@@ -547,6 +547,7 @@ Enables/disables vCPU introspection events. This command can be used with
the following events::
KVMI_EVENT_BREAKPOINT
+ KVMI_EVENT_CR
KVMI_EVENT_HYPERCALL
When an event is enabled, the introspection tool is notified and
@@ -680,6 +681,40 @@ Returns a CPUID leaf (as seen by the guest OS).
* -KVM_EAGAIN - the selected vCPU can't be introspected yet
* -KVM_ENOENT - the selected leaf is not present or is invalid
+14. KVMI_VCPU_CONTROL_CR
+------------------------
+
+:Architectures: x86
+:Versions: >= 1
+:Parameters:
+
+::
+
+ struct kvmi_vcpu_hdr;
+ struct kvmi_vcpu_control_cr {
+ __u16 cr;
+ __u8 enable;
+ __u8 padding1;
+ __u32 padding2;
+ };
+
+:Returns:
+
+::
+
+ struct kvmi_error_code
+
+Enables/disables introspection for a specific control register and must
+be used in addition to *KVMI_VCPU_CONTROL_EVENTS* with the *KVMI_EVENT_CR*
+ID set.
+
+:Errors:
+
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EINVAL - the specified control register is not CR0, CR3 or CR4
+* -KVM_EINVAL - the padding is not zero
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+
Events
======
@@ -855,3 +890,38 @@ trying to perform a certain operation (like creating a process).
``kvmi_event`` and the guest physical address are sent to the introspection tool.
The *RETRY* action is used by the introspection tool for its own breakpoints.
+
+5. KVMI_EVENT_CR
+----------------
+
+:Architectures: x86
+:Versions: >= 1
+:Actions: CONTINUE, CRASH
+:Parameters:
+
+::
+
+ struct kvmi_event;
+ struct kvmi_event_cr {
+ __u16 cr;
+ __u16 padding[3];
+ __u64 old_value;
+ __u64 new_value;
+ };
+
+:Returns:
+
+::
+
+ struct kvmi_vcpu_hdr;
+ struct kvmi_event_reply;
+ struct kvmi_event_cr_reply {
+ __u64 new_val;
+ };
+
+This event is sent when a control register is going to be changed and the
+introspection has been enabled for this event and for this specific
+register (see **KVMI_VCPU_CONTROL_EVENTS**).
+
+``kvmi_event``, the control register number, the old value and the new value
+are sent to the introspection tool. The *CONTINUE* action will set the ``new_val``.
@@ -2,6 +2,8 @@
#ifndef _ASM_X86_KVMI_HOST_H
#define _ASM_X86_KVMI_HOST_H
+#define KVMI_NUM_CR 5
+
struct kvmi_monitor_interception {
bool kvmi_intercepted;
bool kvm_intercepted;
@@ -14,6 +16,7 @@ struct kvmi_interception {
};
struct kvm_vcpu_arch_introspection {
+ DECLARE_BITMAP(cr_mask, KVMI_NUM_CR);
};
struct kvm_arch_introspection {
@@ -22,11 +25,18 @@ struct kvm_arch_introspection {
#ifdef CONFIG_KVM_INTROSPECTION
bool kvmi_monitor_bp_intercept(struct kvm_vcpu *vcpu, u32 dbg);
+bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr,
+ unsigned long old_value, unsigned long *new_value);
+bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu);
#else /* CONFIG_KVM_INTROSPECTION */
static inline bool kvmi_monitor_bp_intercept(struct kvm_vcpu *vcpu, u32 dbg)
{ return false; }
