[PATCH net v2 0/2] Fix VF to VM attach detach

[PATCH net v2 0/2] Fix VF to VM attach detach

[Petr Oros]

v2: fixed typos in the description of the second patch

v1: https://lore.kernel.org/netdev/20230807094831.696626-1-poros@redhat.com/

Petr Oros (2):
  Revert "ice: Fix ice VF reset during iavf initialization"
  ice: Fix NULL pointer deref during VF reset

 drivers/net/ethernet/intel/ice/ice_sriov.c    |  8 ++---
 drivers/net/ethernet/intel/ice/ice_vf_lib.c   | 34 +++++--------------
 drivers/net/ethernet/intel/ice/ice_vf_lib.h   |  1 -
 drivers/net/ethernet/intel/ice/ice_virtchnl.c |  1 -
 4 files changed, 12 insertions(+), 32 deletions(-)

-- 
2.41.0

[PATCH net v2 1/2] Revert "ice: Fix ice VF reset during iavf initialization"

[Petr Oros]

This reverts commit 7255355a0636b4eff08d5e8139c77d98f151c4fc.

After this commit we are not able to attach VF to VM:
virsh attach-interface v0 hostdev --managed 0000:41:01.0 --mac 52:52:52:52:52:52
error: Failed to attach interface
error: Cannot set interface MAC to 52:52:52:52:52:52 for ifname enp65s0f0np0 vf 0: Resource temporarily unavailable

ice_check_vf_ready_for_cfg() already contain waiting for reset.
New condition in ice_check_vf_ready_for_reset() causing only problems.

Fixes: 7255355a0636 ("ice: Fix ice VF reset during iavf initialization")
Signed-off-by: Petr Oros <poros@redhat.com>
---
 drivers/net/ethernet/intel/ice/ice_sriov.c    |  8 ++++----
 drivers/net/ethernet/intel/ice/ice_vf_lib.c   | 19 -------------------
 drivers/net/ethernet/intel/ice/ice_vf_lib.h   |  1 -
 drivers/net/ethernet/intel/ice/ice_virtchnl.c |  1 -
 4 files changed, 4 insertions(+), 25 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_sriov.c b/drivers/net/ethernet/intel/ice/ice_sriov.c
index 1f66914c7a202a..31314e7540f8cf 100644
--- a/drivers/net/ethernet/intel/ice/ice_sriov.c
+++ b/drivers/net/ethernet/intel/ice/ice_sriov.c
@@ -1131,7 +1131,7 @@ int ice_set_vf_spoofchk(struct net_device *netdev, int vf_id, bool ena)
 	if (!vf)
 		return -EINVAL;
 
-	ret = ice_check_vf_ready_for_reset(vf);
+	ret = ice_check_vf_ready_for_cfg(vf);
 	if (ret)
 		goto out_put_vf;
 
@@ -1246,7 +1246,7 @@ int ice_set_vf_mac(struct net_device *netdev, int vf_id, u8 *mac)
 		goto out_put_vf;
 	}
 
-	ret = ice_check_vf_ready_for_reset(vf);
+	ret = ice_check_vf_ready_for_cfg(vf);
 	if (ret)
 		goto out_put_vf;
 
@@ -1300,7 +1300,7 @@ int ice_set_vf_trust(struct net_device *netdev, int vf_id, bool trusted)
 		return -EOPNOTSUPP;
 	}
 
-	ret = ice_check_vf_ready_for_reset(vf);
+	ret = ice_check_vf_ready_for_cfg(vf);
 	if (ret)
 		goto out_put_vf;
 
@@ -1613,7 +1613,7 @@ ice_set_vf_port_vlan(struct net_device *netdev, int vf_id, u16 vlan_id, u8 qos,
 	if (!vf)
 		return -EINVAL;
 
-	ret = ice_check_vf_ready_for_reset(vf);
+	ret = ice_check_vf_ready_for_cfg(vf);
 	if (ret)
 		goto out_put_vf;
 
diff --git a/drivers/net/ethernet/intel/ice/ice_vf_lib.c b/drivers/net/ethernet/intel/ice/ice_vf_lib.c
index b26ce4425f4559..294e91c3453ccd 100644
--- a/drivers/net/ethernet/intel/ice/ice_vf_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_vf_lib.c
@@ -185,25 +185,6 @@ int ice_check_vf_ready_for_cfg(struct ice_vf *vf)
 	return 0;
 }
 
