[v8,70/81] KVM: introspection: add KVMI_EVENT_DESCRIPTOR

Message ID	20200330101308.21702-71-alazar@bitdefender.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=cHma=5P=vger.kernel.org=kvm-owner@kernel.org> From: =?utf-8?q?Adalbert_Laz=C4=83r?= <alazar@bitdefender.com> To: kvm@vger.kernel.org Cc: virtualization@lists.linux-foundation.org, Paolo Bonzini <pbonzini@redhat.com>, =?utf-8?b?TmljdciZb3IgQ8OuyJt1?= <ncitu@bitdefender.com>, =?utf-8?q?Adalber?= =?utf-8?q?t_Laz=C4=83r?= <alazar@bitdefender.com> Subject: [PATCH v8 70/81] KVM: introspection: add KVMI_EVENT_DESCRIPTOR Date: Mon, 30 Mar 2020 13:12:57 +0300 Message-Id: <20200330101308.21702-71-alazar@bitdefender.com> In-Reply-To: <20200330101308.21702-1-alazar@bitdefender.com> References: <20200330101308.21702-1-alazar@bitdefender.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk
Series	VM introspection \| expand [v8,00/81] VM introspection [v8,01/81] sched/swait: add swait_event_killable_exclusive() [v8,02/81] export kill_pid_info() [v8,03/81] KVM: add new error codes for VM introspection [v8,04/81] KVM: add kvm_vcpu_kick_and_wait() [v8,05/81] KVM: add kvm_get_max_gfn() [v8,06/81] KVM: doc: fix the hypercall numbering [v8,07/81] KVM: x86: add kvm_arch_vcpu_get_regs() and kvm_arch_vcpu_get_sregs() [v8,08/81] KVM: x86: add kvm_arch_vcpu_set_regs() [v8,09/81] KVM: x86: avoid injecting #PF when emulate the VMCALL instruction [v8,10/81] KVM: x86: add .bp_intercepted() to struct kvm_x86_ops [v8,11/81] KVM: x86: add .control_cr3_intercept() to struct kvm_x86_ops [v8,12/81] KVM: x86: add .cr3_write_intercepted() [v8,13/81] KVM: x86: add .desc_ctrl_supported() [v8,14/81] KVM: svm: add support for descriptor-table exits [v8,15/81] KVM: x86: add .control_desc_intercept() [v8,16/81] KVM: x86: add .desc_intercepted() [v8,17/81] KVM: x86: export .msr_write_intercepted() [v8,18/81] KVM: x86: use MSR_TYPE_R, MSR_TYPE_W and MSR_TYPE_RW with AMD code too [v8,19/81] KVM: svm: pass struct kvm_vcpu to set_msr_interception() [v8,20/81] KVM: vmx: pass struct kvm_vcpu to the intercept msr related functions [v8,21/81] KVM: x86: add .control_msr_intercept() [v8,22/81] KVM: x86: vmx: use a symbolic constant when checking the exit qualifications [v8,23/81] KVM: x86: save the error code during EPT/NPF exits handling [v8,24/81] KVM: x86: add .fault_gla() [v8,25/81] KVM: x86: add .spt_fault() [v8,26/81] KVM: x86: add .gpt_translation_fault() [v8,27/81] KVM: x86: add .control_singlestep() [v8,28/81] KVM: x86: export kvm_arch_vcpu_set_guest_debug() [v8,29/81] KVM: x86: extend kvm_mmu_gva_to_gpa_system() with the 'access' parameter [v8,30/81] KVM: x86: export kvm_inject_pending_exception() [v8,31/81] KVM: x86: export kvm_vcpu_ioctl_x86_get_xsave() [v8,32/81] KVM: x86: page track: provide all page tracking hooks with the guest virtual address [v8,33/81] KVM: x86: page track: add track_create_slot() callback [v8,34/81] KVM: x86: page_track: add support for preread, prewrite and preexec [v8,35/81] KVM: x86: wire in the preread/prewrite/preexec page trackers [v8,36/81] KVM: x86: intercept the write access on sidt and other emulated instructions [v8,37/81] KVM: x86: disable gpa_available optimization for fetch and page-walk NPF/EPT violations [v8,38/81] KVM: introduce VM introspection [v8,39/81] KVM: introspection: add hook/unhook ioctls [v8,40/81] KVM: introspection: add permission access ioctls [v8,41/81] KVM: introspection: add the read/dispatch message function [v8,42/81] KVM: introspection: add KVMI_GET_VERSION [v8,43/81] KVM: introspection: add