+static inline bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr,
+ unsigned long old_value,
+ unsigned long *new_value) { return true; }
+static inline bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu) { return false; }
#endif /* CONFIG_KVM_INTROSPECTION */
@@ -65,4 +65,22 @@ struct kvmi_event_breakpoint {
__u8 padding[7];
};
+struct kvmi_vcpu_control_cr {
+ __u16 cr;
+ __u8 enable;
+ __u8 padding1;
+ __u32 padding2;
+};
+
+struct kvmi_event_cr {
+ __u16 cr;
+ __u16 padding[3];
+ __u64 old_value;
+ __u64 new_value;
+};
+
+struct kvmi_event_cr_reply {
+ __u64 new_val;
+};
+
#endif /* _UAPI_ASM_X86_KVMI_H */
@@ -390,3 +390,114 @@ void kvmi_arch_request_restore_interception(struct kvm_vcpu *vcpu)
if (arch_vcpui)
arch_vcpui->restore_interception = true;
}
+
+int kvmi_arch_cmd_vcpu_control_cr(struct kvm_vcpu *vcpu,
+ const struct kvmi_vcpu_control_cr *req)
+{
+ u32 cr = req->cr;
+
+ if (req->padding1 || req->padding2 || req->enable > 1)
+ return -KVM_EINVAL;
+
+ switch (cr) {
+ case 0:
+ break;
+ case 3:
+ kvm_x86_ops->control_cr3_intercept(vcpu, CR_TYPE_W,
+ req->enable == 1);
+ break;
+ case 4:
+ break;
+ default:
+ return -KVM_EINVAL;
+ }
+
+ if (req->enable)
+ set_bit(cr, VCPUI(vcpu)->arch.cr_mask);
+ else
+ clear_bit(cr, VCPUI(vcpu)->arch.cr_mask);
+
+ return 0;
+}
+
+static u32 kvmi_send_cr(struct kvm_vcpu *vcpu, u32 cr, u64 old_value,
+ u64 new_value, u64 *ret_value)
+{
+ struct kvmi_event_cr e;
+ struct kvmi_event_cr_reply r;
+ int err, action;
+
+ memset(&e, 0, sizeof(e));
+ e.cr = cr;
+ e.old_value = old_value;
+ e.new_value = new_value;
+
+ err = kvmi_send_event(vcpu, KVMI_EVENT_CR, &e, sizeof(e),
+ &r, sizeof(r), &action);
+ if (err)
+ return KVMI_EVENT_ACTION_CONTINUE;
+
+ *ret_value = r.new_val;
+ return action;
+}
+
+static bool __kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr,
+ unsigned long old_value, unsigned long *new_value)
+{
+ u64 ret_value = *new_value;
+ bool ret = false;
+ u32 action;
+
+ if (!test_bit(cr, VCPUI(vcpu)->arch.cr_mask))
+ return true;
+
+ action = kvmi_send_cr(vcpu, cr, old_value, *new_value, &ret_value);
+ switch (action) {
+ case KVMI_EVENT_ACTION_CONTINUE:
+ *new_value = ret_value;
+ ret = true;
+ break;
+ default:
+ kvmi_handle_common_event_actions(vcpu->kvm, action, "CR");
+ }
+
+ return ret;
+}
+
+bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr,
+ unsigned long old_value, unsigned long *new_value)
+{
+ struct kvm_introspection *kvmi;
+ bool ret = true;
+
+ if (old_value == *new_value)
+ return true;
+
+ kvmi = kvmi_get(vcpu->kvm);
+ if (!kvmi)
+ return true;
+
+ if (is_event_enabled(vcpu, KVMI_EVENT_CR))
+ ret = __kvmi_cr_event(vcpu, cr, old_value, new_value);
+
+ kvmi_put(vcpu->kvm);
+
+ return ret;
+}
+
+bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu)
+{
+ struct kvm_introspection *kvmi;
+ bool ret;
+
+ kvmi = kvmi_get(vcpu->kvm);
+ if (!kvmi)
+ return false;
+
+ ret = test_bit(3, VCPUI(vcpu)->arch.cr_mask);