-/**
- * ice_check_vf_ready_for_reset - check if VF is ready to be reset
- * @vf: VF to check if it's ready to be reset
- *
- * The purpose of this function is to ensure that the VF is not in reset,
- * disabled, and is both initialized and active, thus enabling us to safely
- * initialize another reset.
- */
-int ice_check_vf_ready_for_reset(struct ice_vf *vf)
-{
-	int ret;
-
-	ret = ice_check_vf_ready_for_cfg(vf);
-	if (!ret && !test_bit(ICE_VF_STATE_ACTIVE, vf->vf_states))
-		ret = -EAGAIN;
-
-	return ret;
-}
-
 /**
  * ice_trigger_vf_reset - Reset a VF on HW
  * @vf: pointer to the VF structure
diff --git a/drivers/net/ethernet/intel/ice/ice_vf_lib.h b/drivers/net/ethernet/intel/ice/ice_vf_lib.h
index 67172fdd9bc27f..48fea6fa036210 100644
--- a/drivers/net/ethernet/intel/ice/ice_vf_lib.h
+++ b/drivers/net/ethernet/intel/ice/ice_vf_lib.h
@@ -215,7 +215,6 @@ u16 ice_get_num_vfs(struct ice_pf *pf);
 struct ice_vsi *ice_get_vf_vsi(struct ice_vf *vf);
 bool ice_is_vf_disabled(struct ice_vf *vf);
 int ice_check_vf_ready_for_cfg(struct ice_vf *vf);
-int ice_check_vf_ready_for_reset(struct ice_vf *vf);
 void ice_set_vf_state_dis(struct ice_vf *vf);
 bool ice_is_any_vf_in_unicast_promisc(struct ice_pf *pf);
 void
diff --git a/drivers/net/ethernet/intel/ice/ice_virtchnl.c b/drivers/net/ethernet/intel/ice/ice_virtchnl.c
index efbc2968a7bf6a..dcf628b1fccd93 100644
--- a/drivers/net/ethernet/intel/ice/ice_virtchnl.c
+++ b/drivers/net/ethernet/intel/ice/ice_virtchnl.c
@@ -3947,7 +3947,6 @@ void ice_vc_process_vf_msg(struct ice_pf *pf, struct ice_rq_event_info *event,
 		ice_vc_notify_vf_link_state(vf);
 		break;
 	case VIRTCHNL_OP_RESET_VF:
-		clear_bit(ICE_VF_STATE_ACTIVE, vf->vf_states);
 		ops->reset_vf(vf);
 		break;
 	case VIRTCHNL_OP_ADD_ETH_ADDR:
-- 
2.41.0

[PATCH net v2 2/2] ice: Fix NULL pointer deref during VF reset

[Petr Oros]

During stress test with attaching and detaching VF from KVM and
simultaneously changing VFs spoofcheck and trust there was a
NULL pointer dereference in ice_reset_vf that VF's VSI is null.

More than one instance of ice_reset_vf() can be running at a given
time. When we rebuild the VSI in ice_reset_vf, another reset can be
triaged from ice_service_task. In this case we can access the currently
uninitialized VSI and cause panic. The window for this racing condition
has been around for a long time but it's much worse after commit
227bf4500aaa ("ice: move VSI delete outside deconfig") because
the reset runs faster. ice_reset_vf() using vf->cfg_lock and when
we move this lock before accessing to the VF VSI, we can fix
BUG for all cases.

Panic occurs sometimes in ice_vsi_is_rx_queue_active() and sometimes
in ice_vsi_stop_all_rx_rings()

With our reproducer, we can hit BUG:
~8h before commit 227bf4500aaa ("ice: move VSI delete outside deconfig").
~20m after commit 227bf4500aaa ("ice: move VSI delete outside deconfig").
After this fix we are not able to reproduce it after ~48h

There was commit cf90b74341ee ("ice: Fix call trace with null VSI during
VF reset") which also tried to fix this issue, but it was only
partially resolved and the bug still exists.

