AMD IOMMU: allow command line overrides for broken IVRS tables

With there being so many systems with broken ACPI tables, and with it
generally being known what's wrong with those tables, give people a
handle to overcome the resulting disabling of their IOMMUs.

Inspired by Linux side patches providing similar functionality.

Suggested-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-By: Sander Eikelenboom <linux@eikelenboom.it>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Suravee Suthikulpanit <suravee.suthikulapanit@amd.com>

diff --git a/docs/misc/xen-command-line.markdown b/docs/misc/xen-command-line.markdown
index 13c0306c61166555cdf11cabd9f4a8f35b5676d6..a86014b4d602c9797b6d9a775c91b281e6eaf7f3 100644 (file)
--- a/docs/misc/xen-command-line.markdown
+++ b/docs/misc/xen-command-line.markdown
@@ -578,6 +578,20 @@ debug hypervisor only).
 > `= <integer>`
 
 ### irq\_vector\_map
+### ivrs_hpet[`<hpet>`]
+> `=[<seg>:]<bus>:<device>.<func>`
+
+Force the use of `[<seg>:]<bus>:<device>.<func>` as device ID of HPET
+`<hpet>` instead of the one specified by the IVHD sub-tables of the IVRS
+ACPI table.
+
+### ivrs_ioapic[`<ioapic>`]
+> `=[<seg>:]<bus>:<device>.<func>`
+
+Force the use of `[<seg>:]<bus>:<device>.<func>` as device ID of IO-APIC
+`<ioapic>` instead of the one specified by the IVHD sub-tables of the IVRS
+ACPI table.
+
 ### lapic
 
 Force the use of use of the local APIC on a uniprocessor system, even

diff --git a/xen/common/kernel.c b/xen/common/kernel.c
index 72fb9055b1851766760a10b8f5b7bda9314c6b6d..b8707d90a14bf206da4d4d7e712d41ddfa0887b4 100644 (file)
--- a/xen/common/kernel.c
+++ b/xen/common/kernel.c
@@ -81,9 +81,15 @@ void __init cmdline_parse(const char *cmdline)
         /* Search for value part of a key=value option. */
         optval = strchr(opt, '=');
         if ( optval != NULL )
+        {
             *optval++ = '\0'; /* nul-terminate the option value */
+            q = strpbrk(opt, "([{<");
+        }
         else
+        {
             optval = q;       /* default option value is empty string */
+            q = NULL;
+        }
 
         /* Boolean parameters can be inverted with 'no-' prefix. */
         bool_assert = !!strncmp("no-", optkey, 3);
@@ -93,7 +99,17 @@ void __init cmdline_parse(const char *cmdline)
         for ( param = &__setup_start; param < &__setup_end; param++ )
         {
             if ( strcmp(param->name, optkey) )
+            {
+                if ( param->type == OPT_CUSTOM && q &&
+                     strlen(param->name) == q + 1 - opt &&
+                     !strncmp(param->name, opt, q + 1 - opt) )
+                {
+                    optval[-1] = '=';
+                    ((void (*)(const char *))param->var)(q);
+                    optval[-1] = '\0';
+                }
                 continue;
+            }
 
             switch ( param->type )
             {

diff --git a/xen/drivers/passthrough/amd/iommu_acpi.c b/xen/drivers/passthrough/amd/iommu_acpi.c
index c903f9385c1c18bcd906ff7ff5d958925eefe3fb..89b359c455cd7dc38361bdfe15f793bf5516c1de 100644 (file)
--- a/xen/drivers/passthrough/amd/iommu_acpi.c
+++ b/xen/drivers/passthrough/amd/iommu_acpi.c
@@ -633,6 +633,50 @@ static u16 __init parse_ivhd_device_extended_range(
     return dev_length;
 }
 
