[RFT][PATCH v2 5/9] vfio/ap: Remove redundant pfn

Nicolin Chen
2022-07-06T06:28:39Z

The vfio_ap_ops code maintains both nib address and its PFN, which
is redundant, merely because vfio_pin/unpin_pages API wanted pfn.
Since vfio_pin/unpin_pages() now accept "iova", remove duplicated
pfn code in their callers too.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
drivers/s390/crypto/vfio_ap_ops.c | 42 +++++++++++----------------
drivers/s390/crypto/vfio_ap_private.h | 4 +--
2 files changed, 19 insertions(+), 27 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 8a2018ab3cf0..6945e0ddc08c 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -112,7 +112,7 @@ static void vfio_ap_wait_for_irqclear(int apqn)
*
* Unregisters the ISC in the GIB when the saved ISC not invalid.
* Unpins the guest's page holding the NIB when it exists.
- * Resets the saved_pfn and saved_isc to invalid values.
+ * Resets the saved_iova and saved_isc to invalid values.
*/
static void vfio_ap_free_aqic_resources(struct vfio_ap_queue *q)
{
@@ -123,9 +123,9 @@ static void vfio_ap_free_aqic_resources(struct vfio_ap_queue *q)
kvm_s390_gisc_unregister(q->matrix_mdev->kvm, q->saved_isc);
q->saved_isc = VFIO_AP_ISC_INVALID;
}
- if (q->saved_pfn && !WARN_ON(!q->matrix_mdev)) {
- vfio_unpin_pages(&q->matrix_mdev->vdev, q->saved_pfn << PAGE_SHIFT, 1);
- q->saved_pfn = 0;
+ if (q->saved_iova && !WARN_ON(!q->matrix_mdev)) {
+ vfio_unpin_pages(&q->matrix_mdev->vdev, q->saved_iova, 1);
+ q->saved_iova = 0;
}
}

@@ -189,27 +189,19 @@ static struct ap_queue_status vfio_ap_irq_disable(struct vfio_ap_queue *q)
*
* @vcpu: the object representing the vcpu executing the PQAP(AQIC) instruction.
* @nib: the location for storing the nib address.
- * @g_pfn: the location for storing the page frame number of the page containing
- * the nib.
*
* When the PQAP(AQIC) instruction is executed, general register 2 contains the
* address of the notification indicator byte (nib) used for IRQ notification.
- * This function parses the nib from gr2 and calculates the page frame
- * number for the guest of the page containing the nib. The values are
- * stored in @nib and @g_pfn respectively.
- *
- * The g_pfn of the nib is then validated to ensure the nib address is valid.
+ * This function parses and validate the nib from gr2.
*
* Return: returns zero if the nib address is a valid; otherwise, returns
* -EINVAL.
*/
-static int vfio_ap_validate_nib(struct kvm_vcpu *vcpu, unsigned long *nib,
- unsigned long *g_pfn)
+static int vfio_ap_validate_nib(struct kvm_vcpu *vcpu, dma_addr_t *nib)
{
*nib = vcpu->run->s.regs.gprs[2];
- *g_pfn = *nib >> PAGE_SHIFT;

- if (kvm_is_error_hva(gfn_to_hva(vcpu->kvm, *g_pfn)))
+ if (kvm_is_error_hva(gfn_to_hva(vcpu->kvm, *nib >> PAGE_SHIFT)))
return -EINVAL;

return 0;
@@ -239,34 +231,34 @@ static struct ap_queue_status vfio_ap_irq_enable(struct vfio_ap_queue *q,
int isc,
struct kvm_vcpu *vcpu)
{
- unsigned long nib;
struct ap_qirq_ctrl aqic_gisa = {};
struct ap_queue_status status = {};
struct kvm_s390_gisa *gisa;
int nisc;
struct kvm *kvm;
- unsigned long g_pfn, h_pfn;
+ unsigned long h_pfn;
phys_addr_t h_nib;
+ dma_addr_t nib;
int ret;

/* Verify that the notification indicator byte address is valid */
- if (vfio_ap_validate_nib(vcpu, &nib, &g_pfn)) {
- VFIO_AP_DBF_WARN("%s: invalid NIB address: nib=%#lx, g_pfn=%#lx, apqn=%#04x\n",
- __func__, nib, g_pfn, q->apqn);
+ if (vfio_ap_validate_nib(vcpu, &nib)) {
+ VFIO_AP_DBF_WARN("%s: invalid NIB address: nib=%pad, apqn=%#04x\n",
+ __func__, &nib, q->apqn);

status.response_code = AP_RESPONSE_INVALID_ADDRESS;
return status;
}

- ret = vfio_pin_pages(&q->matrix_mdev->vdev, g_pfn << PAGE_SHIFT, 1,
+ ret = vfio_pin_pages(&q->matrix_mdev->vdev, nib, 1,
IOMMU_READ | IOMMU_WRITE, &h_pfn);
switch (ret) {
case 1:
break;
default:
VFIO_AP_DBF_WARN("%s: vfio_pin_pages failed: rc=%d,"
- "nib=%#lx, g_pfn=%#lx, apqn=%#04x\n",
- __func__, ret, nib, g_pfn, q->apqn);
+ "nib=%pad, apqn=%#04x\n",
+ __func__, ret, &nib, q->apqn);

status.response_code = AP_RESPONSE_INVALID_ADDRESS;
return status;
@@ -296,12 +288,12 @@ static struct ap_queue_status vfio_ap_irq_enable(struct vfio_ap_queue *q,
case AP_RESPONSE_NORMAL:
/* See if we did clear older IRQ configuration */
vfio_ap_free_aqic_resources(q);
- q->saved_pfn = g_pfn;
+ q->saved_iova = nib;
q->saved_isc = isc;
break;
case AP_RESPONSE_OTHERWISE_CHANGED:
/* We could not modify IRQ setings: clear new configuration */
- vfio_unpin_pages(&q->matrix_mdev->vdev, g_pfn << PAGE_SHIFT, 1);
+ vfio_unpin_pages(&q->matrix_mdev->vdev, nib, 1);
kvm_s390_gisc_unregister(kvm, isc);
break;
default:
diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
index a26efd804d0d..479b205179bd 100644
--- a/drivers/s390/crypto/vfio_ap_private.h
+++ b/drivers/s390/crypto/vfio_ap_private.h
@@ -102,13 +102,13 @@ struct ap_matrix_mdev {
* struct vfio_ap_queue - contains the data associated with a queue bound to the
* vfio_ap device driver
* @matrix_mdev: the matrix mediated device
- * @saved_pfn: the guest PFN pinned for the guest
+ * @saved_iova: the notification indicator byte (nib) address
* @apqn: the APQN of the AP queue device
* @saved_isc: the guest ISC registered with the GIB interface
*/
struct vfio_ap_queue {
struct ap_matrix_mdev *matrix_mdev;
- unsigned long saved_pfn;
+ dma_addr_t saved_iova;
int apqn;
#define VFIO_AP_ISC_INVALID 0xff
unsigned char saved_isc;
--
2.17.1