[ 6420.658415] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 6420.665382] #PF: supervisor read access in kernel mode
[ 6420.670521] #PF: error_code(0x0000) - not-present page
[ 6420.675659] PGD 0
[ 6420.677679] Oops: 0000 [#1] PREEMPT SMP NOPTI
[ 6420.682038] CPU: 53 PID: 326472 Comm: kworker/53:0 Kdump: loaded Not tainted 5.14.0-317.el9.x86_64 #1
[ 6420.691250] Hardware name: Dell Inc. PowerEdge R750/04V528, BIOS 1.6.5 04/15/2022
[ 6420.698729] Workqueue: ice ice_service_task [ice]
[ 6420.703462] RIP: 0010:ice_vsi_is_rx_queue_active+0x2d/0x60 [ice]
[ 6420.705860] ice 0000:ca:00.0: VF 0 is now untrusted
[ 6420.709494] Code: 00 00 66 83 bf 76 04 00 00 00 48 8b 77 10 74 3e 31 c0 eb 0f 0f b7 97 76 04 00 00 48 83 c0 01 39 c2 7e 2b 48 8b 97 68 04 00 00 <0f> b7 0c 42 48 8b 96 20 13 00 00 48 8d 94 8a 00 00 12 00 8b 12 83
[ 6420.714426] ice 0000:ca:00.0 ens7f0: Setting MAC 22:22:22:22:22:00 on VF 0. VF driver will be reinitialized
[ 6420.733120] RSP: 0018:ff778d2ff383fdd8 EFLAGS: 00010246
[ 6420.733123] RAX: 0000000000000000 RBX: ff2acf1916294000 RCX: 0000000000000000
[ 6420.733125] RDX: 0000000000000000 RSI: ff2acf1f2c6401a0 RDI: ff2acf1a27301828
[ 6420.762346] RBP: ff2acf1a27301828 R08: 0000000000000010 R09: 0000000000001000
[ 6420.769476] R10: ff2acf1916286000 R11: 00000000019eba3f R12: ff2acf19066460d0
[ 6420.776611] R13: ff2acf1f2c6401a0 R14: ff2acf1f2c6401a0 R15: 00000000ffffffff
[ 6420.783742] FS:  0000000000000000(0000) GS:ff2acf28ffa80000(0000) knlGS:0000000000000000
[ 6420.791829] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 6420.797575] CR2: 0000000000000000 CR3: 00000016ad410003 CR4: 0000000000773ee0
[ 6420.804708] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 6420.811034] vfio-pci 0000:ca:01.0: enabling device (0000 -> 0002)
[ 6420.811840] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 6420.811841] PKRU: 55555554
[ 6420.811842] Call Trace:
[ 6420.811843]  <TASK>
[ 6420.811844]  ice_reset_vf+0x9a/0x450 [ice]
[ 6420.811876]  ice_process_vflr_event+0x8f/0xc0 [ice]
[ 6420.841343]  ice_service_task+0x23b/0x600 [ice]
[ 6420.845884]  ? __schedule+0x212/0x550
[ 6420.849550]  process_one_work+0x1e2/0x3b0
[ 6420.853563]  ? rescuer_thread+0x390/0x390
[ 6420.857577]  worker_thread+0x50/0x3a0
[ 6420.861242]  ? rescuer_thread+0x390/0x390
[ 6420.865253]  kthread+0xdd/0x100
[ 6420.868400]  ? kthread_complete_and_exit+0x20/0x20
[ 6420.873194]  ret_from_fork+0x1f/0x30
[ 6420.876774]  </TASK>
[ 6420.878967] Modules linked in: vfio_pci vfio_pci_core vfio_iommu_type1 vfio iavf vhost_net vhost vhost_iotlb tap tun xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 nft_compat nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_counter nf_tables bridge stp llc sctp ip6_udp_tunnel udp_tunnel nfp tls nfnetlink bluetooth mlx4_en mlx4_core rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs rfkill sunrpc intel_rapl_msr intel_rapl_common i10nm_edac nfit libnvdimm ipmi_ssif x86_pkg_temp_thermal intel_powerclamp coretemp irdma kvm_intel i40e kvm iTCO_wdt dcdbas ib_uverbs irqbypass iTCO_vendor_support mgag200 mei_me ib_core dell_smbios isst_if_mmio isst_if_mbox_pci rapl i2c_algo_bit drm_shmem_helper intel_cstate drm_kms_helper syscopyarea sysfillrect isst_if_common sysimgblt intel_uncore fb_sys_fops dell_wmi_descriptor wmi_bmof intel_vsec mei i2c_i801 acpi_ipmi ipmi_si i2c_smbus ipmi_devintf intel_pch_thermal acpi_power_meter pcspkr

