@@ -1644,19 +1644,39 @@ PCIDevice *pci_create_simple(PCIBus *bus, int devfn, const char *name)
return pci_create_simple_multifunction(bus, devfn, false, name);
}
-static int pci_find_space(PCIDevice *pdev, uint8_t size)
+static int pci_find_space(PCIDevice *pdev, uint32_t start,
+ uint32_t end, uint32_t size)
{
- int config_size = pci_config_size(pdev);
- int offset = PCI_CONFIG_HEADER_SIZE;
+ int offset = start;
int i;
- for (i = PCI_CONFIG_HEADER_SIZE; i < config_size; ++i)
- if (pdev->used[i])
- offset = i + 1;
- else if (i - offset + 1 == size)
+ uint32_t *dword_used = &pdev->used[start];
+
+ assert(pci_config_size(pdev) >= end);
+ assert(!(start & 0x3));
+
+ /* This approach ensures the capability is dword-aligned, as
+ required by the PCI and PCI-E specifications */
+ for (i = start; i < end; i += 4, dword_used++) {
+ if (*dword_used) {
+ offset = i + 4;
+ } else if (i - offset + 4 >= size) {
return offset;
+ }
+ }
+
return 0;
}
+static int pci_find_legacy_space(PCIDevice *pdev, uint8_t size) {
+ return pci_find_space(pdev, PCI_CONFIG_HEADER_SIZE,
+ PCI_CONFIG_SPACE_SIZE, size);
+}
+
+static int pci_find_express_space(PCIDevice *pdev, uint16_t size) {
+ return pci_find_space(pdev, PCI_CONFIG_SPACE_SIZE,
+ PCIE_CONFIG_SPACE_SIZE, size);
+}
+
static uint8_t pci_find_capability_list(PCIDevice *pdev, uint8_t cap_id,
uint8_t *prev_p)
{
@@ -1844,7 +1864,7 @@ int pci_add_capability(PCIDevice *pdev, uint8_t cap_id,
int i, overlapping_cap;
if (!offset) {
- offset = pci_find_space(pdev, size);
+ offset = pci_find_legacy_space(pdev, size);
if (!offset) {
return -ENOSPC;
}
The current implementation of pci_find_space does not correctly align PCI capabilities in the PCI configuration space. It also does not support PCI-Express devices. This patch fixes these issues. Thanks to Alex Williamson for feedback. Signed-off-by: Matt Renzelmann <mjr@cs.wisc.edu> --- Re-sending to add CC Michael S. Tsirkin <mst@redhat.com>. Thanks Andreas for pointing out my mistake. hw/pci.c | 36 ++++++++++++++++++++++++++++-------- 1 files changed, 28 insertions(+), 8 deletions(-)