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author | Mihai Caraman <mihai.caraman@freescale.com> | 2014-07-23 19:06:21 +0300 |
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committer | Alexander Graf <agraf@suse.de> | 2014-07-28 15:23:14 +0200 |
commit | 51f047261e717b74b226f837a16455994b61ae30 (patch) | |
tree | e94a57703fed176a72acef425cea442a8395746b /arch/powerpc/kvm | |
parent | 9a26af64d6bba72c9dfd62cc0cab0e79f8a66d7b (diff) | |
download | lwn-51f047261e717b74b226f837a16455994b61ae30.tar.gz lwn-51f047261e717b74b226f837a16455994b61ae30.zip |
KVM: PPC: Allow kvmppc_get_last_inst() to fail
On book3e, guest last instruction is read on the exit path using load
external pid (lwepx) dedicated instruction. This load operation may fail
due to TLB eviction and execute-but-not-read entries.
This patch lay down the path for an alternative solution to read the guest
last instruction, by allowing kvmppc_get_lat_inst() function to fail.
Architecture specific implmentations of kvmppc_load_last_inst() may read
last guest instruction and instruct the emulation layer to re-execute the
guest in case of failure.
Make kvmppc_get_last_inst() definition common between architectures.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Diffstat (limited to 'arch/powerpc/kvm')
-rw-r--r-- | arch/powerpc/kvm/book3s.c | 17 | ||||
-rw-r--r-- | arch/powerpc/kvm/book3s_64_mmu_hv.c | 17 | ||||
-rw-r--r-- | arch/powerpc/kvm/book3s_paired_singles.c | 38 | ||||
-rw-r--r-- | arch/powerpc/kvm/book3s_pr.c | 45 | ||||
-rw-r--r-- | arch/powerpc/kvm/booke.c | 3 | ||||
-rw-r--r-- | arch/powerpc/kvm/e500_mmu_host.c | 6 | ||||
-rw-r--r-- | arch/powerpc/kvm/emulate.c | 18 | ||||
-rw-r--r-- | arch/powerpc/kvm/powerpc.c | 11 |
8 files changed, 109 insertions, 46 deletions
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index 31facfc1314b..37ca8a0897c3 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -488,6 +488,23 @@ mmio: } EXPORT_SYMBOL_GPL(kvmppc_ld); +int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type, + u32 *inst) +{ + ulong pc = kvmppc_get_pc(vcpu); + int r; + + if (type == INST_SC) + pc -= 4; + + r = kvmppc_ld(vcpu, &pc, sizeof(u32), inst, false); + if (r == EMULATE_DONE) + return r; + else + return EMULATE_AGAIN; +} +EXPORT_SYMBOL_GPL(kvmppc_load_last_inst); + int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) { return 0; diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index 2d154d9319b3..fa944a3abdf0 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -530,21 +530,14 @@ static int instruction_is_store(unsigned int instr) static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, unsigned long gpa, gva_t ea, int is_store) { - int ret; u32 last_inst; - unsigned long srr0 = kvmppc_get_pc(vcpu); - /* We try to load the last instruction. We don't let - * emulate_instruction do it as it doesn't check what - * kvmppc_ld returns. + /* * If we fail, we just return to the guest and try executing it again. */ - if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) { - ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false); - if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED) - return RESUME_GUEST; - vcpu->arch.last_inst = last_inst; - } + if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) != + EMULATE_DONE) + return RESUME_GUEST; /* * WARNING: We do not know for sure whether the instruction we just @@ -558,7 +551,7 @@ static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, * we just return and retry the instruction. */ - if (instruction_is_store(kvmppc_get_last_inst(vcpu)) != !!is_store) + if (instruction_is_store(last_inst) != !!is_store) return RESUME_GUEST; /* diff --git a/arch/powerpc/kvm/book3s_paired_singles.c b/arch/powerpc/kvm/book3s_paired_singles.c index 6c8011fd57e6..bfb8035314e3 100644 --- a/arch/powerpc/kvm/book3s_paired_singles.c +++ b/arch/powerpc/kvm/book3s_paired_singles.c @@ -639,26 +639,36 @@ static int kvmppc_ps_one_in(struct kvm_vcpu *vcpu, bool rc, int kvmppc_emulate_paired_single(struct kvm_run *run, struct kvm_vcpu *vcpu) { - u32 inst = kvmppc_get_last_inst(vcpu); + u32 inst; enum emulation_result emulated = EMULATE_DONE; + int ax_rd, ax_ra, ax_rb, ax_rc; + short full_d; + u64 *fpr_d, *fpr_a, *fpr_b, *fpr_c; - int ax_rd = inst_get_field(inst, 6, 10); - int ax_ra = inst_get_field(inst, 11, 15); - int ax_rb = inst_get_field(inst, 16, 20); - int ax_rc = inst_get_field(inst, 21, 25); - short full_d = inst_get_field(inst, 16, 31); - - u64 *fpr_d = &VCPU_FPR(vcpu, ax_rd); - u64 *fpr_a = &VCPU_FPR(vcpu, ax_ra); - u64 *fpr_b = &VCPU_FPR(vcpu, ax_rb); - u64 *fpr_c = &VCPU_FPR(vcpu, ax_rc); - - bool rcomp = (inst & 1) ? true : false; - u32 cr = kvmppc_get_cr(vcpu); + bool rcomp; + u32 cr; #ifdef DEBUG int i; #endif + emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst); + if (emulated != EMULATE_DONE) + return emulated; + + ax_rd = inst_get_field(inst, 6, 10); + ax_ra = inst_get_field(inst, 11, 15); + ax_rb = inst_get_field(inst, 16, 20); + ax_rc = inst_get_field(inst, 21, 25); + full_d = inst_get_field(inst, 16, 31); + + fpr_d = &VCPU_FPR(vcpu, ax_rd); + fpr_a = &VCPU_FPR(vcpu, ax_ra); + fpr_b = &VCPU_FPR(vcpu, ax_rb); + fpr_c = &VCPU_FPR(vcpu, ax_rc); + + rcomp = (inst & 1) ? true : false; + cr = kvmppc_get_cr(vcpu); + if (!kvmppc_inst_is_paired_single(vcpu, inst)) return EMULATE_FAIL; diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index e76aec38ec21..b18f2d4fac59 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -1018,15 +1018,24 @@ int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu, { enum emulation_result er; ulong flags; + u32 last_inst; + int emul; program_interrupt: flags = vcpu->arch.shadow_srr1 & 0x1f0000ull; + emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst); + if (emul != EMULATE_DONE) { + r = RESUME_GUEST; + break; + } + if (kvmppc_get_msr(vcpu) & MSR_PR) { #ifdef EXIT_DEBUG - printk(KERN_INFO "Userspace triggered 0x700 exception at 0x%lx (0x%x)\n", kvmppc_get_pc(vcpu), kvmppc_get_last_inst(vcpu)); + pr_info("Userspace triggered 0x700 exception at\n 0x%lx (0x%x)\n", + kvmppc_get_pc(vcpu), last_inst); #endif - if ((kvmppc_get_last_inst(vcpu) & 0xff0007ff) != + if ((last_inst & 0xff0007ff) != (INS_DCBZ & 0xfffffff7)) { kvmppc_core_queue_program(vcpu, flags); r = RESUME_GUEST; @@ -1045,7 +1054,7 @@ program_interrupt: break; case EMULATE_FAIL: printk(KERN_CRIT "%s: emulation at %lx failed (%08x)\n", - __func__, kvmppc_get_pc(vcpu), kvmppc_get_last_inst(vcpu)); + __func__, kvmppc_get_pc(vcpu), last_inst); kvmppc_core_queue_program(vcpu, flags); r = RESUME_GUEST; break; @@ -1062,8 +1071,23 @@ program_interrupt: break; } case BOOK3S_INTERRUPT_SYSCALL: + { + u32 last_sc; + int emul; + + /* Get last sc for papr */ + if (vcpu->arch.papr_enabled) { + /* The sc instuction points SRR0 to the next inst */ + emul = kvmppc_get_last_inst(vcpu, INST_SC, &last_sc); + if (emul != EMULATE_DONE) { + kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) - 4); + r = RESUME_GUEST; + break; + } + } + if (vcpu->arch.papr_enabled && - (kvmppc_get_last_sc(vcpu) == 0x44000022) && + (last_sc == 0x44000022) && !