From 6affcbedcac79b01c8d01948a693461040133e46 Mon Sep 17 00:00:00 2001 From: Kyle Huey Date: Tue, 29 Nov 2016 12:40:40 -0800 Subject: [PATCH] KVM: x86: Add kvm_skip_emulated_instruction and use it. MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit kvm_skip_emulated_instruction calls both kvm_x86_ops->skip_emulated_instruction and kvm_vcpu_check_singlestep, skipping the emulated instruction and generating a trap if necessary. Replacing skip_emulated_instruction calls with kvm_skip_emulated_instruction is straightforward, except for: - ICEBP, which is already inside a trap, so avoid triggering another trap. - Instructions that can trigger exits to userspace, such as the IO insns, MOVs to CR8, and HALT. If kvm_skip_emulated_instruction does trigger a KVM_GUESTDBG_SINGLESTEP exit, and the handling code for IN/OUT/MOV CR8/HALT also triggers an exit to userspace, the latter will take precedence. The singlestep will be triggered again on the next instruction, which is the current behavior. - Task switch instructions which would require additional handling (e.g. the task switch bit) and are instead left alone. - Cases where VMLAUNCH/VMRESUME do not proceed to the next instruction, which do not trigger singlestep traps as mentioned previously. Signed-off-by: Kyle Huey Signed-off-by: Radim Krčmář --- arch/x86/include/asm/kvm_host.h | 3 +- arch/x86/kvm/cpuid.c | 3 +- arch/x86/kvm/svm.c | 11 +- arch/x86/kvm/vmx.c | 177 +++++++++++++------------------- arch/x86/kvm/x86.c | 33 ++++-- 5 files changed, 103 insertions(+), 124 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 80bad5c372bf..8d1587092851 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1368,7 +1368,8 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, bool kvm_arch_can_inject_async_page_present(struct kvm_vcpu *vcpu); extern bool kvm_find_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn); -void kvm_complete_insn_gp(struct kvm_vcpu *vcpu, int err); +int kvm_skip_emulated_instruction(struct kvm_vcpu *vcpu); +int kvm_complete_insn_gp(struct kvm_vcpu *vcpu, int err); int kvm_is_in_guest(void); diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 07cc62955520..dc2685e3f8ea 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -890,7 +890,6 @@ int kvm_emulate_cpuid(struct kvm_vcpu *vcpu) kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); kvm_register_write(vcpu, VCPU_REGS_RDX, edx); - kvm_x86_ops->skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 5bdffcd781f5..08a4d3ab3455 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3151,8 +3151,7 @@ static int skinit_interception(struct vcpu_svm *svm) static int wbinvd_interception(struct vcpu_svm *svm) { - kvm_emulate_wbinvd(&svm->vcpu); - return 1; + return kvm_emulate_wbinvd(&svm->vcpu); } static int xsetbv_interception(struct vcpu_svm *svm) @@ -3275,9 +3274,7 @@ static int rdpmc_interception(struct vcpu_svm *svm) return emulate_on_interception(svm); err = kvm_rdpmc(&svm->vcpu); - kvm_complete_insn_gp(&svm->vcpu, err); - - return 1; + return kvm_complete_insn_gp(&svm->vcpu, err); } static bool check_selective_cr0_intercepted(struct vcpu_svm *svm, @@ -3374,9 +3371,7 @@ static int cr_interception(struct vcpu_svm *svm) } kvm_register_write(&svm->vcpu, reg, val); } - kvm_complete_insn_gp(&svm->vcpu, err); - - return 1; + return kvm_complete_insn_gp(&svm->vcpu, err); } static int dr_interception(struct vcpu_svm *svm) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index f4f6304f9583..16a144d22033 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -5556,7 +5556,7 @@ static int handle_triple_fault(struct