KVM: Trace shadow page lifecycle

Create, sync, unsync, zap.

Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index c0dda64..ac121b3 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1122,6 +1122,7 @@ static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
                return 1;
        }
 
+       trace_kvm_mmu_sync_page(sp);
        if (rmap_write_protect(vcpu->kvm, sp->gfn))
                kvm_flush_remote_tlbs(vcpu->kvm);
        kvm_unlink_unsync_page(vcpu->kvm, sp);
@@ -1244,8 +1245,6 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
                quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
                role.quadrant = quadrant;
        }
-       pgprintk("%s: looking gfn %lx role %x\n", __func__,
-                gfn, role.word);
        index = kvm_page_table_hashfn(gfn);
        bucket = &vcpu->kvm->arch.mmu_page_hash[index];
        hlist_for_each_entry_safe(sp, node, tmp, bucket, hash_link)
@@ -1262,14 +1261,13 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
                                set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests);
                                kvm_mmu_mark_parents_unsync(vcpu, sp);
                        }
-                       pgprintk("%s: found\n", __func__);
+                       trace_kvm_mmu_get_page(sp, false);
                        return sp;
                }
        ++vcpu->kvm->stat.mmu_cache_miss;
        sp = kvm_mmu_alloc_page(vcpu, parent_pte);
        if (!sp)
                return sp;
-       pgprintk("%s: adding gfn %lx role %x\n", __func__, gfn, role.word);
        sp->gfn = gfn;
        sp->role = role;
        hlist_add_head(&sp->hash_link, bucket);
@@ -1282,6 +1280,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
                vcpu->arch.mmu.prefetch_page(vcpu, sp);
        else
                nonpaging_prefetch_page(vcpu, sp);
+       trace_kvm_mmu_get_page(sp, true);
        return sp;
 }
 
@@ -1410,6 +1409,8 @@ static int mmu_zap_unsync_children(struct kvm *kvm,
 static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
        int ret;
+
+       trace_kvm_mmu_zap_page(sp);
        ++kvm->stat.mmu_shadow_zapped;
        ret = mmu_zap_unsync_children(kvm, sp);
        kvm_mmu_page_unlink_children(kvm, sp);
@@ -1656,6 +1657,7 @@ static int kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
        struct kvm_mmu_page *s;
        struct hlist_node *node, *n;
 
+       trace_kvm_mmu_unsync_page(sp);
        index = kvm_page_table_hashfn(sp->gfn);
        bucket = &vcpu->kvm->arch.mmu_page_hash[index];
        /* don't unsync if pagetable is shadowed with multiple roles */

diff --git a/arch/x86/kvm/mmutrace.h b/arch/x86/kvm/mmutrace.h
index 1367f82..3e4a5c6 100644 (file)
--- a/arch/x86/kvm/mmutrace.h
+++ b/arch/x86/kvm/mmutrace.h
@@ -2,12 +2,48 @@
 #define _TRACE_KVMMMU_H
 
 #include <linux/tracepoint.h>
+#include <linux/ftrace_event.h>
 
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM kvmmmu
 #define TRACE_INCLUDE_PATH .
 #define TRACE_INCLUDE_FILE mmutrace
 
+#define KVM_MMU_PAGE_FIELDS \
+       __field(__u64, gfn) \
+       __field(__u32, role) \
+       __field(__u32, root_count) \
+       __field(__u32, unsync)
+
+#define KVM_MMU_PAGE_ASSIGN(sp)                             \
+       __entry->gfn = sp->gfn;                      \
+       __entry->role = sp->role.word;               \
+       __entry->root_count = sp->root_count;        \
+       __entry->unsync = sp->unsync;
+
+#define KVM_MMU_PAGE_PRINTK() ({                                       \
+       const char *ret = p->buffer + p->len;                           \
+       static const char *access_str[] = {                             \
+               "---", "--x", "w--", "w-x", "-u-", "-ux", "wu-", "wux"  \
+       };                                                              \
+       union kvm_mmu_page_role role;                                   \
+                                                                       \
+       role.word = __entry->role;                                      \
+                                                                       \
+       trace_seq_printf(p, "sp gfn %llx %u/%u q%u%s %s%s %spge"        \
+                        " %snxe root %u %s%c",                         \
+                        __entry->gfn, role.level, role.glevels,        \
+                        role.quadrant,                                 \
+                        role.direct ? " direct" : "",                  \
+                        access_str[role.access],                       \
+                        role.invalid ? " invalid" : "",                \
+                        role.cr4_pge ? "" : "!",                       \
+                        role.nxe ? "" : "!",                           \
+                        __entry->root_count,                           \
+                        __entry->unsync ? "unsync" : "sync", 0);       \
+       ret;                                                            \
+               })
+
 #define kvm_mmu_trace_pferr_flags       \
        { PFERR_PRESENT_MASK, "P" },    \
        { PFERR_WRITE_MASK, "W" },      \
@@ -111,6 +147,73 @@ TRACE_EVENT(
                  __print_flags(__entry->pferr, "|", kvm_mmu_trace_pferr_flags))
 );
 
+TRACE_EVENT(
+       kvm_mmu_get_page,
+       TP_PROTO(struct kvm_mmu_page *sp, bool created),
+       TP_ARGS(sp, created),
+
+       TP_STRUCT__entry(
+               KVM_MMU_PAGE_FIELDS
+               __field(bool, created)
+               ),
+
+       TP_fast_assign(
+               KVM_MMU_PAGE_ASSIGN(sp)
+               __entry->created = created;
+               ),
+
+       TP_printk("%s %s", KVM_MMU_PAGE_PRINTK(),
+                 __entry->created ? "new" : "existing")
+);
+
+TRACE_EVENT(
+       kvm_mmu_sync_page,
+       TP_PROTO(struct kvm_mmu_page *sp),
+       TP_ARGS(sp),
+
+       TP_STRUCT__entry(
+               KVM_MMU_PAGE_FIELDS
+               ),
+
+       TP_fast_assign(
+               KVM_MMU_PAGE_ASSIGN(sp)
+               ),
+
+       TP_printk("%s", KVM_MMU_PAGE_PRINTK())
+);
+
+TRACE_EVENT(
+       kvm_mmu_unsync_page,
+       TP_PROTO(struct kvm_mmu_page *sp),
+       TP_ARGS(sp),
+
+       TP_STRUCT__entry(
+               KVM_MMU_PAGE_FIELDS
+               ),
+
+       TP_fast_assign(
+               KVM_MMU_PAGE_ASSIGN(sp)
+               ),
+
+       TP_printk("%s", KVM_MMU_PAGE_PRINTK())
+);
+
+TRACE_EVENT(
+       kvm_mmu_zap_page,
+       TP_PROTO(struct kvm_mmu_page *sp),
+       TP_ARGS(sp),
+
+       TP_STRUCT__entry(
+               KVM_MMU_PAGE_FIELDS
+               ),
+
+       TP_fast_assign(
+               KVM_MMU_PAGE_ASSIGN(sp)
+               ),
+
+       TP_printk("%s", KVM_MMU_PAGE_PRINTK())
+);
+
 #endif /* _TRACE_KVMMMU_H */
 
 /* This part must be outside protection */