netdev - [PATCH] ice: Fix enabling SR-IOV with Xen

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240301182810.9808-1-javi.merino@kernel.org>
Date: Fri,  1 Mar 2024 18:28:10 +0000
From: javi.merino@...nel.org
To: netdev@...r.kernel.org
Cc: intel-wired-lan@...ts.osuosl.org,
	Ross Lagerwall <ross.lagerwall@...rix.com>,
	Jesse Brandeburg <jesse.brandeburg@...el.com>,
	Tony Nguyen <anthony.l.nguyen@...el.com>,
	Javi Merino <javi.merino@...nel.org>
Subject: [PATCH] ice: Fix enabling SR-IOV with Xen

From: Ross Lagerwall <ross.lagerwall@...rix.com>

When the PCI functions are created, Xen is informed about them and
caches the number of MSI-X entries each function has.  However, the
number of MSI-X entries is not set until after the hardware has been
configured and the VFs have been started. This prevents
PCI-passthrough from working because Xen rejects mapping MSI-X
interrupts to domains because it thinks the MSI-X interrupts don't
exist.

Fix this by moving the call to pci_enable_sriov() later so that the
number of MSI-X entries is set correctly in hardware by the time Xen
reads it.

Cc: Jesse Brandeburg <jesse.brandeburg@...el.com>
Cc: Tony Nguyen <anthony.l.nguyen@...el.com>
Signed-off-by: Ross Lagerwall <ross.lagerwall@...rix.com>
Signed-off-by: Javi Merino <javi.merino@...nel.org>
---

I'm unsure about the error path if `pci_enable_sriov()` fails.  Do we
have to undo what `ice_start_vfs()` has started?  I can see that
`ice_start_vfs()` has a teardown at the end, so maybe we need the same
code if `pci_enable_sriov()` fails?

 drivers/net/ethernet/intel/ice/ice_sriov.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_sriov.c b/drivers/net/ethernet/intel/ice/ice_sriov.c
index a94a1c48c3de..8a9c8a2fe834 100644
--- a/drivers/net/ethernet/intel/ice/ice_sriov.c
+++ b/drivers/net/ethernet/intel/ice/ice_sriov.c
@@ -878,24 +878,20 @@ static int ice_ena_vfs(struct ice_pf *pf, u16 num_vfs)
 	set_bit(ICE_OICR_INTR_DIS, pf->state);
 	ice_flush(hw);
 
-	ret = pci_enable_sriov(pf->pdev, num_vfs);
-	if (ret)
-		goto err_unroll_intr;
-
 	mutex_lock(&pf->vfs.table_lock);
 
 	ret = ice_set_per_vf_res(pf, num_vfs);
 	if (ret) {
 		dev_err(dev, "Not enough resources for %d VFs, err %d. Try with fewer number of VFs\n",
 			num_vfs, ret);
-		goto err_unroll_sriov;
+		goto err_unroll_intr;
 	}
 
 	ret = ice_create_vf_entries(pf, num_vfs);
 	if (ret) {
 		dev_err(dev, "Failed to allocate VF entries for %d VFs\n",
 			num_vfs);
-		goto err_unroll_sriov;
+		goto err_unroll_intr;
 	}
 
 	ice_eswitch_reserve_cp_queues(pf, num_vfs);
@@ -906,6 +902,10 @@ static int ice_ena_vfs(struct ice_pf *pf, u16 num_vfs)
 		goto err_unroll_vf_entries;
 	}
 
+	ret = pci_enable_sriov(pf->pdev, num_vfs);
+	if (ret)
+		goto err_unroll_vf_entries;
+
 	clear_bit(ICE_VF_DIS, pf->state);
 
 	/* rearm global interrupts */
@@ -918,10 +918,8 @@ static int ice_ena_vfs(struct ice_pf *pf, u16 num_vfs)
 
 err_unroll_vf_entries:
 	ice_free_vf_entries(pf);
-err_unroll_sriov:
-	mutex_unlock(&pf->vfs.table_lock);
-	pci_disable_sriov(pf->pdev);
 err_unroll_intr:
+	mutex_unlock(&pf->vfs.table_lock);
 	/* rearm interrupts here */
 	ice_irq_dynamic_ena(hw, NULL, NULL);
 	clear_bit(ICE_OICR_INTR_DIS, pf->state);
-- 
2.43.1