[PATCH v1 5/7] KVM: PPC: Book3S 64: Move interrupt early register setup to KVM

Fabiano Rosas farosas at linux.ibm.com
Sat Apr 17 04:25:42 AEST 2021


Nicholas Piggin <npiggin at gmail.com> writes:

> Like the earlier patch for hcalls, KVM interrupt entry requires a
> different calling convention than the Linux interrupt handlers
> set up. Move the code that converts from one to the other into KVM.
>
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>

Reviewed-by: Fabiano Rosas <farosas at linux.ibm.com>

> ---
>  arch/powerpc/kernel/exceptions-64s.S | 131 +++++----------------------
>  arch/powerpc/kvm/book3s_64_entry.S   |  50 +++++++++-
>  2 files changed, 71 insertions(+), 110 deletions(-)
>
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index 1bfd0d7af09e..cd1731642b12 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -187,7 +187,6 @@ do_define_int n
>  	.endif
>  .endm
>
> -#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
>  /*
>   * All interrupts which set HSRR registers, as well as SRESET and MCE and
>   * syscall when invoked with "sc 1" switch to MSR[HV]=1 (HVMODE) to be taken,
> @@ -220,54 +219,25 @@ do_define_int n
>   * to KVM to handle.
>   */
>
> -.macro KVMTEST name
> +.macro KVMTEST name handler
> +#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
>  	lbz	r10,HSTATE_IN_GUEST(r13)
>  	cmpwi	r10,0
> -	bne	\name\()_kvm
> -.endm
> -
> -.macro GEN_KVM name
> -	.balign IFETCH_ALIGN_BYTES
> -\name\()_kvm:
> -
> -BEGIN_FTR_SECTION
> -	ld	r10,IAREA+EX_CFAR(r13)
> -	std	r10,HSTATE_CFAR(r13)
> -END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
> -
> -	ld	r10,IAREA+EX_CTR(r13)
> -	mtctr	r10
> -BEGIN_FTR_SECTION
> -	ld	r10,IAREA+EX_PPR(r13)
> -	std	r10,HSTATE_PPR(r13)
> -END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
> -	ld	r11,IAREA+EX_R11(r13)
> -	ld	r12,IAREA+EX_R12(r13)
> -	std	r12,HSTATE_SCRATCH0(r13)
> -	sldi	r12,r9,32
> -	ld	r9,IAREA+EX_R9(r13)
> -	ld	r10,IAREA+EX_R10(r13)
>  	/* HSRR variants have the 0x2 bit added to their trap number */
>  	.if IHSRR_IF_HVMODE
>  	BEGIN_FTR_SECTION
> -	ori	r12,r12,(IVEC + 0x2)
> +	li	r10,(IVEC + 0x2)
>  	FTR_SECTION_ELSE
> -	ori	r12,r12,(IVEC)
> +	li	r10,(IVEC)
>  	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
>  	.elseif IHSRR
> -	ori	r12,r12,(IVEC+ 0x2)
> +	li	r10,(IVEC + 0x2)
>  	.else
> -	ori	r12,r12,(IVEC)
> +	li	r10,(IVEC)
>  	.endif
> -	b	kvmppc_interrupt
> -.endm
> -
> -#else
> -.macro KVMTEST name
> -.endm
> -.macro GEN_KVM name
> -.endm
> +	bne	\handler
>  #endif
> +.endm
>
>  /*
>   * This is the BOOK3S interrupt entry code macro.
