[PATCH 1/1 V3] x86/AMD-Vi: Add additional check for invalid special->handle

[<suravee.suthikulpanit@amd.com>]

From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>

This patch handle additional cases for IVRS bugs where special->handle
is not correctly initialized for IOAPIC and HPETS due to firmware bugs.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>

Provide logic in "is_ioapic_overidden()"

Signed-off-by: Jan Beulich <JBeulich@suse.com>
---
Changes from V2:
	- Add logic from Jan
	- Also invalid handle for HPET
	- Clean up old logics

 xen/drivers/passthrough/amd/iommu_acpi.c | 60 +++++++++++++++++++++++++-------
 1 file changed, 47 insertions(+), 13 deletions(-)

diff --git a/xen/drivers/passthrough/amd/iommu_acpi.c b/xen/drivers/passthrough/amd/iommu_acpi.c
index 89b359c..0e63e35 100644
--- a/xen/drivers/passthrough/amd/iommu_acpi.c
+++ b/xen/drivers/passthrough/amd/iommu_acpi.c
@@ -664,19 +664,46 @@ static void __init parse_ivrs_hpet(char *str)
 
     ASSERT(*s == '[');
     id = simple_strtoul(s + 1, &s, 0);
-    if ( id != (typeof(hpet_sbdf.id))id || *s != ']' || *++s != '=' )
+    if ( (*s != ']') || (*++s != '=') )
         return;
 
     s = parse_pci(s + 1, &seg, &bus, &dev, &func);
     if ( !s || *s )
         return;
 
+    hpet_sbdf.id = id;
     hpet_sbdf.bdf = PCI_BDF(bus, dev, func);
     hpet_sbdf.seg = seg;
     hpet_sbdf.cmdline = 1;
 }
 custom_param("ivrs_hpet[", parse_ivrs_hpet);
 
+static bool_t is_ioapic_overidden(u16 seg, u16 bdf, u8 handle)
+{
+    bool_t ret = 0;
+    int apic = find_first_bit(ioapic_cmdline, ARRAY_SIZE(ioapic_sbdf));
+
+    while ( apic < ARRAY_SIZE(ioapic_sbdf) )
+    {
+        if ( ioapic_sbdf[apic].bdf == bdf &&
+             ioapic_sbdf[apic].seg == seg )
+            break;
+        apic = find_next_bit(ioapic_cmdline, ARRAY_SIZE(ioapic_sbdf),
+                             apic + 1);
+    }
+
+    if ( apic < ARRAY_SIZE(ioapic_sbdf) )
+    {
+        AMD_IOMMU_DEBUG("IVHD: Command line override present for IO-APIC %#x "
+                        "(IVRS: %#x devID %04x:%02x:%02x.%u)\n",
+                        apic, handle, seg, PCI_BUS(bdf),
+                        PCI_SLOT(bdf), PCI_FUNC(bdf));
+        ret = 1;
+    }
+
+    return ret;
+}
+
 static u16 __init parse_ivhd_device_special(
     const struct acpi_ivrs_device8c *special, u16 seg,
     u16 header_length, u16 block_length, struct amd_iommu *iommu)
@@ -698,16 +725,18 @@ static u16 __init parse_ivhd_device_special(
         return 0;
     }
 
-    AMD_IOMMU_DEBUG("IVHD Special: %04x:%02x:%02x.%u variety %#x handle %#x\n",
+    AMD_IOMMU_DEBUG("IVHD Special: %04x:%02x:%02x.%u variety %#x handle %#x used_id %#x\n",
                     seg, PCI_BUS(bdf), PCI_SLOT(bdf), PCI_FUNC(bdf),
-                    special->variety, special->handle);
+                    special->variety, special->handle, special->used_id);
     add_ivrs_mapping_entry(bdf, bdf, special->header.data_setting, iommu);
 
     switch ( special->variety )
     {
     case ACPI_IVHD_IOAPIC:
-        if ( !iommu_intremap )
+        if ( !iommu_intremap ||
+             is_ioapic_overidden(seg, bdf, special->handle) )
             break;
+
         /*
          * Some BIOSes have IOAPIC broken entries so we check for IVRS
          * consistency here --- whether entry's IOAPIC ID is valid and
@@ -725,10 +754,7 @@ static u16 __init parse_ivhd_device_special(
                 return 0;
             }
 
-            if ( test_bit(special->handle, ioapic_cmdline) )
-                AMD_IOMMU_DEBUG("IVHD: Command line override present for IO-APIC %#x\n",
-                                special->handle);
-            else if ( ioapic_sbdf[special->handle].pin_2_idx )
+            if ( ioapic_sbdf[special->handle].pin_2_idx )
             {
                 if ( ioapic_sbdf[special->handle].bdf == bdf &&
                      ioapic_sbdf[special->handle].seg == seg )
@@ -770,6 +796,16 @@ static u16 __init parse_ivhd_device_special(
         }
         break;
     case ACPI_IVHD_HPET:
+        if ( hpet_sbdf.cmdline )
+        {
+            AMD_IOMMU_DEBUG("IVHD: Command line override present for HPET %#x "
+                            "(IVRS: %#x devID %04x:%02x:%02x.%u)\n",
+                            hpet_sbdf.id, special->handle, seg, PCI_BUS(bdf),
+                            PCI_SLOT(bdf), PCI_FUNC(bdf));
+            hpet_sbdf.iommu = iommu;
+            break;
+        }
+
         /* set device id of hpet */
         if ( hpet_sbdf.iommu ||
              (hpet_sbdf.cmdline && hpet_sbdf.id != special->handle) )
@@ -777,12 +813,10 @@ static u16 __init parse_ivhd_device_special(
             printk(XENLOG_WARNING "Only one IVHD HPET entry is supported\n");
             break;
         }
+
         hpet_sbdf.id = special->handle;
-        if ( !hpet_sbdf.cmdline )
-        {
-            hpet_sbdf.bdf = bdf;
-            hpet_sbdf.seg = seg;
-        }
+        hpet_sbdf.bdf = bdf;
+        hpet_sbdf.seg = seg;
         hpet_sbdf.iommu = iommu;
         break;
     default:
-- 
1.8.1.2