On Thu, Oct 07, 2021 at 06:23:55PM +0200, Lukasz Maniak wrote:
> PCIe devices implementing SR-IOV may need to perform certain actions
> before the VFs are unrealized or vice versa.
>
> Signed-off-by: Lukasz Maniak <lukasz.man...@linux.intel.com>
Callbacks are annoying and easy to misuse though.
VFs are enabled through a config cycle, we generally just
have devices invoke the capability handler.
E.g.
static void pci_bridge_dev_write_config(PCIDevice *d,
uint32_t address, uint32_t val, int len)
{
pci_bridge_write_config(d, address, val, len);
if (msi_present(d)) {
msi_write_config(d, address, val, len);
}
}
this makes it easy to do whatever you want before/after
the write. You can also add a helper to check
that SRIOV is being enabled/disabled if necessary.
> ---
> docs/pcie_sriov.txt | 2 +-
> hw/pci/pcie_sriov.c | 14 +++++++++++++-
> include/hw/pci/pcie_sriov.h | 8 +++++++-
> 3 files changed, 21 insertions(+), 3 deletions(-)
>
> diff --git a/docs/pcie_sriov.txt b/docs/pcie_sriov.txt
> index f5e891e1d4..63ca1a7b8e 100644
> --- a/docs/pcie_sriov.txt
> +++ b/docs/pcie_sriov.txt
> @@ -57,7 +57,7 @@ setting up a BAR for a VF.
> /* Add and initialize the SR/IOV capability */
> pcie_sriov_pf_init(d, 0x200, "your_virtual_dev",
> vf_devid, initial_vfs, total_vfs,
> - fun_offset, stride);
> + fun_offset, stride, pre_vfs_update_cb);
>
> /* Set up individual VF BARs (parameters as for normal BARs) */
> pcie_sriov_pf_init_vf_bar( ... )
> diff --git a/hw/pci/pcie_sriov.c b/hw/pci/pcie_sriov.c
> index 501a1ff433..cac2aee061 100644
> --- a/hw/pci/pcie_sriov.c
> +++ b/hw/pci/pcie_sriov.c
> @@ -30,7 +30,8 @@ static void unregister_vfs(PCIDevice *dev);
> void pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset,
> const char *vfname, uint16_t vf_dev_id,
> uint16_t init_vfs, uint16_t total_vfs,
> - uint16_t vf_offset, uint16_t vf_stride)
> + uint16_t vf_offset, uint16_t vf_stride,
> + SriovVfsUpdate pre_vfs_update)
> {
> uint8_t *cfg = dev->config + offset;
> uint8_t *wmask;
> @@ -41,6 +42,7 @@ void pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset,
> dev->exp.sriov_pf.num_vfs = 0;
> dev->exp.sriov_pf.vfname = g_strdup(vfname);
> dev->exp.sriov_pf.vf = NULL;
> + dev->exp.sriov_pf.pre_vfs_update = pre_vfs_update;
>
> pci_set_word(cfg + PCI_SRIOV_VF_OFFSET, vf_offset);
> pci_set_word(cfg + PCI_SRIOV_VF_STRIDE, vf_stride);
> @@ -180,6 +182,11 @@ static void register_vfs(PCIDevice *dev)
> assert(dev->exp.sriov_pf.vf);
>
> trace_sriov_register_vfs(SRIOV_ID(dev), num_vfs);
> +
> + if (dev->exp.sriov_pf.pre_vfs_update) {
> + dev->exp.sriov_pf.pre_vfs_update(dev, dev->exp.sriov_pf.num_vfs,
> num_vfs);
> + }
> +
> for (i = 0; i < num_vfs; i++) {
> dev->exp.sriov_pf.vf[i] = register_vf(dev, devfn,
> dev->exp.sriov_pf.vfname, i);
> if (!dev->exp.sriov_pf.vf[i]) {
> @@ -198,6 +205,11 @@ static void unregister_vfs(PCIDevice *dev)
> uint16_t i;
>
> trace_sriov_unregister_vfs(SRIOV_ID(dev), num_vfs);
> +
> + if (dev->exp.sriov_pf.pre_vfs_update) {
> + dev->exp.sriov_pf.pre_vfs_update(dev, dev->exp.sriov_pf.num_vfs, 0);
> + }
> +
> for (i = 0; i < num_vfs; i++) {
> PCIDevice *vf = dev->exp.sriov_pf.vf[i];
> object_property_set_bool(OBJECT(vf), "realized", false, &local_err);
> diff --git a/include/hw/pci/pcie_sriov.h b/include/hw/pci/pcie_sriov.h
> index 0974f00054..9ab48b79c0 100644
> --- a/include/hw/pci/pcie_sriov.h
> +++ b/include/hw/pci/pcie_sriov.h
> @@ -13,11 +13,16 @@
> #ifndef QEMU_PCIE_SRIOV_H
> #define QEMU_PCIE_SRIOV_H
>
> +typedef void (*SriovVfsUpdate)(PCIDevice *dev, uint16_t prev_num_vfs,
> + uint16_t num_vfs);
> +
> struct PCIESriovPF {
> uint16_t num_vfs; /* Number of virtual functions created */
> uint8_t vf_bar_type[PCI_NUM_REGIONS]; /* Store type for each VF bar */
> const char *vfname; /* Reference to the device type used for the
> VFs */
> PCIDevice **vf; /* Pointer to an array of num_vfs VF devices
> */
> +
> + SriovVfsUpdate pre_vfs_update; /* Callback preceding VFs count change */
> };
>
> struct PCIESriovVF {
> @@ -28,7 +33,8 @@ struct PCIESriovVF {
> void pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset,
> const char *vfname, uint16_t vf_dev_id,
> uint16_t init_vfs, uint16_t total_vfs,
> - uint16_t vf_offset, uint16_t vf_stride);
> + uint16_t vf_offset, uint16_t vf_stride,
> + SriovVfsUpdate pre_vfs_update);
> void pcie_sriov_pf_exit(PCIDevice *dev);
>
> /* Set up a VF bar in the SR/IOV bar area */
> --
> 2.25.1