KVMI_VM_CHECK_COMMAND and KVMI_VM_CHECK_EVENT [v8,44/81] KVM: introspection: add KVMI_VM_GET_INFO [v8,45/81] KVM: introspection: add KVMI_EVENT_UNHOOK [v8,46/81] KVM: introspection: add KVMI_VM_CONTROL_EVENTS [v8,47/81] KVM: introspection: add KVMI_VM_READ_PHYSICAL/KVMI_VM_WRITE_PHYSICAL [v8,48/81] KVM: introspection: add vCPU related data [v8,49/81] KVM: introspection: add a jobs list to every introspected vCPU [v8,50/81] KVM: introspection: handle vCPU introspection requests [v8,51/81] KVM: introspection: handle vCPU commands [v8,52/81] KVM: introspection: add KVMI_VCPU_GET_INFO [v8,53/81] KVM: introspection: add KVMI_VCPU_PAUSE [v8,54/81] KVM: introspection: add KVMI_EVENT_PAUSE_VCPU [v8,55/81] KVM: introspection: add crash action handling on event reply [v8,56/81] KVM: introspection: add KVMI_VCPU_CONTROL_EVENTS [v8,57/81] KVM: introspection: add KVMI_VCPU_GET_REGISTERS [v8,58/81] KVM: introspection: add KVMI_VCPU_SET_REGISTERS [v8,59/81] KVM: introspection: add KVMI_VCPU_GET_CPUID [v8,60/81] KVM: introspection: add KVMI_EVENT_HYPERCALL [v8,61/81] KVM: introspection: add KVMI_EVENT_BREAKPOINT [v8,62/81] KVM: introspection: restore the state of #BP interception on unhook [v8,63/81] KVM: introspection: add KVMI_VCPU_CONTROL_CR and KVMI_EVENT_CR [v8,64/81] KVM: introspection: restore the state of CR3 interception on unhook [v8,65/81] KVM: introspection: add KVMI_VCPU_INJECT_EXCEPTION + KVMI_EVENT_TRAP [v8,66/81] KVM: introspection: add KVMI_VM_GET_MAX_GFN [v8,67/81] KVM: introspection: add KVMI_EVENT_XSETBV [v8,68/81] KVM: introspection: add KVMI_VCPU_GET_XSAVE [v8,69/81] KVM: introspection: add KVMI_VCPU_GET_MTRR_TYPE [v8,70/81] KVM: introspection: add KVMI_EVENT_DESCRIPTOR [v8,71/81] KVM: introspection: restore the state of descriptor-table register interception on unhook [v8,72/81] KVM: introspection: add KVMI_VCPU_CONTROL_MSR and KVMI_EVENT_MSR [v8,73/81] KVM: introspection: restore the state of MSR interception on unhook [v8,74/81] KVM: introspection: add KVMI_VM_SET_PAGE_ACCESS [v8,75/81] KVM: introspection: add KVMI_EVENT_PF [v8,76/81] KVM: introspection: extend KVMI_GET_VERSION with struct kvmi_features [v8,77/81] KVM: introspection: add KVMI_VCPU_CONTROL_SINGLESTEP [v8,78/81] KVM: introspection: add KVMI_EVENT_SINGLESTEP [v8,79/81] KVM: introspection: add KVMI_VCPU_TRANSLATE_GVA [v8,80/81] KVM: introspection: emulate a guest page table walk on SPT violations due to A/D bit upd… [v8,81/81] KVM: x86: call the page tracking code on emulation failure

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst index 9d37030213a6..6f6551230e11 100644 --- a/Documentation/virt/kvm/kvmi.rst +++ b/Documentation/virt/kvm/kvmi.rst @@ -548,6 +548,7 @@ the following events:: KVMI_EVENT_BREAKPOINT KVMI_EVENT_CR + KVMI_EVENT_DESCRIPTOR KVMI_EVENT_HYPERCALL KVMI_EVENT_XSETBV @@ -572,6 +573,8 @@ the *KVMI_VM_CONTROL_EVENTS* command. * -KVM_EINVAL - the event ID is unknown (use *KVMI_VM_CHECK_EVENT* first) * -KVM_EPERM - the access is disallowed (use *KVMI_VM_CHECK_EVENT* first) * -KVM_EAGAIN - the selected vCPU can't be introspected yet +* -KVM_EOPNOTSUPP - the event can't be intercepted in the current setup + (e.g. KVMI_EVENT_DESCRIPTOR with AMD) * -KVM_EBUSY - the event can't be intercepted right now (e.g. KVMI_EVENT_BREAKPOINT if the #BP event is already intercepted by userspace) @@ -1107,3 +1110,41 @@ to be changed and the introspection has been enabled for this event (see *KVMI_VCPU_CONTROL_EVENTS*). ``kvmi_event`` is sent to the introspection tool. + +8. KVMI_EVENT_DESCRIPTOR +------------------------ + +:Architecture: x86 +:Versions: >= 1 +:Actions: CONTINUE, RETRY, CRASH +:Parameters: + +:: + + struct kvmi_event; + struct kvmi_event_descriptor { + __u8 descriptor; + __u8 write; + __u8 padding[6]; + }; + +:Returns: + +:: + + struct kvmi_vcpu_hdr; + struct kvmi_event_reply; + +This event is sent when a descriptor table register is accessed and the +introspection has been enabled for this event (see **KVMI_VCPU_CONTROL_EVENTS**). + +``kvmi_event`` and ``kvmi_event_descriptor`` are sent to the introspection tool. + +``descriptor`` can be one of:: + + KVMI_DESC_IDTR + KVMI_DESC_GDTR + KVMI_DESC_LDTR + KVMI_DESC_TR + +``write`` is 1 if the descriptor was written, 0 otherwise. diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h index b3fa950362db..7633501031d2 100644 --- a/arch/x86/include/asm/kvmi_host.h +++ b/arch/x86/include/asm/kvmi_host.h @@ -31,6 +31,7 @@ bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr, bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu); bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable); void kvmi_xsetbv_event(struct kvm_vcpu *vcpu); +bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor, bool write); #else /* CONFIG_KVM_INTROSPECTION */ @@ -43,6 +44,8 @@ static inline bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu) { return false; } static inline bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable) { return false; } static inline void kvmi_xsetbv_event(struct kvm_vcpu *vcpu) { } +static inline bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor, + bool write) { return true; } #endif /* CONFIG_KVM_INTROSPECTION */ diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h index d622c89a4f2c..691a501200b3 100644 --- a/arch/x86/include/uapi/asm/kvmi.h +++ b/arch/x86/include/uapi/asm/kvmi.h @@ -110,4 +110,15 @@ struct kvmi_vcpu_get_mtrr_type_reply { __u8 padding[7]; }; +#define KVMI_DESC_IDTR 1 +#define KVMI_DESC_GDTR 2 +#define KVMI_DESC_LDTR 3 +#define KVMI_DESC_TR 4 + +struct kvmi_event_descriptor { + __u8 descriptor; + __u8 write; + __u8 padding[6]; +}; + #endif /* _UAPI_ASM_X86_KVMI_H */ diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c index 3de7e98fa426..093ff0da88ff 100644 --- a/arch/x86/kvm/kvmi.c +++ b/arch/x86/kvm/kvmi.c @@ -360,6 +360,21 @@ static void kvmi_arch_disable_cr3w_intercept(struct kvm_vcpu *vcpu) vcpu->arch.kvmi->cr3w.kvm_intercepted = false; } +static int kvmi_control_desc_intercept(struct kvm_vcpu *vcpu, bool enable) +{ + if (!kvm_x86_ops->desc_ctrl_supported()) + return -KVM_EOPNOTSUPP; + + kvm_x86_ops->control_desc_intercept(vcpu, enable); + + return 0; +} + +static void kvmi_arch_disable_desc_intercept(struct kvm_vcpu *vcpu) +{ + kvmi_control_desc_intercept(vcpu, false); +} + int kvmi_arch_cmd_control_intercept(struct kvm_vcpu *vcpu, unsigned int event_id, bool enable) { @@ -369,6 +384,9 @@ int kvmi_arch_cmd_control_intercept(struct kvm_vcpu *vcpu, case KVMI_EVENT_BREAKPOINT: err = kvmi_control_bp_intercept(vcpu, enable); break; + case KVMI_EVENT_DESCRIPTOR: + err = kvmi_control_desc_intercept(vcpu, enable); + break; default: break; } @@ -405,6 +423,7 @@ bool kvmi_arch_restore_interception(struct kvm_vcpu *vcpu) kvmi_arch_disable_bp_intercept(vcpu); kvmi_arch_disable_cr3w_intercept(vcpu); + kvmi_arch_disable_desc_intercept(vcpu); return true; } @@ -729,3 +748,59 @@ int kvmi_arch_cmd_vcpu_get_mtrr_type(struct kvm_vcpu *vcpu, u64 gpa, u8 *type) return 0; } + +static u32 kvmi_msg_send_descriptor(struct kvm_vcpu *vcpu, u8 descriptor, + bool write) +{ + struct kvmi_event_descriptor e; + int err, action; + + memset(&e, 0, sizeof(e)); + e.descriptor = descriptor; + e.write = write ? 