[RFC PATCH 2/9] KVM: PPC: Book3S 64: Move GUEST_MODE_SKIP test into KVM
Fabiano Rosas
farosas at linux.ibm.com
Sat Feb 13 07:33:02 AEDT 2021
Nicholas Piggin <npiggin at gmail.com> writes:
> Move the GUEST_MODE_SKIP logic into KVM code. This is quite a KVM
> internal detail that has no real need to be in common handlers.
LGTM,
>
> (XXX: Need to confirm CBE handlers etc)
Do these interrupts exist only in Cell? I see that they set HSRRs and
MSR_HV, but CPU_FTRS_CELL does not contain CPU_HVMODE. So I don't get
why they use the KVM macros.
And for the instruction_breakpoint (0x1300) I think it would help if we
could at least restrict when it is built. But I don't know what
ISA/processor version it is from.
>
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
> ---
> arch/powerpc/kernel/exceptions-64s.S | 64 ----------------------------
> arch/powerpc/kvm/book3s_64_entry.S | 50 ++++++++++++++++++----
> 2 files changed, 42 insertions(+), 72 deletions(-)
>
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index 65659ea3cec4..e6f7fc7c61a1 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -133,7 +133,6 @@ name:
> #define IBRANCH_TO_COMMON .L_IBRANCH_TO_COMMON_\name\() /* ENTRY branch to common */
> #define IREALMODE_COMMON .L_IREALMODE_COMMON_\name\() /* Common runs in realmode */
> #define IMASK .L_IMASK_\name\() /* IRQ soft-mask bit */
> -#define IKVM_SKIP .L_IKVM_SKIP_\name\() /* Generate KVM skip handler */
> #define IKVM_REAL .L_IKVM_REAL_\name\() /* Real entry tests KVM */
> #define __IKVM_REAL(name) .L_IKVM_REAL_ ## name
> #define IKVM_VIRT .L_IKVM_VIRT_\name\() /* Virt entry tests KVM */
> @@ -191,9 +190,6 @@ do_define_int n
> .ifndef IMASK
> IMASK=0
> .endif
> - .ifndef IKVM_SKIP
> - IKVM_SKIP=0
> - .endif
> .ifndef IKVM_REAL
> IKVM_REAL=0
> .endif
> @@ -254,15 +250,10 @@ do_define_int n
> .balign IFETCH_ALIGN_BYTES
> \name\()_kvm:
>
> - .if IKVM_SKIP
> - cmpwi r10,KVM_GUEST_MODE_SKIP
> - beq 89f
> - .else
> BEGIN_FTR_SECTION
> ld r10,IAREA+EX_CFAR(r13)
> std r10,HSTATE_CFAR(r13)
> END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
> - .endif
>
> ld r10,IAREA+EX_CTR(r13)
> mtctr r10
> @@ -289,27 +280,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
> ori r12,r12,(IVEC)
> .endif
> b kvmppc_interrupt
> -
> - .if IKVM_SKIP
> -89: mtocrf 0x80,r9
> - ld r10,IAREA+EX_CTR(r13)
> - mtctr r10
> - ld r9,IAREA+EX_R9(r13)
> - ld r10,IAREA+EX_R10(r13)
> - ld r11,IAREA+EX_R11(r13)
> - ld r12,IAREA+EX_R12(r13)
> - .if IHSRR_IF_HVMODE
> - BEGIN_FTR_SECTION
> - b kvmppc_skip_Hinterrupt
> - FTR_SECTION_ELSE
> - b kvmppc_skip_interrupt
> - ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
> - .elseif IHSRR
> - b kvmppc_skip_Hinterrupt
> - .else
> - b kvmppc_skip_interrupt
> - .endif
> - .endif
> .endm
>
> #else
> @@ -1128,7 +1098,6 @@ INT_DEFINE_BEGIN(machine_check)
> ISET_RI=0
> IDAR=1
> IDSISR=1
> - IKVM_SKIP=1
> IKVM_REAL=1
> INT_DEFINE_END(machine_check)
>
> @@ -1419,7 +1388,6 @@ INT_DEFINE_BEGIN(data_access)
> IVEC=0x300
> IDAR=1
> IDSISR=1
> - IKVM_SKIP=1
> IKVM_REAL=1
> INT_DEFINE_END(data_access)
>
> @@ -1469,7 +1437,6 @@ INT_DEFINE_BEGIN(data_access_slb)
> IAREA=PACA_EXSLB
> IRECONCILE=0
> IDAR=1
> - IKVM_SKIP=1
> IKVM_REAL=1
> INT_DEFINE_END(data_access_slb)
>
> @@ -2116,7 +2083,6 @@ INT_DEFINE_BEGIN(h_data_storage)
> IHSRR=1
> IDAR=1
> IDSISR=1
> - IKVM_SKIP=1
> IKVM_REAL=1
> IKVM_VIRT=1
> INT_DEFINE_END(h_data_storage)
> @@ -2573,7 +2539,6 @@ EXC_VIRT_NONE(0x5100, 0x100)
> INT_DEFINE_BEGIN(cbe_system_error)
> IVEC=0x1200
> IHSRR=1
> - IKVM_SKIP=1
> IKVM_REAL=1
> INT_DEFINE_END(cbe_system_error)
>
> @@ -2598,7 +2563,6 @@ EXC_VIRT_NONE(0x5200, 0x100)
> INT_DEFINE_BEGIN(instruction_breakpoint)
> IVEC=0x1300
> #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
> - IKVM_SKIP=1
> IKVM_REAL=1
> #endif
> INT_DEFINE_END(instruction_breakpoint)
> @@ -2744,7 +2708,6 @@ EXC_COMMON_BEGIN(denorm_exception_common)
> INT_DEFINE_BEGIN(cbe_maintenance)
> IVEC=0x1600
> IHSRR=1
> - IKVM_SKIP=1
> IKVM_REAL=1
> INT_DEFINE_END(cbe_maintenance)
>
> @@ -2797,7 +2760,6 @@ EXC_COMMON_BEGIN(altivec_assist_common)
> INT_DEFINE_BEGIN(cbe_thermal)
> IVEC=0x1800
> IHSRR=1
> - IKVM_SKIP=1
> IKVM_REAL=1
> INT_DEFINE_END(cbe_thermal)
>
> @@ -3081,32 +3043,6 @@ EXPORT_SYMBOL(do_uaccess_flush)
> MASKED_INTERRUPT
> MASKED_INTERRUPT hsrr=1
>
> -#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
> -kvmppc_skip_interrupt:
> - /*
> - * Here all GPRs are unchanged from when the interrupt happened
> - * except for r13, which is saved in SPRG_SCRATCH0.
