[PATCH 1/5] KVM: Move wiping of the kvm->vcpus array to common code
Marc Zyngier
maz at kernel.org
Sat Nov 6 06:20:57 AEDT 2021
All architectures have similar loops iterating over the vcpus,
freeing one vcpu at a time, and eventually wiping the reference
off the vcpus array. They are also inconsistently taking
the kvm->lock mutex when wiping the references from the array.
Make this code common, which will simplify further changes.
Signed-off-by: Marc Zyngier <maz at kernel.org>
---
arch/arm64/kvm/arm.c | 10 +---------
arch/mips/kvm/mips.c | 21 +--------------------
arch/powerpc/kvm/powerpc.c | 10 +---------
arch/riscv/kvm/vm.c | 10 +---------
arch/s390/kvm/kvm-s390.c | 18 +-----------------
arch/x86/kvm/x86.c | 9 +--------
include/linux/kvm_host.h | 2 +-
virt/kvm/kvm_main.c | 20 ++++++++++++++++++--
8 files changed, 25 insertions(+), 75 deletions(-)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index f5490afe1ebf..75bb7215da03 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -175,19 +175,11 @@ vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
*/
void kvm_arch_destroy_vm(struct kvm *kvm)
{
- int i;
-
bitmap_free(kvm->arch.pmu_filter);
kvm_vgic_destroy(kvm);
- for (i = 0; i < KVM_MAX_VCPUS; ++i) {
- if (kvm->vcpus[i]) {
- kvm_vcpu_destroy(kvm->vcpus[i]);
- kvm->vcpus[i] = NULL;
- }
- }
- atomic_set(&kvm->online_vcpus, 0);
+ kvm_destroy_vcpus(kvm);
}
int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 562aa878b266..ceacca74f808 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -171,25 +171,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
return 0;
}
-void kvm_mips_free_vcpus(struct kvm *kvm)
-{
- unsigned int i;
- struct kvm_vcpu *vcpu;
-
- kvm_for_each_vcpu(i, vcpu, kvm) {
- kvm_vcpu_destroy(vcpu);
- }
-
- mutex_lock(&kvm->lock);
-
- for (i = 0; i < atomic_read(&kvm->online_vcpus); i++)
- kvm->vcpus[i] = NULL;
-
- atomic_set(&kvm->online_vcpus, 0);
-
- mutex_unlock(&kvm->lock);
-}
-
static void kvm_mips_free_gpa_pt(struct kvm *kvm)
{
/* It should always be safe to remove after flushing the whole range */
@@ -199,7 +180,7 @@ static void kvm_mips_free_gpa_pt(struct kvm *kvm)
void kvm_arch_destroy_vm(struct kvm *kvm)
{
- kvm_mips_free_vcpus(kvm);
+ kvm_destroy_vcpus(kvm);
kvm_mips_free_gpa_pt(kvm);
}
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 35e9cccdeef9..492e4a4121cb 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -463,9 +463,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
void kvm_arch_destroy_vm(struct kvm *kvm)
{
- unsigned int i;
- struct kvm_vcpu *vcpu;
-
#ifdef CONFIG_KVM_XICS
/*
* We call kick_all_cpus_sync() to ensure that all
@@ -476,14 +473,9 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
kick_all_cpus_sync();
#endif
- kvm_for_each_vcpu(i, vcpu, kvm)
- kvm_vcpu_destroy(vcpu);
+ kvm_destroy_vcpus(kvm);
mutex_lock(&kvm->lock);
- for (i = 0; i < atomic_read(&kvm->online_vcpus); i++)
- kvm->vcpus[i] = NULL;
-
- atomic_set(&kvm->online_vcpus, 0);
kvmppc_core_destroy_vm(kvm);
diff --git a/arch/riscv/kvm/vm.c b/arch/riscv/kvm/vm.c
index 26399df15b63..6af6cde295eb 100644
--- a/arch/riscv/kvm/vm.c
+++ b/arch/riscv/kvm/vm.c
