The branch stable/13 has been updated by emaste:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=dbd445bbd3d7d5c50914bac20d6595ed344e4c5e

commit dbd445bbd3d7d5c50914bac20d6595ed344e4c5e
Author:     Ed Maste <[email protected]>
AuthorDate: 2023-08-14 16:56:12 +0000
Commit:     Ed Maste <[email protected]>
CommitDate: 2023-09-17 07:18:11 +0000

    msi: handle error from BUS_REMAP_INTR in msi_assign_cpu
    
    Previously errors from BUS_REMAP_INTR were silently ignored, and we
    ended up with non-functional interrupts.
    
    Now we allocate and enable new vectors, but postpone assignment of new
    APIC IDs and vectors where we can, until after BUS_REMAP_INTR is
    successful.  We then disable and free the old vectors.
    
    If BUS_REMAP_INTR fails we restore the old configuration, and disable
    and free the new, unused vectors.
    
    Thanks to AMD for providing hardware (with APIC IDs above 255) for
    testing.
    
    Reviewed by:    jhb
    MFC after:      1 month
    Sponsored by:   The FreeBSD Foundation
    Differential Revision: https://reviews.freebsd.org/D41455
    
    (cherry picked from commit fa5f94140a83b4704c654ababd67cd9addb7cd29)
---
 sys/x86/x86/msi.c | 47 ++++++++++++++++++++++++++++++++---------------
 1 file changed, 32 insertions(+), 15 deletions(-)

diff --git a/sys/x86/x86/msi.c b/sys/x86/x86/msi.c
index 8751c621a5e1..7f4d87c09453 100644
--- a/sys/x86/x86/msi.c
+++ b/sys/x86/x86/msi.c
@@ -244,7 +244,7 @@ msi_assign_cpu(struct intsrc *isrc, u_int apic_id)
        struct msi_intsrc *sib, *msi = (struct msi_intsrc *)isrc;
        int old_vector;
        u_int old_id;
-       int i, vector;
+       int error, i, vector;
 
        /*
         * Only allow CPUs to be assigned to the first message for an
@@ -274,31 +274,48 @@ msi_assign_cpu(struct intsrc *isrc, u_int apic_id)
        if (vector == 0)
                return (ENOSPC);
 
+       /* Must be set before BUS_REMAP_INTR as it may call back into MSI. */
        msi->msi_cpu = apic_id;
        msi->msi_vector = vector;
        if (msi->msi_intsrc.is_handlers > 0)
                apic_enable_vector(msi->msi_cpu, msi->msi_vector);
-       if (bootverbose)
-               printf("msi: Assigning %s IRQ %d to local APIC %u vector %u\n",
-                   msi->msi_msix ? "MSI-X" : "MSI", msi->msi_irq,
-                   msi->msi_cpu, msi->msi_vector);
        for (i = 1; i < msi->msi_count; i++) {
                sib = (struct msi_intsrc *)intr_lookup_source(msi->msi_irqs[i]);
-               sib->msi_cpu = apic_id;
-               sib->msi_vector = vector + i;
                if (sib->msi_intsrc.is_handlers > 0)
-                       apic_enable_vector(sib->msi_cpu, sib->msi_vector);
-               if (bootverbose)
-                       printf(
-                   "msi: Assigning MSI IRQ %d to local APIC %u vector %u\n",
-                           sib->msi_irq, sib->msi_cpu, sib->msi_vector);
+                       apic_enable_vector(apic_id, vector + i);
        }
-       BUS_REMAP_INTR(device_get_parent(msi->msi_dev), msi->msi_dev,
+       error = BUS_REMAP_INTR(device_get_parent(msi->msi_dev), msi->msi_dev,
            msi->msi_irq);
+       if (error == 0) {
+               if (bootverbose) {
+                       printf("msi: Assigning %s IRQ %d to local APIC %u 
vector %u\n",
+                           msi->msi_msix ? "MSI-X" : "MSI", msi->msi_irq,
+                           msi->msi_cpu, msi->msi_vector);
+               }
+               for (i = 1; i < msi->msi_count; i++) {
+                       sib = (struct msi_intsrc *)intr_lookup_source(
+                           msi->msi_irqs[i]);
+                       sib->msi_cpu = apic_id;
+                       sib->msi_vector = vector + i;
+                       if (bootverbose)
+                               printf("msi: Assigning MSI IRQ %d to local APIC 
%u vector %u\n",
+                                   sib->msi_irq, sib->msi_cpu,
+                                   sib->msi_vector);
+               }
+       } else {
+               device_printf(msi->msi_dev,
+                   "remap irq %u to APIC ID %u failed (error %d)\n",
+                   msi->msi_irq, apic_id, error);
+               msi->msi_cpu = old_id;
+               msi->msi_vector = old_vector;
+               old_id = apic_id;
+               old_vector = vector;
+       }
 
        /*
         * Free the old vector after the new one is established.  This is done
-        * to prevent races where we could miss an interrupt.
+        * to prevent races where we could miss an interrupt.  If BUS_REMAP_INTR
+        * failed then we disable and free the new, unused vector(s).
         */
        if (msi->msi_intsrc.is_handlers > 0)
                apic_disable_vector(old_id, old_vector);
@@ -309,7 +326,7 @@ msi_assign_cpu(struct intsrc *isrc, u_int apic_id)
                        apic_disable_vector(old_id, old_vector + i);
                apic_free_vector(old_id, old_vector + i, msi->msi_irqs[i]);
        }
-       return (0);
+       return (error);
 }
 
 void

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