[PATCH v3] pci: correct pci config size default for cap version 2 endpoints

Donald Dutile
2011-07-22T15:59:05Z

v3: remove all boundary tests. just fix the obvious bug.
: boundary test is not necessary; get this fix in &
post boundary test in another separate patch.

v2: do local boundary check with respect to legacy PCI header length,
and don't depend on it in pci_add_capability().
: fix compilation, and change else>2 to simple else for all other cases.

v1: first patch: boundary check in pci_add_capability().

Doing device assignement using a PCIe device with it's
PCI Cap structure at offset 0xcc showed a problem in
the default size mapped for this cap-id.

The failure caused a corruption which might have gone unnoticed
otherwise.

Fix assigned_device_pci_cap_init() to set the default
size of PCIe Cap structure (cap-id 0x10) to 0x34 instead of 0x3c.
0x34 is default, min, for endpoint device with a cap version of 2.

Signed-off-by: Donald Dutile <ddutile@redhat.com>
cc: Alex Williamson <alex.williamson@redhat.com>
cc: Michael S. Tsirkin <mst@redhat.com>

tested-by: ebenes@redhat.com

---

hw/device-assignment.c | 8 +++++---
1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/hw/device-assignment.c b/hw/device-assignment.c
index 36ad6b0..34db52e 100644
--- a/hw/device-assignment.c
+++ b/hw/device-assignment.c
@@ -1419,16 +1419,18 @@ static int assigned_device_pci_cap_init(PCIDevice *pci_dev)
}

if ((pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_EXP, 0))) {
- uint8_t version;
+ uint8_t version, size;
uint16_t type, devctl, lnkcap, lnksta;
uint32_t devcap;
- int size = 0x3c; /* version 2 size */

version = pci_get_byte(pci_dev->config + pos + PCI_EXP_FLAGS);
version &= PCI_EXP_FLAGS_VERS;
if (version == 1) {
size = 0x14;
- } else if (version > 2) {
+ } else if (version == 2) {
+ /* don't include slot cap/stat/ctrl 2 regs; only support endpoints */
+ size = 0x34;
+ } else {
fprintf(stderr, "Unsupported PCI express capability version %d\n",
version);
return -EINVAL;