diff mbox series

ice: Fix enabling SR-IOV with Xen

Message ID 20240301182810.9808-1-javi.merino@kernel.org (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
Headers show
Series ice: Fix enabling SR-IOV with Xen | expand

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netdev/series_format warning Single patches do not need cover letters; Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 940 this patch: 940
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 3 maintainers not CCed: pabeni@redhat.com kuba@kernel.org edumazet@google.com
netdev/build_clang success Errors and warnings before: 956 this patch: 956
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 956 this patch: 956
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 47 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Javi Merino March 1, 2024, 6:28 p.m. UTC 
From: Ross Lagerwall <ross.lagerwall@citrix.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@intel.com>
Cc: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Javi Merino <javi.merino@kernel.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(-)

Comments

Tony Nguyen March 6, 2024, 11:44 p.m. UTC | #1 
On 3/1/2024 10:28 AM, javi.merino@kernel.org wrote:
> From: Ross Lagerwall <ross.lagerwall@citrix.com>
>
> 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?

Yes, we should teardown the ice_start_vfs() work if pci_enable_sriov() 
fails.

Thanks,
Tony
diff mbox series

Patch

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);