Patch-mainline: v5.17-rc1
Git-commit: 27592ae8dbe41033261b6fdf27d78998aabd2665
References: git-fixes
From: Marc Zyngier <maz@kernel.org>
Date: Tue, 16 Nov 2021 16:03:57 +0000
Subject: [PATCH] KVM: Move wiping of the kvm->vcpus array to common code
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.
The locking is dropped altogether, as this should only be called
when there is no further references on the kvm structure.
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Message-Id: <20211116160403.4074052-2-maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
---
arch/arm64/kvm/arm.c | 10 +---------
arch/mips/kvm/mips.c | 21 +--------------------
arch/powerpc/kvm/powerpc.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 | 17 +++++++++++++++--
8 files changed, 22 insertions(+), 75 deletions(-)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index e4727dc771bf..362b10cb992c 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 aa20d074d388..6aa5e3771d05 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 a72920f4f221..98f5d90ebf5a 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/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 14a18ba5ff2c..6eeb59af5d74 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2821,27 +2821,11 @@ 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 e0aa4dd53c7f..0e6d11a726cd 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11423,15 +11423,8 @@ 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 c310648cc8f1..e2f9f8f67c58 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -733,6 +733,7 @@ static inline struct kvm_vcpu *kvm_get_vcpu_by_id(struct kvm *kvm, int id)
} 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 72c4e6b39389..0a504c7988dc 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -450,6 +450,20 @@ void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
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);
+ kvm->vcpus[i] = NULL;
+ }
+
+ atomic_set(&kvm->online_vcpus, 0);
+}
+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)
--
2.35.3