On 01/12/2016 04:43 AM, Cao jin wrote:
From: Chen Fan <chen.fan.f...@cn.fujitsu.com>
Hi, I noticed a type in the subject, extanded -> extended
For vfio pcie device, we could expose the extended capability on PCIE bus. in order to avoid config space broken, we introduce a copy config for parsing extended caps. and rebuild the pcie extended config space.
Maybe we can re-word this. Will someone with better English skills advice :) ?
Signed-off-by: Chen Fan <chen.fan.f...@cn.fujitsu.com> --- hw/vfio/pci.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 69 insertions(+), 1 deletion(-) diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 288f2c7..64b0867 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -1482,6 +1482,21 @@ 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; +}
Can't we reuse vfio_std_cap_max_size here? if only the config size differs, we can pass it as parameter.
+ 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); @@ -1817,16 +1832,69 @@ 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; + + /* + * In order to avoid breaking config space, create a copy to + * use for parsing extended capabilities.
It will be nice to know *how* do we break/*what* will break the config space, I confess that I didn't see it :(.
+ */ + 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)) {
I am curious about the last check, "!pci_get_long(pdev->config + PCI_CONFIG_SPACE_SIZE)", can you please explain? Thank you, Marcel
+ return 0; + } + + return vfio_add_ext_cap(vdev); } static void vfio_pci_pre_reset(VFIOPCIDevice *vdev)