KVM: x86: add tracepoints around __direct_map and FNAME(fetch)

These are useful in debugging shadow paging.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2019-07-01 06:22:57 -04:00
parent e9f2a760b1
commit 335e192a3f
3 changed files with 67 additions and 7 deletions

View File

@ -143,9 +143,6 @@ module_param(dbg, bool, 0644);
#include <trace/events/kvm.h>
#define CREATE_TRACE_POINTS
#include "mmutrace.h"
#define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
#define SPTE_MMU_WRITEABLE (1ULL << (PT_FIRST_AVAIL_BITS_SHIFT + 1))
@ -269,9 +266,13 @@ static u64 __read_mostly shadow_nonpresent_or_rsvd_lower_gfn_mask;
static u8 __read_mostly shadow_phys_bits;
static void mmu_spte_set(u64 *sptep, u64 spte);
static bool is_executable_pte(u64 spte);
static union kvm_mmu_page_role
kvm_mmu_calc_root_page_role(struct kvm_vcpu *vcpu);
#define CREATE_TRACE_POINTS
#include "mmutrace.h"
static inline bool kvm_available_flush_tlb_with_range(void)
{
@ -3086,10 +3087,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned pte_access,
ret = RET_PF_EMULATE;
pgprintk("%s: setting spte %llx\n", __func__, *sptep);
pgprintk("instantiating %s PTE (%s) at %llx (%llx) addr %p\n",
is_large_pte(*sptep)? "2MB" : "4kB",
*sptep & PT_WRITABLE_MASK ? "RW" : "R", gfn,
*sptep, sptep);
trace_kvm_mmu_set_spte(level, gfn, sptep);
if (!was_rmapped && is_large_pte(*sptep))
++vcpu->kvm->stat.lpages;
@ -3200,6 +3198,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t gpa, int write,
if (!VALID_PAGE(vcpu->arch.mmu->root_hpa))
return RET_PF_RETRY;
trace_kvm_mmu_spte_requested(gpa, level, pfn);
for_each_shadow_entry(vcpu, gpa, it) {
base_gfn = gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
if (it.level == level)

View File

@ -301,6 +301,65 @@ TRACE_EVENT(
__entry->kvm_gen == __entry->spte_gen
)
);
TRACE_EVENT(
kvm_mmu_set_spte,
TP_PROTO(int level, gfn_t gfn, u64 *sptep),
TP_ARGS(level, gfn, sptep),
TP_STRUCT__entry(
__field(u64, gfn)
__field(u64, spte)
__field(u64, sptep)
__field(u8, level)
/* These depend on page entry type, so compute them now. */
__field(bool, r)
__field(bool, x)
__field(u8, u)
),
TP_fast_assign(
__entry->gfn = gfn;
__entry->spte = *sptep;
__entry->sptep = virt_to_phys(sptep);
__entry->level = level;
__entry->r = shadow_present_mask || (__entry->spte & PT_PRESENT_MASK);
__entry->x = is_executable_pte(__entry->spte);
__entry->u = shadow_user_mask ? !!(__entry->spte & shadow_user_mask) : -1;
),
TP_printk("gfn %llx spte %llx (%s%s%s%s) level %d at %llx",
__entry->gfn, __entry->spte,
__entry->r ? "r" : "-",
__entry->spte & PT_WRITABLE_MASK ? "w" : "-",
__entry->x ? "x" : "-",
__entry->u == -1 ? "" : (__entry->u ? "u" : "-"),
__entry->level, __entry->sptep
)
);
TRACE_EVENT(
kvm_mmu_spte_requested,
TP_PROTO(gpa_t addr, int level, kvm_pfn_t pfn),
TP_ARGS(addr, level, pfn),
TP_STRUCT__entry(
__field(u64, gfn)
__field(u64, pfn)
__field(u8, level)
),
TP_fast_assign(
__entry->gfn = addr >> PAGE_SHIFT;
__entry->pfn = pfn | (__entry->gfn & (KVM_PAGES_PER_HPAGE(level) - 1));
__entry->level = level;
),
TP_printk("gfn %llx pfn %llx level %d",
__entry->gfn, __entry->pfn, __entry->level
)
);
#endif /* _TRACE_KVMMMU_H */
#undef TRACE_INCLUDE_PATH

View File

@ -670,6 +670,8 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
base_gfn = gw->gfn;
trace_kvm_mmu_spte_requested(addr, gw->level, pfn);
for (; shadow_walk_okay(&it); shadow_walk_next(&it)) {
clear_sp_write_flooding_count(it.sptep);
base_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);