[PATCH 07/12] KVM: MMU: invert return value of FNAME(sync_page) and *kvm_sync_page*

From: Paolo Bonzini
Date: Wed Feb 24 2016 - 08:19:08 EST


Return true if the page was synced (and the TLB must be flushed)
and false if the page was zapped.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/mmu.c | 29 +++++++++++++----------------
arch/x86/kvm/paging_tmpl.h | 4 ++--
2 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 56fa1636c0cf..e3215cc89d97 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1886,20 +1886,20 @@ static void kvm_mmu_commit_zap_page(struct kvm *kvm,
if ((_sp)->role.direct || (_sp)->role.invalid) {} else

/* @sp->gfn should be write-protected at the call site */
-static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
- struct list_head *invalid_list)
+static bool __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
+ struct list_head *invalid_list)
{
if (sp->role.cr4_pae != !!is_pae(vcpu)) {
kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list);
- return 1;
+ return false;
}

- if (vcpu->arch.mmu.sync_page(vcpu, sp)) {
+ if (vcpu->arch.mmu.sync_page(vcpu, sp) == 0) {
kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list);
- return 1;
+ return false;
}

- return 0;
+ return true;
}

static void kvm_mmu_flush_or_zap(struct kvm_vcpu *vcpu,
@@ -1917,14 +1917,14 @@ static void kvm_mmu_flush_or_zap(struct kvm_vcpu *vcpu,
kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
}

-static int kvm_sync_page_transient(struct kvm_vcpu *vcpu,
- struct kvm_mmu_page *sp)
+static bool kvm_sync_page_transient(struct kvm_vcpu *vcpu,
+ struct kvm_mmu_page *sp)
{
LIST_HEAD(invalid_list);
int ret;

ret = __kvm_sync_page(vcpu, sp, &invalid_list);
- kvm_mmu_flush_or_zap(vcpu, &invalid_list, false, !ret);
+ kvm_mmu_flush_or_zap(vcpu, &invalid_list, false, ret);

return ret;
}
@@ -1936,7 +1936,7 @@ static void kvm_mmu_audit(struct kvm_vcpu *vcpu, int point) { }
static void mmu_audit_disable(void) { }
#endif

-static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
+static bool kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
struct list_head *invalid_list)
{
kvm_unlink_unsync_page(vcpu->kvm, sp);
@@ -1955,8 +1955,7 @@ static void kvm_sync_pages(struct kvm_vcpu *vcpu, gfn_t gfn)
continue;

WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL);
- if (!kvm_sync_page(vcpu, s, &invalid_list))
- flush = true;
+ flush |= kvm_sync_page(vcpu, s, &invalid_list);
}

kvm_mmu_flush_or_zap(vcpu, &invalid_list, false, flush);
@@ -2054,9 +2053,7 @@ static void mmu_sync_children(struct kvm_vcpu *vcpu,
kvm_flush_remote_tlbs(vcpu->kvm);

for_each_sp(pages, sp, parents, i) {
- if (!kvm_sync_page(vcpu, sp, &invalid_list))
- flush = true;
-
+ flush |= kvm_sync_page(vcpu, sp, &invalid_list);
mmu_pages_clear_parents(&parents);
}
kvm_mmu_flush_or_zap(vcpu, &invalid_list, false, flush);
@@ -2115,7 +2112,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
if (sp->role.word != role.word)
continue;

- if (sp->unsync && kvm_sync_page_transient(vcpu, sp))
+ if (sp->unsync && !kvm_sync_page_transient(vcpu, sp))
break;

if (sp->unsync_children)
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 05827ff7bd2e..2e019b103249 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -938,7 +938,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)

if (kvm_vcpu_read_guest_atomic(vcpu, pte_gpa, &gpte,
sizeof(pt_element_t)))
- return -EINVAL;
+ return 0;

if (FNAME(prefetch_invalid_gpte)(vcpu, sp, &sp->spt[i], gpte)) {
vcpu->kvm->tlbs_dirty++;
@@ -970,7 +970,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
host_writable);
}

- return !nr_present;
+ return nr_present;
}

#undef pt_element_t
--
1.8.3.1