> @@ -409,7 +379,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
>  DEFINE_FIXED_SYMBOL(\name\()_common_real)
>  \name\()_common_real:
>  	.if IKVM_REAL
> -		KVMTEST \name
> +		KVMTEST \name kvm_interrupt
>  	.endif
>
>  	ld	r10,PACAKMSR(r13)	/* get MSR value for kernel */
> @@ -432,7 +402,7 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real)
>  DEFINE_FIXED_SYMBOL(\name\()_common_virt)
>  \name\()_common_virt:
>  	.if IKVM_VIRT
> -		KVMTEST \name
> +		KVMTEST \name kvm_interrupt
>  1:
>  	.endif
>  	.endif /* IVIRT */
> @@ -446,7 +416,7 @@ DEFINE_FIXED_SYMBOL(\name\()_common_virt)
>  DEFINE_FIXED_SYMBOL(\name\()_common_real)
>  \name\()_common_real:
>  	.if IKVM_REAL
> -		KVMTEST \name
> +		KVMTEST \name kvm_interrupt
>  	.endif
>  .endm
>
> @@ -967,8 +937,6 @@ EXC_COMMON_BEGIN(system_reset_common)
>  	EXCEPTION_RESTORE_REGS
>  	RFI_TO_USER_OR_KERNEL
>
> -	GEN_KVM system_reset
> -
>
>  /**
>   * Interrupt 0x200 - Machine Check Interrupt (MCE).
> @@ -1132,7 +1100,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
>  	/*
>  	 * Check if we are coming from guest. If yes, then run the normal
>  	 * exception handler which will take the
> -	 * machine_check_kvm->kvmppc_interrupt branch to deliver the MC event
> +	 * machine_check_kvm->kvm_interrupt branch to deliver the MC event
>  	 * to guest.
>  	 */
>  	lbz	r11,HSTATE_IN_GUEST(r13)
> @@ -1203,8 +1171,6 @@ EXC_COMMON_BEGIN(machine_check_common)
>  	bl	machine_check_exception
>  	b	interrupt_return
>
> -	GEN_KVM machine_check
> -
>
>  #ifdef CONFIG_PPC_P7_NAP
>  /*
> @@ -1339,8 +1305,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
>  	REST_NVGPRS(r1)
>  	b	interrupt_return
>
> -	GEN_KVM data_access
> -
>
>  /**
>   * Interrupt 0x380 - Data Segment Interrupt (DSLB).
> @@ -1390,8 +1354,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
>  	bl	do_bad_slb_fault
>  	b	interrupt_return
>
> -	GEN_KVM data_access_slb
> -
>
>  /**
>   * Interrupt 0x400 - Instruction Storage Interrupt (ISI).
> @@ -1428,8 +1390,6 @@ MMU_FTR_SECTION_ELSE
>  ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
>  	b	interrupt_return
>
> -	GEN_KVM instruction_access
> -
>
>  /**
>   * Interrupt 0x480 - Instruction Segment Interrupt (ISLB).
> @@ -1474,8 +1434,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
>  	bl	do_bad_slb_fault
>  	b	interrupt_return
>
> -	GEN_KVM instruction_access_slb
> -
>
>  /**
>   * Interrupt 0x500 - External Interrupt.
> @@ -1521,8 +1479,6 @@ EXC_COMMON_BEGIN(hardware_interrupt_common)
>  	bl	do_IRQ
>  	b	interrupt_return
>
> -	GEN_KVM hardware_interrupt
> -
>
>  /**
>   * Interrupt 0x600 - Alignment Interrupt
> @@ -1550,8 +1506,6 @@ EXC_COMMON_BEGIN(alignment_common)
>  	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
>  	b	interrupt_return
>
> -	GEN_KVM alignment
> -
>
>  /**
>   * Interrupt 0x700 - Program Interrupt (program check).
> @@ -1659,8 +1613,6 @@ EXC_COMMON_BEGIN(program_check_common)
>  	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
>  	b	interrupt_return
>
> -	GEN_KVM program_check
> -
>
>  /*
>   * Interrupt 0x800 - Floating-Point Unavailable Interrupt.
> @@ -1710,8 +1662,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_TM)
>  	b	interrupt_return
>  #endif
>
> -	GEN_KVM fp_unavailable
> -
>
>  /**
>   * Interrupt 0x900 - Decrementer Interrupt.
> @@ -1751,8 +1701,6 @@ EXC_COMMON_BEGIN(decrementer_common)
>  	bl	timer_interrupt
>  	b	interrupt_return
>
> -	GEN_KVM decrementer
> -
>
>  /**
>   * Interrupt 0x980 - Hypervisor Decrementer Interrupt.