@@ -46,15 +46,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
void kvm_arch_destroy_vm(struct kvm *kvm)
{
- int i;
-
- for (i = 0; i < KVM_MAX_VCPUS; ++i) {
- if (kvm->vcpus[i]) {
- kvm_vcpu_destroy(kvm->vcpus[i]);
- kvm->vcpus[i] = NULL;
- }
- }
- atomic_set(&kvm->online_vcpus, 0);
+ kvm_destroy_vcpus(kvm);
}
int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index c6257f625929..7af53b8788fa 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2819,27 +2819,11 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
free_page((unsigned long)(vcpu->arch.sie_block));
}
-static void kvm_free_vcpus(struct kvm *kvm)
-{
- unsigned int i;
- struct kvm_vcpu *vcpu;
-
- kvm_for_each_vcpu(i, vcpu, kvm)
- kvm_vcpu_destroy(vcpu);
-
- mutex_lock(&kvm->lock);
- for (i = 0; i < atomic_read(&kvm->online_vcpus); i++)
- kvm->vcpus[i] = NULL;
-
- atomic_set(&kvm->online_vcpus, 0);
- mutex_unlock(&kvm->lock);
-}
-
void kvm_arch_destroy_vm(struct kvm *kvm)
{
u16 rc, rrc;
- kvm_free_vcpus(kvm);
+ kvm_destroy_vcpus(kvm);
sca_dispose(kvm);
kvm_s390_gisa_destroy(kvm);
/*
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c1c4e2b05a63..498a43126615 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11302,15 +11302,8 @@ static void kvm_free_vcpus(struct kvm *kvm)
kvm_clear_async_pf_completion_queue(vcpu);
kvm_unload_vcpu_mmu(vcpu);
}
- kvm_for_each_vcpu(i, vcpu, kvm)
- kvm_vcpu_destroy(vcpu);
-
- mutex_lock(&kvm->lock);
- for (i = 0; i < atomic_read(&kvm->online_vcpus); i++)
- kvm->vcpus[i] = NULL;
- atomic_set(&kvm->online_vcpus, 0);
- mutex_unlock(&kvm->lock);
+ kvm_destroy_vcpus(kvm);
}
void kvm_arch_sync_events(struct kvm *kvm)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 60a35d9fe259..36967291b8c6 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -725,7 +725,7 @@ static inline struct kvm_vcpu *kvm_get_vcpu_by_id(struct kvm *kvm, int id)
if (WARN_ON_ONCE(!memslot->npages)) { \
} else
-void kvm_vcpu_destroy(struct kvm_vcpu *vcpu);
+void kvm_destroy_vcpus(struct kvm *kvm);
void vcpu_load(struct kvm_vcpu *vcpu);
void vcpu_put(struct kvm_vcpu *vcpu);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 3f6d450355f0..d83553eeea21 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -435,7 +435,7 @@ static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
vcpu->last_used_slot = 0;
}
-void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
+static void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
{
kvm_dirty_ring_free(&vcpu->dirty_ring);
kvm_arch_vcpu_destroy(vcpu);
@@ -450,7 +450,23 @@ void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
free_page((unsigned long)vcpu->run);
kmem_cache_free(kvm_vcpu_cache, vcpu);
}
-EXPORT_SYMBOL_GPL(kvm_vcpu_destroy);
+
+void kvm_destroy_vcpus(struct kvm *kvm)
+{
+ unsigned int i;
+ struct kvm_vcpu *vcpu;
+
+ kvm_for_each_vcpu(i, vcpu, kvm)
+ kvm_vcpu_destroy(vcpu);
+
+ mutex_lock(&kvm->lock);
+ for (i = 0; i < atomic_read(&kvm->online_vcpus); i++)
+ kvm->vcpus[i] = NULL;
+
+ atomic_set(&kvm->online_vcpus, 0);
+ mutex_unlock(&kvm->lock);
+}
+EXPORT_SYMBOL_GPL(kvm_destroy_vcpus);
#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
--
2.30.2
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