102 lines
3.8 KiB
Diff
102 lines
3.8 KiB
Diff
From: Paolo Bonzini <pbonzini@redhat.com>
|
|
Date: Mon, 30 Sep 2019 18:48:44 +0200
|
|
Subject: kvm: x86, powerpc: do not allow clearing largepages debugfs entry
|
|
|
|
commit 833b45de69a6016c4b0cebe6765d526a31a81580 upstream.
|
|
|
|
The largepages debugfs entry is incremented/decremented as shadow
|
|
pages are created or destroyed. Clearing it will result in an
|
|
underflow, which is harmless to KVM but ugly (and could be
|
|
misinterpreted by tools that use debugfs information), so make
|
|
this particular statistic read-only.
|
|
|
|
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
[bwh: Backported to 4.19: drop powerpc changes and the Cc to kvm-ppc]
|
|
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
|
|
---
|
|
arch/x86/kvm/x86.c | 6 +++---
|
|
include/linux/kvm_host.h | 2 ++
|
|
virt/kvm/kvm_main.c | 10 +++++++---
|
|
3 files changed, 12 insertions(+), 6 deletions(-)
|
|
|
|
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
|
|
index 0c085b895e6e..2714c1a0e59f 100644
|
|
--- a/arch/x86/kvm/x86.c
|
|
+++ b/arch/x86/kvm/x86.c
|
|
@@ -92,8 +92,8 @@ u64 __read_mostly efer_reserved_bits = ~((u64)(EFER_SCE | EFER_LME | EFER_LMA));
|
|
static u64 __read_mostly efer_reserved_bits = ~((u64)EFER_SCE);
|
|
#endif
|
|
|
|
-#define VM_STAT(x) offsetof(struct kvm, stat.x), KVM_STAT_VM
|
|
-#define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU
|
|
+#define VM_STAT(x, ...) offsetof(struct kvm, stat.x), KVM_STAT_VM, ## __VA_ARGS__
|
|
+#define VCPU_STAT(x, ...) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU, ## __VA_ARGS__
|
|
|
|
#define KVM_X2APIC_API_VALID_FLAGS (KVM_X2APIC_API_USE_32BIT_IDS | \
|
|
KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK)
|
|
@@ -205,7 +205,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
|
|
{ "mmu_cache_miss", VM_STAT(mmu_cache_miss) },
|
|
{ "mmu_unsync", VM_STAT(mmu_unsync) },
|
|
{ "remote_tlb_flush", VM_STAT(remote_tlb_flush) },
|
|
- { "largepages", VM_STAT(lpages) },
|
|
+ { "largepages", VM_STAT(lpages, .mode = 0444) },
|
|
{ "max_mmu_page_hash_collisions",
|
|
VM_STAT(max_mmu_page_hash_collisions) },
|
|
{ NULL }
|
|
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
|
|
index 5246a480d15a..553a3115a735 100644
|
|
--- a/include/linux/kvm_host.h
|
|
+++ b/include/linux/kvm_host.h
|
|
@@ -1034,6 +1034,7 @@ enum kvm_stat_kind {
|
|
|
|
struct kvm_stat_data {
|
|
int offset;
|
|
+ int mode;
|
|
struct kvm *kvm;
|
|
};
|
|
|
|
@@ -1041,6 +1042,7 @@ struct kvm_stats_debugfs_item {
|
|
const char *name;
|
|
int offset;
|
|
enum kvm_stat_kind kind;
|
|
+ int mode;
|
|
};
|
|
extern struct kvm_stats_debugfs_item debugfs_entries[];
|
|
extern struct dentry *kvm_debugfs_dir;
|
|
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
|
|
index 6a8fe26198b9..5482949b452c 100644
|
|
--- a/virt/kvm/kvm_main.c
|
|
+++ b/virt/kvm/kvm_main.c
|
|
@@ -616,8 +616,9 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
|
|
|
|
stat_data->kvm = kvm;
|
|
stat_data->offset = p->offset;
|
|
+ stat_data->mode = p->mode ? p->mode : 0644;
|
|
kvm->debugfs_stat_data[p - debugfs_entries] = stat_data;
|
|
- debugfs_create_file(p->name, 0644, kvm->debugfs_dentry,
|
|
+ debugfs_create_file(p->name, stat_data->mode, kvm->debugfs_dentry,
|
|
stat_data, stat_fops_per_vm[p->kind]);
|
|
}
|
|
return 0;
|
|
@@ -3714,7 +3715,9 @@ static int kvm_debugfs_open(struct inode *inode, struct file *file,
|
|
if (!refcount_inc_not_zero(&stat_data->kvm->users_count))
|
|
return -ENOENT;
|
|
|
|
- if (simple_attr_open(inode, file, get, set, fmt)) {
|
|
+ if (simple_attr_open(inode, file, get,
|
|
+ stat_data->mode & S_IWUGO ? set : NULL,
|
|
+ fmt)) {
|
|
kvm_put_kvm(stat_data->kvm);
|
|
return -ENOMEM;
|
|
}
|
|
@@ -3962,7 +3965,8 @@ static void kvm_init_debug(void)
|
|
|
|
kvm_debugfs_num_entries = 0;
|
|
for (p = debugfs_entries; p->name; ++p, kvm_debugfs_num_entries++) {
|
|
- debugfs_create_file(p->name, 0644, kvm_debugfs_dir,
|
|
+ int mode = p->mode ? p->mode : 0644;
|
|
+ debugfs_create_file(p->name, mode, kvm_debugfs_dir,
|
|
(void *)(long)p->offset,
|
|
stat_fops[p->kind]);
|
|
}
|