The branch main has been updated by jhb:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=346020138a0fd20085ebc285f090df38d7d18527

commit 346020138a0fd20085ebc285f090df38d7d18527
Author:     John Baldwin <j...@freebsd.org>
AuthorDate: 2025-02-11 14:11:48 +0000
Commit:     John Baldwin <j...@freebsd.org>
CommitDate: 2025-02-11 14:11:48 +0000

    pci: Don't cache the count of MSI/MSI-X messages before allocation
    
    A device can in theory change the read-only fields in the MSI/MSI-X
    control registers that indicate the maximum number of supported
    registers in response to changing other device registers.  For
    example, certain Intel networking VFs change the number of messages as
    a result of changes in the PCI_IOV_ADD_VF callback.
    
    To support this, always read the current value of the relevant control
    register in the *_count and *_alloc methods.  Once messages have been
    allocated, the control register value remains cached.
    
    Reported by:    Krzysztof Galazka <krzysztof.gala...@intel.com>
    Reviewed by:    Krzysztof Galazka <krzysztof.gala...@intel.com>, erj
    Differential Revision:  https://reviews.freebsd.org/D48890
---
 sys/dev/iavf/iavf_lib.c      | 25 ----------------
 sys/dev/iavf/iavf_lib.h      |  1 -
 sys/dev/iavf/if_iavf_iflib.c |  3 --
 sys/dev/pci/pci.c            | 70 ++++++++++++++++++++++++++------------------
 sys/dev/pci/pcireg.h         |  3 ++
 sys/dev/pci/pcivar.h         |  2 --
 6 files changed, 45 insertions(+), 59 deletions(-)

diff --git a/sys/dev/iavf/iavf_lib.c b/sys/dev/iavf/iavf_lib.c
index 3116ce0501c2..433d31904ea4 100644
--- a/sys/dev/iavf/iavf_lib.c
+++ b/sys/dev/iavf/iavf_lib.c
@@ -1463,31 +1463,6 @@ iavf_mark_del_vlan_filter(struct iavf_sc *sc, u16 vtag)
        return (i);
 }
 
-/**
- * iavf_update_msix_devinfo - Fix MSIX values for pci_msix_count()
- * @dev: pointer to kernel device
- *
- * Fix cached MSI-X control register information. This is a workaround
- * for an issue where VFs spawned in non-passthrough mode on FreeBSD
- * will have their PCI information cached before the PF driver
- * finishes updating their PCI information.
- *
- * @pre Must be called before pci_msix_count()
- */
-void
-iavf_update_msix_devinfo(device_t dev)
-{
-       struct pci_devinfo *dinfo;
-       u32 msix_ctrl;
-       u8 msix_location;
-
-       dinfo = (struct pci_devinfo *)device_get_ivars(dev);
-       msix_location = dinfo->cfg.msix.msix_location;
-       msix_ctrl = pci_read_config(dev, msix_location + PCIR_MSIX_CTRL, 2);
-       dinfo->cfg.msix.msix_ctrl = msix_ctrl;
-       dinfo->cfg.msix.msix_msgnum = (msix_ctrl & PCIM_MSIXCTRL_TABLE_SIZE) + 
1;
-}
-
 /**
  * iavf_disable_queues_with_retries - Send PF multiple DISABLE_QUEUES messages
  * @sc: device softc
diff --git a/sys/dev/iavf/iavf_lib.h b/sys/dev/iavf/iavf_lib.h
index f3ccd9f0c52f..2f874b2e4410 100644
--- a/sys/dev/iavf/iavf_lib.h
+++ b/sys/dev/iavf/iavf_lib.h
@@ -474,7 +474,6 @@ struct iavf_mac_filter *
 u64 iavf_baudrate_from_link_speed(struct iavf_sc *sc);
 void iavf_add_vlan_filter(struct iavf_sc *sc, u16 vtag);
 int iavf_mark_del_vlan_filter(struct iavf_sc *sc, u16 vtag);
-void iavf_update_msix_devinfo(device_t dev);
 void iavf_disable_queues_with_retries(struct iavf_sc *);
 
 int iavf_sysctl_current_speed(SYSCTL_HANDLER_ARGS);
diff --git a/sys/dev/iavf/if_iavf_iflib.c b/sys/dev/iavf/if_iavf_iflib.c
index d460df6e0d25..e4dd3b1e59a4 100644
--- a/sys/dev/iavf/if_iavf_iflib.c
+++ b/sys/dev/iavf/if_iavf_iflib.c
@@ -379,9 +379,6 @@ iavf_if_attach_pre(if_ctx_t ctx)
        scctx->isc_capabilities = scctx->isc_capenable = IAVF_CAPS;
        scctx->isc_tx_csum_flags = CSUM_OFFLOAD;
 
