diff options
| -rw-r--r-- | arch/powerpc/include/asm/kvm_asm.h | 6 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_64_rmhandlers.S | 39 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_64_slb.S | 16 | ||||
| -rw-r--r-- | arch/powerpc/kvm/emulate.c | 4 |
4 files changed, 59 insertions, 6 deletions
diff --git a/arch/powerpc/include/asm/kvm_asm.h b/arch/powerpc/include/asm/kvm_asm.h index af2abe74f54..aadf2dd6f84 100644 --- a/arch/powerpc/include/asm/kvm_asm.h +++ b/arch/powerpc/include/asm/kvm_asm.h @@ -97,4 +97,10 @@ #define RESUME_HOST RESUME_FLAG_HOST #define RESUME_HOST_NV (RESUME_FLAG_HOST|RESUME_FLAG_NV) +#define KVM_GUEST_MODE_NONE 0 +#define KVM_GUEST_MODE_GUEST 1 +#define KVM_GUEST_MODE_SKIP 2 + +#define KVM_INST_FETCH_FAILED -1 + #endif /* __POWERPC_KVM_ASM_H__ */ diff --git a/arch/powerpc/kvm/book3s_64_rmhandlers.S b/arch/powerpc/kvm/book3s_64_rmhandlers.S index cd9f0b609e4..9ad1c2645d6 100644 --- a/arch/powerpc/kvm/book3s_64_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_64_rmhandlers.S @@ -49,7 +49,7 @@ kvmppc_trampoline_\intno: mfcr r12 stw r12, PACA_KVM_SCRATCH1(r13) lbz r12, PACA_KVM_IN_GUEST(r13) - cmpwi r12, 0 + cmpwi r12, KVM_GUEST_MODE_NONE bne ..kvmppc_handler_hasmagic_\intno /* No KVM guest? Then jump back to the Linux handler! */ lwz r12, PACA_KVM_SCRATCH1(r13) @@ -60,6 +60,11 @@ kvmppc_trampoline_\intno: /* Now we know we're handling a KVM guest */ ..kvmppc_handler_hasmagic_\intno: + + /* Should we just skip the faulting instruction? */ + cmpwi r12, KVM_GUEST_MODE_SKIP + beq kvmppc_handler_skip_ins + /* Let's store which interrupt we're handling */ li r12, \intno @@ -86,6 +91,38 @@ INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_ALTIVEC INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_VSX /* + * Bring us back to the faulting code, but skip the + * faulting instruction. + * + * This is a generic exit path from the interrupt + * trampolines above. + * + * Input Registers: + * + * R12 = free + * R13 = PACA + * PACA.KVM.SCRATCH0 = guest R12 + * PACA.KVM.SCRATCH1 = guest CR + * SPRG_SCRATCH0 = guest R13 + * + */ +kvmppc_handler_skip_ins: + + /* Patch the IP to the next instruction */ + mfsrr0 r12 + addi r12, r12, 4 + mtsrr0 r12 + + /* Clean up all state */ + lwz r12, PACA_KVM_SCRATCH1(r13) + mtcr r12 + ld r12, PACA_KVM_SCRATCH0(r13) + mfspr r13, SPRN_SPRG_SCRATCH0 + + /* And get back into the code */ + RFI + +/* * This trampoline brings us back to a real mode handler * * Input Registers: diff --git a/arch/powerpc/kvm/book3s_64_slb.S b/arch/powerpc/kvm/book3s_64_slb.S index 7188c11ed7d..d07b88617b2 100644 --- a/arch/powerpc/kvm/book3s_64_slb.S +++ b/arch/powerpc/kvm/book3s_64_slb.S @@ -212,10 +212,6 @@ kvmppc_handler_trampoline_exit: mfdar r5 mfdsisr r6 - /* Unset guest state */ - li r9, 0 - stb r9, PACA_KVM_IN_GUEST(r13) - /* * In order for us to easily get the last instruction, * we got the #vmexit at, we exploit the fact that the @@ -233,18 +229,28 @@ kvmppc_handler_trampoline_exit: ld_last_inst: /* Save off the guest instruction we're at */ + + /* Set guest mode to 'jump over instruction' so if lwz faults + * we'll just continue at the next IP. */ + li r9, KVM_GUEST_MODE_SKIP + stb r9, PACA_KVM_IN_GUEST(r13) + /* 1) enable paging for data */ mfmsr r9 ori r11, r9, MSR_DR /* Enable paging for data */ mtmsr r11 /* 2) fetch the instruction */ - /* XXX implement PACA_KVM_IN_GUEST=2 path to safely jump over this */ + li r0, KVM_INST_FETCH_FAILED /* In case lwz faults */ lwz r0, 0(r3) /* 3) disable paging again */ mtmsr r9 no_ld_last_inst: + /* Unset guest mode */ + li r9, KVM_GUEST_MODE_NONE + stb r9, PACA_KVM_IN_GUEST(r13) + /* Restore bolted entries from the shadow and fix it along the way */ /* We don't store anything in entry 0, so we don't need to take care of it */ diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c index 38219af0cd0..04e317c1bbe 100644 --- a/arch/powerpc/kvm/emulate.c +++ b/arch/powerpc/kvm/emulate.c @@ -143,6 +143,10 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu) pr_debug(KERN_INFO "Emulating opcode %d / %d\n", get_op(inst), get_xop(inst)); + /* Try again next time */ + if (inst == KVM_INST_FETCH_FAILED) + return EMULATE_DONE; + switch (get_op(inst)) { case OP_TRAP: #ifdef CONFIG_PPC64 |