diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index e726d76..7a35c64 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2253,6 +2253,32 @@ The possible hypercalls are defined in the Power Architecture Platform Requirements (PAPR) document available from www.power.org (free developer registration required to access it). + /* KVM_EXIT_SPR */ + struct { + __u64 sprn; + __u64 data; + __u64 msr; + __u8 is_write; +#define SPR_STATUS_OK 0 +#define SPR_STATUS_FAIL 1 + __u8 status; + } spr; + +This is used on PowerPC for Special Purpose Register emulation that +the kernel can not deal with. + +It occurs when the guest triggers an mtspr or mfspr instruction on +an SPR that is not handled by kvm's SPR emulation code. In these +cases, 'sprn' contains the SPR ID. That ID is target CPU specific. +'data' contains the value to write to the SPR when 'is_write'==1 (mtspr) +or is used as result buffer for 'is_write'==0 (mfspr). Status is used +to tell the kernel that an SPR read/write was successful. It is set to +SPR_STATUS_OK by default. If user space fails to emulate an SPR access, +it should set it to SPR_STATUS_FAIL, so that the kernel can inject +an exception into the guest context. The field 'msr' contains the MSR +register state at the point of time the SPR read/write occured. It can +be used by user space for permission checks. + /* Fix the size of the union. */ char padding[256]; }; @@ -2374,3 +2400,14 @@ For mmu types KVM_MMU_FSL_BOOKE_NOHV and KVM_MMU_FSL_BOOKE_HV: where "num_sets" is the tlb_sizes[] value divided by the tlb_ways[] value. - The tsize field of mas1 shall be set to 4K on TLB0, even though the hardware ignores this value for TLB0. + +6.4 KVM_CAP_PPC_SPR_EXIT + +Architectures: ppc +Parameters: none +Returns: 0 on success; -1 on error + +With this CAP enabled, KVM returns KVM_EXIT_SPR exits to have user space emulate +SPRs that it can not handle itself. + +When this capability is enabled, KVM_EXIT_SPR can occur. diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 68f5a30..d72ea96 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -510,6 +510,9 @@ struct kvm_vcpu_arch { u8 osi_enabled; u8 papr_enabled; u8 watchdog_enabled; + u8 spr_needed; + u8 spr_is_write; + u8 spr_exit_enabled; u8 sane; u8 cpu_type; u8 hcall_needed; diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h index 609cca3..f9cdd42 100644 --- a/arch/powerpc/include/asm/kvm_ppc.h +++ b/arch/powerpc/include/asm/kvm_ppc.h @@ -42,6 +42,7 @@ enum emulation_result { EMULATE_DONE, /* no further processing */ EMULATE_DO_MMIO, /* kvm_run filled with MMIO request */ EMULATE_DO_DCR, /* kvm_run filled with DCR request */ + EMULATE_DO_SPR, /* kvm_run filled with SPR request */ EMULATE_FAIL, /* can't emulate this instruction */ EMULATE_AGAIN, /* something went wrong. go again */ }; diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index b853696..8d4dbc8 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -748,6 +748,10 @@ program_interrupt: run->exit_reason = KVM_EXIT_MMIO; r = RESUME_HOST_NV; break; + case EMULATE_DO_SPR: + run->exit_reason = KVM_EXIT_SPR; + r = RESUME_HOST_NV; + break; default: BUG(); } diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index 3d1f35d..07fff68 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -694,6 +694,10 @@ static int emulation_exit(struct kvm_run *run, struct kvm_vcpu *vcpu) run->exit_reason = KVM_EXIT_DCR; return RESUME_HOST; + case EMULATE_DO_SPR: + run->exit_reason = KVM_EXIT_SPR; + return RESUME_HOST; + case EMULATE_FAIL: printk(KERN_CRIT "%s: emulation at %lx failed (%08x)\n", __func__, vcpu->arch.pc, vcpu->arch.last_inst); diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c index b0855e5..c35cec5 100644 --- a/arch/powerpc/kvm/emulate.c +++ b/arch/powerpc/kvm/emulate.c @@ -172,9 +172,23 @@ static int kvmppc_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs) default: emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, spr_val); - if (emulated == EMULATE_FAIL) - printk(KERN_INFO "mtspr: unknown spr " - "0x%x\n", sprn); + if (unlikely(emulated == EMULATE_FAIL)) { + if (vcpu->arch.spr_exit_enabled) { + /* In-kernel code can't handle this SPR. + Forward it on to user space */ + vcpu->run->spr.sprn = sprn; + vcpu->run->spr.data = spr_val; + vcpu->run->spr.is_write = 1; + vcpu->run->spr.status = SPR_STATUS_OK; + vcpu->run->spr.msr = vcpu->arch.shared->msr; + vcpu->arch.spr_is_write = 1; + vcpu->arch.spr_needed = 1; + emulated = EMULATE_DO_SPR; + } else { + printk(KERN_INFO "mfspr: unknown spr " + "0x%x\n", sprn); + } + } break; } @@ -237,8 +251,22 @@ static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt) emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, &spr_val); if (unlikely(emulated == EMULATE_FAIL)) { - printk(KERN_INFO "mfspr: unknown spr " - "0x%x\n", sprn); + if (vcpu->arch.spr_exit_enabled) { + /* In-kernel code can't handle this SPR. + Forward it on to user space */ + vcpu->run->spr.sprn = sprn; + vcpu->run->spr.data = 0; + vcpu->run->spr.is_write = 0; + vcpu->run->spr.status = SPR_STATUS_OK; + vcpu->run->spr.msr = vcpu->arch.shared->msr; + vcpu->arch.spr_is_write = 0; + vcpu->arch.io_gpr = rt; + vcpu->arch.spr_needed = 1; + emulated = EMULATE_DO_SPR; + } else { + printk(KERN_INFO "mfspr: unknown spr " + "0x%x\n", sprn); + } } break; } diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index deb0d59..7d120dc 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -530,6 +530,12 @@ static void kvmppc_complete_dcr_load(struct kvm_vcpu *vcpu, kvmppc_set_gpr(vcpu, vcpu->arch.io_gpr, run->dcr.data); } +static void kvmppc_complete_spr_load(struct kvm_vcpu *vcpu, + struct kvm_run *run) +{ + kvmppc_set_gpr(vcpu, vcpu->arch.io_gpr, run->spr.data); +} + static void kvmppc_complete_mmio_load(struct kvm_vcpu *vcpu, struct kvm_run *run) { @@ -680,6 +686,16 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) if (!vcpu->arch.dcr_is_write) kvmppc_complete_dcr_load(vcpu, run); vcpu->arch.dcr_needed = 0; + } else if (vcpu->arch.spr_needed) { + int flags = 0; + if (!vcpu->arch.spr_is_write) + kvmppc_complete_spr_load(vcpu, run); +#if !defined(CONFIG_PPC_BOOK3S) + /* Indicate an illegal instruction for BookE */ + flags = ESR_PIL; +#endif + kvmppc_core_queue_program(vcpu, flags); + vcpu->arch.spr_needed = 0; } else if (vcpu->arch.osi_needed) { u64 *gprs = run->osi.gprs; int i; @@ -735,6 +751,10 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu, r = 0; vcpu->arch.papr_enabled = true; break; + case KVM_CAP_PPC_SPR_EXIT: + r = 0; + vcpu->arch.spr_exit_enabled = true; + break; #ifdef CONFIG_BOOKE case KVM_CAP_PPC_BOOKE_WATCHDOG: r = 0; diff --git a/include/linux/kvm.h b/include/linux/kvm.h index 65ad5c6..2e8f536 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -168,6 +168,7 @@ struct kvm_pit_config { #define KVM_EXIT_PAPR_HCALL 19 #define KVM_EXIT_S390_UCONTROL 20 #define KVM_EXIT_WATCHDOG 21 +#define KVM_EXIT_SPR 22 /* For KVM_EXIT_INTERNAL_ERROR */ #define KVM_INTERNAL_ERROR_EMULATION 1 @@ -281,6 +282,16 @@ struct kvm_run { __u64 ret; __u64 args[9]; } papr_hcall; + /* KVM_EXIT_SPR */ + struct { + __u64 sprn; + __u64 data; + __u64 msr; + __u8 is_write; +#define SPR_STATUS_OK 0 +#define SPR_STATUS_FAIL 1 + __u8 status; + } spr; /* Fix the size of the union. */ char padding[256]; }; @@ -630,6 +641,7 @@ struct kvm_ppc_smmu_info { #endif #define KVM_CAP_IRQFD_RESAMPLE 82 #define KVM_CAP_PPC_BOOKE_WATCHDOG 83 +#define KVM_CAP_PPC_SPR_EXIT 84 #ifdef KVM_CAP_IRQ_ROUTING