KVM: MIPS: rework flush_shadow_* callbacks into one that prepares the flush

Both trap-and-emulate and VZ have a single implementation that covers
both .flush_shadow_all and .flush_shadow_memslot, and both of them end
with a call to kvm_flush_remote_tlbs.

Unify the callbacks into one and extract the call to kvm_flush_remote_tlbs.
The next patches will pull it further out of the the architecture-specific
MMU notifier functions kvm_unmap_hva_range and kvm_set_spte_hva.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/mips/include/asm/kvm_host.h

@@ -815,14 +815,7 @@ struct kvm_mips_callbacks {
 	int (*vcpu_init)(struct kvm_vcpu *vcpu);
 	void (*vcpu_uninit)(struct kvm_vcpu *vcpu);
 	int (*vcpu_setup)(struct kvm_vcpu *vcpu);
-	void (*flush_shadow_all)(struct kvm *kvm);
-	/*
-	 * Must take care of flushing any cached GPA PTEs (e.g. guest entries in
-	 * VZ root TLB, or T&E GVA page tables and corresponding root TLB
-	 * mappings).
-	 */
-	void (*flush_shadow_memslot)(struct kvm *kvm,
-				     const struct kvm_memory_slot *slot);
+	void (*prepare_flush_shadow)(struct kvm *kvm);
 	gpa_t (*gva_to_gpa)(gva_t gva);
 	void (*queue_timer_int)(struct kvm_vcpu *vcpu);
 	void (*dequeue_timer_int)(struct kvm_vcpu *vcpu);

arch/mips/kvm/mips.c

@@ -206,7 +206,8 @@ void kvm_arch_flush_shadow_all(struct kvm *kvm)
 	kvm_mips_flush_gpa_pt(kvm, 0, ~0);
 
 	/* Let implementation do the rest */
-	kvm_mips_callbacks->flush_shadow_all(kvm);
+	kvm_mips_callbacks->prepare_flush_shadow(kvm);
+	kvm_flush_remote_tlbs(kvm);
 }
 
 void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
@@ -221,8 +222,7 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
 	/* Flush slot from GPA */
 	kvm_mips_flush_gpa_pt(kvm, slot->base_gfn,
 			      slot->base_gfn + slot->npages - 1);
-	/* Let implementation do the rest */
-	kvm_mips_callbacks->flush_shadow_memslot(kvm, slot);
+	kvm_arch_flush_remote_tlbs_memslot(kvm, slot);
 	spin_unlock(&kvm->mmu_lock);
 }
 
@@ -262,9 +262,8 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
 		/* Write protect GPA page table entries */
 		needs_flush = kvm_mips_mkclean_gpa_pt(kvm, new->base_gfn,
 					new->base_gfn + new->npages - 1);
-		/* Let implementation do the rest */
 		if (needs_flush)
-			kvm_mips_callbacks->flush_shadow_memslot(kvm, new);
+			kvm_arch_flush_remote_tlbs_memslot(kvm, new);
 		spin_unlock(&kvm->mmu_lock);
 	}
 }
@@ -1000,7 +999,8 @@ void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
 					const struct kvm_memory_slot *memslot)
 {
 	/* Let implementation handle TLB/GVA invalidation */
-	kvm_mips_callbacks->flush_shadow_memslot(kvm, memslot);
+	kvm_mips_callbacks->prepare_flush_shadow(kvm);
+	kvm_flush_remote_tlbs(kvm);
 }
 
 long kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)

arch/mips/kvm/mmu.c

@@ -491,7 +491,8 @@ int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end,
 {
 	handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL);
 
-	kvm_mips_callbacks->flush_shadow_all(kvm);
+	kvm_mips_callbacks->prepare_flush_shadow(kvm);
+	kvm_flush_remote_tlbs(kvm);
 	return 0;
 }
 
