KVM: MMU: Trace guest pagetable walker

Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Avi Kivity 2009-07-06 12:21:32 +03:00
parent dc7e795e3d
commit 0742017159
3 changed files with 128 additions and 3 deletions

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@ -140,6 +140,9 @@ module_param(oos_shadow, bool, 0644);
#define ACC_USER_MASK PT_USER_MASK
#define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
#define CREATE_TRACE_POINTS
#include "mmutrace.h"
#define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
struct kvm_rmap_desc {

117
arch/x86/kvm/mmutrace.h Normal file
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@ -0,0 +1,117 @@
#if !defined(_TRACE_KVMMMU_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_KVMMMU_H
#include <linux/tracepoint.h>
#undef TRACE_SYSTEM
#define TRACE_SYSTEM kvmmmu
#define TRACE_INCLUDE_PATH .
#define TRACE_INCLUDE_FILE mmutrace
#define kvm_mmu_trace_pferr_flags \
{ PFERR_PRESENT_MASK, "P" }, \
{ PFERR_WRITE_MASK, "W" }, \
{ PFERR_USER_MASK, "U" }, \
{ PFERR_RSVD_MASK, "RSVD" }, \
{ PFERR_FETCH_MASK, "F" }
/*
* A pagetable walk has started
*/
TRACE_EVENT(
kvm_mmu_pagetable_walk,
TP_PROTO(u64 addr, int write_fault, int user_fault, int fetch_fault),
TP_ARGS(addr, write_fault, user_fault, fetch_fault),
TP_STRUCT__entry(
__field(__u64, addr)
__field(__u32, pferr)
),
TP_fast_assign(
__entry->addr = addr;
__entry->pferr = (!!write_fault << 1) | (!!user_fault << 2)
| (!!fetch_fault << 4);
),
TP_printk("addr %llx pferr %x %s", __entry->addr, __entry->pferr,
__print_flags(__entry->pferr, "|", kvm_mmu_trace_pferr_flags))
);
/* We just walked a paging element */
TRACE_EVENT(
kvm_mmu_paging_element,
TP_PROTO(u64 pte, int level),
TP_ARGS(pte, level),
TP_STRUCT__entry(
__field(__u64, pte)
__field(__u32, level)
),
TP_fast_assign(
__entry->pte = pte;
__entry->level = level;
),
TP_printk("pte %llx level %u", __entry->pte, __entry->level)
);
/* We set a pte accessed bit */
TRACE_EVENT(
kvm_mmu_set_accessed_bit,
TP_PROTO(unsigned long table_gfn, unsigned index, unsigned size),
TP_ARGS(table_gfn, index, size),
TP_STRUCT__entry(
__field(__u64, gpa)
),
TP_fast_assign(
__entry->gpa = ((u64)table_gfn << PAGE_SHIFT)
+ index * size;
),
TP_printk("gpa %llx", __entry->gpa)
);
/* We set a pte dirty bit */
TRACE_EVENT(
kvm_mmu_set_dirty_bit,
TP_PROTO(unsigned long table_gfn, unsigned index, unsigned size),
TP_ARGS(table_gfn, index, size),
TP_STRUCT__entry(
__field(__u64, gpa)
),
TP_fast_assign(
__entry->gpa = ((u64)table_gfn << PAGE_SHIFT)
+ index * size;
),
TP_printk("gpa %llx", __entry->gpa)
);
TRACE_EVENT(
kvm_mmu_walker_error,
TP_PROTO(u32 pferr),
TP_ARGS(pferr),
TP_STRUCT__entry(
__field(__u32, pferr)
),
TP_fast_assign(
__entry->pferr = pferr;
),
TP_printk("pferr %x %s", __entry->pferr,
__print_flags(__entry->pferr, "|", kvm_mmu_trace_pferr_flags))
);
#endif /* _TRACE_KVMMMU_H */
/* This part must be outside protection */
#include <trace/define_trace.h>

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@ -125,13 +125,15 @@ static int FNAME(walk_addr)(struct guest_walker *walker,
gpa_t pte_gpa;
int rsvd_fault = 0;
pgprintk("%s: addr %lx\n", __func__, addr);
trace_kvm_mmu_pagetable_walk(addr, write_fault, user_fault,
fetch_fault);
walk:
walker->level = vcpu->arch.mmu.root_level;
pte = vcpu->arch.cr3;
#if PTTYPE == 64
if (!is_long_mode(vcpu)) {
pte = kvm_pdptr_read(vcpu, (addr >> 30) & 3);
trace_kvm_mmu_paging_element(pte, walker->level);
if (!is_present_gpte(pte))
goto not_present;
--walker->level;
@ -150,10 +152,9 @@ walk:
pte_gpa += index * sizeof(pt_element_t);
walker->table_gfn[walker->level - 1] = table_gfn;
walker->pte_gpa[walker->level - 1] = pte_gpa;
pgprintk("%s: table_gfn[%d] %lx\n", __func__,
walker->level - 1, table_gfn);
kvm_read_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte));
trace_kvm_mmu_paging_element(pte, walker->level);
if (!is_present_gpte(pte))
goto not_present;
@ -175,6 +176,8 @@ walk:
#endif
if (!(pte & PT_ACCESSED_MASK)) {
trace_kvm_mmu_set_accessed_bit(table_gfn, index,
sizeof(pte));
mark_page_dirty(vcpu->kvm, table_gfn);
if (FNAME(cmpxchg_gpte)(vcpu->kvm, table_gfn,
index, pte, pte|PT_ACCESSED_MASK))
@ -208,6 +211,7 @@ walk:
if (write_fault && !is_dirty_gpte(pte)) {
bool ret;
trace_kvm_mmu_set_dirty_bit(table_gfn, index, sizeof(pte));
mark_page_dirty(vcpu->kvm, table_gfn);
ret = FNAME(cmpxchg_gpte)(vcpu->kvm, table_gfn, index, pte,
pte|PT_DIRTY_MASK);
@ -239,6 +243,7 @@ err:
walker->error_code |= PFERR_FETCH_MASK;
if (rsvd_fault)
walker->error_code |= PFERR_RSVD_MASK;
trace_kvm_mmu_walker_error(walker->error_code);
return 0;
}