[Xen-changelog] [xen stable-4.2] IOMMU: properly check whether interrupt remapping is enabled

[patchbot@xxxxxxx]

commit fd1993bc6b1d5999534344fab2c73124079671d4
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Tue Apr 2 10:50:52 2013 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Apr 2 10:50:52 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 54ec8e7..bf6b542 100644
--- a/xen/arch/x86/msi.c
+++ b/xen/arch/x86/msi.c
@@ -204,7 +204,7 @@ 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);
 }
 
@@ -212,7 +212,7 @@ 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);
@@ -482,7 +482,7 @@ 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 92e54e2..4e275a6 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -404,6 +404,8 @@ 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) )
@@ -420,9 +422,12 @@ 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 6291574..f38a62c 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -2086,6 +2086,9 @@ 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 cee283e..2360222 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-4.2

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