Every time kvm_mmu_get_page() is called with a non-NULL parent_pte
argument, link_shadow_page() follows that to set the parent entry so
that the new mapping will point to the returned page table.
Moving parent_pte handling there allows to clean up the code because
parent_pte is passed to kvm_mmu_get_page() just for mark_unsync() and
mmu_page_add_parent_pte().
In addition, the patch avoids calling mark_unsync() for other parents in
the sp->parent_ptes chain than the newly added parent_pte, because they
have been there since before the current page fault handling started.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya...@lab.ntt.co.jp>
Cc: Xiao Guangrong <guangrong.x...@linux.intel.com>
---
arch/x86/kvm/mmu.c | 23 +++++++++--------------
arch/x86/kvm/paging_tmpl.h | 6 ++----
2 files changed, 11 insertions(+), 18 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 7f46e3e..ec61b22 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2119,12 +2119,8 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct
kvm_vcpu *vcpu,
if (sp->unsync && kvm_sync_page_transient(vcpu, sp))
break;
- mmu_page_add_parent_pte(vcpu, sp, parent_pte);
- if (sp->unsync_children) {
+ if (sp->unsync_children)
kvm_make_request(KVM_REQ_MMU_SYNC, vcpu);
- kvm_mmu_mark_parents_unsync(sp);
- } else if (sp->unsync)
- kvm_mmu_mark_parents_unsync(sp);
__clear_sp_write_flooding_count(sp);
trace_kvm_mmu_get_page(sp, false);
@@ -2135,8 +2131,6 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct
kvm_vcpu *vcpu,
sp = kvm_mmu_alloc_page(vcpu, direct);
- mmu_page_add_parent_pte(vcpu, sp, parent_pte);
-
sp->gfn = gfn;
sp->role = role;
hlist_add_head(&sp->hash_link,
@@ -2204,7 +2198,8 @@ static void shadow_walk_next(struct
kvm_shadow_walk_iterator *iterator)
return __shadow_walk_next(iterator, *iterator->sptep);
}
-static void link_shadow_page(u64 *sptep, struct kvm_mmu_page *sp)
+static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep,
+ struct kvm_mmu_page *sp)
{
u64 spte;
@@ -2215,6 +2210,11 @@ static void link_shadow_page(u64 *sptep, struct
kvm_mmu_page *sp)
shadow_user_mask | shadow_x_mask | shadow_accessed_mask;
mmu_spte_set(sptep, spte);
+
+ mmu_page_add_parent_pte(vcpu, sp, sptep);
+
+ if (sp->unsync_children || sp->unsync)
+ mark_unsync(sptep);
}
static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep,
@@ -2273,11 +2273,6 @@ static void kvm_mmu_page_unlink_children(struct kvm *kvm,
mmu_page_zap_pte(kvm, sp, sp->spt + i);
}
-static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
-{
- mmu_page_remove_parent_pte(sp, parent_pte);
-}
-
static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
{
u64 *sptep;
@@ -2743,7 +2738,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, int write,
int map_writable,
iterator.level - 1,
1, ACC_ALL, iterator.sptep);
- link_shadow_page(iterator.sptep, sp);
+ link_shadow_page(vcpu, iterator.sptep, sp);
}
}
return emulate;
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 11650ea..0dcf9c8 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -598,7 +598,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
goto out_gpte_changed;
if (sp)
- link_shadow_page(it.sptep, sp);
+ link_shadow_page(vcpu, it.sptep, sp);
}
for (;
@@ -618,7 +618,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, it.level-1,
true, direct_access, it.sptep);
- link_shadow_page(it.sptep, sp);
+ link_shadow_page(vcpu, it.sptep, sp);
}
clear_sp_write_flooding_count(it.sptep);
@@ -629,8 +629,6 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
return emulate;
out_gpte_changed:
- if (sp)
- kvm_mmu_put_page(sp, it.sptep);
kvm_release_pfn_clean(pfn);
return 0;
}
--
2.1.0
--
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