+static __initdata DECLARE_BITMAP(ioapic_cmdline, ARRAY_SIZE(ioapic_sbdf));
+
+static void __init parse_ivrs_ioapic(char *str)
+{
+    const char *s = str;
+    unsigned long id;
+    unsigned int seg, bus, dev, func;
+
+    ASSERT(*s == '[');
+    id = simple_strtoul(s + 1, &s, 0);
+    if ( id >= ARRAY_SIZE(ioapic_sbdf) || *s != ']' || *++s != '=' )
+        return;
+
+    s = parse_pci(s + 1, &seg, &bus, &dev, &func);
+    if ( !s || *s )
+        return;
+
+    ioapic_sbdf[id].bdf = PCI_BDF(bus, dev, func);
+    ioapic_sbdf[id].seg = seg;
+    __set_bit(id, ioapic_cmdline);
+}
+custom_param("ivrs_ioapic[", parse_ivrs_ioapic);
+
+static void __init parse_ivrs_hpet(char *str)
+{
+    const char *s = str;
+    unsigned long id;
+    unsigned int seg, bus, dev, func;
+
+    ASSERT(*s == '[');
+    id = simple_strtoul(s + 1, &s, 0);
+    if ( id != (typeof(hpet_sbdf.id))id || *s != ']' || *++s != '=' )
+        return;
+
+    s = parse_pci(s + 1, &seg, &bus, &dev, &func);
+    if ( !s || *s )
+        return;
+
+    hpet_sbdf.bdf = PCI_BDF(bus, dev, func);
+    hpet_sbdf.seg = seg;
+    hpet_sbdf.cmdline = 1;
+}
+custom_param("ivrs_hpet[", parse_ivrs_hpet);
+
 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)
@@ -681,7 +725,10 @@ static u16 __init parse_ivhd_device_special(
                 return 0;
             }
 
-            if ( ioapic_sbdf[special->handle].pin_2_idx )
+            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].bdf == bdf &&
                      ioapic_sbdf[special->handle].seg == seg )
@@ -724,14 +771,18 @@ static u16 __init parse_ivhd_device_special(
         break;
     case ACPI_IVHD_HPET:
         /* set device id of hpet */
-        if ( hpet_sbdf.iommu )
+        if ( hpet_sbdf.iommu ||
+             (hpet_sbdf.cmdline && hpet_sbdf.id != special->handle) )
         {
             printk(XENLOG_WARNING "Only one IVHD HPET entry is supported\n");
             break;
         }
         hpet_sbdf.id = special->handle;
-        hpet_sbdf.bdf = bdf;
-        hpet_sbdf.seg = seg;
+        if ( !hpet_sbdf.cmdline )
+        {
+            hpet_sbdf.bdf = bdf;
+            hpet_sbdf.seg = seg;
+        }
         hpet_sbdf.iommu = iommu;
         break;
     default:
@@ -942,22 +993,23 @@ static int __init parse_ivrs_table(struct acpi_table_header *table)
              ioapic_sbdf[IO_APIC_ID(apic)].pin_2_idx )
             continue;
 
-        printk(XENLOG_ERR "IVHD Error: no information for IO-APIC %#x\n",
-               IO_APIC_ID(apic));
-        if ( amd_iommu_perdev_intremap )
-            error = -ENXIO;
+        if ( !test_bit(IO_APIC_ID(apic), ioapic_cmdline) )
+        {
+            printk(XENLOG_ERR "IVHD Error: no information for IO-APIC %#x\n",
+                   IO_APIC_ID(apic));
+            if ( amd_iommu_perdev_intremap )
+                return -ENXIO;
+        }
+
+        ioapic_sbdf[IO_APIC_ID(apic)].pin_2_idx = xmalloc_array(
+            u16, nr_ioapic_entries[apic]);
+        if ( ioapic_sbdf[IO_APIC_ID(apic)].pin_2_idx )
+            memset(ioapic_sbdf[IO_APIC_ID(apic)].pin_2_idx, -1,
+                   nr_ioapic_entries[apic] * sizeof(*ioapic_sbdf->pin_2_idx));
         else
         {
-            ioapic_sbdf[IO_APIC_ID(apic)].pin_2_idx = xmalloc_array(
-                u16, nr_ioapic_entries[apic]);
-            if ( ioapic_sbdf[IO_APIC_ID(apic)].pin_2_idx )
-                memset(ioapic_sbdf[IO_APIC_ID(apic)].pin_2_idx, -1,
-                       nr_ioapic_entries[apic] * sizeof(*ioapic_sbdf->pin_2_idx));
-            else
-            {
-                printk(XENLOG_ERR "IVHD Error: Out of memory\n");
-                error = -ENOMEM;
-            }
+            printk(XENLOG_ERR "IVHD Error: Out of memory\n");
+            error = -ENOMEM;
         }
     }
 

diff --git a/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h b/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h
index 7736ff4d6889e0514cca5f79da94fac7f881e152..3e6961d5c0dec252684cea03fa4dd44873c26d08 100644 (file)
--- a/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h
+++ b/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h
@@ -108,6 +108,7 @@ extern struct ioapic_sbdf {
 
 extern struct hpet_sbdf {
     u16 bdf, seg, id;
+    bool_t cmdline;
     struct amd_iommu *iommu;
 } hpet_sbdf;