kvm: x86: Do not release the page inside mmu_set_spte()

commit 43fdcda96e2550c6d1c46fb8a78801aa2f7276ed upstream.

Release the page at the call-site where it was originally acquired.
This makes the exit code cleaner for most call sites, since they
do not need to duplicate code between success and the failure
label.

Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 57aa700a1cac12a5700e94e01babaad7b7456614..2cf1ff7e3af7a385371041411f12c5bd4c9a6d57 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2671,8 +2671,6 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned pte_access,
                }
        }
 
-       kvm_release_pfn_clean(pfn);
-
        return ret;
 }
 
@@ -2707,9 +2705,11 @@ static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu,
        if (ret <= 0)
                return -1;
 
-       for (i = 0; i < ret; i++, gfn++, start++)
+       for (i = 0; i < ret; i++, gfn++, start++) {
                mmu_set_spte(vcpu, start, access, 0, sp->role.level, gfn,
                             page_to_pfn(pages[i]), true, true);
+               put_page(pages[i]);
+       }
 
        return 0;
 }
@@ -3055,6 +3055,7 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, u32 error_code,
        if (handle_abnormal_pfn(vcpu, v, gfn, pfn, ACC_ALL, &r))
                return r;
 
+       r = RET_PF_RETRY;
        spin_lock(&vcpu->kvm->mmu_lock);
        if (mmu_notifier_retry(vcpu->kvm, mmu_seq))
                goto out_unlock;
@@ -3062,14 +3063,11 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, u32 error_code,
        if (likely(!force_pt_level))
                transparent_hugepage_adjust(vcpu, &gfn, &pfn, &level);
        r = __direct_map(vcpu, write, map_writable, level, gfn, pfn, prefault);
-       spin_unlock(&vcpu->kvm->mmu_lock);
-
-       return r;
 
 out_unlock:
        spin_unlock(&vcpu->kvm->mmu_lock);
        kvm_release_pfn_clean(pfn);
-       return RET_PF_RETRY;
+       return r;
 }
 
 
@@ -3593,6 +3591,7 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code,
        if (handle_abnormal_pfn(vcpu, 0, gfn, pfn, ACC_ALL, &r))
                return r;
 
+       r = RET_PF_RETRY;
        spin_lock(&vcpu->kvm->mmu_lock);
        if (mmu_notifier_retry(vcpu->kvm, mmu_seq))
                goto out_unlock;
@@ -3600,14 +3599,11 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code,
        if (likely(!force_pt_level))
                transparent_hugepage_adjust(vcpu, &gfn, &pfn, &level);
        r = __direct_map(vcpu, write, map_writable, level, gfn, pfn, prefault);
-       spin_unlock(&vcpu->kvm->mmu_lock);
-
-       return r;
 
 out_unlock:
        spin_unlock(&vcpu->kvm->mmu_lock);
        kvm_release_pfn_clean(pfn);
-       return RET_PF_RETRY;
+       return r;
 }
 
 static void nonpaging_init_context(struct kvm_vcpu *vcpu,

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 82ff96773ab7a1d3139300c15da782f1ce9e8883..3763edaa01a4b18501c6e907aec4b72e030a0607 100644 (file)
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -499,6 +499,7 @@ FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
        mmu_set_spte(vcpu, spte, pte_access, 0, PT_PAGE_TABLE_LEVEL, gfn, pfn,
                     true, true);
 
+       kvm_release_pfn_clean(pfn);
        return true;
 }
 
@@ -650,7 +651,6 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
        return ret;
 
 out_gpte_changed:
-       kvm_release_pfn_clean(pfn);
        return RET_PF_RETRY;
 }
 
@@ -799,6 +799,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
                        walker.pte_access &= ~ACC_EXEC_MASK;
        }
 
+       r = RET_PF_RETRY;
        spin_lock(&vcpu->kvm->mmu_lock);
        if (mmu_notifier_retry(vcpu->kvm, mmu_seq))
                goto out_unlock;
@@ -811,14 +812,11 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
                         level, pfn, map_writable, prefault);
        ++vcpu->stat.pf_fixed;
        kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT);
-       spin_unlock(&vcpu->kvm->mmu_lock);
-
-       return r;
 
 out_unlock:
        spin_unlock(&vcpu->kvm->mmu_lock);
        kvm_release_pfn_clean(pfn);
-       return RET_PF_RETRY;
+       return r;
 }
 
 static gpa_t FNAME(get_level1_sp_gpa)(struct kvm_mmu_page *sp)