From: Thomas Huth <thuth@xxxxxxxxxxxxxxxxxx>
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 <thuth@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Reviewed-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
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 0a01744..d91feb2 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 38b589d..e489945 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);
--
1.8.4.2
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