@@ -532,8 +533,10 @@ int kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
 	int ret;
 
 	ret = handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &pte);
-	if (ret)
-		kvm_mips_callbacks->flush_shadow_all(kvm);
+	if (ret) {
+		kvm_mips_callbacks->prepare_flush_shadow(kvm);
+		kvm_flush_remote_tlbs(kvm);
+	}
 	return 0;
 }
 

arch/mips/kvm/trap_emul.c

@@ -687,16 +687,8 @@ static int kvm_trap_emul_vcpu_setup(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
-static void kvm_trap_emul_flush_shadow_all(struct kvm *kvm)
+static void kvm_trap_emul_prepare_flush_shadow(struct kvm *kvm)
 {
-	/* Flush GVA page tables and invalidate GVA ASIDs on all VCPUs */
-	kvm_flush_remote_tlbs(kvm);
-}
-
-static void kvm_trap_emul_flush_shadow_memslot(struct kvm *kvm,
-					const struct kvm_memory_slot *slot)
-{
-	kvm_trap_emul_flush_shadow_all(kvm);
 }
 
 static u64 kvm_trap_emul_get_one_regs[] = {
@@ -1280,8 +1272,7 @@ static struct kvm_mips_callbacks kvm_trap_emul_callbacks = {
 	.vcpu_init = kvm_trap_emul_vcpu_init,
 	.vcpu_uninit = kvm_trap_emul_vcpu_uninit,
 	.vcpu_setup = kvm_trap_emul_vcpu_setup,
-	.flush_shadow_all = kvm_trap_emul_flush_shadow_all,
-	.flush_shadow_memslot = kvm_trap_emul_flush_shadow_memslot,
+	.prepare_flush_shadow = kvm_trap_emul_prepare_flush_shadow,
 	.gva_to_gpa = kvm_trap_emul_gva_to_gpa_cb,
 	.queue_timer_int = kvm_mips_queue_timer_int_cb,
 	.dequeue_timer_int = kvm_mips_dequeue_timer_int_cb,

arch/mips/kvm/vz.c

@@ -3211,32 +3211,22 @@ static int kvm_vz_vcpu_setup(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
-static void kvm_vz_flush_shadow_all(struct kvm *kvm)
+static void kvm_vz_prepare_flush_shadow(struct kvm *kvm)
 {
-	if (cpu_has_guestid) {
-		/* Flush GuestID for each VCPU individually */
-		kvm_flush_remote_tlbs(kvm);
-	} else {
+	if (!cpu_has_guestid) {
 		/*
 		 * For each CPU there is a single GPA ASID used by all VCPUs in
 		 * the VM, so it doesn't make sense for the VCPUs to handle
 		 * invalidation of these ASIDs individually.
 		 *
 		 * Instead mark all CPUs as needing ASID invalidation in
-		 * asid_flush_mask, and just use kvm_flush_remote_tlbs(kvm) to
+		 * asid_flush_mask, and kvm_flush_remote_tlbs(kvm) will
 		 * kick any running VCPUs so they check asid_flush_mask.
 		 */
 		cpumask_setall(&kvm->arch.asid_flush_mask);
-		kvm_flush_remote_tlbs(kvm);
 	}
 }
 
-static void kvm_vz_flush_shadow_memslot(struct kvm *kvm,
-					const struct kvm_memory_slot *slot)
-{
-	kvm_vz_flush_shadow_all(kvm);
-}
-
 static void kvm_vz_vcpu_reenter(struct kvm_vcpu *vcpu)
 {
 	int cpu = smp_processor_id();
@@ -3292,8 +3282,7 @@ static struct kvm_mips_callbacks kvm_vz_callbacks = {
 	.vcpu_init = kvm_vz_vcpu_init,
 	.vcpu_uninit = kvm_vz_vcpu_uninit,
 	.vcpu_setup = kvm_vz_vcpu_setup,
-	.flush_shadow_all = kvm_vz_flush_shadow_all,
-	.flush_shadow_memslot = kvm_vz_flush_shadow_memslot,
+	.prepare_flush_shadow = kvm_vz_prepare_flush_shadow,
 	.gva_to_gpa = kvm_vz_gva_to_gpa_cb,
 	.queue_timer_int = kvm_vz_queue_timer_int_cb,
 	.dequeue_timer_int = kvm_vz_dequeue_timer_int_cb,