On 05/23/2010 03:14 PM, Xiao Guangrong wrote:
In current code, shadow page can become asynchronous only if one
shadow page for a gfn, this rule is too strict, in fact, we can
let all last mapping page(i.e, it's the pte page) become unsync,
and sync them at invlpg or flush tlb time.
This patch allow more page become asynchronous at gfn mapping time
+
+static void kvm_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn)
{
- unsigned index;
struct hlist_head *bucket;
struct kvm_mmu_page *s;
struct hlist_node *node, *n;
+ unsigned index;
- index = kvm_page_table_hashfn(sp->gfn);
+ index = kvm_page_table_hashfn(gfn);
bucket =&vcpu->kvm->arch.mmu_page_hash[index];
- /* don't unsync if pagetable is shadowed with multiple roles */
+
hlist_for_each_entry_safe(s, node, n, bucket, hash_link) {
- if (s->gfn != sp->gfn || s->role.direct)
+ if (s->gfn != gfn || s->role.direct || s->unsync)
continue;
role.invalid?
- if (s->role.word != sp->role.word)
- return 1;
+ WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL);
+ __kvm_unsync_page(vcpu, s);
}
- trace_kvm_mmu_unsync_page(sp);
- ++vcpu->kvm->stat.mmu_unsync;
- sp->unsync = 1;
-
- kvm_mmu_mark_parents_unsync(sp);
-
- mmu_convert_notrap(sp);
- return 0;
}
static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
bool can_unsync)
{
- struct kvm_mmu_page *shadow;
+ unsigned index;
+ struct hlist_head *bucket;
+ struct kvm_mmu_page *s;
+ struct hlist_node *node, *n;
+ bool need_unsync = false;
+
+ index = kvm_page_table_hashfn(gfn);
+ bucket =&vcpu->kvm->arch.mmu_page_hash[index];
+ hlist_for_each_entry_safe(s, node, n, bucket, hash_link) {
+ if (s->gfn != gfn || s->role.direct)
+ continue;
- shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
- if (shadow) {
- if (shadow->role.level != PT_PAGE_TABLE_LEVEL)
+ if (s->role.level != PT_PAGE_TABLE_LEVEL)
return 1;
role.invalid?
- if (shadow->unsync)
- return 0;
- if (can_unsync&& oos_shadow)
- return kvm_unsync_page(vcpu, shadow);
- return 1;
+
+ if (!need_unsync&& !s->unsync) {
+ if (!can_unsync || !oos_shadow)
+ return 1;
+ need_unsync = true;
+ }
}
+ if (need_unsync)
+ kvm_unsync_pages(vcpu, gfn);
return 0;
}
Looks good, I'm just uncertain about role.invalid handling. What's the
reasoning here?
--
error compiling committee.c: too many arguments to function
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