Re: [PATCH net-next v2 11/14] sfc: use PF's IOMMU domain for running VF's MCDI commands

From: Martin Habets
Date: Wed Mar 08 2023 - 13:01:38 EST


On Tue, Mar 07, 2023 at 05:06:13PM +0530, Gautam Dawar wrote:
> This changeset uses MC_CMD_CLIENT_CMD to execute VF's MCDI
> commands when running in vDPA mode (STATE_VDPA).
> Also, use the PF's IOMMU domain for executing the encapsulated
> VF's MCDI commands to isolate DMA of guest buffers in the VF's
> IOMMU domain.
> This patch also updates the PCIe FN's client id in the efx_nic
> structure which is required while running MC_CMD_CLIENT_CMD.
>
> Signed-off-by: Gautam Dawar <gautam.dawar@xxxxxxx>
> ---
> drivers/net/ethernet/sfc/ef100.c | 1 +
> drivers/net/ethernet/sfc/ef100_nic.c | 35 +++++++++
> drivers/net/ethernet/sfc/mcdi.c | 108 ++++++++++++++++++++++----
> drivers/net/ethernet/sfc/mcdi.h | 2 +-
> drivers/net/ethernet/sfc/net_driver.h | 2 +
> drivers/net/ethernet/sfc/ptp.c | 4 +-
> 6 files changed, 132 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/net/ethernet/sfc/ef100.c b/drivers/net/ethernet/sfc/ef100.c
> index c1c69783db7b..8453c9ba0f41 100644
> --- a/drivers/net/ethernet/sfc/ef100.c
> +++ b/drivers/net/ethernet/sfc/ef100.c
> @@ -465,6 +465,7 @@ static int ef100_pci_probe(struct pci_dev *pci_dev,
> efx->type = (const struct efx_nic_type *)entry->driver_data;
>
> efx->pci_dev = pci_dev;
> + efx->client_id = MC_CMD_CLIENT_ID_SELF;
> pci_set_drvdata(pci_dev, efx);
> rc = efx_init_struct(efx, pci_dev);
> if (rc)
> diff --git a/drivers/net/ethernet/sfc/ef100_nic.c b/drivers/net/ethernet/sfc/ef100_nic.c
> index bda4fcbe1126..cd9f724a9e64 100644
> --- a/drivers/net/ethernet/sfc/ef100_nic.c
> +++ b/drivers/net/ethernet/sfc/ef100_nic.c
> @@ -206,9 +206,11 @@ static int efx_ef100_init_datapath_caps(struct efx_nic *efx)
> "firmware reports num_mac_stats = %u\n",
> efx->num_mac_stats);
>
> +#ifdef CONFIG_SFC_VDPA

More opportunities to use IS_ENABLED(CONFIG_SFC_VDPA) in this patch
in stead of the #ifdef.

Martin

> nic_data->vdpa_supported = efx_ef100_has_cap(nic_data->datapath_caps3,
> CLIENT_CMD_VF_PROXY) &&
> efx->type->is_vf;
> +#endif
> return 0;
> }
>
> @@ -1086,6 +1088,35 @@ static int ef100_check_design_params(struct efx_nic *efx)
> return rc;
> }
>
> +static int efx_ef100_update_client_id(struct efx_nic *efx)
> +{
> + struct ef100_nic_data *nic_data = efx->nic_data;
> + unsigned int pf_index = PCIE_FUNCTION_PF_NULL;
> + unsigned int vf_index = PCIE_FUNCTION_VF_NULL;
> + efx_qword_t pciefn;
> + int rc;
> +
> + if (efx->pci_dev->is_virtfn)
> + vf_index = nic_data->vf_index;
> + else
> + pf_index = nic_data->pf_index;
> +
> + /* Construct PCIE_FUNCTION structure */
> + EFX_POPULATE_QWORD_3(pciefn,
> + PCIE_FUNCTION_PF, pf_index,
> + PCIE_FUNCTION_VF, vf_index,
> + PCIE_FUNCTION_INTF, PCIE_INTERFACE_CALLER);
> + /* look up self client ID */
> + rc = efx_ef100_lookup_client_id(efx, pciefn, &efx->client_id);
> + if (rc) {
> + pci_warn(efx->pci_dev,
> + "%s: Failed to get client ID, rc %d\n",
> + __func__, rc);
> + }
> +
> + return rc;
> +}
> +
> /* NIC probe and remove
> */
> static int ef100_probe_main(struct efx_nic *efx)
> @@ -1173,6 +1204,10 @@ static int ef100_probe_main(struct efx_nic *efx)
> goto fail;
> efx->port_num = rc;
>
> + rc = efx_ef100_update_client_id(efx);
> + if (rc)
> + goto fail;
> +
> efx_mcdi_print_fwver(efx, fw_version, sizeof(fw_version));
> pci_dbg(efx->pci_dev, "Firmware version %s\n", fw_version);
>
> diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
> index a7f2c31071e8..3bf1ebe05775 100644
> --- a/drivers/net/ethernet/sfc/mcdi.c
> +++ b/drivers/net/ethernet/sfc/mcdi.c
> @@ -145,14 +145,15 @@ void efx_mcdi_fini(struct efx_nic *efx)
> kfree(efx->mcdi);
> }
>
> -static void efx_mcdi_send_request(struct efx_nic *efx, unsigned cmd,
> - const efx_dword_t *inbuf, size_t inlen)
> +static void efx_mcdi_send_request(struct efx_nic *efx, u32 client_id,
> + unsigned int cmd, const efx_dword_t *inbuf,
> + size_t inlen)
> {
> struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
> #ifdef CONFIG_SFC_MCDI_LOGGING
> char *buf = mcdi->logging_buffer; /* page-sized */
> #endif
> - efx_dword_t hdr[2];
> + efx_dword_t hdr[5];
> size_t hdr_len;
> u32 xflags, seqno;
>
> @@ -179,7 +180,7 @@ static void efx_mcdi_send_request(struct efx_nic *efx, unsigned cmd,
> MCDI_HEADER_XFLAGS, xflags,
> MCDI_HEADER_NOT_EPOCH, !mcdi->new_epoch);
> hdr_len = 4;
> - } else {
> + } else if (client_id == efx->client_id) {
> /* MCDI v2 */
> BUG_ON(inlen > MCDI_CTL_SDU_LEN_MAX_V2);
> EFX_POPULATE_DWORD_7(hdr[0],
> @@ -194,6 +195,35 @@ static void efx_mcdi_send_request(struct efx_nic *efx, unsigned cmd,
> MC_CMD_V2_EXTN_IN_EXTENDED_CMD, cmd,
> MC_CMD_V2_EXTN_IN_ACTUAL_LEN, inlen);
> hdr_len = 8;
> + } else {
> + /* MCDI v2 */
> + WARN_ON(inlen > MCDI_CTL_SDU_LEN_MAX_V2);
> + /* MCDI v2 with credentials of a different client */
> + BUILD_BUG_ON(MC_CMD_CLIENT_CMD_IN_LEN != 4);
> + /* Outer CLIENT_CMD wrapper command with client ID */
> + EFX_POPULATE_DWORD_7(hdr[0],
> + MCDI_HEADER_RESPONSE, 0,
> + MCDI_HEADER_RESYNC, 1,
> + MCDI_HEADER_CODE, MC_CMD_V2_EXTN,
> + MCDI_HEADER_DATALEN, 0,
> + MCDI_HEADER_SEQ, seqno,
> + MCDI_HEADER_XFLAGS, xflags,
> + MCDI_HEADER_NOT_EPOCH, !mcdi->new_epoch);
> + EFX_POPULATE_DWORD_2(hdr[1],
> + MC_CMD_V2_EXTN_IN_EXTENDED_CMD,
> + MC_CMD_CLIENT_CMD,
> + MC_CMD_V2_EXTN_IN_ACTUAL_LEN, inlen + 12);
> + MCDI_SET_DWORD(&hdr[2],
> + CLIENT_CMD_IN_CLIENT_ID, client_id);
> +
> + /* MCDIv2 header for inner command */
> + EFX_POPULATE_DWORD_2(hdr[3],
> + MCDI_HEADER_CODE, MC_CMD_V2_EXTN,
> + MCDI_HEADER_DATALEN, 0);
> + EFX_POPULATE_DWORD_2(hdr[4],
> + MC_CMD_V2_EXTN_IN_EXTENDED_CMD, cmd,
> + MC_CMD_V2_EXTN_IN_ACTUAL_LEN, inlen);
> + hdr_len = 20;
> }
>
> #ifdef CONFIG_SFC_MCDI_LOGGING
> @@ -474,7 +504,8 @@ static void efx_mcdi_release(struct efx_mcdi_iface *mcdi)
> &mcdi->async_list, struct efx_mcdi_async_param, list);
> if (async) {
> mcdi->state = MCDI_STATE_RUNNING_ASYNC;
> - efx_mcdi_send_request(efx, async->cmd,
> + efx_mcdi_send_request(efx, efx->client_id,
> + async->cmd,
> (const efx_dword_t *)(async + 1),
> async->inlen);
> mod_timer(&mcdi->async_timer,
> @@ -797,7 +828,7 @@ static int efx_mcdi_proxy_wait(struct efx_nic *efx, u32 handle, bool quiet)
> return mcdi->proxy_rx_status;
> }
>
> -static int _efx_mcdi_rpc(struct efx_nic *efx, unsigned int cmd,
> +static int _efx_mcdi_rpc(struct efx_nic *efx, u32 client_id, unsigned int cmd,
> const efx_dword_t *inbuf, size_t inlen,
> efx_dword_t *outbuf, size_t outlen,
> size_t *outlen_actual, bool quiet, int *raw_rc)
> @@ -811,7 +842,7 @@ static int _efx_mcdi_rpc(struct efx_nic *efx, unsigned int cmd,
> return -EINVAL;
> }
>
> - rc = efx_mcdi_rpc_start(efx, cmd, inbuf, inlen);
> + rc = efx_mcdi_rpc_start(efx, client_id, cmd, inbuf, inlen);
> if (rc)
> return rc;
>
> @@ -836,7 +867,8 @@ static int _efx_mcdi_rpc(struct efx_nic *efx, unsigned int cmd,
>
> /* We now retry the original request. */
> mcdi->state = MCDI_STATE_RUNNING_SYNC;
> - efx_mcdi_send_request(efx, cmd, inbuf, inlen);
> + efx_mcdi_send_request(efx, efx->client_id, cmd,
> + inbuf, inlen);
>
> rc = _efx_mcdi_rpc_finish(efx, cmd, inlen,
> outbuf, outlen, outlen_actual,
> @@ -855,16 +887,44 @@ static int _efx_mcdi_rpc(struct efx_nic *efx, unsigned int cmd,
> return rc;
> }
>
> +#ifdef CONFIG_SFC_VDPA
> +static bool is_mode_vdpa(struct efx_nic *efx)
> +{
> + if (efx->pci_dev->is_virtfn &&
> + efx->pci_dev->physfn &&
> + efx->state == STATE_VDPA &&
> + efx->vdpa_nic)
> + return true;
> +
> + return false;
> +}
> +#endif
> +
> static int _efx_mcdi_rpc_evb_retry(struct efx_nic *efx, unsigned cmd,
> const efx_dword_t *inbuf, size_t inlen,
> efx_dword_t *outbuf, size_t outlen,
> size_t *outlen_actual, bool quiet)
> {
> +#ifdef CONFIG_SFC_VDPA
> + struct efx_nic *efx_pf;
> +#endif
> int raw_rc = 0;
> int rc;
>
> - rc = _efx_mcdi_rpc(efx, cmd, inbuf, inlen,
> - outbuf, outlen, outlen_actual, true, &raw_rc);
> +#ifdef CONFIG_SFC_VDPA
> + if (is_mode_vdpa(efx)) {
> + efx_pf = pci_get_drvdata(efx->pci_dev->physfn);
> + rc = _efx_mcdi_rpc(efx_pf, efx->client_id, cmd, inbuf,
> + inlen, outbuf, outlen, outlen_actual,
> + true, &raw_rc);
> + } else {
> +#endif
> + rc = _efx_mcdi_rpc(efx, efx->client_id, cmd, inbuf,
> + inlen, outbuf, outlen, outlen_actual, true,
> + &raw_rc);
> +#ifdef CONFIG_SFC_VDPA
> + }
> +#endif
>
> if ((rc == -EPROTO) && (raw_rc == MC_CMD_ERR_NO_EVB_PORT) &&
> efx->type->is_vf) {
> @@ -881,9 +941,22 @@ static int _efx_mcdi_rpc_evb_retry(struct efx_nic *efx, unsigned cmd,
>
> do {
> usleep_range(delay_us, delay_us + 10000);
> - rc = _efx_mcdi_rpc(efx, cmd, inbuf, inlen,
> - outbuf, outlen, outlen_actual,
> - true, &raw_rc);
> +#ifdef CONFIG_SFC_VDPA
> + if (is_mode_vdpa(efx)) {
> + efx_pf = pci_get_drvdata(efx->pci_dev->physfn);
> + rc = _efx_mcdi_rpc(efx_pf, efx->client_id, cmd,
> + inbuf, inlen, outbuf, outlen,
> + outlen_actual, true,
> + &raw_rc);
> + } else {
> +#endif
> + rc = _efx_mcdi_rpc(efx, efx->client_id,
> + cmd, inbuf, inlen, outbuf,
> + outlen, outlen_actual, true,
> + &raw_rc);
> +#ifdef CONFIG_SFC_VDPA
> + }
> +#endif
> if (delay_us < 100000)
> delay_us <<= 1;
> } while ((rc == -EPROTO) &&
> @@ -939,7 +1012,7 @@ int efx_mcdi_rpc(struct efx_nic *efx, unsigned cmd,
> * function and is then responsible for calling efx_mcdi_display_error
> * as needed.
> */
> -int efx_mcdi_rpc_quiet(struct efx_nic *efx, unsigned cmd,
> +int efx_mcdi_rpc_quiet(struct efx_nic *efx, unsigned int cmd,
> const efx_dword_t *inbuf, size_t inlen,
> efx_dword_t *outbuf, size_t outlen,
> size_t *outlen_actual)
> @@ -948,7 +1021,7 @@ int efx_mcdi_rpc_quiet(struct efx_nic *efx, unsigned cmd,
> outlen_actual, true);
> }
>
> -int efx_mcdi_rpc_start(struct efx_nic *efx, unsigned cmd,
> +int efx_mcdi_rpc_start(struct efx_nic *efx, u32 client_id, unsigned int cmd,
> const efx_dword_t *inbuf, size_t inlen)
> {
> struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
> @@ -965,7 +1038,7 @@ int efx_mcdi_rpc_start(struct efx_nic *efx, unsigned cmd,
> return -ENETDOWN;
>
> efx_mcdi_acquire_sync(mcdi);
> - efx_mcdi_send_request(efx, cmd, inbuf, inlen);
> + efx_mcdi_send_request(efx, client_id, cmd, inbuf, inlen);
> return 0;
> }
>
> @@ -1009,7 +1082,8 @@ static int _efx_mcdi_rpc_async(struct efx_nic *efx, unsigned int cmd,
> */
> if (mcdi->async_list.next == &async->list &&
> efx_mcdi_acquire_async(mcdi)) {
> - efx_mcdi_send_request(efx, cmd, inbuf, inlen);
> + efx_mcdi_send_request(efx, efx->client_id,
> + cmd, inbuf, inlen);
> mod_timer(&mcdi->async_timer,
> jiffies + MCDI_RPC_TIMEOUT);
> }
> diff --git a/drivers/net/ethernet/sfc/mcdi.h b/drivers/net/ethernet/sfc/mcdi.h
> index dafab52aaef7..2c526d2edeb6 100644
> --- a/drivers/net/ethernet/sfc/mcdi.h
> +++ b/drivers/net/ethernet/sfc/mcdi.h
> @@ -150,7 +150,7 @@ int efx_mcdi_rpc_quiet(struct efx_nic *efx, unsigned cmd,
> efx_dword_t *outbuf, size_t outlen,
> size_t *outlen_actual);
>
> -int efx_mcdi_rpc_start(struct efx_nic *efx, unsigned cmd,
> +int efx_mcdi_rpc_start(struct efx_nic *efx, u32 client_id, unsigned int cmd,
> const efx_dword_t *inbuf, size_t inlen);
> int efx_mcdi_rpc_finish(struct efx_nic *efx, unsigned cmd, size_t inlen,
> efx_dword_t *outbuf, size_t outlen,
> diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
> index 1da71deac71c..948c7a06403a 100644
> --- a/drivers/net/ethernet/sfc/net_driver.h
> +++ b/drivers/net/ethernet/sfc/net_driver.h
> @@ -859,6 +859,7 @@ struct efx_mae;
> * @secondary_list: List of &struct efx_nic instances for the secondary PCI
> * functions of the controller, if this is for the primary function.
> * Serialised by rtnl_lock.
> + * @client_id: client ID of this PCIe function
> * @type: Controller type attributes
> * @legacy_irq: IRQ number
> * @workqueue: Workqueue for port reconfigures and the HW monitor.
> @@ -1022,6 +1023,7 @@ struct efx_nic {
> struct list_head secondary_list;
> struct pci_dev *pci_dev;
> unsigned int port_num;
> + u32 client_id;
> const struct efx_nic_type *type;
> int legacy_irq;
> bool eeh_disabled_legacy_irq;
> diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
> index 9f07e1ba7780..d90d4f6b3824 100644
> --- a/drivers/net/ethernet/sfc/ptp.c
> +++ b/drivers/net/ethernet/sfc/ptp.c
> @@ -1052,8 +1052,8 @@ static int efx_ptp_synchronize(struct efx_nic *efx, unsigned int num_readings)
>
> /* Clear flag that signals MC ready */
> WRITE_ONCE(*start, 0);
> - rc = efx_mcdi_rpc_start(efx, MC_CMD_PTP, synch_buf,
> - MC_CMD_PTP_IN_SYNCHRONIZE_LEN);
> + rc = efx_mcdi_rpc_start(efx, MC_CMD_CLIENT_ID_SELF, MC_CMD_PTP,
> + synch_buf, MC_CMD_PTP_IN_SYNCHRONIZE_LEN);
> EFX_WARN_ON_ONCE_PARANOID(rc);
>
> /* Wait for start from MCDI (or timeout) */
> --
> 2.30.1