[PATCH RFC 5/5] virtio_pci: macros for PCI layout offsets.
QEMU wants it, so why not? Trust, but verify.
Signed-off-by: Rusty Russell ru...@rustcorp.com.au
---
include/uapi/linux/virtio_pci.h| 30 ++
drivers/virtio/virtio_pci_modern.c | 63 ++
2 files changed, 93 insertions(+)
diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h
index 28c2ce0..5d546c6 100644
--- a/include/uapi/linux/virtio_pci.h
+++ b/include/uapi/linux/virtio_pci.h
@@ -159,6 +159,36 @@ struct virtio_pci_common_cfg {
__le32 queue_used_hi; /* read-write */
};
+/* Macro versions of offsets for the Old Timers! */
+#define VIRTIO_PCI_CAP_VNDR0
+#define VIRTIO_PCI_CAP_NEXT1
+#define VIRTIO_PCI_CAP_LEN 2
+#define VIRTIO_PCI_CAP_TYPE_AND_BAR3
+#define VIRTIO_PCI_CAP_OFFSET 4
+#define VIRTIO_PCI_CAP_LENGTH 8
+
+#define VIRTIO_PCI_NOTIFY_CAP_MULT 12
+
+#define VIRTIO_PCI_COMMON_DFSELECT 0
+#define VIRTIO_PCI_COMMON_DF 4
+#define VIRTIO_PCI_COMMON_GFSELECT 8
+#define VIRTIO_PCI_COMMON_GF 12
+#define VIRTIO_PCI_COMMON_MSIX 16
+#define VIRTIO_PCI_COMMON_NUMQ 18
+#define VIRTIO_PCI_COMMON_STATUS 20
+#define VIRTIO_PCI_COMMON_CFGGENERATION21
+#define VIRTIO_PCI_COMMON_Q_SELECT 22
+#define VIRTIO_PCI_COMMON_Q_SIZE 24
+#define VIRTIO_PCI_COMMON_Q_MSIX 26
+#define VIRTIO_PCI_COMMON_Q_ENABLE 28
+#define VIRTIO_PCI_COMMON_Q_NOFF 30
+#define VIRTIO_PCI_COMMON_Q_DESCLO 32
+#define VIRTIO_PCI_COMMON_Q_DESCHI 36
+#define VIRTIO_PCI_COMMON_Q_AVAILLO40
+#define VIRTIO_PCI_COMMON_Q_AVAILHI44
+#define VIRTIO_PCI_COMMON_Q_USEDLO 48
+#define VIRTIO_PCI_COMMON_Q_USEDHI 52
+
#endif /* VIRTIO_PCI_NO_MODERN */
#endif
diff --git a/drivers/virtio/virtio_pci_modern.c
b/drivers/virtio/virtio_pci_modern.c
index 63c..5b0c012 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -446,6 +446,67 @@ static inline int virtio_pci_find_capability(struct
pci_dev *dev, u8 cfg_type,
return 0;
}
+/* This is part of the ABI. Don't screw with it. */
+static inline void check_offsets(void)
+{
+ /* Note: disk space was harmed in compilation of this function. */
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR !=
+offsetof(struct virtio_pci_cap, cap_vndr));
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT !=
+offsetof(struct virtio_pci_cap, cap_next));
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN !=
+offsetof(struct virtio_pci_cap, cap_len));
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_TYPE_AND_BAR !=
+offsetof(struct virtio_pci_cap, type_and_bar));
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET !=
+offsetof(struct virtio_pci_cap, offset));
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH !=
+offsetof(struct virtio_pci_cap, length));
+ BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT !=
+offsetof(struct virtio_pci_notify_cap,
+ notify_off_multiplier));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT !=
+offsetof(struct virtio_pci_common_cfg,
+ device_feature_select));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF !=
+offsetof(struct virtio_pci_common_cfg, device_feature));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT !=
+offsetof(struct virtio_pci_common_cfg,
+ guest_feature_select));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF !=
+offsetof(struct virtio_pci_common_cfg, guest_feature));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX !=
+offsetof(struct virtio_pci_common_cfg, msix_config));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ !=
+offsetof(struct virtio_pci_common_cfg, num_queues));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS !=
+offsetof(struct virtio_pci_common_cfg, device_status));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_CFGGENERATION !=
+offsetof(struct virtio_pci_common_cfg, config_generation));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT !=
+offsetof(struct virtio_pci_common_cfg, queue_select));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE !=
+offsetof(struct virtio_pci_common_cfg, queue_size));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX !=
+offsetof(struct virtio_pci_common_cfg, queue_msix_vector));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE !=
+offsetof(struct virtio_pci_common_cfg, queue_enable));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF !=
+offsetof(struct virtio_pci_common_cfg, queue_notify_off));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO !=
+offsetof(struct virtio_pci_common_cfg, queue_desc_lo));
+
[PATCH RFC 5/5] virtio_pci: macros for PCI layout offsets.