Fixes: efe41860008e ("ice: Fix memory corruption in VF driver")
Fixes: f23df5220d2b ("ice: Fix spurious interrupt during removal of trusted VF")
Signed-off-by: Petr Oros <poros@redhat.com>
---
v2: fixed typos in the description
---
drivers/net/ethernet/intel/ice/ice_vf_lib.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_vf_lib.c b/drivers/net/ethernet/intel/ice/ice_vf_lib.c
index 294e91c3453ccd..ea3310be8354cf 100644
--- a/drivers/net/ethernet/intel/ice/ice_vf_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_vf_lib.c
@@ -612,11 +612,17 @@ int ice_reset_vf(struct ice_vf *vf, u32 flags)
 		return 0;
 	}
 
+	if (flags & ICE_VF_RESET_LOCK)
+		mutex_lock(&vf->cfg_lock);
+	else
+		lockdep_assert_held(&vf->cfg_lock);
+
 	if (ice_is_vf_disabled(vf)) {
 		vsi = ice_get_vf_vsi(vf);
 		if (!vsi) {
 			dev_dbg(dev, "VF is already removed\n");
-			return -EINVAL;
+			err = -EINVAL;
+			goto out_unlock;
 		}
 		ice_vsi_stop_lan_tx_rings(vsi, ICE_NO_RESET, vf->vf_id);
 
@@ -625,14 +631,9 @@ int ice_reset_vf(struct ice_vf *vf, u32 flags)
 
 		dev_dbg(dev, "VF is already disabled, there is no need for resetting it, telling VM, all is fine %d\n",
 			vf->vf_id);
-		return 0;
+		goto out_unlock;
 	}
 
-	if (flags & ICE_VF_RESET_LOCK)
-		mutex_lock(&vf->cfg_lock);
-	else
-		lockdep_assert_held(&vf->cfg_lock);
-
 	/* Set VF disable bit state here, before triggering reset */
 	set_bit(ICE_VF_STATE_DIS, vf->vf_states);
 	ice_trigger_vf_reset(vf, flags & ICE_VF_RESET_VFLR, false);
-- 
2.41.0

Re: [PATCH net v2 0/2] Fix VF to VM attach detach

[Przemek Kitszel]

On 8/9/23 17:15, Petr Oros wrote:
> v2: fixed typos in the description of the second patch
> 
> v1: https://lore.kernel.org/netdev/20230807094831.696626-1-poros@redhat.com/
> 
> Petr Oros (2):
>    Revert "ice: Fix ice VF reset during iavf initialization"
>    ice: Fix NULL pointer deref during VF reset
> 
>   drivers/net/ethernet/intel/ice/ice_sriov.c    |  8 ++---
>   drivers/net/ethernet/intel/ice/ice_vf_lib.c   | 34 +++++--------------
>   drivers/net/ethernet/intel/ice/ice_vf_lib.h   |  1 -
>   drivers/net/ethernet/intel/ice/ice_virtchnl.c |  1 -
>   4 files changed, 12 insertions(+), 32 deletions(-)
> 

You have forgot to propagate reviewed-by tags from v1 (Simon's, Jake's, 
mine)

Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>

(I'm not sure if I should copy-paste not mine RBs here?)

Re: [PATCH net v2 0/2] Fix VF to VM attach detach

[Jakub Kicinski]

On Thu, 10 Aug 2023 14:52:33 +0200 Przemek Kitszel wrote:
> You have forgot to propagate reviewed-by tags from v1 (Simon's, Jake's, 
> mine)
> 
> Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
> 
> (I'm not sure if I should copy-paste not mine RBs here?)

Not 100% sure either but most of the time I reckon it'd be a good thing.
Higher probability that we may miss a tag than that the person intended
to withdraw it. Just make sure the person who's tag you're copying is
on CC and that you add a link to where the tag was provided.