diff options
| author | Alex Williamson <alex.williamson@redhat.com> | 2016-01-18 16:06:03 -0700 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2018-12-20 11:25:36 -0500 |
| commit | c2077e2ca0da75b6b97e2485a41b8168e2a387c2 (patch) | |
| tree | 17861c7c23b58919a45094647ffc727d943e83e5 /hw/pci | |
| parent | 27c1da512994b34912dbb8d12982045da1450e65 (diff) | |
| download | qemu-c2077e2ca0da75b6b97e2485a41b8168e2a387c2.zip | |
pci: Adjust PCI config limit based on bus topology
A conventional PCI bus does not support config space accesses above
the standard 256 byte configuration space. PCIe-to-PCI bridges are
not permitted to forward transactions if the extended register address
field is non-zero and must handle it as an unsupported request (PCIe
bridge spec rev 1.0, 4.1.3, 4.1.4). Therefore, we should not support
extended config space if there is a conventional bus anywhere on the
path to a device.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/pci')
| -rw-r--r-- | hw/pci/pci_host.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/hw/pci/pci_host.c b/hw/pci/pci_host.c index 5eaa935cb5..5f5345dbac 100644 --- a/hw/pci/pci_host.c +++ b/hw/pci/pci_host.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "hw/pci/pci.h" +#include "hw/pci/pci_bridge.h" #include "hw/pci/pci_host.h" #include "hw/pci/pci_bus.h" #include "trace.h" @@ -50,9 +51,29 @@ static inline PCIDevice *pci_dev_find_by_addr(PCIBus *bus, uint32_t addr) return pci_find_device(bus, bus_num, devfn); } +static void pci_adjust_config_limit(PCIBus *bus, uint32_t *limit) +{ + if (*limit > PCI_CONFIG_SPACE_SIZE) { + if (!pci_bus_is_express(bus)) { + *limit = PCI_CONFIG_SPACE_SIZE; + return; + } + + if (!pci_bus_is_root(bus)) { + PCIDevice *bridge = pci_bridge_get_device(bus); + pci_adjust_config_limit(pci_get_bus(bridge), limit); + } + } +} + void pci_host_config_write_common(PCIDevice *pci_dev, uint32_t addr, uint32_t limit, uint32_t val, uint32_t len) { + pci_adjust_config_limit(pci_get_bus(pci_dev), &limit); + if (limit <= addr) { + return; + } + assert(len <= 4); /* non-zero functions are only exposed when function 0 is present, * allowing direct removal of unexposed functions. @@ -71,6 +92,11 @@ uint32_t pci_host_config_read_common(PCIDevice *pci_dev, uint32_t addr, { uint32_t ret; + pci_adjust_config_limit(pci_get_bus(pci_dev), &limit); + if (limit <= addr) { + return ~0x0; + } + assert(len <= 4); /* non-zero functions are only exposed when function 0 is present, * allowing direct removal of unexposed functions. |