From fa576c583d877d667d9acaed909a3dfc6b03e138 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Tue, 6 May 2014 17:20:16 +0200 Subject: [PATCH] KVM: s390: Introduce helper function for faulting-in a guest page Rework the function kvm_arch_fault_in_sync() to become a proper helper function for faulting-in a guest page. Now it takes the guest address as a parameter and does not ignore the possible error code from gmap_fault() anymore (which could cause undetected error conditions before). Signed-off-by: Thomas Huth Reviewed-by: Christian Borntraeger Reviewed-by: Cornelia Huck Signed-off-by: Christian Borntraeger --- arch/s390/kvm/kvm-s390.c | 32 +++++++++++++++++++++++++------- arch/s390/kvm/kvm-s390.h | 1 + 2 files changed, 26 insertions(+), 7 deletions(-) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 0a01744cbdd9..d91feb2f03ea 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -1045,15 +1045,30 @@ retry: return 0; } -static long kvm_arch_fault_in_sync(struct kvm_vcpu *vcpu) +/** + * kvm_arch_fault_in_page - fault-in guest page if necessary + * @vcpu: The corresponding virtual cpu + * @gpa: Guest physical address + * @writable: Whether the page should be writable or not + * + * Make sure that a guest page has been faulted-in on the host. + * + * Return: Zero on success, negative error code otherwise. + */ +long kvm_arch_fault_in_page(struct kvm_vcpu *vcpu, gpa_t gpa, int writable) { - long rc; - hva_t fault = gmap_fault(current->thread.gmap_addr, vcpu->arch.gmap); struct mm_struct *mm = current->mm; + hva_t hva; + long rc; + + hva = gmap_fault(gpa, vcpu->arch.gmap); + if (IS_ERR_VALUE(hva)) + return (long)hva; down_read(&mm->mmap_sem); - rc = get_user_pages(current, mm, fault, 1, 1, 0, NULL, NULL); + rc = get_user_pages(current, mm, hva, 1, writable, 0, NULL, NULL); up_read(&mm->mmap_sem); - return rc; + + return rc < 0 ? rc : 0; } static void __kvm_inject_pfault_token(struct kvm_vcpu *vcpu, bool start_token, @@ -1191,9 +1206,12 @@ static int vcpu_post_run(struct kvm_vcpu *vcpu, int exit_reason) } else if (current->thread.gmap_pfault) { trace_kvm_s390_major_guest_pfault(vcpu); current->thread.gmap_pfault = 0; - if (kvm_arch_setup_async_pf(vcpu) || - (kvm_arch_fault_in_sync(vcpu) >= 0)) + if (kvm_arch_setup_async_pf(vcpu)) { rc = 0; + } else { + gpa_t gpa = current->thread.gmap_addr; + rc = kvm_arch_fault_in_page(vcpu, gpa, 1); + } } if (rc == -1) { diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index 38b589d69951..e489945921ac 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -156,6 +156,7 @@ int kvm_s390_handle_eb(struct kvm_vcpu *vcpu); int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu); /* implemented in kvm-s390.c */ +long kvm_arch_fault_in_page(struct kvm_vcpu *vcpu, gpa_t gpa, int writable); int kvm_s390_store_status_unloaded(struct kvm_vcpu *vcpu, unsigned long addr); int kvm_s390_vcpu_store_status(struct kvm_vcpu *vcpu, unsigned long addr); void kvm_s390_vcpu_start(struct kvm_vcpu *vcpu); -- 2.20.1