Propagate any error returned by make_mmu_pages_available() out to userspace instead of resuming the guest if the error occurs while handling a page fault. Now that zapping the oldest MMU pages skips active roots, i.e. fails if and only if there are no zappable pages, there is no chance for a false positive, i.e. no chance of returning a spurious error to userspace. Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> --- arch/x86/kvm/mmu/mmu.c | 3 ++- arch/x86/kvm/mmu/paging_tmpl.h | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 4d40b21a67bd..82086d9eecb0 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4157,7 +4157,8 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, spin_lock(&vcpu->kvm->mmu_lock); if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) goto out_unlock; - if (make_mmu_pages_available(vcpu) < 0) + r = make_mmu_pages_available(vcpu); + if (r) goto out_unlock; r = __direct_map(vcpu, gpa, write, map_writable, max_level, pfn, prefault, is_tdp && lpage_disallowed); diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 58234bfaca07..a2db6971231d 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -865,7 +865,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, goto out_unlock; kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT); - if (make_mmu_pages_available(vcpu) < 0) + r = make_mmu_pages_available(vcpu); + if (r) goto out_unlock; r = FNAME(fetch)(vcpu, addr, &walker, write_fault, max_level, pfn, map_writable, prefault, lpage_disallowed); -- 2.26.0
