOST_STACK(k1) INT_ADDIU k1,k1, -PT_SIZE /* Restore host DDATA_LO */ LONG_L k0, PT_HOST_USERLOCAL(k1) mtc0 k0, CP0_DDATA_LO /* Restore host ASID */ LONG_L k0, PT_HOST_ASID(sp) andi k0, 0xff mtc0 k0,CP0_ENTRYHI ehb /* Load context saved on the host stack */ LONG_L $0, PT_R0(k1) LONG_L $1, PT_R1(k1) /* * r2/v0 is the return code, shift it down by 2 (arithmetic) * to recover the err code */ INT_SRA k0, v0, 2 move $2, k0 LONG_L $3, PT_R3(k1) LONG_L $4, PT_R4(k1) LONG_L $5, PT_R5(k1) LONG_L $6, PT_R6(k1) LONG_L $7, PT_R7(k1) LONG_L $8, PT_R8(k1) LONG_L $9, PT_R9(k1) LONG_L $10, PT_R10(k1) LONG_L $11, PT_R11(k1) LONG_L $12, PT_R12(k1) LONG_L $13, PT_R13(k1) LONG_L $14, PT_R14(k1) LONG_L $15, PT_R15(k1) LONG_L $16, PT_R16(k1) LONG_L $17, PT_R17(k1) LONG_L $18, PT_R18(k1) LONG_L $19, PT_R19(k1) LONG_L $20, PT_R20(k1) LONG_L $21, PT_R21(k1) LONG_L $22, PT_R22(k1) LONG_L $23, PT_R23(k1) LONG_L $24, PT_R24(k1) LONG_L $25, PT_R25(k1) /* Host k0/k1 were not saved */ LONG_L $28, PT_R28(k1) LONG_L $29, PT_R29(k1) LONG_L $30, PT_R30(k1) LONG_L k0, PT_HI(k1) mthi k0 LONG_L k0, PT_LO(k1) mtlo k0 /* Restore RDHWR access */ PTR_LI k0, 0x2000000F mtc0 k0, CP0_HWRENA /* Restore RA, which is the address we will return to */ LONG_L ra, PT_R31(k1) j ra nop VECTOR_END(MIPSX(GuestExceptionEnd)) .end MIPSX(GuestException) MIPSX(exceptions): #### ##### The exception handlers. ##### .word _C_LABEL(MIPSX(GuestException)) # 0 .word _C_LABEL(MIPSX(GuestException)) # 1 .word _C_LABEL(MIPSX(GuestException)) # 2 .word _C_LABEL(MIPSX(GuestException)) # 3 .word _C_LABEL(MIPSX(GuestException)) # 4 .word _C_LABEL(MIPSX(GuestException)) # 5 .word _C_LABEL(MIPSX(GuestException)) # 6 .word _C_LABEL(MIPSX(GuestException)) # 7 .word _C_LABEL(MIPSX(GuestException)) # 8 .word _C_LABEL(MIPSX(GuestException)) # 9 .word _C_LABEL(MIPSX(GuestException)) # 10 .word _C_LABEL(MIPSX(GuestException)) # 11 .word _C_LABEL(MIPSX(GuestException)) # 12 .word _C_LABEL(MIPSX(GuestException)) # 13 .word _C_LABEL(MIPSX(GuestException)) # 14 .word _C_LABEL(MIPSX(GuestException)) # 15 .word _C_LABEL(MIPSX(GuestException)) # 16 .word _C_LABEL(MIPSX(GuestException)) # 17 .word _C_LABEL(MIPSX(GuestException)) # 18 .word _C_LABEL(MIPSX(GuestException)) # 19 .word _C_LABEL(MIPSX(GuestException)) # 20 .word _C_LABEL(MIPSX(GuestException)) # 21 .word _C_LABEL(MIPSX(GuestException)) # 22 .word _C_LABEL(MIPSX(GuestException)) # 23 .word _C_LABEL(MIPSX(GuestException)) # 24 .word _C_LABEL(MIPSX(GuestException)) # 25 .word _C_LABEL(MIPSX(GuestException)) # 26 .word _C_LABEL(MIPSX(GuestException)) # 27 .word _C_LABEL(MIPSX(GuestException)) # 28 .word _C_LABEL(MIPSX(GuestException)) # 29 .word _C_LABEL(MIPSX(GuestException)) # 30 .word _C_LABEL(MIPSX(GuestException)) # 31