[PATCH kernel] KVM: PPC: Book3S: Merge powerpc's debugfs entry content into generic entry
Alexey Kardashevskiy
aik at ozlabs.ru
Fri Sep 3 15:22:57 AEST 2021
At the moment the generic KVM code creates an "%pid-%fd" entry per a KVM
instance; and the PPC HV KVM creates its own at "vm%pid".
The rproblems with the PPC entries are:
1. they do not allow multiple VMs in the same process (which is extremely
rare case mostly used by syzkaller fuzzer);
2. prone to race bugs like the generic KVM code had fixed in
commit 85cd39af14f4 ("KVM: Do not leak memory for duplicate debugfs
directories").
This defines kvm_arch_create_kvm_debugfs() similar to one for vcpus.
This defines 2 hooks in kvmppc_ops for allowing specific KVM
implementations to add necessary entries.
This makes use of already existing kvm_arch_create_vcpu_debugfs.
This removes no more used debugfs_dir pointers from PPC kvm_arch structs.
Suggested-by: Fabiano Rosas <farosas at linux.ibm.com>
Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
---
arch/powerpc/include/asm/kvm_host.h | 6 +++---
arch/powerpc/include/asm/kvm_ppc.h | 2 ++
include/linux/kvm_host.h | 3 +++
arch/powerpc/kvm/book3s_64_mmu_hv.c | 2 +-
arch/powerpc/kvm/book3s_64_mmu_radix.c | 2 +-
arch/powerpc/kvm/book3s_hv.c | 30 +++++++++-----------------
arch/powerpc/kvm/powerpc.c | 12 +++++++++++
virt/kvm/kvm_main.c | 3 +++
8 files changed, 35 insertions(+), 25 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 2bcac6da0a4b..e4f2feb67b53 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -296,7 +296,6 @@ struct kvm_arch {
bool dawr1_enabled;
pgd_t *pgtable;
u64 process_table;
- struct dentry *debugfs_dir;
struct kvm_resize_hpt *resize_hpt; /* protected by kvm->lock */
#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
@@ -828,8 +827,6 @@ struct kvm_vcpu_arch {
struct kvmhv_tb_accumulator rm_exit; /* real-mode exit code */
struct kvmhv_tb_accumulator guest_time; /* guest execution */
struct kvmhv_tb_accumulator cede_time; /* time napping inside guest */
-
- struct dentry *debugfs_dir;
#endif /* CONFIG_KVM_BOOK3S_HV_EXIT_TIMING */
};
@@ -868,4 +865,7 @@ static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {}
+#define __KVM_HAVE_ARCH_VCPU_DEBUGFS
+#define __KVM_HAVE_ARCH_KVM_DEBUGFS
+
#endif /* __POWERPC_KVM_HOST_H__ */
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 6355a6980ccf..8b3f7f6e3f12 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -316,6 +316,8 @@ struct kvmppc_ops {
int (*svm_off)(struct kvm *kvm);
int (*enable_dawr1)(struct kvm *kvm);
bool (*hash_v3_possible)(void);
+ void (*create_kvm_debugfs)(struct kvm *kvm);
+ void (*create_vcpu_debugfs)(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry);
};
extern struct kvmppc_ops *kvmppc_hv_ops;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ae7735b490b4..74d2c1c3df1b 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1021,6 +1021,9 @@ int kvm_arch_pm_notifier(struct kvm *kvm, unsigned long state);
#ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry);
#endif
+#ifdef __KVM_HAVE_ARCH_KVM_DEBUGFS
+void kvm_arch_create_kvm_debugfs(struct kvm *kvm);
+#endif
int kvm_arch_hardware_enable(void);
void kvm_arch_hardware_disable(void);
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index c63e263312a4..33dae253a0ac 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -2112,7 +2112,7 @@ static const struct file_operations debugfs_htab_fops = {
void kvmppc_mmu_debugfs_init(struct kvm *kvm)
{
- debugfs_create_file("htab", 0400, kvm->arch.debugfs_dir, kvm,
+ debugfs_create_file("htab", 0400, kvm->debugfs_dentry, kvm,
&debugfs_htab_fops);
}
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index c5508744e14c..f4e083c20872 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -1452,7 +1452,7 @@ static const struct file_operations debugfs_radix_fops = {
