[PATCH v2 3/5] iommu: make iommu_inclusive_mapping a suboption of dom0-iommu

[Roger Pau Monne <roger.pau@citrix.com>]

Introduce a new dom0-iommu=inclusive generic option that supersedes
iommu_inclusive_mapping. The prevcious behaviour is preserved and the
option should only be enabled by default on Intel hardware.

No functional change intended.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
Changes since v1:
 - Use dom0-iommu instead of the iommu option.
 - Only enable by default on Intel hardware.
---
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: George Dunlap <George.Dunlap@eu.citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Julien Grall <julien.grall@arm.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Tim Deegan <tim@xen.org>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Kevin Tian <kevin.tian@intel.com>
---
 docs/misc/xen-command-line.markdown   | 14 +++++++
 xen/drivers/passthrough/arm/iommu.c   |  4 ++
 xen/drivers/passthrough/iommu.c       |  5 +++
 xen/drivers/passthrough/vtd/extern.h  |  2 -
 xen/drivers/passthrough/vtd/iommu.c   |  6 ---
 xen/drivers/passthrough/vtd/x86/vtd.c | 58 +-------------------------
 xen/drivers/passthrough/x86/iommu.c   | 60 +++++++++++++++++++++++++++
 xen/include/xen/iommu.h               |  2 +
 8 files changed, 86 insertions(+), 65 deletions(-)

diff --git a/docs/misc/xen-command-line.markdown b/docs/misc/xen-command-line.markdown
index a2a07cc6c8..30d970bc2e 100644
--- a/docs/misc/xen-command-line.markdown
+++ b/docs/misc/xen-command-line.markdown
@@ -1230,6 +1230,17 @@ detection of systems known to misbehave upon accesses to that port.
 >> Controls whether to setup DMA remappings for all the host RAM except regions
 >> in use by Xen.
 
+> `inclusive`
+
+> Default: `true` on Intel hardware, `false` otherwise
+
+>> Use this to work around firmware issues providing incorrect RMRR or IVMD
+>> entries. Rather than only mapping RAM pages for IOMMU accesses for Dom0,
+>> with this option all pages up to 4GB, not marked as unusable in the E820
+>> table, will get a mapping established. Note that this option is only
+>> applicable to a PV dom0. Also note that if `strict` mode is enabled
+>> then conventional RAM pages not assigned to dom0 will not be mapped.
+
 ### iommu\_dev\_iotlb\_timeout
 > `= <integer>`
 
@@ -1242,6 +1253,9 @@ wait descriptor timed out', try increasing this value.
 ### iommu\_inclusive\_mapping (VT-d)
 > `= <boolean>`
 
+**WARNING: This command line option is deprecated, and superseded by
+_dom0-iommu=inclusive_ - using both options in combination is undefined.**
+
 > Default: `true`
 
 Use this to work around firmware issues providing incorrect RMRR entries.
diff --git a/xen/drivers/passthrough/arm/iommu.c b/xen/drivers/passthrough/arm/iommu.c
index 95b1abb972..325997b19f 100644
--- a/xen/drivers/passthrough/arm/iommu.c
+++ b/xen/drivers/passthrough/arm/iommu.c
@@ -73,3 +73,7 @@ int arch_iommu_populate_page_table(struct domain *d)
     /* The IOMMU shares the p2m with the CPU */
     return -ENOSYS;
 }
+
+void __hwdom_init arch_iommu_hwdom_init(struct domain *d)
+{
+}
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index 88e23bbd04..6611e13cc2 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -74,6 +74,7 @@ bool_t __read_mostly amd_iommu_perdev_intremap = 1;
 custom_param("dom0-iommu", parse_dom0_iommu_param);
 bool __hwdom_initdata iommu_dom0_strict;
 bool __read_mostly iommu_dom0_passthrough;
+int8_t __hwdom_initdata iommu_dom0_inclusive = -1;
 
 DEFINE_PER_CPU(bool_t, iommu_dont_flush_iotlb);
 
