KVM: PPC: Merge powerpc's debugfs entry content into generic entry

At the moment KVM on PPC creates 4 types of entries under the kvm debugfs:
1) "%pid-%fd" per a KVM instance (for all platforms);
2) "vm%pid" (for PPC Book3s HV KVM);
3) "vm%u_vcpu%u_timing" (for PPC Book3e KVM);
4) "kvm-xive-%p" (for XIVE PPC Book3s KVM, the same for XICS);

The problem with this is that multiple VMs per process is not allowed for
2) and 3) which makes it possible for userspace to trigger errors when
creating duplicated debugfs entries.

This merges all these into 1).

This defines kvm_arch_create_kvm_debugfs() similar to
kvm_arch_create_vcpu_debugfs().

This defines 2 hooks in kvmppc_ops that allow specific KVM implementations
add necessary entries, this adds the _e500 suffix to
kvmppc_create_vcpu_debugfs_e500() to make it clear what platform it is for.

This makes use of already existing kvm_arch_create_vcpu_debugfs() on PPC.

This removes no more used debugfs_dir pointers from PPC kvm_arch structs.

This stops removing vcpu entries as once created vcpus stay around
for the entire life of a VM and removed when the KVM instance is closed,
see commit d56f5136b010 ("KVM: let kvm_destroy_vm_debugfs clean up vCPU
debugfs directories").

Suggested-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220111005404.162219-1-aik@ozlabs.ru

2 files changed, 4 insertions, 4 deletions

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index d9bf60bf0816..faf301d0dec0 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -26,6 +26,8 @@
 #include <asm/hvcall.h>
 #include <asm/mce.h>
 
+#define __KVM_HAVE_ARCH_VCPU_DEBUGFS
+
 #define KVM_MAX_VCPUS		NR_CPUS
 #define KVM_MAX_VCORES		NR_CPUS
 
@@ -295,7 +297,6 @@ 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
@@ -673,7 +674,6 @@ struct kvm_vcpu_arch {
 	u64 timing_min_duration[__NUMBER_OF_KVM_EXIT_TYPES];
 	u64 timing_max_duration[__NUMBER_OF_KVM_EXIT_TYPES];
 	u64 timing_last_exit;
-	struct dentry *debugfs_exit_timing;
 #endif
 
 #ifdef CONFIG_PPC_BOOK3S
@@ -831,8 +831,6 @@ 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 */
 };
 
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index a14dbcd1b8ce..c583d0c37f31 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -314,6 +314,8 @@ struct kvmppc_ops {
 	int (*svm_off)(struct kvm *kvm);
 	int (*enable_dawr1)(struct kvm *kvm);
 	bool (*hash_v3_possible)(void);
+	int (*create_vm_debugfs)(struct kvm *kvm);
+	int (*create_vcpu_debugfs)(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry);
 };
 
 extern struct kvmppc_ops *kvmppc_hv_ops;