kvm_vcpu *vcpu) static int handle_io(struct kvm_vcpu *vcpu) { unsigned long exit_qualification; - int size, in, string; + int size, in, string, ret; unsigned port; exit_qualification = vmcs_readl(EXIT_QUALIFICATION); @@ -5570,9 +5570,14 @@ static int handle_io(struct kvm_vcpu *vcpu) port = exit_qualification >> 16; size = (exit_qualification & 7) + 1; - skip_emulated_instruction(vcpu); - return kvm_fast_pio_out(vcpu, size, port); + ret = kvm_skip_emulated_instruction(vcpu); + + /* + * TODO: we might be squashing a KVM_GUESTDBG_SINGLESTEP-triggered + * KVM_EXIT_DEBUG here. + */ + return kvm_fast_pio_out(vcpu, size, port) && ret; } static void @@ -5670,6 +5675,7 @@ static int handle_cr(struct kvm_vcpu *vcpu) int cr; int reg; int err; + int ret; exit_qualification = vmcs_readl(EXIT_QUALIFICATION); cr = exit_qualification & 15; @@ -5681,25 +5687,27 @@ static int handle_cr(struct kvm_vcpu *vcpu) switch (cr) { case 0: err = handle_set_cr0(vcpu, val); - kvm_complete_insn_gp(vcpu, err); - return 1; + return kvm_complete_insn_gp(vcpu, err); case 3: err = kvm_set_cr3(vcpu, val); - kvm_complete_insn_gp(vcpu, err); - return 1; + return kvm_complete_insn_gp(vcpu, err); case 4: err = handle_set_cr4(vcpu, val); - kvm_complete_insn_gp(vcpu, err); - return 1; + return kvm_complete_insn_gp(vcpu, err); case 8: { u8 cr8_prev = kvm_get_cr8(vcpu); u8 cr8 = (u8)val; err = kvm_set_cr8(vcpu, cr8); - kvm_complete_insn_gp(vcpu, err); + ret = kvm_complete_insn_gp(vcpu, err); if (lapic_in_kernel(vcpu)) - return 1; + return ret; if (cr8_prev <= cr8) - return 1; + return ret; + /* + * TODO: we might be squashing a + * KVM_GUESTDBG_SINGLESTEP-triggered + * KVM_EXIT_DEBUG here. + */ vcpu->run->exit_reason = KVM_EXIT_SET_TPR; return 0; } @@ -5709,22 +5717,19 @@ static int handle_cr(struct kvm_vcpu *vcpu) handle_clts(vcpu); trace_kvm_cr_write(0, kvm_read_cr0(vcpu)); vmx_fpu_activate(vcpu); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); case 1: /*mov from cr*/ switch (cr) { case 3: val = kvm_read_cr3(vcpu); kvm_register_write(vcpu, reg, val); trace_kvm_cr_read(cr, val); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); case 8: val = kvm_get_cr8(vcpu); kvm_register_write(vcpu, reg, val); trace_kvm_cr_read(cr, val); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } break; case 3: /* lmsw */ @@ -5732,8 +5737,7 @@ static int handle_cr(struct kvm_vcpu *vcpu) trace_kvm_cr_write(0, (kvm_read_cr0(vcpu) & ~0xful) | val); kvm_lmsw(vcpu, val); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); default: break; } @@ -5804,8 +5808,7 @@ static int handle_dr(struct kvm_vcpu *vcpu) if (kvm_set_dr(vcpu, dr, kvm_register_readl(vcpu, reg))) return 1; - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } static u64 vmx_get_dr6(struct kvm_vcpu *vcpu) @@ -5858,8 +5861,7 @@ static int handle_rdmsr(struct kvm_vcpu *vcpu) /* FIXME: handling of bits 32:63 of rax, rdx */ vcpu->arch.regs[VCPU_REGS_RAX] = msr_info.data & -1u; vcpu->arch.regs[VCPU_REGS_RDX] = (msr_info.data >> 32) & -1u; - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } static int handle_wrmsr(struct kvm_vcpu *vcpu) @@ -5879,8 +5881,7 @@ static int handle_wrmsr(struct kvm_vcpu *vcpu) } trace_kvm_msr_write(ecx, data); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } static int handle_tpr_below_threshold(struct kvm_vcpu *vcpu) @@ -5924,8 +5925,7 @@ static int handle_invlpg(struct kvm_vcpu *vcpu) unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION); kvm_mmu_invlpg(vcpu, exit_qualification); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } static int handle_rdpmc(struct kvm_vcpu *vcpu) @@ -5933,15 +5933,12 @@ static int handle_rdpmc(struct kvm_vcpu *vcpu) int err; err = kvm_rdpmc(vcpu); - kvm_complete_insn_gp(vcpu, err); - - return 1; + return kvm_complete_insn_gp(vcpu, err); } static int handle_wbinvd(struct kvm_vcpu *vcpu) { - kvm_emulate_wbinvd(vcpu); - return 1; + return kvm_emulate_wbinvd(vcpu); } static int handle_xsetbv(struct kvm_vcpu *vcpu) @@ -5950,20 +5947,20 @@ static int handle_xsetbv(struct kvm_vcpu *vcpu) u32 index = kvm_register_read(vcpu, VCPU_REGS_RCX); if (kvm_set_xcr(vcpu, index, new_bv) == 0) - skip_emulated_instruction(vcpu); + return kvm_skip_emulated_instruction(vcpu); return 1; } static int handle_xsaves(struct kvm_vcpu *vcpu) { - skip_emulated_instruction(vcpu); + kvm_skip_emulated_instruction(vcpu); WARN(1, "this should never happen\n"); return 1; } static int handle_xrstors(struct kvm_vcpu *vcpu) { - skip_emulated_instruction(vcpu); + kvm_skip_emulated_instruction(vcpu); WARN(1, "this should never happen\n"); return 1; } @@ -5984,8 +5981,7 @@ static int handle_apic_access(struct kvm_vcpu *vcpu) if ((access_type == TYPE_LINEAR_APIC_INST_WRITE) && (offset == APIC_EOI)) { kvm_lapic_set_eoi(vcpu); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } } return emulate_instruction(vcpu, 0) == EMULATE_DONE; @@ -6134,8 +6130,7 @@ static int handle_ept_misconfig(struct kvm_vcpu *vcpu) gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS); if (!kvm_io_bus_write(vcpu, KVM_FAST_MMIO_BUS, gpa, 0, NULL)) { trace_kvm_fast_mmio(gpa); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } ret = handle_mmio_page_fault(vcpu, gpa, true); @@ -6508,15 +6503,12 @@ static int handle_pause(struct kvm_vcpu *vcpu) grow_ple_window(vcpu); kvm_vcpu_on_spin(vcpu); - skip_emulated_instruction(vcpu); - - return 1; + return kvm_skip_emulated_instruction(vcpu); } static int handle_nop(struct kvm_vcpu *vcpu) { - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } static int handle_mwait(struct kvm_vcpu *vcpu) @@ -6823,8 +6815,7 @@ static int nested_vmx_check_vmptr(struct kvm_vcpu *vcpu, int exit_reason, */ if (!PAGE_ALIGNED(vmptr) || (vmptr >> maxphyaddr)) { nested_vmx_failInvalid(vcpu); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } page = nested_get_page(vcpu, vmptr); @@ -6832,8 +6823,7 @@ static int nested_vmx_check_vmptr(struct kvm_vcpu *vcpu, int exit_reason, *(u32 *)kmap(page) != VMCS12_REVISION) { nested_vmx_failInvalid(vcpu); kunmap(page); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } kunmap(page); vmx->nested.vmxon_ptr = vmptr; @@ -6842,30 +6832,26 @@ static int nested_vmx_check_vmptr(struct kvm_vcpu *vcpu, int exit_reason, if (!PAGE_ALIGNED(vmptr) || (vmptr >> maxphyaddr)) { nested_vmx_failValid(vcpu, VMXERR_VMCLEAR_INVALID_ADDRESS); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } if (vmptr == vmx->nested.vmxon_ptr) { nested_vmx_failValid(vcpu, VMXERR_VMCLEAR_VMXON_POINTER); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } break; case EXIT_REASON_VMPTRLD: if (!PAGE_ALIGNED(vmptr) || (vmptr >> maxphyaddr)) { nested_vmx_failValid(vcpu, VMXERR_VMPTRLD_INVALID_ADDRESS); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } if (vmptr == vmx->nested.vmxon_ptr) { nested_vmx_failValid(vcpu, VMXERR_VMCLEAR_VMXON_POINTER); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } break; default: @@ -6921,8 +6907,7 @@ static int handle_vmon(struct kvm_vcpu *vcpu) if (vmx->nested.vmxon) { nested_vmx_failValid(vcpu, VMXERR_VMXON_IN_VMX_ROOT_OPERATION); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } if ((vmx->msr_ia32_feature_control & VMXON_NEEDED_FEATURES) @@ -6963,8 +6948,7 @@ static int