From: Jedrzej Jagielski <[email protected]> [ Upstream commit 823be089f9c8ab136ba382b516aedd3f7ac854bd ]
Send to VF information about features supported by the PF driver. Increase API version to 1.7. Reviewed-by: Przemek Kitszel <[email protected]> Reviewed-by: Aleksandr Loktionov <[email protected]> Signed-off-by: Jedrzej Jagielski <[email protected]> Tested-by: Rafal Romanowski <[email protected]> Signed-off-by: Jacob Keller <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- LLM Generated explanations, may be completely bogus: Based on my analysis using semantic code analysis tools and git history examination, here is my determination: **Answer: YES** **Extensive Explanation:** ## 1. Analysis Performed Using Semantic Tools I used the following semantic code analysis tools to examine this commit: - **mcp__semcode__find_function**: Located `ixgbe_rcv_msg_from_vf()`, `ixgbe_negotiate_vf_api()`, and `ixgbe_msg_task()` to understand the mailbox message handling flow - **mcp__semcode__find_callers**: Traced the call chain: `ixgbe_msix_other()` (IRQ handler) → `ixgbe_msg_task()` → `ixgbe_rcv_msg_from_vf()`, confirming this code is triggered by VF interrupts - **Git tools**: Examined commit history, found companion VF-side fix (a7075f501bd33), and traced the problematic commits back to v4.20 ## 2. Code Changes Analysis The commit adds: - **New API version**: `ixgbe_mbox_api_17` (line 56 in ixgbe_mbx.h) - **New mailbox command**: `IXGBE_VF_FEATURES_NEGOTIATE` (0x12) for VF- to-PF feature negotiation - **Feature flags**: `IXGBEVF_PF_SUP_IPSEC` and `IXGBEVF_PF_SUP_ESX_MBX` to indicate PF capabilities - **New handler function**: `ixgbe_negotiate_vf_features()` at drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c:1268 - **Case statement addition**: Adds handling for the new mailbox command in `ixgbe_rcv_msg_from_vf()` - **API version updates**: Adds `ixgbe_mbox_api_17` cases to 8 existing switch statements for backward compatibility ## 3. Impact Scope (from semantic analysis) **Call graph analysis** shows: - 1 direct caller of `ixgbe_rcv_msg_from_vf()`: the `ixgbe_msg_task()` function - User-space can trigger this code path through SR-IOV VF operations - The code runs in interrupt context (from MSI-X handler) - Affects all SR-IOV deployments using ixgbe PF with ixgbevf VF drivers ## 4. This Is a Bug Fix, Not a New Feature The companion VF-side commit (a7075f501bd33) clearly indicates this is a **critical bug fix**: ``` Fixes: 0062e7cc955e ("ixgbevf: add VF IPsec offload code") Fixes: 339f28964147 ("ixgbevf: Add support for new mailbox communication between PF and VF") Cc: [email protected] ``` The VF commit message explains: - "API 1.6 cannot be supported for Linux ixgbe driver as it causes **crashes**" - Backward compatibility was broken since API 1.4 (introduced in v4.20, August 2018) - VF drivers attempting to use IPsec or ESX mailbox features crash when PF doesn't support them - No negotiation mechanism existed, causing interoperability failures between Linux/ESX/FreeBSD drivers ## 5. Why This Must Be Backported **Critical reasons:** 1. **Fixes crashes**: VFs crash when attempting to use features not supported by the PF (drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c:1268-1282) 2. **Paired fix**: The VF-side fix (a7075f501bd33) has explicit "Cc: [email protected]" tag and is already being backported (as evidenced by commit a376e29b1b196 showing "commit a7075f501bd33 upstream") 3. **Incomplete without both sides**: The VF asks "what features do you support?" but the PF needs this commit to answer. Without the PF handler, VF gets -EOPNOTSUPP, defeating the fix 4. **Affects all kernels ≥ v4.20**: The problematic commits exist in all kernels from v4.20 onwards (confirmed via `git tag --contains 0062e7cc955e`) 5. **Small, contained change**: Only adds 47 lines across 2 files, focused on one specific mailbox command ## 6. Compliance with Stable Tree Rules **Passes all stable tree criteria:** - ✅ Fixes important bug (crashes in SR-IOV scenarios) - ✅ Small and obviously correct (adds one mailbox handler) - ✅ No architectural changes (extends existing switch/case pattern) - ✅ Minimal regression risk (only affects new API 1.7, old APIs unchanged) - ✅ Companion to explicit stable-tagged commit (a7075f501bd33) - ✅ Already tested (Tested-by: Rafal Romanowski tag) ## 7. Dependency Check The commit depends on: - `ixgbe_send_vf_link_status()` function (added in f7f97cbc03a47, which immediately precedes this commit in the series) - Standard ixgbe mailbox infrastructure (present in all affected kernels) **Recommendation**: Backport as part of the series with its VF counterpart and the link status fix. drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h | 10 +++++ .../net/ethernet/intel/ixgbe/ixgbe_sriov.c | 37 +++++++++++++++++++ 2 files