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

Marc Zyngier
2019-06-21T09:40:25Z

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