RE: [PATCH v8 03/15] pcie_sriov: Reset SR-IOV extended capability

[Sriram Yagnaraman]

> -----Original Message-----
> From: Akihiko Odaki <akihiko.odaki@daynix.com>
> Sent: Wednesday, 28 February 2024 12:33
> To: Philippe Mathieu-Daudé <philmd@linaro.org>; Michael S. Tsirkin
> <mst@redhat.com>; Marcel Apfelbaum <marcel.apfelbaum@gmail.com>;
> Alex Williamson <alex.williamson@redhat.com>; Cédric Le Goater
> <clg@redhat.com>; Paolo Bonzini <pbonzini@redhat.com>; Daniel P.
> Berrangé <berrange@redhat.com>; Eduardo Habkost
> <eduardo@habkost.net>; Sriram Yagnaraman
> <sriram.yagnaraman@ericsson.com>; Jason Wang <jasowang@redhat.com>;
> Keith Busch <kbusch@kernel.org>; Klaus Jensen <its@irrelevant.dk>; Markus
> Armbruster <armbru@redhat.com>
> Cc: qemu-devel@nongnu.org; qemu-block@nongnu.org; Akihiko Odaki
> <akihiko.odaki@daynix.com>
> Subject: [PATCH v8 03/15] pcie_sriov: Reset SR-IOV extended capability
> 
> pcie_sriov_pf_disable_vfs() is called when resetting the PF, but it only 
> disables
> VFs and does not reset SR-IOV extended capability, leaking the state and
> making the VF Enable register inconsistent with the actual state.
> 
> Replace pcie_sriov_pf_disable_vfs() with pcie_sriov_pf_reset(), which does
> not only disable VFs but also resets the capability.
> 
> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
> ---
>  include/hw/pci/pcie_sriov.h |  4 ++--
>  hw/net/igb.c                |  2 +-
>  hw/nvme/ctrl.c              |  2 +-
>  hw/pci/pcie_sriov.c         | 26 ++++++++++++++++++--------
>  4 files changed, 22 insertions(+), 12 deletions(-)
> 
> diff --git a/include/hw/pci/pcie_sriov.h b/include/hw/pci/pcie_sriov.h index
> 095fb0c9edf9..b77eb7bf58ac 100644
> --- a/include/hw/pci/pcie_sriov.h
> +++ b/include/hw/pci/pcie_sriov.h
> @@ -58,8 +58,8 @@ void pcie_sriov_pf_add_sup_pgsize(PCIDevice *dev,
> uint16_t opt_sup_pgsize);  void pcie_sriov_config_write(PCIDevice *dev,
> uint32_t address,
>                               uint32_t val, int len);
> 
> -/* Reset SR/IOV VF Enable bit to unregister all VFs */ -void
> pcie_sriov_pf_disable_vfs(PCIDevice *dev);
> +/* Reset SR/IOV */
> +void pcie_sriov_pf_reset(PCIDevice *dev);
> 
>  /* Get logical VF number of a VF - only valid for VFs */  uint16_t
> pcie_sriov_vf_number(PCIDevice *dev); diff --git a/hw/net/igb.c
> b/hw/net/igb.c index 0b5c31a58bba..9345506f81ec 100644
> --- a/hw/net/igb.c
> +++ b/hw/net/igb.c
> @@ -493,7 +493,7 @@ static void igb_qdev_reset_hold(Object *obj)
> 
>      trace_e1000e_cb_qdev_reset_hold();
> 
> -    pcie_sriov_pf_disable_vfs(d);
> +    pcie_sriov_pf_reset(d);
>      igb_core_reset(&s->core);
>  }
> 
> diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c index
> 7a56e7b79b4d..7c0d3f108724 100644
> --- a/hw/nvme/ctrl.c
> +++ b/hw/nvme/ctrl.c
> @@ -7116,7 +7116,7 @@ static void nvme_ctrl_reset(NvmeCtrl *n,
> NvmeResetType rst)
>              }
> 
>              if (rst != NVME_RESET_CONTROLLER) {
> -                pcie_sriov_pf_disable_vfs(pci_dev);
> +                pcie_sriov_pf_reset(pci_dev);
>              }
>          }
> 
> diff --git a/hw/pci/pcie_sriov.c b/hw/pci/pcie_sriov.c index
> da209b7f47fd..51b66d1bb342 100644
> --- a/hw/pci/pcie_sriov.c
> +++ b/hw/pci/pcie_sriov.c
> @@ -249,16 +249,26 @@ void pcie_sriov_config_write(PCIDevice *dev,
> uint32_t address,  }
> 
> 
> -/* Reset SR/IOV VF Enable bit to trigger an unregister of all VFs */ -void
> pcie_sriov_pf_disable_vfs(PCIDevice *dev)
> +/* Reset SR/IOV */
> +void pcie_sriov_pf_reset(PCIDevice *dev)
>  {
>      uint16_t sriov_cap = dev->exp.sriov_cap;
> -    if (sriov_cap) {
> -        uint32_t val = pci_get_byte(dev->config + sriov_cap + 
> PCI_SRIOV_CTRL);
> -        if (val & PCI_SRIOV_CTRL_VFE) {
> -            val &= ~PCI_SRIOV_CTRL_VFE;
> -            pcie_sriov_config_write(dev, sriov_cap + PCI_SRIOV_CTRL, val, 1);
> -        }
> +    if (!sriov_cap) {
> +        return;
> +    }
> +
> +    pci_set_word(dev->config + sriov_cap + PCI_SRIOV_CTRL, 0);
> +    unregister_vfs(dev);
> +
> +    /*
> +     * Default is to use 4K pages, software can modify it
> +     * to any of the supported bits
> +     */
> +    pci_set_word(dev->config + sriov_cap + PCI_SRIOV_SYS_PGSIZE, 0x1);
> +

Just curious, do we need this?
On Linux, I thought the PCI subsystem restores the page size after reset.

Otherwise, 
Assuming change of my mail address from sriram.yagnaraman@est.tech to 
@ericsson.com is accepted,
Reviewed-by: Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>

> +    for (uint16_t i = 0; i < PCI_NUM_REGIONS; i++) {
> +        pci_set_quad(dev->config + sriov_cap + PCI_SRIOV_BAR + i * 4,
> +                     dev->exp.sriov_pf.vf_bar_type[i]);
>      }
>  }
> 
> 
> --
> 2.43.2