> @@ -1798,8 +1746,6 @@ EXC_COMMON_BEGIN(hdecrementer_common)
>  	ld	r13,PACA_EXGEN+EX_R13(r13)
>  	HRFI_TO_KERNEL
>
> -	GEN_KVM hdecrementer
> -
>
>  /**
>   * Interrupt 0xa00 - Directed Privileged Doorbell Interrupt.
> @@ -1840,8 +1786,6 @@ EXC_COMMON_BEGIN(doorbell_super_common)
>  #endif
>  	b	interrupt_return
>
> -	GEN_KVM doorbell_super
> -
>
>  EXC_REAL_NONE(0xb00, 0x100)
>  EXC_VIRT_NONE(0x4b00, 0x100)
> @@ -1891,7 +1835,7 @@ INT_DEFINE_END(system_call)
>  	GET_PACA(r13)
>  	std	r10,PACA_EXGEN+EX_R10(r13)
>  	INTERRUPT_TO_KERNEL
> -	KVMTEST system_call /* uses r10, branch to system_call_kvm */
> +	KVMTEST system_call kvm_hcall /* uses r10, branch to kvm_hcall */
>  	mfctr	r9
>  #else
>  	mr	r9,r13
> @@ -1947,7 +1891,7 @@ EXC_VIRT_BEGIN(system_call, 0x4c00, 0x100)
>  EXC_VIRT_END(system_call, 0x4c00, 0x100)
>
>  #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
> -TRAMP_REAL_BEGIN(system_call_kvm)
> +TRAMP_REAL_BEGIN(kvm_hcall)
>  	mfctr	r10
>  	SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */
>  #ifdef CONFIG_RELOCATABLE
> @@ -1987,8 +1931,6 @@ EXC_COMMON_BEGIN(single_step_common)
>  	bl	single_step_exception
>  	b	interrupt_return
>
> -	GEN_KVM single_step
> -
>
>  /**
>   * Interrupt 0xe00 - Hypervisor Data Storage Interrupt (HDSI).
> @@ -2027,8 +1969,6 @@ MMU_FTR_SECTION_ELSE
>  ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_TYPE_RADIX)
>  	b       interrupt_return
>
> -	GEN_KVM h_data_storage
> -
>
>  /**
>   * Interrupt 0xe20 - Hypervisor Instruction Storage Interrupt (HISI).
> @@ -2054,8 +1994,6 @@ EXC_COMMON_BEGIN(h_instr_storage_common)
>  	bl	unknown_exception
>  	b	interrupt_return
>
> -	GEN_KVM h_instr_storage
> -
>
>  /**
>   * Interrupt 0xe40 - Hypervisor Emulation Assistance Interrupt.
> @@ -2080,8 +2018,6 @@ EXC_COMMON_BEGIN(emulation_assist_common)
>  	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
>  	b	interrupt_return
>
> -	GEN_KVM emulation_assist
> -
>
>  /**
>   * Interrupt 0xe60 - Hypervisor Maintenance Interrupt (HMI).
> @@ -2153,8 +2089,6 @@ EXC_COMMON_BEGIN(hmi_exception_early_common)
>  	EXCEPTION_RESTORE_REGS hsrr=1
>  	GEN_INT_ENTRY hmi_exception, virt=0
>
> -	GEN_KVM hmi_exception_early
> -
>  EXC_COMMON_BEGIN(hmi_exception_common)
>  	GEN_COMMON hmi_exception
>  	FINISH_NAP
> @@ -2162,8 +2096,6 @@ EXC_COMMON_BEGIN(hmi_exception_common)
>  	bl	handle_hmi_exception
>  	b	interrupt_return
>
> -	GEN_KVM hmi_exception
> -
>
>  /**
>   * Interrupt 0xe80 - Directed Hypervisor Doorbell Interrupt.