-       /* Update OS cache of MSIX control register values */
-       iavf_update_msix_devinfo(dev);
-
        return (0);
 
 err_vc_tq:
diff --git a/sys/dev/pci/pci.c b/sys/dev/pci/pci.c
index 06bff2e96e89..ad13e7f9a3a4 100644
--- a/sys/dev/pci/pci.c
+++ b/sys/dev/pci/pci.c
@@ -952,14 +952,10 @@ pci_read_cap(device_t pcib, pcicfgregs *cfg)
                case PCIY_MSI:          /* PCI MSI */
                        cfg->msi.msi_location = ptr;
                        cfg->msi.msi_ctrl = REG(ptr + PCIR_MSI_CTRL, 2);
-                       cfg->msi.msi_msgnum = 1 << ((cfg->msi.msi_ctrl &
-                                                    PCIM_MSICTRL_MMC_MASK)>>1);
                        break;
                case PCIY_MSIX:         /* PCI MSI-X */
                        cfg->msix.msix_location = ptr;
                        cfg->msix.msix_ctrl = REG(ptr + PCIR_MSIX_CTRL, 2);
-                       cfg->msix.msix_msgnum = (cfg->msix.msix_ctrl &
-                           PCIM_MSIXCTRL_TABLE_SIZE) + 1;
                        val = REG(ptr + PCIR_MSIX_TABLE, 4);
                        cfg->msix.msix_table_bar = PCIR_BAR(val &
                            PCIM_MSIX_BIR_MASK);
@@ -1734,7 +1730,7 @@ pci_mask_msix(device_t dev, u_int index)
        struct pcicfg_msix *msix = &dinfo->cfg.msix;
        uint32_t offset, val;
 
-       KASSERT(msix->msix_msgnum > index, ("bogus index"));
+       KASSERT(PCI_MSIX_MSGNUM(msix->msix_ctrl) > index, ("bogus index"));
        offset = msix->msix_table_offset + index * 16 + 12;
        val = bus_read_4(msix->msix_table_res, offset);
        val |= PCIM_MSIX_VCTRL_MASK;
@@ -1753,7 +1749,7 @@ pci_unmask_msix(device_t dev, u_int index)
        struct pcicfg_msix *msix = &dinfo->cfg.msix;
        uint32_t offset, val;
 
-       KASSERT(msix->msix_table_len > index, ("bogus index"));
+       KASSERT(PCI_MSIX_MSGNUM(msix->msix_ctrl) > index, ("bogus index"));
        offset = msix->msix_table_offset + index * 16 + 12;
        val = bus_read_4(msix->msix_table_res, offset);
        val &= ~PCIM_MSIX_VCTRL_MASK;
@@ -1790,11 +1786,13 @@ pci_resume_msix(device_t dev)
        struct pcicfg_msix *msix = &dinfo->cfg.msix;
        struct msix_table_entry *mte;
        struct msix_vector *mv;
-       u_int i;
+       u_int i, msgnum;
 
        if (msix->msix_alloc > 0) {
+               msgnum = PCI_MSIX_MSGNUM(msix->msix_ctrl);
+
                /* First, mask all vectors. */
-               for (i = 0; i < msix->msix_msgnum; i++)
+               for (i = 0; i < msgnum; i++)
                        pci_mask_msix(dev, i);
 
                /* Second, program any messages with at least one handler. */
@@ -1825,6 +1823,7 @@ pci_alloc_msix_method(device_t dev, device_t child, int 
*count)
        struct resource_list_entry *rle;
        u_int actual, i, max;
        int error, irq;
+       uint16_t ctrl, msgnum;
 
        /* Don't let count == 0 get us into trouble. */
        if (*count < 1)
@@ -1863,11 +1862,14 @@ pci_alloc_msix_method(device_t dev, device_t child, int 
*count)
        }
        cfg->msix.msix_pba_res = rle->res;
 