(kvmppc_get_msr(vcpu) & MSR_PR)) { /* SC 1 papr hypercalls */ ulong cmd = kvmppc_get_gpr(vcpu, 3); @@ -1108,21 +1132,19 @@ program_interrupt: r = RESUME_GUEST; } break; + } case BOOK3S_INTERRUPT_FP_UNAVAIL: case BOOK3S_INTERRUPT_ALTIVEC: case BOOK3S_INTERRUPT_VSX: { int ext_msr = 0; int emul; - ulong pc; u32 last_inst; if (vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE) { /* Do paired single instruction emulation */ - pc = kvmppc_get_pc(vcpu); - last_inst = kvmppc_get_last_inst(vcpu); - emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst, - false); + emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, + &last_inst); if (emul == EMULATE_DONE) goto program_interrupt; else @@ -1151,9 +1173,8 @@ program_interrupt: } case BOOK3S_INTERRUPT_ALIGNMENT: { - ulong pc = kvmppc_get_pc(vcpu); - u32 last_inst = kvmppc_get_last_inst(vcpu); - int emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst, false); + u32 last_inst; + int emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst); if (emul == EMULATE_DONE) { u32 dsisr; diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index a06ef6b30258..50df5e3072cc 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -702,6 +702,9 @@ static int emulation_exit(struct kvm_run *run, struct kvm_vcpu *vcpu) * they were actually modified by emulation. */ return RESUME_GUEST_NV; + case EMULATE_AGAIN: + return RESUME_GUEST; + case EMULATE_DO_DCR: run->exit_reason = KVM_EXIT_DCR; return RESUME_HOST; diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c index 79677d76d1a4..4385c14fca84 100644 --- a/arch/powerpc/kvm/e500_mmu_host.c +++ b/arch/powerpc/kvm/e500_mmu_host.c @@ -610,6 +610,12 @@ void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 eaddr, gpa_t gpaddr, } } +int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type, + u32 *instr) +{ + return EMULATE_AGAIN; +} + /************* MMU Notifiers *************/ int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c index da86d9ba3476..c5c64b6e7eb2 100644 --- a/arch/powerpc/kvm/emulate.c +++ b/arch/powerpc/kvm/emulate.c @@ -224,19 +224,25 @@ static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt) * from opcode tables in the future. */ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu) { - u32 inst = kvmppc_get_last_inst(vcpu); - int ra = get_ra(inst); - int rs = get_rs(inst); - int rt = get_rt(inst); - int sprn = get_sprn(inst); - enum emulation_result emulated = EMULATE_DONE; + u32 inst; + int ra, rs, rt, sprn; + enum emulation_result emulated; int advance = 1; /* this default type might be overwritten by subcategories */ kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS); + emulated = kvmppc_get_last_inst(vcpu, false, &inst); + if (emulated != EMULATE_DONE) + return emulated; + pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst)); + ra = get_ra(inst); + rs = get_rs(inst); + rt = get_rt(inst); + sprn = get_sprn(inst); + switch (get_op(inst)) { case OP_TRAP: #ifdef CONFIG_PPC_BOOK3S diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index fe0257a8e335..cfa6cfabf4a3 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -280,6 +280,9 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu) * actually modified. */ r = RESUME_GUEST_NV; break; + case EMULATE_AGAIN: + r = RESUME_GUEST; + break; case EMULATE_DO_MMIO: run->exit_reason = KVM_EXIT_MMIO; /* We must reload nonvolatiles because "update" load/store @@ -289,11 +292,15 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu) r = RESUME_HOST_NV; break; case EMULATE_FAIL: + { + u32 last_inst; + + kvmppc_get_last_inst(vcpu, false, &last_inst); /* XXX Deliver Program interrupt to guest. */ - printk(KERN_EMERG "%s: emulation failed (%08x)\n", __func__, - kvmppc_get_last_inst(vcpu)); + pr_emerg("%s: emulation failed (%08x)\n", __func__, last_inst); r = RESUME_HOST; break; + } default: WARN_ON(1); r = RESUME_GUEST; |