changed, 47 insertions(+) diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h index f7256a339c99b..0334ed4b8fa39 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h @@ -52,6 +52,7 @@ enum ixgbe_pfvf_api_rev { ixgbe_mbox_api_14, /* API version 1.4, linux/freebsd VF driver */ ixgbe_mbox_api_15, /* API version 1.5, linux/freebsd VF driver */ ixgbe_mbox_api_16, /* API version 1.6, linux/freebsd VF driver */ + ixgbe_mbox_api_17, /* API version 1.7, linux/freebsd VF driver */ /* This value should always be last */ ixgbe_mbox_api_unknown, /* indicates that API version is not known */ }; @@ -91,6 +92,9 @@ enum ixgbe_pfvf_api_rev { /* mailbox API, version 1.6 VF requests */ #define IXGBE_VF_GET_PF_LINK_STATE 0x11 /* request PF to send link info */ +/* mailbox API, version 1.7 VF requests */ +#define IXGBE_VF_FEATURES_NEGOTIATE 0x12 /* get features supported by PF */ + /* length of permanent address message returned from PF */ #define IXGBE_VF_PERMADDR_MSG_LEN 4 /* word in permanent address message with the current multicast type */ @@ -101,6 +105,12 @@ enum ixgbe_pfvf_api_rev { #define IXGBE_VF_MBX_INIT_TIMEOUT 2000 /* number of retries on mailbox */ #define IXGBE_VF_MBX_INIT_DELAY 500 /* microseconds between retries */ +/* features negotiated between PF/VF */ +#define IXGBEVF_PF_SUP_IPSEC BIT(0) +#define IXGBEVF_PF_SUP_ESX_MBX BIT(1) + +#define IXGBE_SUPPORTED_FEATURES IXGBEVF_PF_SUP_IPSEC + struct ixgbe_hw; int ixgbe_read_mbx(struct ixgbe_hw *, u32 *, u16, u16); diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c index b09271d61a4ef..ee133d6749b37 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c @@ -511,6 +511,7 @@ static int ixgbe_set_vf_lpe(struct ixgbe_adapter *adapter, u32 max_frame, u32 vf case ixgbe_mbox_api_13: case ixgbe_mbox_api_14: case ixgbe_mbox_api_16: + case ixgbe_mbox_api_17: /* Version 1.1 supports jumbo frames on VFs if PF has * jumbo frames enabled which means legacy VFs are * disabled @@ -1048,6 +1049,7 @@ static int ixgbe_negotiate_vf_api(struct ixgbe_adapter *adapter, case ixgbe_mbox_api_13: case ixgbe_mbox_api_14: case ixgbe_mbox_api_16: + case ixgbe_mbox_api_17: adapter->vfinfo[vf].vf_api = api; return 0; default: @@ -1075,6 +1077,7 @@ static int ixgbe_get_vf_queues(struct ixgbe_adapter *adapter, case ixgbe_mbox_api_13: case ixgbe_mbox_api_14: case ixgbe_mbox_api_16: + case ixgbe_mbox_api_17: break; default: return -1; @@ -1115,6 +1118,7 @@ static int ixgbe_get_vf_reta(struct ixgbe_adapter *adapter, u32 *msgbuf, u32 vf) /* verify the PF is supporting the correct API */ switch (adapter->vfinfo[vf].vf_api) { + case ixgbe_mbox_api_17: case ixgbe_mbox_api_16: case ixgbe_mbox_api_14: case ixgbe_mbox_api_13: @@ -1149,6 +1153,7 @@ static int ixgbe_get_vf_rss_key(struct ixgbe_adapter *adapter, /* verify the PF is supporting the correct API */ switch (adapter->vfinfo[vf].vf_api) { + case ixgbe_mbox_api_17: case ixgbe_mbox_api_16: case ixgbe_mbox_api_14: case ixgbe_mbox_api_13: @@ -1180,6 +1185,7 @@ static int ixgbe_update_vf_xcast_mode(struct ixgbe_adapter *adapter, case ixgbe_mbox_api_13: case ixgbe_mbox_api_14: case ixgbe_mbox_api_16: + case ixgbe_mbox_api_17: break; default: return -EOPNOTSUPP; @@ -1251,6 +1257,7 @@ static int ixgbe_get_vf_link_state(struct ixgbe_adapter *adapter, case ixgbe_mbox_api_13: case ixgbe_mbox_api_14: case ixgbe_mbox_api_16: + case ixgbe_mbox_api_17: break; default: return -EOPNOTSUPP; @@ -1278,6 +1285,7 @@ static int ixgbe_send_vf_link_status(struct ixgbe_adapter *adapter, switch (adapter->vfinfo[vf].vf_api) { case ixgbe_mbox_api_16: + case ixgbe_mbox_api_17: if (hw->mac.type != ixgbe_mac_e610) return -EOPNOTSUPP; break; @@ -1293,6 +1301,32 @@ static int ixgbe_send_vf_link_status(struct ixgbe_adapter *adapter, return 0; } +/** + * ixgbe_negotiate_vf_features - negotiate supported features with VF driver + * @adapter: pointer to adapter struct + * @msgbuf: pointer to message buffers + * @vf: VF identifier + * + * Return: 0 on success or -EOPNOTSUPP when operation is not supported. + */ +static int ixgbe_negotiate_vf_features(struct ixgbe_adapter *adapter, + u32 *msgbuf, u32 vf) +{ + u32 features = msgbuf[1]; + + switch (adapter->vfinfo[vf].vf_api) { + case ixgbe_mbox_api_17: + break; + default: + return -EOPNOTSUPP; + } + + features &= IXGBE_SUPPORTED_FEATURES; + msgbuf[1] = features; + + return 0; +} + static int ixgbe_rcv_msg_from_vf(struct ixgbe_adapter *adapter, u32 vf) { u32 mbx_size = IXGBE_VFMAILBOX_SIZE; @@ -1370,6 +1404,9 @@ static int ixgbe_rcv_msg_from_vf(struct ixgbe_adapter *adapter, u32 vf) case IXGBE_VF_GET_PF_LINK_STATE: retval = ixgbe_send_vf_link_status(adapter, msgbuf, vf); break; + case IXGBE_VF_FEATURES_NEGOTIATE: + retval = ixgbe_negotiate_vf_features(adapter, msgbuf, vf); + break; default: e_err(drv, "Unhandled Msg %8.8x\n", msgbuf[0]); retval = -EIO; -- 2.51.0