> @@ -2195,8 +2127,6 @@ EXC_COMMON_BEGIN(h_doorbell_common)
>  #endif
>  	b	interrupt_return
>
> -	GEN_KVM h_doorbell
> -
>
>  /**
>   * Interrupt 0xea0 - Hypervisor Virtualization Interrupt.
> @@ -2224,8 +2154,6 @@ EXC_COMMON_BEGIN(h_virt_irq_common)
>  	bl	do_IRQ
>  	b	interrupt_return
>
> -	GEN_KVM h_virt_irq
> -
>
>  EXC_REAL_NONE(0xec0, 0x20)
>  EXC_VIRT_NONE(0x4ec0, 0x20)
> @@ -2270,8 +2198,6 @@ EXC_COMMON_BEGIN(performance_monitor_common)
>  	bl	performance_monitor_exception
>  	b	interrupt_return
>
> -	GEN_KVM performance_monitor
> -
>
>  /**
>   * Interrupt 0xf20 - Vector Unavailable Interrupt.
> @@ -2321,8 +2247,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
>  	bl	altivec_unavailable_exception
>  	b	interrupt_return
>
> -	GEN_KVM altivec_unavailable
> -
>
>  /**
>   * Interrupt 0xf40 - VSX Unavailable Interrupt.
> @@ -2371,8 +2295,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
>  	bl	vsx_unavailable_exception
>  	b	interrupt_return
>
> -	GEN_KVM vsx_unavailable
> -
>
>  /**
>   * Interrupt 0xf60 - Facility Unavailable Interrupt.
> @@ -2401,8 +2323,6 @@ EXC_COMMON_BEGIN(facility_unavailable_common)
>  	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
>  	b	interrupt_return
>
> -	GEN_KVM facility_unavailable
> -
>
>  /**
>   * Interrupt 0xf60 - Hypervisor Facility Unavailable Interrupt.
> @@ -2431,8 +2351,6 @@ EXC_COMMON_BEGIN(h_facility_unavailable_common)
>  	REST_NVGPRS(r1) /* XXX Shouldn't be necessary in practice */
>  	b	interrupt_return
>
> -	GEN_KVM h_facility_unavailable
> -
>
>  EXC_REAL_NONE(0xfa0, 0x20)
>  EXC_VIRT_NONE(0x4fa0, 0x20)
> @@ -2462,8 +2380,6 @@ EXC_COMMON_BEGIN(cbe_system_error_common)
>  	bl	cbe_system_error_exception
>  	b	interrupt_return
>
> -	GEN_KVM cbe_system_error
> -
>  #else /* CONFIG_CBE_RAS */
>  EXC_REAL_NONE(0x1200, 0x100)
>  EXC_VIRT_NONE(0x5200, 0x100)
> @@ -2495,8 +2411,6 @@ EXC_COMMON_BEGIN(instruction_breakpoint_common)
>  	bl	instruction_breakpoint_exception
>  	b	interrupt_return
>
> -	GEN_KVM instruction_breakpoint
> -
>
>  EXC_REAL_NONE(0x1400, 0x100)
>  EXC_VIRT_NONE(0x5400, 0x100)
> @@ -2617,8 +2531,6 @@ EXC_COMMON_BEGIN(denorm_exception_common)
>  	bl	unknown_exception
>  	b	interrupt_return
>
> -	GEN_KVM denorm_exception
> -
>
>  #ifdef CONFIG_CBE_RAS
>  INT_DEFINE_BEGIN(cbe_maintenance)
> @@ -2636,8 +2548,6 @@ EXC_COMMON_BEGIN(cbe_maintenance_common)
>  	bl	cbe_maintenance_exception
>  	b	interrupt_return
>
> -	GEN_KVM cbe_maintenance
> -
>  #else /* CONFIG_CBE_RAS */
>  EXC_REAL_NONE(0x1600, 0x100)
>  EXC_VIRT_NONE(0x5600, 0x100)
> @@ -2668,8 +2578,6 @@ EXC_COMMON_BEGIN(altivec_assist_common)
>  #endif
>  	b	interrupt_return
>
> -	GEN_KVM altivec_assist
> -
>
>  #ifdef CONFIG_CBE_RAS
>  INT_DEFINE_BEGIN(cbe_thermal)
> @@ -2687,8 +2595,6 @@ EXC_COMMON_BEGIN(cbe_thermal_common)
>  	bl	cbe_thermal_exception
>  	b	interrupt_return
>
> -	GEN_KVM cbe_thermal
> -
>  #else /* CONFIG_CBE_RAS */
>  EXC_REAL_NONE(0x1800, 0x100)
>  EXC_VIRT_NONE(0x5800, 0x100)
> @@ -2941,6 +2847,15 @@ TRAMP_REAL_BEGIN(rfscv_flush_fallback)
>
>  USE_TEXT_SECTION()
>
> +#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
> +kvm_interrupt:
> +	/*
> +	 * The conditional branch in KVMTEST can't reach all the way,
> +	 * make a stub.