1 : 0; + + err = kvmi_send_event(vcpu, KVMI_EVENT_DESCRIPTOR, &e, sizeof(e), + NULL, 0, &action); + if (err) + return KVMI_EVENT_ACTION_CONTINUE; + + return action; +} + +static bool __kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor, + bool write) +{ + bool ret = false; + u32 action; + + action = kvmi_msg_send_descriptor(vcpu, descriptor, write); + switch (action) { + case KVMI_EVENT_ACTION_CONTINUE: + ret = true; + break; + case KVMI_EVENT_ACTION_RETRY: + break; + default: + kvmi_handle_common_event_actions(vcpu->kvm, action, "DESC"); + } + + return ret; +} + +bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor, bool write) +{ + struct kvm_introspection *kvmi; + bool ret = true; + + kvmi = kvmi_get(vcpu->kvm); + if (!kvmi) + return true; + + if (is_event_enabled(vcpu, KVMI_EVENT_DESCRIPTOR)) + ret = __kvmi_descriptor_event(vcpu, descriptor, write); + + kvmi_put(vcpu->kvm); + + return ret; +} +EXPORT_SYMBOL(kvmi_descriptor_event); diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 1021ff2f9e57..b377acc3410c 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -4854,6 +4854,39 @@ static int descriptor_access_interception(struct vcpu_svm *svm) { struct kvm_vcpu *vcpu = &svm->vcpu; +#ifdef CONFIG_KVM_INTROSPECTION + struct vmcb_control_area *c = &svm->vmcb->control; + bool cont; + + switch (c->exit_code) { + case SVM_EXIT_IDTR_READ: + case SVM_EXIT_IDTR_WRITE: + cont = kvmi_descriptor_event(vcpu, KVMI_DESC_IDTR, + c->exit_code == SVM_EXIT_IDTR_WRITE); + break; + case SVM_EXIT_GDTR_READ: + case SVM_EXIT_GDTR_WRITE: + cont = kvmi_descriptor_event(vcpu, KVMI_DESC_GDTR, + c->exit_code == SVM_EXIT_GDTR_WRITE); + break; + case SVM_EXIT_LDTR_READ: + case SVM_EXIT_LDTR_WRITE: + cont = kvmi_descriptor_event(vcpu, KVMI_DESC_LDTR, + c->exit_code == SVM_EXIT_LDTR_WRITE); + break; + case SVM_EXIT_TR_READ: + case SVM_EXIT_TR_WRITE: + cont = kvmi_descriptor_event(vcpu, KVMI_DESC_TR, + c->exit_code == SVM_EXIT_TR_WRITE); + break; + default: + cont = true; + break; + } + if (!cont) + return 1; +#endif /* CONFIG_KVM_INTROSPECTION */ + return kvm_emulate_instruction(vcpu, 0); } diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index f6180ecf15ba..c54c01e088b6 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4866,7 +4866,30 @@ static int handle_set_cr4(struct kvm_vcpu *vcpu, unsigned long val) static int handle_desc(struct kvm_vcpu *vcpu) { +#ifdef CONFIG_KVM_INTROSPECTION + struct vcpu_vmx *vmx = to_vmx(vcpu); + u32 exit_reason = vmx->exit_reason; + u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO); + u8 store = (vmx_instruction_info >> 29) & 0x1; + u8 descriptor = 0; + + if (exit_reason == EXIT_REASON_GDTR_IDTR) { + if ((vmx_instruction_info >> 28) & 0x1) + descriptor = KVMI_DESC_IDTR; + else + descriptor = KVMI_DESC_GDTR; + } else { + if ((vmx_instruction_info >> 28) & 0x1) + descriptor = KVMI_DESC_TR; + else + descriptor = KVMI_DESC_LDTR; + } + + if (!kvmi_descriptor_event(vcpu, descriptor, store)) + return 1; +#else WARN_ON(!