@@ -158,6 +159,8 @@ static int __init parse_dom0_iommu_param(const char *s)
             iommu_dom0_strict = val;
         else if ( !strncmp(s, "relaxed", ss - s) )
             iommu_dom0_strict = !val;
+        else if ( !strncmp(s, "inclusive", ss - s) )
+            iommu_dom0_inclusive = val;
         else
             rc = -EINVAL;
 
@@ -240,6 +243,8 @@ void __hwdom_init iommu_hwdom_init(struct domain *d)
     }
 
     hd->platform_ops->hwdom_init(d);
+
+    arch_iommu_hwdom_init(d);
 }
 
 void iommu_teardown(struct domain *d)
diff --git a/xen/drivers/passthrough/vtd/extern.h b/xen/drivers/passthrough/vtd/extern.h
index fb7edfaef9..91cadc602e 100644
--- a/xen/drivers/passthrough/vtd/extern.h
+++ b/xen/drivers/passthrough/vtd/extern.h
@@ -99,6 +99,4 @@ void pci_vtd_quirk(const struct pci_dev *);
 bool_t platform_supports_intremap(void);
 bool_t platform_supports_x2apic(void);
 
-void vtd_set_hwdom_mapping(struct domain *d);
-
 #endif // _VTD_EXTERN_H_
diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
index 8ac774215b..c880b0ce21 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -1304,12 +1304,6 @@ static void __hwdom_init intel_iommu_hwdom_init(struct domain *d)
 {
     struct acpi_drhd_unit *drhd;
 
-    if ( !iommu_dom0_passthrough && is_pv_domain(d) )
-    {
-        /* Set up 1:1 page table for hardware domain. */
-        vtd_set_hwdom_mapping(d);
-    }
-
     setup_hwdom_pci_devices(d, setup_hwdom_device);
     setup_hwdom_rmrr(d);
 
diff --git a/xen/drivers/passthrough/vtd/x86/vtd.c b/xen/drivers/passthrough/vtd/x86/vtd.c
index 00a9891005..20323051d0 100644
--- a/xen/drivers/passthrough/vtd/x86/vtd.c
+++ b/xen/drivers/passthrough/vtd/x86/vtd.c
@@ -25,7 +25,6 @@
 #include <xen/irq.h>
 #include <xen/numa.h>
 #include <asm/fixmap.h>
-#include <asm/setup.h>
 #include "../iommu.h"
 #include "../dmar.h"
 #include "../vtd.h"
@@ -35,8 +34,7 @@
  * iommu_inclusive_mapping: when set, all memory below 4GB is included in dom0
  * 1:1 iommu mappings except xen and unusable regions.
  */
-static bool_t __hwdom_initdata iommu_inclusive_mapping = 1;
-boolean_param("iommu_inclusive_mapping", iommu_inclusive_mapping);
+boolean_param("iommu_inclusive_mapping", iommu_dom0_inclusive);
 
 void *map_vtd_domain_page(u64 maddr)
 {
@@ -108,57 +106,3 @@ void hvm_dpci_isairq_eoi(struct domain *d, unsigned int isairq)
     spin_unlock(&d->event_lock);
 }
 