handle_vmon(struct kvm_vcpu *vcpu) vmx->nested.vmxon = true; nested_vmx_succeed(vcpu); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); out_shadow_vmcs: kfree(vmx->nested.cached_vmcs12); @@ -7084,8 +7068,7 @@ static int handle_vmoff(struct kvm_vcpu *vcpu) return 1; free_nested(to_vmx(vcpu)); nested_vmx_succeed(vcpu); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } /* Emulate the VMCLEAR instruction */ @@ -7125,8 +7108,7 @@ static int handle_vmclear(struct kvm_vcpu *vcpu) nested_free_vmcs02(vmx, vmptr); nested_vmx_succeed(vcpu); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch); @@ -7340,18 +7322,15 @@ static int handle_vmread(struct kvm_vcpu *vcpu) if (!nested_vmx_check_permission(vcpu)) return 1; - if (!nested_vmx_check_vmcs12(vcpu)) { - skip_emulated_instruction(vcpu); - return 1; - } + if (!nested_vmx_check_vmcs12(vcpu)) + return kvm_skip_emulated_instruction(vcpu); /* Decode instruction info and find the field to read */ field = kvm_register_readl(vcpu, (((vmx_instruction_info) >> 28) & 0xf)); /* Read the field, zero-extended to a u64 field_value */ if (vmcs12_read_any(vcpu, field, &field_value) < 0) { nested_vmx_failValid(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } /* * Now copy part of this value to register or memory, as requested. @@ -7371,8 +7350,7 @@ static int handle_vmread(struct kvm_vcpu *vcpu) } nested_vmx_succeed(vcpu); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } @@ -7394,10 +7372,8 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu) if (!nested_vmx_check_permission(vcpu)) return 1; - if (!nested_vmx_check_vmcs12(vcpu)) { - skip_emulated_instruction(vcpu); - return 1; - } + if (!nested_vmx_check_vmcs12(vcpu)) + return kvm_skip_emulated_instruction(vcpu); if (vmx_instruction_info & (1u << 10)) field_value = kvm_register_readl(vcpu, @@ -7418,19 +7394,16 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu) if (vmcs_field_readonly(field)) { nested_vmx_failValid(vcpu, VMXERR_VMWRITE_READ_ONLY_VMCS_COMPONENT); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } if (vmcs12_write_any(vcpu, field, field_value) < 0) { nested_vmx_failValid(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } nested_vmx_succeed(vcpu); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } /* Emulate the VMPTRLD instruction */ @@ -7451,8 +7424,7 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu) page = nested_get_page(vcpu, vmptr); if (page == NULL) { nested_vmx_failInvalid(vcpu); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } new_vmcs12 = kmap(page); if (new_vmcs12->revision_id != VMCS12_REVISION) { @@ -7460,8 +7432,7 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu) nested_release_page_clean(page); nested_vmx_failValid(vcpu, VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } nested_release_vmcs12(vmx); @@ -7485,8 +7456,7 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu) } nested_vmx_succeed(vcpu); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } /* Emulate the VMPTRST instruction */ @@ -7511,8 +7481,7 @@ static int handle_vmptrst(struct kvm_vcpu *vcpu) return 1; } nested_vmx_succeed(vcpu); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } /* Emulate the INVEPT instruction */ @@ -7550,8 +7519,7 @@ static int handle_invept(struct kvm_vcpu *vcpu) if (type >= 32 || !(types & (1 << type))) { nested_vmx_failValid(vcpu, VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } /* According to the Intel VMX instruction reference, the memory @@ -7582,8 +7550,7 @@ static int handle_invept(struct kvm_vcpu *vcpu) break; } - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } static int handle_invvpid(struct kvm_vcpu *vcpu) @@ -7614,8 +7581,7 @@ static int handle_invvpid(struct kvm_vcpu *vcpu) if (type >= 32 || !