[RFC PATCH V3 09/26] vfio/pci: Move per-interrupt contexts to generic interrupt struct

From: Reinette Chatre
Date: Fri Oct 27 2023 - 13:02:12 EST


VFIO PCI interrupt management maintains per-interrupt context within an
xarray using the interrupt vector as index.

Move the per-interrupt context to the generic interrupt context in
struct vfio_pci_intr_ctx to enable the per-interrupt context to be
managed by different backends.

Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
---
Changes since RFC V2:
- Improve changelog.

drivers/vfio/pci/vfio_pci_core.c | 1 -
drivers/vfio/pci/vfio_pci_intrs.c | 9 +++++----
include/linux/vfio_pci_core.h | 3 ++-
3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index bf4de137ad2f..cf303a9555f0 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -2162,7 +2162,6 @@ int vfio_pci_core_init_dev(struct vfio_device *core_vdev)
INIT_LIST_HEAD(&vdev->vma_list);
INIT_LIST_HEAD(&vdev->sriov_pfs_item);
init_rwsem(&vdev->memory_lock);
- xa_init(&vdev->ctx);
vfio_pci_init_intr_ctx(vdev, &vdev->intr_ctx);

return 0;
diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
index 5d600548b5d7..3cfd7fdec87b 100644
--- a/drivers/vfio/pci/vfio_pci_intrs.c
+++ b/drivers/vfio/pci/vfio_pci_intrs.c
@@ -52,13 +52,13 @@ static
struct vfio_pci_irq_ctx *vfio_irq_ctx_get(struct vfio_pci_core_device *vdev,
unsigned long index)
{
- return xa_load(&vdev->ctx, index);
+ return xa_load(&vdev->intr_ctx.ctx, index);
}

static void vfio_irq_ctx_free(struct vfio_pci_core_device *vdev,
struct vfio_pci_irq_ctx *ctx, unsigned long index)
{
- xa_erase(&vdev->ctx, index);
+ xa_erase(&vdev->intr_ctx.ctx, index);
kfree(ctx);
}

@@ -72,7 +72,7 @@ vfio_irq_ctx_alloc(struct vfio_pci_core_device *vdev, unsigned long index)
if (!ctx)
return NULL;

- ret = xa_insert(&vdev->ctx, index, ctx, GFP_KERNEL_ACCOUNT);
+ ret = xa_insert(&vdev->intr_ctx.ctx, index, ctx, GFP_KERNEL_ACCOUNT);
if (ret) {
kfree(ctx);
return NULL;
@@ -530,7 +530,7 @@ static void vfio_msi_disable(struct vfio_pci_core_device *vdev, bool msix)
unsigned long i;
u16 cmd;

- xa_for_each(&vdev->ctx, i, ctx) {
+ xa_for_each(&vdev->intr_ctx.ctx, i, ctx) {
vfio_virqfd_disable(&ctx->unmask);
vfio_virqfd_disable(&ctx->mask);
vfio_msi_set_vector_signal(vdev, i, -1, msix);
@@ -810,6 +810,7 @@ void vfio_pci_init_intr_ctx(struct vfio_pci_core_device *vdev,
intr_ctx->ops = &vfio_pci_intr_ops;
intr_ctx->priv = vdev;
mutex_init(&intr_ctx->igate);
+ xa_init(&intr_ctx->ctx);
}
EXPORT_SYMBOL_GPL(vfio_pci_init_intr_ctx);

diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
index 1eb5842cff11..0f9df87aedd9 100644
--- a/include/linux/vfio_pci_core.h
+++ b/include/linux/vfio_pci_core.h
@@ -56,6 +56,7 @@ struct vfio_pci_region {
* @igate: Protects members of struct vfio_pci_intr_ctx
* @err_trigger: Eventfd associated with error reporting IRQ
* @req_trigger: Eventfd associated with device request notification
+ * @ctx: Per-interrupt context indexed by vector
*/
struct vfio_pci_intr_ctx {
const struct vfio_pci_intr_ops *ops;
@@ -63,6 +64,7 @@ struct vfio_pci_intr_ctx {
struct mutex igate;
struct eventfd_ctx *err_trigger;
struct eventfd_ctx *req_trigger;
+ struct xarray ctx;
};

struct vfio_pci_intr_ops {
@@ -98,7 +100,6 @@ struct vfio_pci_core_device {
u8 *vconfig;
struct perm_bits *msi_perm;
spinlock_t irqlock;
- struct xarray ctx;
int irq_type;
int num_regions;
struct vfio_pci_region *region;
--
2.34.1