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Re: [Qemu-devel] [PATCH v16 05/14] vfio: add pcie extanded capability su
From: |
Marcel Apfelbaum |
Subject: |
Re: [Qemu-devel] [PATCH v16 05/14] vfio: add pcie extanded capability support |
Date: |
Sun, 17 Jan 2016 15:22:37 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 |
On 01/12/2016 04:43 AM, Cao jin wrote:
From: Chen Fan <address@hidden>
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 <address@hidden>
---
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)
- [Qemu-devel] [PATCH v16 00/14] vfio-pci: pass the aer error to guest, Cao jin, 2016/01/11
- [Qemu-devel] [PATCH v16 01/14] vfio: extract vfio_get_hot_reset_info as a single function, Cao jin, 2016/01/11
- [Qemu-devel] [PATCH v16 02/14] vfio: squeeze out vfio_pci_do_hot_reset for support bus reset, Cao jin, 2016/01/11
- [Qemu-devel] [PATCH v16 03/14] pcie: modify the capability size assert, Cao jin, 2016/01/11
- [Qemu-devel] [PATCH v16 04/14] vfio: make the 4 bytes aligned for capability size, Cao jin, 2016/01/11
- [Qemu-devel] [PATCH v16 05/14] vfio: add pcie extanded capability support, Cao jin, 2016/01/11
- Re: [Qemu-devel] [PATCH v16 05/14] vfio: add pcie extanded capability support,
Marcel Apfelbaum <=
- [Qemu-devel] [PATCH v16 07/14] vfio: add aer support for vfio device, Cao jin, 2016/01/11
- [Qemu-devel] [PATCH v16 06/14] aer: impove pcie_aer_init to support vfio device, Cao jin, 2016/01/11
- [Qemu-devel] [PATCH v16 08/14] vfio: add check host bus reset is support or not, Cao jin, 2016/01/11
- [Qemu-devel] [PATCH v16 10/14] pci: introduce pci bus pre reset, Cao jin, 2016/01/11