(types & (1 << type))) { nested_vmx_failValid(vcpu, VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } /* according to the intel vmx instruction reference, the memory @@ -7637,23 +7603,20 @@ static int handle_invvpid(struct kvm_vcpu *vcpu) if (!vpid) { nested_vmx_failValid(vcpu, VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } break; case VMX_VPID_EXTENT_ALL_CONTEXT: break; default: WARN_ON_ONCE(1); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } __vmx_flush_tlb(vcpu, vmx->nested.vpid02); nested_vmx_succeed(vcpu); - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } static int handle_pml_full(struct kvm_vcpu *vcpu) @@ -10194,6 +10157,11 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) if (!vmcs02) return -ENOMEM; + /* + * After this point, the trap flag no longer triggers a singlestep trap + * on the vm entry instructions. Don't call + * kvm_skip_emulated_instruction. + */ skip_emulated_instruction(vcpu); enter_guest_mode(vcpu); @@ -10238,8 +10206,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) return 1; out: - skip_emulated_instruction(vcpu); - return 1; + return kvm_skip_emulated_instruction(vcpu); } /* diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ec59301f5192..7b38c5e6f412 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -425,12 +425,14 @@ void kvm_requeue_exception(struct kvm_vcpu *vcpu, unsigned nr) } EXPORT_SYMBOL_GPL(kvm_requeue_exception); -void kvm_complete_insn_gp(struct kvm_vcpu *vcpu, int err) +int kvm_complete_insn_gp(struct kvm_vcpu *vcpu, int err) { if (err) kvm_inject_gp(vcpu, 0); else - kvm_x86_ops->skip_emulated_instruction(vcpu); + return kvm_skip_emulated_instruction(vcpu); + + return 1; } EXPORT_SYMBOL_GPL(kvm_complete_insn_gp); @@ -4813,8 +4815,8 @@ static int kvm_emulate_wbinvd_noskip(struct kvm_vcpu *vcpu) int kvm_emulate_wbinvd(struct kvm_vcpu *vcpu) { - kvm_x86_ops->skip_emulated_instruction(vcpu); - return kvm_emulate_wbinvd_noskip(vcpu); + kvm_emulate_wbinvd_noskip(vcpu); + return kvm_skip_emulated_instruction(vcpu); } EXPORT_SYMBOL_GPL(kvm_emulate_wbinvd); @@ -5430,6 +5432,17 @@ static void kvm_vcpu_check_singlestep(struct kvm_vcpu *vcpu, unsigned long rflag } } +int kvm_skip_emulated_instruction(struct kvm_vcpu *vcpu) +{ + unsigned long rflags = kvm_x86_ops->get_rflags(vcpu); + int r = EMULATE_DONE; + + kvm_x86_ops->skip_emulated_instruction(vcpu); + kvm_vcpu_check_singlestep(vcpu, rflags, &r); + return r == EMULATE_DONE; +} +EXPORT_SYMBOL_GPL(kvm_skip_emulated_instruction); + static bool kvm_vcpu_check_breakpoint(struct kvm_vcpu *vcpu, int *r) { if (unlikely(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) && @@ -6007,8 +6020,12 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_halt); int kvm_emulate_halt(struct kvm_vcpu *vcpu) { - kvm_x86_ops->skip_emulated_instruction(vcpu); - return kvm_vcpu_halt(vcpu); + int ret = kvm_skip_emulated_instruction(vcpu); + /* + * TODO: we might be squashing a GUESTDBG_SINGLESTEP-triggered + * KVM_EXIT_DEBUG here. + */ + return kvm_vcpu_halt(vcpu) && ret; } EXPORT_SYMBOL_GPL(kvm_emulate_halt); @@ -6039,9 +6056,9 @@ void kvm_vcpu_deactivate_apicv(struct kvm_vcpu *vcpu) int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) { unsigned long nr, a0, a1, a2, a3, ret; - int op_64_bit, r = 1; + int op_64_bit, r; - kvm_x86_ops->skip_emulated_instruction(vcpu); + r = kvm_skip_emulated_instruction(vcpu); if (kvm_hv_hypercall_enabled(vcpu->kvm)) return kvm_hv_hypercall(vcpu); -- 2.20.1