[PATCH 39/59] KVM: arm64: nv: Move last_vcpu_ran to be per s2 mmu

[Marc Zyngier <marc.zyngier@arm.com>]

last_vcpu_ran has to be per s2 mmu now that we can have multiple S2
per VM. Let's take this opportunity to perform some cleanup.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm/include/asm/kvm_host.h   |  6 +++---
 arch/arm/include/asm/kvm_mmu.h    |  2 +-
 arch/arm64/include/asm/kvm_host.h |  6 +++---
 arch/arm64/include/asm/kvm_mmu.h  |  2 +-
 arch/arm64/kvm/nested.c           | 13 ++++++-------
 virt/kvm/arm/arm.c                | 22 ++++------------------
 virt/kvm/arm/mmu.c                | 26 ++++++++++++++++++++------
 7 files changed, 38 insertions(+), 39 deletions(-)

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index b821eb2383ad..cc761610e41e 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -63,15 +63,15 @@ struct kvm_s2_mmu {
 	pgd_t *pgd;
 	phys_addr_t pgd_phys;
 
+	/* The last vcpu id that ran on each physical CPU */
+	int __percpu *last_vcpu_ran;
+
 	struct kvm *kvm;
 };
 
 struct kvm_arch {
 	struct kvm_s2_mmu mmu;
 
-	/* The last vcpu id that ran on each physical CPU */
-	int __percpu *last_vcpu_ran;
-
 	/* Stage-2 page table */
 	pgd_t *pgd;
 	phys_addr_t pgd_phys;
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index afabf1fd1d17..7a6e9008ed45 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -52,7 +52,7 @@ int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size,
 void free_hyp_pgds(void);
 
 void stage2_unmap_vm(struct kvm *kvm);
-int kvm_alloc_stage2_pgd(struct kvm_s2_mmu *mmu);
+int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu);
 void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu);
 int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
 			  phys_addr_t pa, unsigned long size, bool writable);
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index cc238de170d2..b71a7a237f95 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -104,6 +104,9 @@ struct kvm_s2_mmu {
 	 * >0: Somebody is actively using this.
 	 */
 	atomic_t refcnt;
+
+	/* The last vcpu id that ran on each physical CPU */
+	int __percpu *last_vcpu_ran;
 };
 
 static inline bool kvm_s2_mmu_valid(struct kvm_s2_mmu *mmu)
@@ -124,9 +127,6 @@ struct kvm_arch {
 	/* VTCR_EL2 value for this VM */
 	u64    vtcr;
 
-	/* The last vcpu id that ran on each physical CPU */
-	int __percpu *last_vcpu_ran;
-
 	/* The maximum number of vCPUs depends on the used GIC model */
 	int max_vcpus;
 
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index f4c5ac5eb95f..53103607065a 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -169,7 +169,7 @@ void free_hyp_pgds(void);
 
 void kvm_unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size);
 void stage2_unmap_vm(struct kvm *kvm);
-int kvm_alloc_stage2_pgd(struct kvm_s2_mmu *mmu);
+int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu);
 void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu);
 int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
 			  phys_addr_t pa, unsigned long size, bool writable);
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 8880033fb6e0..09afafbdc8fe 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -52,18 +52,17 @@ int kvm_vcpu_init_nested(struct kvm_vcpu *vcpu)
 			 GFP_KERNEL | __GFP_ZERO);
 
 	if (tmp) {
-		if (tmp != kvm->arch.nested_mmus)
+		if (tmp != kvm->arch.nested_mmus) {
 			kfree(kvm->arch.nested_mmus);
+			kvm->arch.nested_mmus = NULL;
+			kvm->arch.nested_mmus_size = 0;
+		}
 
-		tmp[num_mmus - 1].kvm = kvm;
-		atomic_set(&tmp[num_mmus - 1].refcnt, 0);
-		ret = kvm_alloc_stage2_pgd(&tmp[num_mmus - 1]);
+		ret = kvm_init_stage2_mmu(kvm, &tmp[num_mmus - 1]);
 		if (ret)
 			goto out;
 
-		tmp[num_mmus - 2].kvm = kvm;
-		atomic_set(&tmp[num_mmus - 2].refcnt, 0);
-		ret = kvm_alloc_stage2_pgd(&tmp[num_mmus - 2]);
+		ret = kvm_init_stage2_mmu(kvm, &tmp[num_mmus - 2]);
 		if (ret) {
 			kvm_free_stage2_pgd(&tmp[num_mmus - 1]);
 			goto out;
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index bcca27d5c481..e8b584b79847 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -99,29 +99,21 @@ void kvm_arch_check_processor_compat(void *rtn)
 	*(int *)rtn = 0;
 }
 
-
 /**
  * kvm_arch_init_vm - initializes a VM data structure
  * @kvm:	pointer to the KVM struct
  */
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 {
-	int ret, cpu;
+	int ret;
 
 	ret = kvm_arm_setup_stage2(kvm, type);
 	if (ret)
 		return ret;
 