+       ctrl = pci_read_config(child, cfg->msix.msix_location + PCIR_MSIX_CTRL,
+           2);
+       msgnum = PCI_MSIX_MSGNUM(ctrl);
        if (bootverbose)
                device_printf(child,
                    "attempting to allocate %d MSI-X vectors (%d supported)\n",
-                   *count, cfg->msix.msix_msgnum);
-       max = min(*count, cfg->msix.msix_msgnum);
+                   *count, msgnum);
+       max = min(*count, msgnum);
        for (i = 0; i < max; i++) {
                /* Allocate a message. */
                error = PCIB_ALLOC_MSIX(device_get_parent(dev), child, &irq);
@@ -1927,7 +1929,7 @@ pci_alloc_msix_method(device_t dev, device_t child, int 
*count)
        }
 
        /* Mask all vectors. */
-       for (i = 0; i < cfg->msix.msix_msgnum; i++)
+       for (i = 0; i < msgnum; i++)
                pci_mask_msix(child, i);
 
        /* Allocate and initialize vector data and virtual table. */
@@ -1942,9 +1944,10 @@ pci_alloc_msix_method(device_t dev, device_t child, int 
*count)
        }
 
        /* Update control register to enable MSI-X. */
-       cfg->msix.msix_ctrl |= PCIM_MSIXCTRL_MSIX_ENABLE;
+       ctrl |= PCIM_MSIXCTRL_MSIX_ENABLE;
        pci_write_config(child, cfg->msix.msix_location + PCIR_MSIX_CTRL,
-           cfg->msix.msix_ctrl, 2);
+           ctrl, 2);
+       cfg->msix.msix_ctrl = ctrl;
 
        /* Update counts of alloc'd messages. */
        cfg->msix.msix_alloc = actual;
@@ -2007,7 +2010,7 @@ pci_remap_msix_method(device_t dev, device_t child, int 
count,
         * table can't be bigger than the actual MSI-X table in the
         * device.
         */
-       if (count < 1 || count > msix->msix_msgnum)
+       if (count < 1 || count > PCI_MSIX_MSGNUM(msix->msix_ctrl))
                return (EINVAL);
 
        /* Sanity check the vectors. */
@@ -2173,9 +2176,13 @@ pci_msix_count_method(device_t dev, device_t child)
 {
        struct pci_devinfo *dinfo = device_get_ivars(child);
        struct pcicfg_msix *msix = &dinfo->cfg.msix;
+       uint16_t ctrl;
 
-       if (pci_do_msix && msix->msix_location != 0)
-               return (msix->msix_msgnum);
+       if (pci_do_msix && msix->msix_location != 0) {
+               ctrl = pci_read_config(child, msix->msix_location +
+                   PCIR_MSI_CTRL, 2);
+               return (PCI_MSIX_MSGNUM(ctrl));
+       }
        return (0);
 }
 
@@ -2610,7 +2617,7 @@ pci_alloc_msi_method(device_t dev, device_t child, int 
*count)
        struct resource_list_entry *rle;
        u_int actual, i;
        int error, irqs[32];
-       uint16_t ctrl;
+       uint16_t ctrl, msgnum;
 
        /* Don't let count == 0 get us into trouble. */
        if (*count < 1)
@@ -2633,13 +2640,15 @@ pci_alloc_msi_method(device_t dev, device_t child, int 
*count)
        if (cfg->msi.msi_location == 0 || !pci_do_msi)
                return (ENODEV);
 
+       ctrl = pci_read_config(child, cfg->msi.msi_location + PCIR_MSI_CTRL, 2);
+       msgnum = PCI_MSI_MSGNUM(ctrl);
        if (bootverbose)
                device_printf(child,
-                   "attempting to allocate %d MSI vectors (%d supported)\n",
-                   *count, cfg->msi.msi_msgnum);
+                   "attempting to allocate %d MSI vectors (%u supported)\n",
+                   *count, msgnum);
 
        /* Don't ask for more than the device supports. */
-       actual = min(*count, cfg->msi.msi_msgnum);
+       actual = min(*count, msgnum);
 
        /* Don't ask for more than 32 messages. */
        actual = min(actual, 32);
@@ -2708,7 +2717,6 @@ pci_alloc_msi_method(device_t dev, device_t child, int 
*count)
        }
 
        /* Update control register with actual count. */
-       ctrl = cfg->msi.msi_ctrl;
        ctrl &= ~PCIM_MSICTRL_MME_MASK;
        ctrl |= (ffs(actual) - 1) << 4;
        cfg->msi.msi_ctrl = ctrl;
@@ -2782,9 +2790,13 @@ pci_msi_count_method(device_t dev, device_t child)
 {
        struct pci_devinfo *dinfo = device_get_ivars(child);
        struct pcicfg_msi *msi = &dinfo->cfg.msi;
+       uint16_t ctrl;
 
