virtio-pci: introduce modern device module

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-17-jasowang@redhat.com

Including a bugfix:

virtio: don't prompt CONFIG_VIRTIO_PCI_MODERN

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Fixes: 86b87c9 ("virtio-pci: introduce modern device module")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20210223061905.422659-2-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/virtio/Kconfig

@@ -12,6 +12,14 @@ config ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
 	  This option is selected if the architecture may need to enforce
 	  VIRTIO_F_ACCESS_PLATFORM
 
+config VIRTIO_PCI_LIB
+	tristate
+	help
+	  Modern PCI device implementation. This module implements the
+	  basic probe and control for devices which are based on modern
+	  PCI device with possible vendor specific extensions. Any
+	  module that selects this module must depend on PCI.
+
 menuconfig VIRTIO_MENU
 	bool "Virtio drivers"
 	default y
@@ -21,6 +29,7 @@ if VIRTIO_MENU
 config VIRTIO_PCI
 	tristate "PCI driver for virtio devices"
 	depends on PCI
+	select VIRTIO_PCI_LIB
 	select VIRTIO
 	help
 	  This driver provides support for virtio based paravirtual device

drivers/virtio/Makefile

@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o
+obj-$(CONFIG_VIRTIO_PCI_LIB) += virtio_pci_modern_dev.o
 obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
 obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o
 virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o

drivers/virtio/virtio_pci_common.h

@@ -25,6 +25,7 @@
 #include <linux/virtio_config.h>
 #include <linux/virtio_ring.h>
 #include <linux/virtio_pci.h>
+#include <linux/virtio_pci_modern.h>
 #include <linux/highmem.h>
 #include <linux/spinlock.h>
 
@@ -39,32 +40,6 @@ struct virtio_pci_vq_info {
 	unsigned msix_vector;
 };
 
-struct virtio_pci_modern_device {
-	struct pci_dev *pci_dev;
-
-	struct virtio_pci_common_cfg __iomem *common;
-	/* Device-specific data (non-legacy mode)  */
-	void __iomem *device;
-	/* Base of vq notifications (non-legacy mode). */
-	void __iomem *notify_base;
-	/* Where to read and clear interrupt */
-	u8 __iomem *isr;
-
-	/* So we can sanity-check accesses. */
-	size_t notify_len;
-	size_t device_len;
-
-	/* Capability for when we need to map notifications per-vq. */
-	int notify_map_cap;
-
-	/* Multiply queue_notify_off by this value. (non-legacy mode). */
-	u32 notify_offset_multiplier;
-
-	int modern_bars;
-
-	struct virtio_device_id id;
-};
-
 /* Our device structure */
 struct virtio_pci_device {
 	struct virtio_device vdev;