(vcpu->arch.cr4 & X86_CR4_UMIP)); +#endif /* CONFIG_KVM_INTROSPECTION */ return kvm_emulate_instruction(vcpu, 0); } diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h index 0827bd90691b..2ccc4045137f 100644 --- a/include/uapi/linux/kvmi.h +++ b/include/uapi/linux/kvmi.h @@ -50,6 +50,7 @@ enum { KVMI_EVENT_CR = 4, KVMI_EVENT_TRAP = 5, KVMI_EVENT_XSETBV = 6, + KVMI_EVENT_DESCRIPTOR = 7, KVMI_NUM_EVENTS }; diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c index b984c3704baf..4f2de304a6f8 100644 --- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c +++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c @@ -55,6 +55,7 @@ enum { GUEST_TEST_NOOP = 0, GUEST_TEST_BP, GUEST_TEST_CR, + GUEST_TEST_DESCRIPTOR, GUEST_TEST_HYPERCALL, GUEST_TEST_XSETBV, }; @@ -80,6 +81,14 @@ static void guest_cr_test(void) set_cr4(get_cr4() | X86_CR4_OSXSAVE); } +static void guest_descriptor_test(void) +{ + void *ptr; + + asm volatile("sgdt %0" :: "m"(ptr)); + asm volatile("lgdt %0" :: "m"(ptr)); +} + static void guest_hypercall_test(void) { asm volatile("mov $34, %rax"); @@ -139,6 +148,9 @@ static void guest_code(void) case GUEST_TEST_CR: guest_cr_test(); break; + case GUEST_TEST_DESCRIPTOR: + guest_descriptor_test(); + break; case GUEST_TEST_HYPERCALL: guest_hypercall_test(); break; @@ -1363,6 +1375,68 @@ static void test_cmd_vcpu_get_mtrr_type(struct kvm_vm *vm) DEBUG("mtrr_type: gpa 0x%lx type 0x%x\n", test_gpa, rpl.type); } +static void test_desc_read_access(__u16 event_id) +{ + struct kvmi_msg_hdr hdr; + struct { + struct kvmi_event common; + struct kvmi_event_descriptor desc; + } ev; + struct vcpu_reply rpl = {}; + + receive_event(&hdr, &ev.common, sizeof(ev), event_id); + + DEBUG("Descriptor event (read), descriptor %u, write %u\n", + ev.desc.descriptor, ev.desc.write); + + TEST_ASSERT(ev.desc.write == 0, + "Received a write descriptor access\n"); + + reply_to_event(&hdr, &ev.common, KVMI_EVENT_ACTION_CONTINUE, + &rpl, sizeof(rpl)); +} + +static void test_desc_write_access(__u16 event_id) +{ + struct kvmi_msg_hdr hdr; + struct { + struct kvmi_event common; + struct kvmi_event_descriptor desc; + } ev; + struct vcpu_reply rpl = {}; + + receive_event(&hdr, &ev.common, sizeof(ev), event_id); + + DEBUG("Descriptor event (write), descriptor %u, write %u\n", + ev.desc.descriptor, ev.desc.write); + + TEST_ASSERT(ev.desc.write == 1, + "Received a read descriptor access\n"); + + reply_to_event(&hdr, &ev.common, KVMI_EVENT_ACTION_CONTINUE, + &rpl, sizeof(rpl)); +} + +static void test_event_descriptor(struct kvm_vm *vm) +{ + struct vcpu_worker_data data = { + .vm = vm, + .vcpu_id = VCPU_ID, + .test_id = GUEST_TEST_DESCRIPTOR, + }; + __u16 event_id = KVMI_EVENT_DESCRIPTOR; + pthread_t vcpu_thread; + + enable_vcpu_event(vm, event_id); + vcpu_thread = start_vcpu_worker(&data); + + test_desc_read_access(event_id); + test_desc_write_access(event_id); + + stop_vcpu_worker(vcpu_thread, &data); + disable_vcpu_event(vm, event_id); +} + static void test_introspection(struct kvm_vm *vm) { srandom(time(0)); @@ -1391,6 +1465,7 @@ static void test_introspection(struct kvm_vm *vm) test_event_xsetbv(vm); test_cmd_vcpu_get_xsave(vm); test_cmd_vcpu_get_mtrr_type(vm); + test_event_descriptor(vm); unhook_introspection(vm); } diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c index d358686fce76..db79744e5d2f 100644 --- a/virt/kvm/introspection/kvmi.c +++ b/virt/kvm/introspection/kvmi.c @@ -80,6 +80,7 @@ static void setup_known_events(void) bitmap_zero(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS); set_bit(KVMI_EVENT_BREAKPOINT, Kvmi_known_vcpu_events); set_bit(KVMI_EVENT_CR, Kvmi_known_vcpu_events); + set_bit(KVMI_EVENT_DESCRIPTOR, Kvmi_known_vcpu_events); set_bit(KVMI_EVENT_HYPERCALL, Kvmi_known_vcpu_events); set_bit(KVMI_EVENT_PAUSE_VCPU, Kvmi_known_vcpu_events); set_bit(KVMI_EVENT_TRAP, Kvmi_known_vcpu_events);

[v8,70/81] KVM: introspection: add KVMI_EVENT_DESCRIPTOR

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