diff options
Diffstat (limited to 'drivers/s390/crypto/vfio_ap_ops.c')
| -rw-r--r-- | drivers/s390/crypto/vfio_ap_ops.c | 32 |
1 files changed, 22 insertions, 10 deletions
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c index 8c0b40d8eb39..a52c2690933f 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -360,10 +360,26 @@ static int vfio_ap_validate_nib(struct kvm_vcpu *vcpu, dma_addr_t *nib) return 0; } -static int ensure_nib_shared(unsigned long addr, struct gmap *gmap) +/** + * ensure_nib_shared() - Ensure the address of the NIB is secure and shared + * @addr: the physical (absolute) address of the NIB + * + * This function checks whether the NIB page, which has been pinned with + * vfio_pin_pages(), is a shared page belonging to a secure guest. + * + * It will call uv_pin_shared() on it; if the page was already pinned shared + * (i.e. if the NIB belongs to a secure guest and is shared), then 0 + * (success) is returned. If the NIB was not shared, vfio_pin_pages() had + * exported it and now it does not belong to the secure guest anymore. In + * that case, an error is returned. + * + * Context: the NIB (at physical address @addr) has to be pinned with + * vfio_pin_pages() before calling this function. + * + * Return: 0 in case of success, otherwise an error < 0. + */ +static int ensure_nib_shared(unsigned long addr) { - int ret; - /* * The nib has to be located in shared storage since guest and * host access it. vfio_pin_pages() will do a pin shared and @@ -374,12 +390,7 @@ static int ensure_nib_shared(unsigned long addr, struct gmap *gmap) * * If the page is already pinned shared the UV will return a success. */ - ret = uv_pin_shared(addr); - if (ret) { - /* vfio_pin_pages() likely exported the page so let's re-import */ - gmap_convert_to_secure(gmap, addr); - } - return ret; + return uv_pin_shared(addr); } /** @@ -425,6 +436,7 @@ static struct ap_queue_status vfio_ap_irq_enable(struct vfio_ap_queue *q, return status; } + /* The pin will probably be successful even if the NIB was not shared */ ret = vfio_pin_pages(&q->matrix_mdev->vdev, nib, 1, IOMMU_READ | IOMMU_WRITE, &h_page); switch (ret) { @@ -447,7 +459,7 @@ static struct ap_queue_status vfio_ap_irq_enable(struct vfio_ap_queue *q, /* NIB in non-shared storage is a rc 6 for PV guests */ if (kvm_s390_pv_cpu_is_protected(vcpu) && - ensure_nib_shared(h_nib & PAGE_MASK, kvm->arch.gmap)) { + ensure_nib_shared(h_nib & PAGE_MASK)) { vfio_unpin_pages(&q->matrix_mdev->vdev, nib, 1); status.response_code = AP_RESPONSE_INVALID_ADDRESS; return status; |