-	kvm->arch.last_vcpu_ran = alloc_percpu(typeof(*kvm->arch.last_vcpu_ran));
-	if (!kvm->arch.last_vcpu_ran)
-		return -ENOMEM;
-
-	for_each_possible_cpu(cpu)
-		*per_cpu_ptr(kvm->arch.last_vcpu_ran, cpu) = -1;
-
-	ret = kvm_alloc_stage2_pgd(&kvm->arch.mmu);
+	ret = kvm_init_stage2_mmu(kvm, &kvm->arch.mmu);
 	if (ret)
-		goto out_fail_alloc;
+		return ret;
 
 	/* Mark the initial VMID generation invalid */
 	kvm->arch.mmu.vmid.vmid_gen = 0;
@@ -142,9 +134,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 	return ret;
 out_free_stage2_pgd:
 	kvm_free_stage2_pgd(&kvm->arch.mmu);
-out_fail_alloc:
-	free_percpu(kvm->arch.last_vcpu_ran);
-	kvm->arch.last_vcpu_ran = NULL;
 	return ret;
 }
 
@@ -174,9 +163,6 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 
 	kvm_vgic_destroy(kvm);
 
-	free_percpu(kvm->arch.last_vcpu_ran);
-	kvm->arch.last_vcpu_ran = NULL;
-
 	for (i = 0; i < KVM_MAX_VCPUS; ++i) {
 		if (kvm->vcpus[i]) {
 			kvm_arch_vcpu_free(kvm->vcpus[i]);
@@ -359,7 +345,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	if (nested_virt_in_use(vcpu))
 		kvm_vcpu_load_hw_mmu(vcpu);
 
-	last_ran = this_cpu_ptr(vcpu->kvm->arch.last_vcpu_ran);
+	last_ran = this_cpu_ptr(vcpu->arch.hw_mmu->last_vcpu_ran);
 	cpu_data = this_cpu_ptr(&kvm_host_data);
 
 	/*
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 94d400e7af57..6a7cba077bce 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -903,8 +903,9 @@ int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size,
 }
 
 /**
- * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
- * @mmu:	The stage 2 mmu struct pointer
+ * kvm_init_stage2_mmu - Initialise a S2 MMU strucrure
+ * @kvm:	The pointer to the KVM structure
+ * @mmu:	The pointer to the s2 MMU structure
  *
  * Allocates only the stage-2 HW PGD level table(s) of size defined by
  * stage2_pgd_size(mmu->kvm).
@@ -912,10 +913,11 @@ int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size,
  * Note we don't need locking here as this is only called when the VM is
  * created, which can only be done once.
  */
-int kvm_alloc_stage2_pgd(struct kvm_s2_mmu *mmu)
+int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu)
 {
 	phys_addr_t pgd_phys;
 	pgd_t *pgd;
+	int cpu;
 
 	if (mmu->pgd != NULL) {
 		kvm_err("kvm_arch already initialized?\n");
@@ -923,18 +925,28 @@ int kvm_alloc_stage2_pgd(struct kvm_s2_mmu *mmu)
 	}
 
 	/* Allocate the HW PGD, making sure that each page gets its own refcount */
-	pgd = alloc_pages_exact(stage2_pgd_size(mmu->kvm), GFP_KERNEL | __GFP_ZERO);
+	pgd = alloc_pages_exact(stage2_pgd_size(kvm), GFP_KERNEL | __GFP_ZERO);
 	if (!pgd)
 		return -ENOMEM;
 
 	pgd_phys = virt_to_phys(pgd);
-	if (WARN_ON(pgd_phys & ~kvm_vttbr_baddr_mask(mmu->kvm)))
+	if (WARN_ON(pgd_phys & ~kvm_vttbr_baddr_mask(kvm)))
 		return -EINVAL;
 
+	mmu->last_vcpu_ran = alloc_percpu(typeof(*mmu->last_vcpu_ran));
+	if (!mmu->last_vcpu_ran) {
+		free_pages_exact(pgd, stage2_pgd_size(kvm));
+		return -ENOMEM;
+	}
+
+	mmu->kvm = kvm;
 	mmu->pgd = pgd;
 	mmu->pgd_phys = pgd_phys;
 	mmu->vmid.vmid_gen = 0;
 
+	for_each_possible_cpu(cpu)
+		*per_cpu_ptr(mmu->last_vcpu_ran, cpu) = -1;
+
 	kvm_init_s2_mmu(mmu);
 
 	return 0;
@@ -1021,8 +1033,10 @@ void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu)
 	spin_unlock(&kvm->mmu_lock);
 
 	/* Free the HW pgd, one page at a time */
-	if (pgd)
+	if (pgd) {
 		free_pages_exact(pgd, stage2_pgd_size(kvm));
+		free_percpu(mmu->last_vcpu_ran);
+	}
 }
 
 static pud_t *stage2_get_pud(struct kvm_s2_mmu *mmu, struct kvm_mmu_memory_cache *cache,
-- 
2.20.1