void kvmhv_radix_debugfs_init(struct kvm *kvm)
{
- debugfs_create_file("radix", 0400, kvm->arch.debugfs_dir, kvm,
+ debugfs_create_file("radix", 0400, kvm->debugfs_dentry, kvm,
&debugfs_radix_fops);
}
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index c8f12b056968..325b388c725a 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -2771,19 +2771,14 @@ static const struct file_operations debugfs_timings_ops = {
};
/* Create a debugfs directory for the vcpu */
-static void debugfs_vcpu_init(struct kvm_vcpu *vcpu, unsigned int id)
+static void kvmppc_arch_create_vcpu_debugfs_hv(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry)
{
- char buf[16];
- struct kvm *kvm = vcpu->kvm;
-
- snprintf(buf, sizeof(buf), "vcpu%u", id);
- vcpu->arch.debugfs_dir = debugfs_create_dir(buf, kvm->arch.debugfs_dir);
- debugfs_create_file("timings", 0444, vcpu->arch.debugfs_dir, vcpu,
+ debugfs_create_file("timings", 0444, debugfs_dentry, vcpu,
&debugfs_timings_ops);
}
#else /* CONFIG_KVM_BOOK3S_HV_EXIT_TIMING */
-static void debugfs_vcpu_init(struct kvm_vcpu *vcpu, unsigned int id)
+static void kvmppc_arch_create_vcpu_debugfs_hv(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry)
{
}
#endif /* CONFIG_KVM_BOOK3S_HV_EXIT_TIMING */
@@ -2907,8 +2902,6 @@ static int kvmppc_core_vcpu_create_hv(struct kvm_vcpu *vcpu)
vcpu->arch.cpu_type = KVM_CPU_3S_64;
kvmppc_sanity_check(vcpu);
- debugfs_vcpu_init(vcpu, id);
-
return 0;
}
@@ -5186,7 +5179,6 @@ void kvmppc_free_host_rm_ops(void)
static int kvmppc_core_init_vm_hv(struct kvm *kvm)
{
unsigned long lpcr, lpid;
- char buf[32];
int ret;
mutex_init(&kvm->arch.uvmem_lock);
@@ -5319,16 +5311,14 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm)
kvm->arch.smt_mode = 1;
kvm->arch.emul_smt_mode = 1;
- /*
- * Create a debugfs directory for the VM
- */
- snprintf(buf, sizeof(buf), "vm%d", current->pid);
- kvm->arch.debugfs_dir = debugfs_create_dir(buf, kvm_debugfs_dir);
+ return 0;
+}
+
+static void kvmppc_arch_create_kvm_debugfs_hv(struct kvm *kvm)
+{
kvmppc_mmu_debugfs_init(kvm);
if (radix_enabled())
kvmhv_radix_debugfs_init(kvm);
-
- return 0;
}
static void kvmppc_free_vcores(struct kvm *kvm)
@@ -5342,8 +5332,6 @@ static void kvmppc_free_vcores(struct kvm *kvm)
static void kvmppc_core_destroy_vm_hv(struct kvm *kvm)
{
- debugfs_remove_recursive(kvm->arch.debugfs_dir);
-
if (!cpu_has_feature(CPU_FTR_ARCH_300))
kvm_hv_vm_deactivated();
@@ -5996,6 +5984,8 @@ static struct kvmppc_ops kvm_ops_hv = {
.svm_off = kvmhv_svm_off,
.enable_dawr1 = kvmhv_enable_dawr1,
.hash_v3_possible = kvmppc_hash_v3_possible,
+ .create_vcpu_debugfs = kvmppc_arch_create_vcpu_debugfs_hv,
+ .create_kvm_debugfs = kvmppc_arch_create_kvm_debugfs_hv,
};
static int kvm_init_subcore_bitmap(void)
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index b4e6f70b97b9..9c18d599171b 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -2505,3 +2505,15 @@ int kvm_arch_init(void *opaque)
}
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_ppc_instr);
+
+void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry)
+{
+ if (vcpu->kvm->arch.kvm_ops->create_vcpu_debugfs)
+ vcpu->kvm->arch.kvm_ops->create_vcpu_debugfs(vcpu, debugfs_dentry);
+}
+
+void kvm_arch_create_kvm_debugfs(struct kvm *kvm)
+{
+ if (kvm->arch.kvm_ops->create_kvm_debugfs)
+ kvm->arch.kvm_ops->create_kvm_debugfs(kvm);
+}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index b50dbe269f4b..f9d423535f00 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -954,6 +954,9 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
kvm->debugfs_dentry, stat_data,
&stat_fops_per_vm);
}
+#ifdef __KVM_HAVE_ARCH_KVM_DEBUGFS
+ kvm_arch_create_kvm_debugfs(kvm);
+#endif
return 0;
}
--
2.30.2
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