> +	 */
> +	b	kvmppc_interrupt
> +#endif
> +
>  _GLOBAL(do_uaccess_flush)
>  	UACCESS_FLUSH_FIXUP_SECTION
>  	nop
> diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
> index f527e16707db..2c9d106145e8 100644
> --- a/arch/powerpc/kvm/book3s_64_entry.S
> +++ b/arch/powerpc/kvm/book3s_64_entry.S
> @@ -44,15 +44,61 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
>  	sldi	r12,r10,32
>  	ori	r12,r12,0xc00
>  	ld	r10,PACA_EXGEN+EX_R10(r13)
> +	b	do_kvm_interrupt
>
> +/*
> + * KVM interrupt entry occurs after GEN_INT_ENTRY runs, and follows that
> + * call convention:
> + *
> + * guest R9-R13, CTR, CFAR, PPR saved in PACA EX_xxx save area
> + * guest (H)DAR, (H)DSISR are also in the save area for relevant interrupts
> + * guest R13 also saved in SCRATCH0
> + * R13		= PACA
> + * R11		= (H)SRR0
> + * R12		= (H)SRR1
> + * R9		= guest CR
> + * PPR is set to medium
> + *
> + * With the addition for KVM:
> + * R10		= trap vector
> + */
>  .global	kvmppc_interrupt
>  .balign IFETCH_ALIGN_BYTES
>  kvmppc_interrupt:
> +	li	r11,PACA_EXGEN
> +	cmpdi	r10,0x200
> +	bgt+	1f
> +	li	r11,PACA_EXMC
> +	beq	1f
> +	li	r11,PACA_EXNMI
> +1:	add	r11,r11,r13
> +
> +BEGIN_FTR_SECTION
> +	ld	r12,EX_CFAR(r11)
> +	std	r12,HSTATE_CFAR(r13)
> +END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
> +	ld	r12,EX_CTR(r11)
> +	mtctr	r12
> +BEGIN_FTR_SECTION
> +	ld	r12,EX_PPR(r11)
> +	std	r12,HSTATE_PPR(r13)
> +END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
> +	ld	r12,EX_R12(r11)
> +	std	r12,HSTATE_SCRATCH0(r13)
> +	sldi	r12,r9,32
> +	or	r12,r12,r10
> +	ld	r9,EX_R9(r11)
> +	ld	r10,EX_R10(r11)
> +	ld	r11,EX_R11(r11)
> +
> +do_kvm_interrupt:
>  	/*
> -	 * Register contents:
> +	 * Hcalls and other interrupts come here after normalising register
> +	 * contents and save locations:
> +	 *
>  	 * R12		= (guest CR << 32) | interrupt vector
>  	 * R13		= PACA
> -	 * guest R12 saved in shadow VCPU SCRATCH0
> +	 * guest R12 saved in shadow HSTATE_SCRATCH0
>  	 * guest R13 saved in SPRN_SCRATCH0
>  	 */
>  	std	r9,HSTATE_SCRATCH2(r13)


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