+
+ kvmi_put(vcpu->kvm);
+
+ return ret;
+}
+EXPORT_SYMBOL(kvmi_cr3_intercepted);
@@ -4885,7 +4885,8 @@ static int handle_cr(struct kvm_vcpu *vcpu)
err = handle_set_cr0(vcpu, val);
return kvm_complete_insn_gp(vcpu, err);
case 3:
- WARN_ON_ONCE(enable_unrestricted_guest);
+ WARN_ON_ONCE(enable_unrestricted_guest &&
+ !kvmi_cr3_intercepted(vcpu));
err = kvm_set_cr3(vcpu, val);
return kvm_complete_insn_gp(vcpu, err);
case 4:
@@ -4918,7 +4919,8 @@ static int handle_cr(struct kvm_vcpu *vcpu)
case 1: /*mov from cr*/
switch (cr) {
case 3:
- WARN_ON_ONCE(enable_unrestricted_guest);
+ WARN_ON_ONCE(enable_unrestricted_guest &&
+ !kvmi_cr3_intercepted(vcpu));
val = kvm_read_cr3(vcpu);
kvm_register_write(vcpu, reg, val);
trace_kvm_cr_read(cr, val);
@@ -773,6 +773,9 @@ int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
if (!(cr0 & X86_CR0_PG) && kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE))
return 1;
+ if (!kvmi_cr_event(vcpu, 0, old_cr0, &cr0))
+ return 1;
+
kvm_x86_ops->set_cr0(vcpu, cr0);
if ((cr0 ^ old_cr0) & X86_CR0_PG) {
@@ -950,6 +953,9 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
return 1;
}
+ if (!kvmi_cr_event(vcpu, 4, old_cr4, &cr4))
+ return 1;
+
if (kvm_x86_ops->set_cr4(vcpu, cr4))
return 1;
@@ -966,6 +972,7 @@ EXPORT_SYMBOL_GPL(kvm_set_cr4);
int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
{
+ unsigned long old_cr3 = kvm_read_cr3(vcpu);
bool skip_tlb_flush = false;
#ifdef CONFIG_X86_64
bool pcid_enabled = kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE);
@@ -976,7 +983,7 @@ int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
}
#endif
- if (cr3 == kvm_read_cr3(vcpu) && !pdptrs_changed(vcpu)) {
+ if (cr3 == old_cr3 && !pdptrs_changed(vcpu)) {
if (!skip_tlb_flush) {
kvm_mmu_sync_roots(vcpu);
kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
@@ -991,6 +998,9 @@ int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
!load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3))
return 1;
+ if (!kvmi_cr_event(vcpu, 3, old_cr3, &cr3))
+ return 1;
+
kvm_mmu_new_cr3(vcpu, cr3, skip_tlb_flush);
vcpu->arch.cr3 = cr3;
kvm_register_mark_available(vcpu, VCPU_EXREG_CR3);
@@ -31,6 +31,7 @@ enum {
KVMI_VCPU_GET_REGISTERS = 12,
KVMI_VCPU_SET_REGISTERS = 13,
KVMI_VCPU_GET_CPUID = 14,
+ KVMI_VCPU_CONTROL_CR = 15,
KVMI_NUM_MESSAGES
};
@@ -40,6 +41,7 @@ enum {
KVMI_EVENT_PAUSE_VCPU = 1,
KVMI_EVENT_HYPERCALL = 2,
KVMI_EVENT_BREAKPOINT = 3,
+ KVMI_EVENT_CR = 4,
KVMI_NUM_EVENTS
};
@@ -50,6 +50,7 @@ struct vcpu_worker_data {
enum {
GUEST_TEST_NOOP = 0,
GUEST_TEST_BP,
+ GUEST_TEST_CR,
GUEST_TEST_HYPERCALL,
};
@@ -69,6 +70,11 @@ static void guest_bp_test(void)
asm volatile("int3");
}
+static void guest_cr_test(void)
+{
+ set_cr4(get_cr4() | X86_CR4_OSXSAVE);
+}
+
static void guest_hypercall_test(void)
{
asm volatile("mov $34, %rax");
@@ -86,6 +92,9 @@ static void guest_code(void)
case GUEST_TEST_BP:
guest_bp_test();
break;