-       if (pci_do_msi && msi->msi_location != 0)
-               return (msi->msi_msgnum);
+       if (pci_do_msi && msi->msi_location != 0) {
+               ctrl = pci_read_config(child, msi->msi_location + PCIR_MSI_CTRL,
+                   2);
+               return (PCI_MSI_MSGNUM(ctrl));
+       }
        return (0);
 }
 
@@ -3038,19 +3050,21 @@ pci_print_verbose(struct pci_devinfo *dinfo)
                            status & PCIM_PSTAT_DMASK);
                }
                if (cfg->msi.msi_location) {
-                       int ctrl;
+                       uint16_t ctrl, msgnum;
 
                        ctrl = cfg->msi.msi_ctrl;
+                       msgnum = PCI_MSI_MSGNUM(ctrl);
                        printf("\tMSI supports %d message%s%s%s\n",
-                           cfg->msi.msi_msgnum,
-                           (cfg->msi.msi_msgnum == 1) ? "" : "s",
+                           msgnum, (msgnum == 1) ? "" : "s",
                            (ctrl & PCIM_MSICTRL_64BIT) ? ", 64 bit" : "",
                            (ctrl & PCIM_MSICTRL_VECTOR) ? ", vector masks":"");
                }
                if (cfg->msix.msix_location) {
+                       uint16_t msgnum;
+
+                       msgnum = PCI_MSIX_MSGNUM(cfg->msix.msix_ctrl);
                        printf("\tMSI-X supports %d message%s ",
-                           cfg->msix.msix_msgnum,
-                           (cfg->msix.msix_msgnum == 1) ? "" : "s");
+                           msgnum, (msgnum == 1) ? "" : "s");
                        if (cfg->msix.msix_table_bar == cfg->msix.msix_pba_bar)
                                printf("in map 0x%x\n",
                                    cfg->msix.msix_table_bar);
diff --git a/sys/dev/pci/pcireg.h b/sys/dev/pci/pcireg.h
index 623deb8b4505..f6aaf30611e4 100644
--- a/sys/dev/pci/pcireg.h
+++ b/sys/dev/pci/pcireg.h
@@ -616,6 +616,8 @@
 #define        PCIM_MSICTRL_MMC_16             0x0008
 #define        PCIM_MSICTRL_MMC_32             0x000A
 #define        PCIM_MSICTRL_MSI_ENABLE         0x0001
+#define        PCI_MSI_MSGNUM(ctrl)                                            
\
+       (1 << (((ctrl) & PCIM_MSICTRL_MMC_MASK) >> 1))
 #define        PCIR_MSI_ADDR           0x4
 #define        PCIR_MSI_ADDR_HIGH      0x8
 #define        PCIR_MSI_DATA           0x8
@@ -965,6 +967,7 @@
 #define        PCIM_MSIXCTRL_MSIX_ENABLE       0x8000
 #define        PCIM_MSIXCTRL_FUNCTION_MASK     0x4000
 #define        PCIM_MSIXCTRL_TABLE_SIZE        0x07FF
+#define        PCI_MSIX_MSGNUM(ctrl)   (((ctrl) & PCIM_MSIXCTRL_TABLE_SIZE) + 
1)
 #define        PCIR_MSIX_TABLE         0x4
 #define        PCIR_MSIX_PBA           0x8
 #define        PCIM_MSIX_BIR_MASK              0x7
diff --git a/sys/dev/pci/pcivar.h b/sys/dev/pci/pcivar.h
index 0041c5a22b49..c0d54f8e58e0 100644
--- a/sys/dev/pci/pcivar.h
+++ b/sys/dev/pci/pcivar.h
@@ -90,7 +90,6 @@ struct pcicfg_vpd {
 struct pcicfg_msi {
     uint16_t   msi_ctrl;       /* Message Control */
     uint8_t    msi_location;   /* Offset of MSI capability registers. */
-    uint8_t    msi_msgnum;     /* Number of messages */
     int                msi_alloc;      /* Number of allocated messages. */
     uint64_t   msi_addr;       /* Contents of address register. */
     uint16_t   msi_data;       /* Contents of data register. */
@@ -111,7 +110,6 @@ struct msix_table_entry {
 
 struct pcicfg_msix {
     uint16_t   msix_ctrl;      /* Message Control */
-    uint16_t   msix_msgnum;    /* Number of messages */
     uint8_t    msix_location;  /* Offset of MSI-X capability registers. */
     uint8_t    msix_table_bar; /* BAR containing vector table. */
     uint8_t    msix_pba_bar;   /* BAR containing PBA. */

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