[Xen-changelog] [xen stable-4.1] IOMMU: properly check whether interrupt remapping is enabled

[patchbot@xxxxxxx]

commit bbfb6a516f1af90981bcfbbcff0795474d0759ef
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Tue Apr 2 12:29:34 2013 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Apr 2 12:29:34 2013 +0200

    IOMMU: properly check whether interrupt remapping is enabled
    
    ... rather than the IOMMU as a whole.
    
    That in turn required to make sure iommu_intremap gets properly
    cleared when the respective initialization fails (or isn't being
    done at all).
    
    Along with making sure interrupt remapping doesn't get inconsistently
    enabled on some IOMMUs and not on others in the VT-d code, this in turn
    allowed quite a bit of cleanup on the VT-d side (removed from the
    backport).
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: "Zhang, Xiantao" <xiantao.zhang@xxxxxxxxx>
    master changeset: fae0372140befb88d890a30704a8ec058c902af8
    master date: 2013-03-25 14:28:31 +0100
---
 xen/arch/x86/msi.c                  |    6 +++---
 xen/drivers/passthrough/iommu.c     |    5 +++++
 xen/drivers/passthrough/vtd/iommu.c |    3 +++
 xen/include/asm-x86/io_apic.h       |    2 +-
 4 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/xen/arch/x86/msi.c b/xen/arch/x86/msi.c
index ef332fb..ef3e4bd 100644
--- a/xen/arch/x86/msi.c
+++ b/xen/arch/x86/msi.c
@@ -201,7 +201,7 @@ static void read_msi_msg(struct msi_desc *entry, struct 
msi_msg *msg)
         BUG();
     }
 
-    if ( iommu_enabled )
+    if ( iommu_intremap )
         iommu_read_msi_from_ire(entry, msg);
 }
 
@@ -222,7 +222,7 @@ static void write_msi_msg(struct msi_desc *entry, struct 
msi_msg *msg)
 {
     entry->msg = *msg;
 
-    if ( iommu_enabled )
+    if ( iommu_intremap )
     {
         ASSERT(msg != &entry->msg);
         iommu_update_ire_from_msi(entry, msg);
@@ -438,7 +438,7 @@ int msi_free_irq(struct msi_desc *entry)
     }
 
     /* Free the unused IRTE if intr remap enabled */
-    if ( iommu_enabled )
+    if ( iommu_intremap )
         iommu_update_ire_from_msi(entry, NULL);
 
     list_del(&entry->list);
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index 456014a..cf506e2 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -323,6 +323,8 @@ int __init iommu_setup(void)
         rc = iommu_hardware_setup();
         iommu_enabled = (rc == 0);
     }
+    if ( !iommu_enabled )
+        iommu_intremap = 0;
 
     if ( (force_iommu && !iommu_enabled) ||
          (force_intremap && !iommu_intremap) )
@@ -339,9 +341,12 @@ int __init iommu_setup(void)
     }
     printk("I/O virtualisation %sabled\n", iommu_enabled ? "en" : "dis");
     if ( iommu_enabled )
+    {
         printk(" - Dom0 mode: %s\n",
                iommu_passthrough ? "Passthrough" :
                iommu_dom0_strict ? "Strict" : "Relaxed");
+        printk("Interrupt remapping %sabled\n", iommu_intremap ? "en" : "dis");
+    }
 
     return rc;
 }
diff --git a/xen/drivers/passthrough/vtd/iommu.c 
b/xen/drivers/passthrough/vtd/iommu.c
index c218ec3..22e757c 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -2101,6 +2101,9 @@ static int init_vtd_hw(void)
                 break;
             }
         }
+        if ( !iommu_intremap )
+            for_each_drhd_unit ( drhd )
+                disable_intremap(drhd->iommu);
     }
 
     /*
diff --git a/xen/include/asm-x86/io_apic.h b/xen/include/asm-x86/io_apic.h
index 1b42f85..bbb6f38 100644
--- a/xen/include/asm-x86/io_apic.h
+++ b/xen/include/asm-x86/io_apic.h
@@ -129,7 +129,7 @@ struct IO_APIC_route_entry {
 extern struct mpc_config_ioapic mp_ioapics[MAX_IO_APICS];
 
 /* Only need to remap ioapic RTE (reg: 10~3Fh) */
-#define ioapic_reg_remapped(reg) (iommu_enabled && ((reg) >= 0x10))
+#define ioapic_reg_remapped(reg) (iommu_intremap && ((reg) >= 0x10))
 
 static inline unsigned int __io_apic_read(unsigned int apic, unsigned int reg)
 {
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.1

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