HVM-538 Implement smp_rmb/smp_wmb in kvm

8 files changed, 18 insertions, 41 deletions

diff --git a/kvm.c b/kvm.c
index ff803ea..eaf655b 100644
--- a/kvm.c
+++ b/kvm.c
@@ -496,11 +496,7 @@ vcpu_load(struct kvm_vcpu *vcpu)
 struct kvm_vcpu *
 kvm_get_vcpu(struct kvm *kvm, int i)
 {
-#ifdef XXX
 	smp_rmb();
-#else
-	XXX_KVM_PROBE;
-#endif
 	return (kvm->vcpus[i]);
 }
 
@@ -1555,11 +1551,8 @@ kvm_vm_ioctl_create_vcpu(struct kvm *kvm, uint32_t id, int *rval_p)
 	/* XXX need to protect online_vcpus */
 	kvm->vcpus[kvm->online_vcpus] = vcpu;
 
-#ifdef XXX
 	smp_wmb();
-#else
-	XXX_KVM_SYNC_PROBE;
-#endif
+
 	atomic_inc_32(&kvm->online_vcpus);
 
 	if (kvm->bsp_vcpu_id == id)
@@ -2438,17 +2431,11 @@ kvm_ioctl(dev_t dev, int cmd, intptr_t arg, int md, cred_t *cr, int *rv)
 			}
 		} else
 			goto create_irqchip_unlock;
-#ifdef XXX
+
 		smp_wmb();
-#else
-		XXX_KVM_SYNC_PROBE;
-#endif
 		kvmp->arch.vpic = vpic;
-#ifdef XXX
 		smp_wmb();
-#else
-		XXX_KVM_SYNC_PROBE;
-#endif
+
 		rval = kvm_setup_default_irq_routing(kvmp);
 		if (rval) {
 			mutex_enter(&kvmp->irq_lock);
diff --git a/kvm_coalesced_mmio.c b/kvm_coalesced_mmio.c
index 7c097e3..d231c2e 100644
--- a/kvm_coalesced_mmio.c
+++ b/kvm_coalesced_mmio.c
@@ -72,11 +72,8 @@ coalesced_mmio_write(struct kvm_io_device *this, gpa_t addr,
 	ring->coalesced_mmio[ring->last].phys_addr = addr;
 	ring->coalesced_mmio[ring->last].len = len;
 	memcpy(ring->coalesced_mmio[ring->last].data, val, len);
-#ifdef XXX
+
 	smp_wmb();
-#else
-	XXX_KVM_SYNC_PROBE;
-#endif
 	ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX;
 	mutex_exit(&dev->lock);
 	return (0);
diff --git a/kvm_ioapic.c b/kvm_ioapic.c
index 05a5323..b8fe29a 100644
--- a/kvm_ioapic.c
+++ b/kvm_ioapic.c
@@ -112,11 +112,8 @@ update_handled_vectors(struct kvm_ioapic *ioapic)
 		__set_bit(ioapic->redirtbl[i].fields.vector, handled_vectors);
 	memcpy(ioapic->handled_vectors, handled_vectors,
 	    sizeof (handled_vectors));
-#ifdef XXX
+
 	smp_wmb();
-#else
-	XXX_KVM_SYNC_PROBE;
-#endif
 }
 
 static void
@@ -265,11 +262,7 @@ kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode)
 {
 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 
-#ifdef XXX
 	smp_rmb();
-#else
-	XXX_KVM_SYNC_PROBE;
-#endif
 
 	if (!test_bit(vector, ioapic->handled_vectors))
 		return;
diff --git a/kvm_irq.c b/kvm_irq.c
index 8772afc..1e8eb8f 100644
--- a/kvm_irq.c
+++ b/kvm_irq.c
@@ -37,11 +37,7 @@ irqchip_in_kernel(struct kvm *kvm)
 	int ret;
 
 	ret = (pic_irqchip(kvm) != NULL);
-#ifdef XXX
 	smp_rmb();
-#else
-	XXX_KVM_SYNC_PROBE;
-#endif
 	return (ret);
 }
 
diff --git a/kvm_mmu.c b/kvm_mmu.c
index 6e97936..6d60ed1 100644
--- a/kvm_mmu.c
+++ b/kvm_mmu.c
@@ -1844,10 +1844,10 @@ nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
 
 #ifdef XXX
 	mmu_seq = vcpu->kvm->mmu_notifier_seq;
-	smp_rmb();
 #else
 	XXX_KVM_PROBE;
 #endif
+	smp_rmb();
 	pfn = gfn_to_pfn(vcpu->kvm, gfn);
 
 	/* mmio */
@@ -2069,11 +2069,10 @@ tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, uint32_t error_code)
 
 #ifdef XXX
 	mmu_seq = vcpu->kvm->mmu_notifier_seq;
-	smp_rmb();
 #else
 	XXX_KVM_PROBE;
 #endif
-
+	smp_rmb();
 	pfn = gfn_to_pfn(vcpu->kvm, gfn);
 	if (is_error_pfn(pfn)) {
 		kvm_release_pfn_clean(pfn);
@@ -2508,10 +2507,10 @@ mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
 
 #ifdef XXX
 	vcpu->arch.update_pte.mmu_seq = vcpu->kvm->mmu_notifier_seq;
-	smp_rmb();
 #else
 	XXX_KVM_PROBE;
 #endif
+	smp_rmb();
 	pfn = gfn_to_pfn(vcpu->kvm, gfn);
 
 	if (is_error_pfn(pfn)) {
diff --git a/kvm_paging_tmpl.h b/kvm_paging_tmpl.h
index 46f26fe..84a1c85 100644
--- a/kvm_paging_tmpl.h
+++ b/kvm_paging_tmpl.h
@@ -471,8 +471,8 @@ FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
 	}
 #ifdef XXX
 	mmu_seq = vcpu->kvm->mmu_notifier_seq;
-	smp_rmb();
 #endif /* XXX */
+	smp_rmb();
 	pfn = gfn_to_pfn(vcpu->kvm, walker.gfn);
 
 	/* mmio */
diff --git a/kvm_x86.c b/kvm_x86.c
index a1ab497..7a661a6 100644
--- a/kvm_x86.c
+++ b/kvm_x86.c
@@ -137,12 +137,9 @@ kvm_define_shared_msr(unsigned slot, uint32_t msr)
 	if (slot >= shared_msrs_global.nr)
 		shared_msrs_global.nr = slot + 1;
 	shared_msrs_global.msrs[slot] = msr;
-#ifdef XXX
+
 	/* we need ensured the shared_msr_global have been updated */
 	smp_wmb();
-#else
-	XXX_KVM_SYNC_PROBE;
-#endif
 }
 
 static void
diff --git a/kvm_x86.h b/kvm_x86.h
index af6a38b..bbe2daf 100644
--- a/kvm_x86.h
+++ b/kvm_x86.h
@@ -274,4 +274,12 @@ typedef struct kvm_vcpu_events {
 	0;				\
 	})
 
+/*
+ * The following should provide an optimization barrier.
+ * If the system does reorder loads and stores, this needs to be changed.
+ */
+
+#define	smp_wmb()   __asm__ __volatile__("" ::: "memory")
+#define	smp_rmb()   __asm__ __volatile__("" ::: "memory")
+
 #endif /* __KVM_X86_H */