Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

torvalds · torvalds · commit 8d473320eebf · 2017-10-06T11:28:34.000-07:00
Pull KVM fixes from Radim Krčmář:

 - fix PPC XIVE interrupt delivery

 - fix x86 RCU breakage from asynchronous page faults when built without
   PREEMPT_COUNT

 - fix x86 build with -frecord-gcc-switches

 - fix x86 build without X86_LOCAL_APIC

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: add X86_LOCAL_APIC dependency
  x86/kvm: Move kvm_fastop_exception to .fixup section
  kvm/x86: Avoid async PF preempting the kernel incorrectly
  KVM: PPC: Book3S: Fix server always zero from kvmppc_xive_get_xive()
diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
@@ -622,7 +622,7 @@ int kvmppc_xive_get_xive(struct kvm *kvm, u32 irq, u32 *server,
 		return -EINVAL;
 	state = &sb->irq_state[idx];
 	arch_spin_lock(&sb->lock);
-	*server = state->guest_server;
+	*server = state->act_server;
 	*priority = state->guest_priority;
 	arch_spin_unlock(&sb->lock);
 
@@ -1331,7 +1331,7 @@ static int xive_get_source(struct kvmppc_xive *xive, long irq, u64 addr)
 	xive->saved_src_count++;
 
 	/* Convert saved state into something compatible with xics */
-	val = state->guest_server;
+	val = state->act_server;
 	prio = state->saved_scan_prio;
 
 	if (prio == MASKED) {
@@ -1507,7 +1507,6 @@ static int xive_set_source(struct kvmppc_xive *xive, long irq, u64 addr)
 	/* First convert prio and mark interrupt as untargetted */
 	act_prio = xive_prio_from_guest(guest_prio);
 	state->act_priority = MASKED;
-	state->guest_server = server;
 
 	/*
 	 * We need to drop the lock due to the mutex below. Hopefully
diff --git a/arch/powerpc/kvm/book3s_xive.h b/arch/powerpc/kvm/book3s_xive.h
@@ -35,7 +35,6 @@ struct kvmppc_xive_irq_state {
 	struct xive_irq_data *pt_data;	/* XIVE Pass-through associated data */
 
 	/* Targetting as set by guest */
-	u32 guest_server;		/* Current guest selected target */
 	u8 guest_priority;		/* Guest set priority */
 	u8 saved_priority;		/* Saved priority when masking */
 
diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
@@ -88,7 +88,7 @@ static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
 bool kvm_para_available(void);
 unsigned int kvm_arch_para_features(void);
 void __init kvm_guest_init(void);
-void kvm_async_pf_task_wait(u32 token);
+void kvm_async_pf_task_wait(u32 token, int interrupt_kernel);
 void kvm_async_pf_task_wake(u32 token);
 u32 kvm_read_and_reset_pf_reason(void);
 extern void kvm_disable_steal_time(void);
@@ -103,7 +103,7 @@ static inline void kvm_spinlock_init(void)
 
 #else /* CONFIG_KVM_GUEST */
 #define kvm_guest_init() do {} while (0)
-#define kvm_async_pf_task_wait(T) do {} while(0)
+#define kvm_async_pf_task_wait(T, I) do {} while(0)
 #define kvm_async_pf_task_wake(T) do {} while(0)
 
 static inline bool kvm_para_available(void)
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
@@ -117,7 +117,11 @@ static struct kvm_task_sleep_node *_find_apf_task(struct kvm_task_sleep_head *b,
 	return NULL;
 }
 
-void kvm_async_pf_task_wait(u32 token)
+/*
+ * @interrupt_kernel: Is this called from a routine which interrupts the kernel
+ * 		      (other than user space)?
+ */
+void kvm_async_pf_task_wait(u32 token, int interrupt_kernel)
 {
 	u32 key = hash_32(token, KVM_TASK_SLEEP_HASHBITS);
 	struct kvm_task_sleep_head *b = &async_pf_sleepers[key];
@@ -140,8 +144,10 @@ void kvm_async_pf_task_wait(u32 token)
 
 	n.token = token;
 	n.cpu = smp_processor_id();
-	n.halted = is_idle_task(current) || preempt_count() > 1 ||
-		   rcu_preempt_depth();
+	n.halted = is_idle_task(current) ||
+		   (IS_ENABLED(CONFIG_PREEMPT_COUNT)
+		    ? preempt_count() > 1 || rcu_preempt_depth()
+		    : interrupt_kernel);
 	init_swait_queue_head(&n.wq);
 	hlist_add_head(&n.link, &b->list);
 	raw_spin_unlock(&b->lock);
@@ -269,7 +275,7 @@ do_async_page_fault(struct pt_regs *regs, unsigned long error_code)
 	case KVM_PV_REASON_PAGE_NOT_PRESENT:
 		/* page is swapped out by the host. */
 		prev_state = exception_enter();
-		kvm_async_pf_task_wait((u32)read_cr2());
+		kvm_async_pf_task_wait((u32)read_cr2(), !user_mode(regs));
 		exception_exit(prev_state);
 		break;
 	case KVM_PV_REASON_PAGE_READY:
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
@@ -23,6 +23,7 @@ config KVM
 	depends on HIGH_RES_TIMERS
 	# for TASKSTATS/TASK_DELAY_ACCT:
 	depends on NET && MULTIUSER
+	depends on X86_LOCAL_APIC
 	select PREEMPT_NOTIFIERS
 	select MMU_NOTIFIER
 	select ANON_INODES
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
@@ -425,8 +425,10 @@ static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *));
 	#op " %al \n\t" \
 	FOP_RET
 
-asm(".global kvm_fastop_exception \n"
-    "kvm_fastop_exception: xor %esi, %esi; ret");
+asm(".pushsection .fixup, \"ax\"\n"
+    ".global kvm_fastop_exception \n"
+    "kvm_fastop_exception: xor %esi, %esi; ret\n"
+    ".popsection");
 
 FOP_START(setcc)
 FOP_SETCC(seto)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
@@ -3837,7 +3837,7 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
 	case KVM_PV_REASON_PAGE_NOT_PRESENT:
 		vcpu->arch.apf.host_apf_reason = 0;
 		local_irq_disable();
-		kvm_async_pf_task_wait(fault_address);
+		kvm_async_pf_task_wait(fault_address, 0);
 		local_irq_enable();
 		break;
 	case KVM_PV_REASON_PAGE_READY:
