Commit fa576c58 authored by Thomas Huth's avatar Thomas Huth Committed by Christian Borntraeger
Browse files

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: default avatarThomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 684135e0

arch/s390/kvm/kvm-s390.c

+25 −7
Original line number Diff line number Diff line
@@ -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) {

arch/s390/kvm/kvm-s390.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

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