[PATCH 4.14 1/3] KVM: Add infrastructure and macro to mark VM as bugged

[Stefan Ghinea <stefan.ghinea@xxxxxxxxxxxxx>]

From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>

commit 0b8f11737cffc1a406d1134b58687abc29d76b52 upstream

Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Message-Id: <3a0998645c328bf0895f1290e61821b70f048549.1625186503.git.isaku.yamahata@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
[SG: Adjusted context for kernel version 4.14]
Signed-off-by: Stefan Ghinea <stefan.ghinea@xxxxxxxxxxxxx>
---
 include/linux/kvm_host.h | 28 +++++++++++++++++++++++++++-
 virt/kvm/kvm_main.c      | 10 +++++-----
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d5e38ebcfa47..2c6a321899e8 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -127,6 +127,7 @@ static inline bool is_error_page(struct page *page)
 #define KVM_REQ_MMU_RELOAD        (1 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
 #define KVM_REQ_PENDING_TIMER     2
 #define KVM_REQ_UNHALT            3
+#define KVM_REQ_VM_BUGGED         (4 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
 #define KVM_REQUEST_ARCH_BASE     8
 
 #define KVM_ARCH_REQ_FLAGS(nr, flags) ({ \
@@ -446,6 +447,7 @@ struct kvm {
 	struct kvm_stat_data **debugfs_stat_data;
 	struct srcu_struct srcu;
 	struct srcu_struct irq_srcu;
+	bool vm_bugged;
 	pid_t userspace_pid;
 };
 
@@ -475,6 +477,31 @@ struct kvm {
 #define vcpu_err(vcpu, fmt, ...)					\
 	kvm_err("vcpu%i " fmt, (vcpu)->vcpu_id, ## __VA_ARGS__)
 
+bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req);
+static inline void kvm_vm_bugged(struct kvm *kvm)
+{
+	kvm->vm_bugged = true;
+	kvm_make_all_cpus_request(kvm, KVM_REQ_VM_BUGGED);
+}
+
+#define KVM_BUG(cond, kvm, fmt...)				\
+({								\
+	int __ret = (cond);					\
+								\
+	if (WARN_ONCE(__ret && !(kvm)->vm_bugged, fmt))		\
+		kvm_vm_bugged(kvm);				\
+	unlikely(__ret);					\
+})
+
+#define KVM_BUG_ON(cond, kvm)					\
+({								\
+	int __ret = (cond);					\
+								\
+	if (WARN_ON_ONCE(__ret && !(kvm)->vm_bugged))		\
+		kvm_vm_bugged(kvm);				\
+	unlikely(__ret);					\
+})
+
 static inline struct kvm_io_bus *kvm_get_bus(struct kvm *kvm, enum kvm_bus idx)
 {
 	return srcu_dereference_check(kvm->buses[idx], &kvm->srcu,
@@ -732,7 +759,6 @@ void kvm_put_guest_fpu(struct kvm_vcpu *vcpu);
 
 void kvm_flush_remote_tlbs(struct kvm *kvm);
 void kvm_reload_remote_mmus(struct kvm *kvm);
-bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req);
 
 long kvm_arch_dev_ioctl(struct file *filp,
 			unsigned int ioctl, unsigned long arg);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 87d522eefbb4..7c4de635f00a 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2660,7 +2660,7 @@ static long kvm_vcpu_ioctl(struct file *filp,
 	struct kvm_fpu *fpu = NULL;
 	struct kvm_sregs *kvm_sregs = NULL;
 
-	if (vcpu->kvm->mm != current->mm)
+	if (vcpu->kvm->mm != current->mm || vcpu->kvm->vm_bugged)
 		return -EIO;
 
 	if (unlikely(_IOC_TYPE(ioctl) != KVMIO))
@@ -2864,7 +2864,7 @@ static long kvm_vcpu_compat_ioctl(struct file *filp,
 	void __user *argp = compat_ptr(arg);
 	int r;
 
-	if (vcpu->kvm->mm != current->mm)
+	if (vcpu->kvm->mm != current->mm || vcpu->kvm->vm_bugged)
 		return -EIO;
 
 	switch (ioctl) {
@@ -2922,7 +2922,7 @@ static long kvm_device_ioctl(struct file *filp, unsigned int ioctl,
 {
 	struct kvm_device *dev = filp->private_data;
 
-	if (dev->kvm->mm != current->mm)
+	if (dev->kvm->mm != current->mm || dev->kvm->vm_bugged)
 		return -EIO;
 
 	switch (ioctl) {
@@ -3087,7 +3087,7 @@ static long kvm_vm_ioctl(struct file *filp,
 	void __user *argp = (void __user *)arg;
 	int r;
 
-	if (kvm->mm != current->mm)
+	if (kvm->mm != current->mm || kvm->vm_bugged)
 		return -EIO;
 	switch (ioctl) {
 	case KVM_CREATE_VCPU:
@@ -3264,7 +3264,7 @@ static long kvm_vm_compat_ioctl(struct file *filp,
 	struct kvm *kvm = filp->private_data;
 	int r;
 
-	if (kvm->mm != current->mm)
+	if (kvm->mm != current->mm || kvm->vm_bugged)
 		return -EIO;
 	switch (ioctl) {
 	case KVM_GET_DIRTY_LOG: {
-- 
2.37.1