From: Rusty Russell ru...@rustcorp.com.au
QEMU wants it, so why not? Trust, but verify.
Signed-off-by: Rusty Russell ru...@rustcorp.com.au
---
drivers/virtio/virtio_pci_modern.c | 61 ++
1 file changed, 61 insertions(+)
diff --git a/drivers/virtio/virtio_pci_modern.c
b/drivers/virtio/virtio_pci_modern.c
index e6e65e1..19568da 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -406,6 +406,65 @@ static void __iomem *map_capability(struct pci_dev *dev,
int off, size_t minlen,
return p;
}
+/* This is part of the ABI. Don't screw with it. */
+static inline void check_offsets(void)
+{
+ /* Note: disk space was harmed in compilation of this function. */
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR !=
+offsetof(struct virtio_pci_cap, cap_vndr));
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT !=
+offsetof(struct virtio_pci_cap, cap_next));
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN !=
+offsetof(struct virtio_pci_cap, cap_len));
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_TYPE_AND_BAR !=
+offsetof(struct virtio_pci_cap, type_and_bar));
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET !=
+offsetof(struct virtio_pci_cap, offset));
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH !=
+offsetof(struct virtio_pci_cap, length));
+ BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT !=
+offsetof(struct virtio_pci_notify_cap,
+ notify_off_multiplier));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT !=
+offsetof(struct virtio_pci_common_cfg,
+ device_feature_select));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF !=
+offsetof(struct virtio_pci_common_cfg, device_feature));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT !=
+offsetof(struct virtio_pci_common_cfg,
+ guest_feature_select));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF !=
+offsetof(struct virtio_pci_common_cfg, guest_feature));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX !=
+offsetof(struct virtio_pci_common_cfg, msix_config));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ !=
+offsetof(struct virtio_pci_common_cfg, num_queues));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS !=
+offsetof(struct virtio_pci_common_cfg, device_status));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT !=
+offsetof(struct virtio_pci_common_cfg, queue_select));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE !=
+offsetof(struct virtio_pci_common_cfg, queue_size));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX !=
+offsetof(struct virtio_pci_common_cfg, queue_msix_vector));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE !=
+offsetof(struct virtio_pci_common_cfg, queue_enable));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF !=
+offsetof(struct virtio_pci_common_cfg, queue_notify_off));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO !=
+offsetof(struct virtio_pci_common_cfg, queue_desc_lo));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI !=
+offsetof(struct virtio_pci_common_cfg, queue_desc_hi));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO !=
+offsetof(struct virtio_pci_common_cfg, queue_avail_lo));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI !=
+offsetof(struct virtio_pci_common_cfg, queue_avail_hi));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO !=
+offsetof(struct virtio_pci_common_cfg, queue_used_lo));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI !=
+offsetof(struct virtio_pci_common_cfg, queue_used_hi));
+}
+
/* the PCI probing function */
static int virtio_pci_probe(struct pci_dev *pci_dev,
const struct pci_device_id *id)
@@ -413,6 +472,8 @@ static int virtio_pci_probe(struct pci_dev *pci_dev,
struct virtio_pci_device *vp_dev;
int err, common, isr, notify, device;
+ check_offsets();
+
/* We only own devices = 0x1000 and = 0x107f: leave the rest. */
if (pci_dev-device 0x1000 || pci_dev-device 0x107f)
return -ENODEV;
--
MST
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