Commit 335e192a authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

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



These are useful in debugging shadow paging.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent e9f2a760

arch/x86/kvm/mmu.c

+6 −7
Original line number Diff line number Diff line
@@ -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)

arch/x86/kvm/mmutrace.h

+59 −0
Original line number Diff line number Diff line
@@ -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

arch/x86/kvm/paging_tmpl.h

+2 −0
Original line number Diff line number Diff line
@@ -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);