> - */
> - mfspr r13, SPRN_SRR0
> - addi r13, r13, 4
> - mtspr SPRN_SRR0, r13
> - GET_SCRATCH0(r13)
> - RFI_TO_KERNEL
> - b .
> -
> -kvmppc_skip_Hinterrupt:
> - /*
> - * Here all GPRs are unchanged from when the interrupt happened
> - * except for r13, which is saved in SPRG_SCRATCH0.
> - */
> - mfspr r13, SPRN_HSRR0
> - addi r13, r13, 4
> - mtspr SPRN_HSRR0, r13
> - GET_SCRATCH0(r13)
> - HRFI_TO_KERNEL
> - b .
> -#endif
> -
> /*
> * Relocation-on interrupts: A subset of the interrupts can be delivered
> * with IR=1/DR=1, if AIL==2 and MSR.HV won't be changed by delivering
> diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
> index 22e34b95f478..8e7216f3c3ee 100644
> --- a/arch/powerpc/kvm/book3s_64_entry.S
> +++ b/arch/powerpc/kvm/book3s_64_entry.S
> @@ -1,9 +1,10 @@
> +#include <asm/asm-offsets.h>
> #include <asm/cache.h>
> -#include <asm/ppc_asm.h>
> +#include <asm/exception-64s.h>
> #include <asm/kvm_asm.h>
> -#include <asm/reg.h>
> -#include <asm/asm-offsets.h>
> #include <asm/kvm_book3s_asm.h>
> +#include <asm/ppc_asm.h>
> +#include <asm/reg.h>
>
> /*
> * We come here from the first-level interrupt handlers.
> @@ -18,17 +19,50 @@ kvmppc_interrupt:
> * guest R12 saved in shadow VCPU SCRATCH0
> * guest R13 saved in SPRN_SCRATCH0
> */
> + std r9,HSTATE_SCRATCH2(r13)
> + lbz r9,HSTATE_IN_GUEST(r13)
> + cmpwi r9,KVM_GUEST_MODE_SKIP
> + beq maybe_skip
> +no_skip:
> #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> - std r9, HSTATE_SCRATCH2(r13)
> - lbz r9, HSTATE_IN_GUEST(r13)
> - cmpwi r9, KVM_GUEST_MODE_HOST_HV
> + cmpwi r9,KVM_GUEST_MODE_HOST_HV
> beq kvmppc_bad_host_intr
> #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
> - cmpwi r9, KVM_GUEST_MODE_GUEST
> - ld r9, HSTATE_SCRATCH2(r13)
> + cmpwi r9,KVM_GUEST_MODE_GUEST
> + ld r9,HSTATE_SCRATCH2(r13)
> beq kvmppc_interrupt_pr
> #endif
> b kvmppc_interrupt_hv
> #else
> b kvmppc_interrupt_pr
> #endif
> +
> +maybe_skip:
> + cmpwi r12,0x200
> + beq 1f
> + cmpwi r12,0x300
> + beq 1f
> + cmpwi r12,0x380
> + beq 1f
> +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> + /* XXX: cbe stuff? instruction breakpoint? */
> + cmpwi r12,0xe02
> + beq 2f
> +#endif
> + b no_skip
> +1: mfspr r9,SPRN_SRR0
> + addi r9,r9,4
> + mtspr SPRN_SRR0,r9
> + ld r12,HSTATE_SCRATCH0(r13)
> + ld r9,HSTATE_SCRATCH2(r13)
> + GET_SCRATCH0(r13)
> + RFI_TO_KERNEL
> +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> +2: mfspr r9,SPRN_HSRR0
> + addi r9,r9,4
> + mtspr SPRN_HSRR0,r9
> + ld r12,HSTATE_SCRATCH0(r13)
> + ld r9,HSTATE_SCRATCH2(r13)
> + GET_SCRATCH0(r13)
> + HRFI_TO_KERNEL
> +#endif
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