From: Mihai Donțu <mdontu@xxxxxxxxxxxxxxx>
The introspection requests (KVM_REQ_INTROSPECTION) are checked before
entering guest or when the vCPU is halted.
Signed-off-by: Mihai Donțu <mdontu@xxxxxxxxxxxxxxx>
Co-developed-by: Mircea Cîrjaliu <mcirjaliu@xxxxxxxxxxxxxxx>
Signed-off-by: Mircea Cîrjaliu <mcirjaliu@xxxxxxxxxxxxxxx>
Co-developed-by: Adalbert Lazăr <alazar@xxxxxxxxxxxxxxx>
Signed-off-by: Adalbert Lazăr <alazar@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/x86.c | 3 ++
include/linux/kvm_host.h | 2 +
include/linux/kvmi_host.h | 4 ++
virt/kvm/introspection/kvmi.c | 72 +++++++++++++++++++++++++++++++++
virt/kvm/kvm_main.c | 2 +
6 files changed, 84 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 378a094ceb5b..9cf45ca73af5 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -78,6 +78,7 @@
#define KVM_REQ_HV_STIMER KVM_ARCH_REQ(22)
#define KVM_REQ_LOAD_EOI_EXITMAP KVM_ARCH_REQ(23)
#define KVM_REQ_GET_VMCS12_PAGES KVM_ARCH_REQ(24)
+#define KVM_REQ_INTROSPECTION KVM_ARCH_REQ(25)
#define CR0_RESERVED_BITS \
(~(unsigned long)(X86_CR0_PE | X86_CR0_MP | X86_CR0_EM | X86_CR0_TS \
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 46aeb32cb07f..46a135595893 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8391,6 +8391,9 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
vcpu->arch.l1tf_flush_l1d = true;
for (;;) {
+ if (kvm_check_request(KVM_REQ_INTROSPECTION, vcpu))
+ kvmi_handle_requests(vcpu);
+
if (kvm_vcpu_running(vcpu)) {
r = vcpu_enter_guest(vcpu);
} else {
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 52e98720d0f6..d2d9b814093e 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -505,6 +505,8 @@ struct kvm {
struct srcu_struct irq_srcu;
pid_t userspace_pid;
struct mutex kvmi_lock;
+ refcount_t kvmi_ref;
+ struct completion kvmi_complete;
struct kvm_introspection *kvmi;
};
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index 1d80d233fbd5..6a0fb481b192 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -56,6 +56,8 @@ int kvmi_ioctl_command(struct kvm *kvm, void __user *argp);
int kvmi_ioctl_event(struct kvm *kvm, void __user *argp);
int kvmi_ioctl_preunhook(struct kvm *kvm);
+void kvmi_handle_requests(struct kvm_vcpu *vcpu);
+
#else
static inline int kvmi_init(void) { return 0; }
@@ -64,6 +66,8 @@ static inline void kvmi_create_vm(struct kvm *kvm) { }
static inline void kvmi_destroy_vm(struct kvm *kvm) { }
static inline void kvmi_vcpu_uninit(struct kvm_vcpu *vcpu) { }
+static inline void kvmi_handle_requests(struct kvm_vcpu *vcpu) { }
+
#endif /* CONFIG_KVM_INTROSPECTION */
#endif
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 5149f8e06131..ea86512ca81e 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -65,6 +65,12 @@ void kvmi_uninit(void)
kvmi_cache_destroy();
}
+static void kvmi_make_request(struct kvm_vcpu *vcpu)
+{
+ kvm_make_request(KVM_REQ_INTROSPECTION, vcpu);
+ kvm_vcpu_kick(vcpu);
+}
+
static int __kvmi_add_job(struct kvm_vcpu *vcpu,
void (*fct)(struct kvm_vcpu *vcpu, void *ctx),
void *ctx, void (*free_fct)(void *ctx))
@@ -96,6 +102,9 @@ int kvmi_add_job(struct kvm_vcpu *vcpu,
err = __kvmi_add_job(vcpu, fct, ctx, free_fct);
+ if (!err)
+ kvmi_make_request(vcpu);
+
return err;
}
@@ -217,6 +226,7 @@ static void __kvmi_unhook(struct kvm *kvm)
{
struct kvm_introspection *kvmi = KVMI(kvm);
+ wait_for_completion_killable(&kvm->kvmi_complete);
kvmi_sock_put(kvmi);
}
@@ -242,8 +252,23 @@ int kvmi_ioctl_unhook(struct kvm *kvm)
return 0;
}
+struct kvm_introspection * __must_check kvmi_get(struct kvm *kvm)
+{
+ if (refcount_inc_not_zero(&kvm->kvmi_ref))
+ return kvm->kvmi;
+
+ return NULL;
+}
+
+void kvmi_put(struct kvm *kvm)
+{
+ if (refcount_dec_and_test(&kvm->kvmi_ref))
+ complete(&kvm->kvmi_complete);
+}
+
static int __kvmi_hook(struct kvm *kvm,
const struct kvm_introspection_hook *hook)
+
{
struct kvm_introspection *kvmi = KVMI(kvm);
@@ -266,6 +291,7 @@ static int kvmi_recv_thread(void *arg)
*/
kvmi_sock_shutdown(kvmi);
+ kvmi_put(kvmi->kvm);
return 0;
}
@@ -293,9 +319,18 @@ int kvmi_hook(struct kvm *kvm, const struct kvm_introspection_hook *hook)
if (err)
goto destroy;
+ init_completion(&kvm->kvmi_complete);
+
+ refcount_set(&kvm->kvmi_ref, 1);
+ /*
+ * Paired with refcount_inc_not_zero() from kvmi_get().
+ */
+ smp_wmb();
+
kvmi->recv = kthread_run(kvmi_recv_thread, kvmi, "kvmi-recv");
if (IS_ERR(kvmi->recv)) {
err = -ENOMEM;
+ kvmi_put(kvm);
goto unhook;
}
@@ -616,3 +651,40 @@ int kvmi_cmd_write_physical(struct kvm *kvm, u64 gpa, u64 size, const void *buf)
return 0;
}
+
+static struct kvmi_job *kvmi_pull_job(struct kvm_vcpu_introspection *vcpui)
+{
+ struct kvmi_job *job = NULL;
+
+ spin_lock(&vcpui->job_lock);
+ job = list_first_entry_or_null(&vcpui->job_list, typeof(*job), link);
+ if (job)
+ list_del(&job->link);
+ spin_unlock(&vcpui->job_lock);
+
+ return job;
+}
+
+void kvmi_run_jobs(struct kvm_vcpu *vcpu)
+{
+ struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+ struct kvmi_job *job;
+
+ while ((job = kvmi_pull_job(vcpui))) {
+ job->fct(vcpu, job->ctx);
+ kvmi_free_job(job);
+ }
+}
+
+void kvmi_handle_requests(struct kvm_vcpu *vcpu)
+{
+ struct kvm_introspection *kvmi;
+
+ kvmi = kvmi_get(vcpu->kvm);
+ if (!kvmi)
+ return;
+
+ kvmi_run_jobs(vcpu);
+
+ kvmi_put(vcpu->kvm);
+}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index ef7d14ef8e86..b701254f1125 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2414,6 +2414,8 @@ static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu)
goto out;
if (signal_pending(current))
goto out;
+ if (kvm_test_request(KVM_REQ_INTROSPECTION, vcpu))
+ goto out;
ret = 0;
out:
