[PATCH net-next 12/14] sfc: do not allow VFs to be destroyed if assigned to guests

[Shradha Shah <sshah@solarflare.com>]

From: Daniel Pieczko <dpieczko@solarflare.com>

Signed-off-by: Shradha Shah <sshah@solarflare.com>
---
 drivers/net/ethernet/sfc/ef10_sriov.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/net/ethernet/sfc/ef10_sriov.c b/drivers/net/ethernet/sfc/ef10_sriov.c
index cd52454..083c534 100644
--- a/drivers/net/ethernet/sfc/ef10_sriov.c
+++ b/drivers/net/ethernet/sfc/ef10_sriov.c
@@ -417,6 +417,15 @@ static int efx_ef10_pci_sriov_disable(struct efx_nic *efx)
 {
 	struct pci_dev *dev = efx->pci_dev;
 
+	if (!efx->vf_count)
+		return 0;
+
+	if (pci_vfs_assigned(dev)) {
+		netif_err(efx, drv, efx->net_dev, "VFs are assigned to guests; "
+			  "please detach them before disabling SR-IOV\n");
+		return -EBUSY;
+	}
+
 	pci_disable_sriov(dev);
 	efx_ef10_sriov_free_vf_vswitching(efx);
 	efx->vf_count = 0;