+ case GUEST_TEST_CR:
+ guest_cr_test();
+ break;
case GUEST_TEST_HYPERCALL:
guest_hypercall_test();
break;
@@ -1029,6 +1038,94 @@ static void test_event_breakpoint(struct kvm_vm *vm)
disable_vcpu_event(vm, event_id);
}
+static int cmd_control_cr(struct kvm_vm *vm, __u32 cr, bool enable)
+{
+ struct {
+ struct kvmi_msg_hdr hdr;
+ struct kvmi_vcpu_hdr vcpu_hdr;
+ struct kvmi_vcpu_control_cr cmd;
+ } req = {};
+
+ req.cmd.cr = cr;
+ req.cmd.enable = enable ? 1 : 0;
+
+ return do_vcpu0_command(vm, KVMI_VCPU_CONTROL_CR, &req.hdr, sizeof(req),
+ NULL, 0);
+}
+
+static void enable_cr_events(struct kvm_vm *vm, __u32 cr)
+{
+ int r;
+
+ enable_vcpu_event(vm, KVMI_EVENT_CR);
+
+ r = cmd_control_cr(vm, cr, true);
+ TEST_ASSERT(r == 0,
+ "KVMI_VCPU_CONTROL_CR failed, error %d(%s)\n",
+ -r, kvm_strerror(-r));
+}
+
+static void disable_cr_events(struct kvm_vm *vm, __u32 cr)
+{
+ int r;
+
+ r = cmd_control_cr(vm, cr, false);
+ TEST_ASSERT(r == 0,
+ "KVMI_VCPU_CONTROL_CR failed, error %d(%s)\n",
+ -r, kvm_strerror(-r));
+
+ disable_vcpu_event(vm, KVMI_EVENT_CR);
+}
+
+static void test_cmd_vcpu_control_cr(struct kvm_vm *vm)
+{
+ struct vcpu_worker_data data = {
+ .vm = vm,
+ .vcpu_id = VCPU_ID,
+ .test_id = GUEST_TEST_CR,
+ };
+ struct kvmi_msg_hdr hdr;
+ struct {
+ struct kvmi_event common;
+ struct kvmi_event_cr cr;
+ } ev;
+ struct {
+ struct vcpu_reply common;
+ struct kvmi_event_cr_reply cr;
+ } rpl = {};
+ __u16 event_id = KVMI_EVENT_CR;
+ __u32 cr_no = 4;
+ struct kvm_sregs sregs;
+ pthread_t vcpu_thread;
+
+ enable_cr_events(vm, cr_no);
+
+ vcpu_thread = start_vcpu_worker(&data);
+
+ receive_event(&hdr, &ev.common, sizeof(ev), event_id);
+
+ DEBUG("CR%u, old 0x%llx, new 0x%llx\n",
+ ev.cr.cr, ev.cr.old_value, ev.cr.new_value);
+
+ TEST_ASSERT(ev.cr.cr == cr_no,
+ "Unexpected CR event, received CR%u, expected CR%u",
+ ev.cr.cr, cr_no);
+
+ rpl.cr.new_val = ev.cr.old_value;
+
+ reply_to_event(&hdr, &ev.common, KVMI_EVENT_ACTION_CONTINUE,
+ &rpl.common, sizeof(rpl));
+
+ stop_vcpu_worker(vcpu_thread, &data);
+
+ disable_cr_events(vm, cr_no);
+
+ vcpu_sregs_get(vm, VCPU_ID, &sregs);
+ TEST_ASSERT(sregs.cr4 == ev.cr.old_value,
+ "Failed to block CR4 update, CR4 0x%x, expected 0x%x",
+ sregs.cr4, ev.cr.old_value);
+}
+
static void test_introspection(struct kvm_vm *vm)
{
srandom(time(0));
@@ -1051,6 +1148,7 @@ static void test_introspection(struct kvm_vm *vm)
test_cmd_vcpu_get_cpuid(vm);
test_event_hypercall(vm);
test_event_breakpoint(vm);
+ test_cmd_vcpu_control_cr(vm);
unhook_introspection(vm);
}
@@ -79,6 +79,7 @@ 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_HYPERCALL, Kvmi_known_vcpu_events);
set_bit(KVMI_EVENT_PAUSE_VCPU, Kvmi_known_vcpu_events);
@@ -33,6 +33,9 @@ bool kvmi_sock_get(struct kvm_introspection *kvmi, int fd);
void kvmi_sock_shutdown(struct kvm_introspection *kvmi);
void kvmi_sock_put(struct kvm_introspection *kvmi);
bool kvmi_msg_process(struct kvm_introspection *kvmi);
