From: Chen Fan <chen.fan.f...@cn.fujitsu.com>
For vfio pcie device, we could expose the extended capability on
PCIE bus. due to add a new pcie capability at the tail of the chain,
in order to avoid config space overwritten, we introduce a copy config
for parsing extended caps. and rebuild the pcie extended config space.
Signed-off-by: Chen Fan <chen.fan.f...@cn.fujitsu.com>
---
hw/vfio/pci.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 71 insertions(+), 1 deletion(-)
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 0a0c5b3..c662fea 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -1518,6 +1518,21 @@ static uint8_t vfio_std_cap_max_size(PCIDevice *pdev,
uint8_t pos)
return next - pos;
}
+
+static uint16_t vfio_ext_cap_max_size(const uint8_t *config, uint16_t pos)
+{
+ uint16_t tmp, next = PCIE_CONFIG_SPACE_SIZE;
+
+ for (tmp = PCI_CONFIG_SPACE_SIZE; tmp;
+ tmp = PCI_EXT_CAP_NEXT(pci_get_long(config + tmp))) {
+ if (tmp > pos && tmp < next) {
+ next = tmp;
+ }
+ }
+
+ return next - pos;
+}
+
static void vfio_set_word_bits(uint8_t *buf, uint16_t val, uint16_t mask)
{
pci_set_word(buf, (pci_get_word(buf) & ~mask) | val);
@@ -1853,16 +1868,71 @@ static int vfio_add_std_cap(VFIOPCIDevice *vdev,
uint8_t pos)
return 0;
}
+static int vfio_add_ext_cap(VFIOPCIDevice *vdev)
+{
+ PCIDevice *pdev = &vdev->pdev;
+ uint32_t header;
+ uint16_t cap_id, next, size;
+ uint8_t cap_ver;
+ uint8_t *config;
+
+ /*
+ * pcie_add_capability always inserts the new capability at the tail
+ * of the chain. Therefore to end up with a chain that matches the
+ * physical device, we cache the config space to avoid overwriting
+ * the original config space when we parse the extended capabilities.
+ */
+ config = g_memdup(pdev->config, vdev->config_size);
+
+ for (next = PCI_CONFIG_SPACE_SIZE; next;
+ next = PCI_EXT_CAP_NEXT(pci_get_long(config + next))) {
+ header = pci_get_long(config + next);
+ cap_id = PCI_EXT_CAP_ID(header);
+ cap_ver = PCI_EXT_CAP_VER(header);
+
+ /*
+ * If it becomes important to configure extended capabilities to their
+ * actual size, use this as the default when it's something we don't
+ * recognize. Since QEMU doesn't actually handle many of the config
+ * accesses, exact size doesn't seem worthwhile.
+ */
+ size = vfio_ext_cap_max_size(config, next);
+
+ pcie_add_capability(pdev, cap_id, cap_ver, next, size);
+ pci_set_long(dev->config + next, PCI_EXT_CAP(cap_id, cap_ver, 0));
+
+ /* Use emulated next pointer to allow dropping extended caps */
+ pci_long_test_and_set_mask(vdev->emulated_config_bits + next,
+ PCI_EXT_CAP_NEXT_MASK);
+ }
+
+ g_free(config);
+ return 0;
+}
+
static int vfio_add_capabilities(VFIOPCIDevice *vdev)
{
PCIDevice *pdev = &vdev->pdev;
+ int ret;
if (!(pdev->config[PCI_STATUS] & PCI_STATUS_CAP_LIST) ||
!pdev->config[PCI_CAPABILITY_LIST]) {
return 0; /* Nothing to add */
}
- return vfio_add_std_cap(vdev, pdev->config[PCI_CAPABILITY_LIST]);
+ ret = vfio_add_std_cap(vdev, pdev->config[PCI_CAPABILITY_LIST]);
+ if (ret) {
+ return ret;
+ }
+
+ /* on PCI bus, it doesn't make sense to expose extended capabilities. */
+ if (!pci_is_express(pdev) ||
+ !pci_bus_is_express(pdev->bus) ||
+ !pci_get_long(pdev->config + PCI_CONFIG_SPACE_SIZE)) {
+ return 0;
+ }
+
+ return vfio_add_ext_cap(vdev);
}
static void vfio_pci_pre_reset(VFIOPCIDevice *vdev)
--
1.9.3
