Merge branch 'kvm-lapic-fix-and-cleanup' into HEAD

The first half or so patches fix semi-urgent, real-world relevant APICv
and AVIC bugs.

The second half fixes a variety of AVIC and optimized APIC map bugs
where KVM doesn't play nice with various edge cases that are
architecturally legal(ish), but are unlikely to occur in most real world
scenarios

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 39 insertions, 13 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8d0a0a7c34fc..4d2bc08794e4 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1022,19 +1022,30 @@ struct kvm_arch_memory_slot {
 };
 
 /*
- * We use as the mode the number of bits allocated in the LDR for the
- * logical processor ID.  It happens that these are all powers of two.
- * This makes it is very easy to detect cases where the APICs are
- * configured for multiple modes; in that case, we cannot use the map and
- * hence cannot use kvm_irq_delivery_to_apic_fast either.
+ * Track the mode of the optimized logical map, as the rules for decoding the
+ * destination vary per mode.  Enabling the optimized logical map requires all
+ * software-enabled local APIs to be in the same mode, each addressable APIC to
+ * be mapped to only one MDA, and each MDA to map to at most one APIC.
  */
-#define KVM_APIC_MODE_XAPIC_CLUSTER          4
-#define KVM_APIC_MODE_XAPIC_FLAT             8
-#define KVM_APIC_MODE_X2APIC                16
+enum kvm_apic_logical_mode {
+	/* All local APICs are software disabled. */
+	KVM_APIC_MODE_SW_DISABLED,
+	/* All software enabled local APICs in xAPIC cluster addressing mode. */
+	KVM_APIC_MODE_XAPIC_CLUSTER,
+	/* All software enabled local APICs in xAPIC flat addressing mode. */
+	KVM_APIC_MODE_XAPIC_FLAT,
+	/* All software enabled local APICs in x2APIC mode. */
+	KVM_APIC_MODE_X2APIC,
+	/*
+	 * Optimized map disabled, e.g. not all local APICs in the same logical
+	 * mode, same logical ID assigned to multiple APICs, etc.
+	 */
+	KVM_APIC_MODE_MAP_DISABLED,
+};
 
 struct kvm_apic_map {
 	struct rcu_head rcu;
-	u8 mode;
+	enum kvm_apic_logical_mode logical_mode;
 	u32 max_apic_id;
 	union {
 		struct kvm_lapic *xapic_flat_map[8];
@@ -1165,6 +1176,12 @@ enum kvm_apicv_inhibit {
 	APICV_INHIBIT_REASON_BLOCKIRQ,
 
 	/*
+	 * APICv is disabled because not all vCPUs have a 1:1 mapping between
+	 * APIC ID and vCPU, _and_ KVM is not applying its x2APIC hotplug hack.
+	 */
+	APICV_INHIBIT_REASON_PHYSICAL_ID_ALIASED,
+
+	/*
 	 * For simplicity, the APIC acceleration is inhibited
 	 * first time either APIC ID or APIC base are changed by the guest
 	 * from their reset values.
@@ -1202,6 +1219,12 @@ enum kvm_apicv_inhibit {
 	 * AVIC is disabled because SEV doesn't support it.
 	 */
 	APICV_INHIBIT_REASON_SEV,
+
+	/*
+	 * AVIC is disabled because not all vCPUs with a valid LDR have a 1:1
+	 * mapping between logical ID and vCPU.
+	 */
+	APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED,
 };
 
 struct kvm_arch {
@@ -1250,10 +1273,11 @@ struct kvm_arch {
 	struct kvm_apic_map __rcu *apic_map;
 	atomic_t apic_map_dirty;
 
-	/* Protects apic_access_memslot_enabled and apicv_inhibit_reasons */
-	struct rw_semaphore apicv_update_lock;
-
 	bool apic_access_memslot_enabled;
+	bool apic_access_memslot_inhibited;
+
+	/* Protects apicv_inhibit_reasons */
+	struct rw_semaphore apicv_update_lock;
 	unsigned long apicv_inhibit_reasons;
 
 	gpa_t wall_clock;
@@ -1602,6 +1626,8 @@ struct kvm_x86_ops {
 	void (*enable_irq_window)(struct kvm_vcpu *vcpu);
 	void (*update_cr8_intercept)(struct kvm_vcpu *vcpu, int tpr, int irr);
 	bool (*check_apicv_inhibit_reasons)(enum kvm_apicv_inhibit reason);
+	const unsigned long required_apicv_inhibits;
+	bool allow_apicv_in_x2apic_without_x2apic_virtualization;
 	void (*refresh_apicv_exec_ctrl)(struct kvm_vcpu *vcpu);
 	void (*hwapic_irr_update)(struct kvm_vcpu *vcpu, int max_irr);
 	void (*hwapic_isr_update)(int isr);
@@ -1976,7 +2002,7 @@ gpa_t kvm_mmu_gva_to_gpa_system(struct kvm_vcpu *vcpu, gva_t gva,
 
 bool kvm_apicv_activated(struct kvm *kvm);
 bool kvm_vcpu_apicv_activated(struct kvm_vcpu *vcpu);
-void kvm_vcpu_update_apicv(struct kvm_vcpu *vcpu);
+void __kvm_vcpu_update_apicv(struct kvm_vcpu *vcpu);
 void __kvm_set_or_clear_apicv_inhibit(struct kvm *kvm,
 				      enum kvm_apicv_inhibit reason, bool set);
 void kvm_set_or_clear_apicv_inhibit(struct kvm *kvm,