+int kvmi_send_event(struct kvm_vcpu *vcpu, u32 ev_id,
+ void *ev, size_t ev_size,
+ void *rpl, size_t rpl_size, int *action);
int kvmi_msg_send_unhook(struct kvm_introspection *kvmi);
u32 kvmi_msg_send_vcpu_pause(struct kvm_vcpu *vcpu);
u32 kvmi_msg_send_hypercall(struct kvm_vcpu *vcpu);
@@ -49,6 +52,8 @@ void kvmi_run_jobs(struct kvm_vcpu *vcpu);
void kvmi_post_reply(struct kvm_vcpu *vcpu);
void kvmi_handle_common_event_actions(struct kvm *kvm,
u32 action, const char *str);
+struct kvm_introspection * __must_check kvmi_get(struct kvm *kvm);
+void kvmi_put(struct kvm *kvm);
int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi,
unsigned int event_id, bool enable);
int kvmi_cmd_vcpu_control_events(struct kvm_vcpu *vcpu,
@@ -88,5 +93,7 @@ void kvmi_arch_hypercall_event(struct kvm_vcpu *vcpu);
void kvmi_arch_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len);
int kvmi_arch_cmd_control_intercept(struct kvm_vcpu *vcpu,
unsigned int event_id, bool enable);
+int kvmi_arch_cmd_vcpu_control_cr(struct kvm_vcpu *vcpu,
+ const struct kvmi_vcpu_control_cr *req);
#endif
@@ -28,6 +28,7 @@ static const char *const msg_IDs[] = {
[KVMI_VM_GET_INFO] = "KVMI_VM_GET_INFO",
[KVMI_VM_READ_PHYSICAL] = "KVMI_VM_READ_PHYSICAL",
[KVMI_VM_WRITE_PHYSICAL] = "KVMI_VM_WRITE_PHYSICAL",
+ [KVMI_VCPU_CONTROL_CR] = "KVMI_VCPU_CONTROL_CR",
[KVMI_VCPU_CONTROL_EVENTS] = "KVMI_VCPU_CONTROL_EVENTS",
[KVMI_VCPU_GET_CPUID] = "KVMI_VCPU_GET_CPUID",
[KVMI_VCPU_GET_INFO] = "KVMI_VCPU_GET_INFO",
@@ -514,6 +515,17 @@ static int handle_get_cpuid(const struct kvmi_vcpu_cmd_job *job,
return kvmi_msg_vcpu_reply(job, msg, ec, &rpl, sizeof(rpl));
}
+static int handle_vcpu_control_cr(const struct kvmi_vcpu_cmd_job *job,
+ const struct kvmi_msg_hdr *msg,
+ const void *req)
+{
+ int ec;
+
+ ec = kvmi_arch_cmd_vcpu_control_cr(job->vcpu, req);
+
+ return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0);
+}
+
/*
* These commands are executed from the vCPU thread. The receiving thread
* passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
@@ -523,6 +535,7 @@ static int handle_get_cpuid(const struct kvmi_vcpu_cmd_job *job,
static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
const struct kvmi_msg_hdr *, const void *) = {
[KVMI_EVENT] = handle_event_reply,
+ [KVMI_VCPU_CONTROL_CR] = handle_vcpu_control_cr,
[KVMI_VCPU_CONTROL_EVENTS] = handle_vcpu_control_events,
[KVMI_VCPU_GET_CPUID] = handle_get_cpuid,
[KVMI_VCPU_GET_INFO] = handle_get_vcpu_info,
@@ -784,9 +797,9 @@ static void kvmi_setup_vcpu_reply(struct kvm_vcpu_introspection *vcpui,
vcpui->waiting_for_reply = true;
}
-static int kvmi_send_event(struct kvm_vcpu *vcpu, u32 ev_id,
- void *ev, size_t ev_size,
- void *rpl, size_t rpl_size, int *action)
+int kvmi_send_event(struct kvm_vcpu *vcpu, u32 ev_id,
+ void *ev, size_t ev_size,
+ void *rpl, size_t rpl_size, int *action)
{
struct kvmi_msg_hdr hdr;
struct kvmi_event common;