-void __hwdom_init vtd_set_hwdom_mapping(struct domain *d)
-{
-    unsigned long i, top, max_pfn;
-
-    BUG_ON(!is_hardware_domain(d));
-
-    max_pfn = (GB(4) >> PAGE_SHIFT) - 1;
-    top = max(max_pdx, pfn_to_pdx(max_pfn) + 1);
-
-    for ( i = 0; i < top; i++ )
-    {
-        unsigned long pfn = pdx_to_pfn(i);
-        bool map;
-        int rc;
-
-        /*
-         * Set up 1:1 mapping for dom0. Default to include only
-         * conventional RAM areas and let RMRRs include needed reserved
-         * regions. When set, the inclusive mapping additionally maps in
-         * every pfn up to 4GB except those that fall in unusable ranges.
-         */
-        if ( pfn > max_pfn && !mfn_valid(_mfn(pfn)) )
-            continue;
-
-        if ( iommu_inclusive_mapping && pfn <= max_pfn )
-            map = !page_is_ram_type(pfn, RAM_TYPE_UNUSABLE);
-        else
-            map = page_is_ram_type(pfn, RAM_TYPE_CONVENTIONAL);
-
-        if ( !map )
-            continue;
-
-        /* Exclude Xen bits */
-        if ( xen_in_range(pfn) )
-            continue;
-
-        /*
-         * If dom0-strict mode is enabled then exclude conventional RAM
-         * and let the common code map dom0's pages.
-         */
-        if ( iommu_dom0_strict &&
-             page_is_ram_type(pfn, RAM_TYPE_CONVENTIONAL) )
-            continue;
-
-        rc = iommu_map_page(d, pfn, pfn, IOMMUF_readable|IOMMUF_writable);
-        if ( rc )
-            printk(XENLOG_WARNING VTDPREFIX " d%d: IOMMU mapping failed: %d\n",
-                   d->domain_id, rc);
-
-        if (!(i & 0xfffff))
-            process_pending_softirqs();
-    }
-}
-
diff --git a/xen/drivers/passthrough/x86/iommu.c b/xen/drivers/passthrough/x86/iommu.c
index 68182afd91..bf6edf4c04 100644
--- a/xen/drivers/passthrough/x86/iommu.c
+++ b/xen/drivers/passthrough/x86/iommu.c
@@ -20,6 +20,8 @@
 #include <xen/softirq.h>
 #include <xsm/xsm.h>
 
+#include <asm/setup.h>
+
 void iommu_update_ire_from_apic(
     unsigned int apic, unsigned int reg, unsigned int value)
 {
@@ -132,6 +134,64 @@ void arch_iommu_domain_destroy(struct domain *d)
 {
 }
 
+void __hwdom_init arch_iommu_hwdom_init(struct domain *d)
+{
+    unsigned long i, top, max_pfn;
+
+    BUG_ON(!is_hardware_domain(d));
+
+    /* Set the default value of inclusive depending on the hardware. */
+    if ( iommu_dom0_inclusive == -1 )
+        iommu_dom0_inclusive = boot_cpu_data.x86_vendor == X86_VENDOR_INTEL;
+
+    max_pfn = (GB(4) >> PAGE_SHIFT) - 1;
+    top = max(max_pdx, pfn_to_pdx(max_pfn) + 1);
+
+    for ( i = 0; i < top; i++ )
+    {
+        unsigned long pfn = pdx_to_pfn(i);
+        bool map;
+        int rc;
+
+        /*
+         * Set up 1:1 mapping for dom0. Default to include only
+         * conventional RAM areas and let RMRRs include needed reserved
+         * regions. When set, the inclusive mapping additionally maps in
+         * every pfn up to 4GB except those that fall in unusable ranges.
+         */
+        if ( pfn > max_pfn && !mfn_valid(_mfn(pfn)) )
+            continue;
+
+        if ( iommu_dom0_inclusive && pfn <= max_pfn )
+            map = !page_is_ram_type(pfn, RAM_TYPE_UNUSABLE);
+        else
+            map = page_is_ram_type(pfn, RAM_TYPE_CONVENTIONAL);
+
+        if ( !map )
+            continue;
+
+        /* Exclude Xen bits */
+        if ( xen_in_range(pfn) )
+            continue;
+
+        /*
+         * If dom0-strict mode is enabled then exclude conventional RAM
+         * and let the common code map dom0's pages.
+         */
+        if ( iommu_dom0_strict &&
+             page_is_ram_type(pfn, RAM_TYPE_CONVENTIONAL) )
+            continue;
+
+        rc = iommu_map_page(d, pfn, pfn, IOMMUF_readable|IOMMUF_writable);
+        if ( rc )
+            printk(XENLOG_WARNING " d%d: IOMMU mapping failed: %d\n",
+                   d->domain_id, rc);
+
+        if (!(i & 0xfffff))
+            process_pending_softirqs();
+    }
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index c0c6975ac4..99e5b89c0f 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -37,6 +37,7 @@ extern bool_t iommu_debug;
 extern bool_t amd_iommu_perdev_intremap;
 
 extern bool iommu_dom0_strict, iommu_dom0_passthrough;
+extern int8_t iommu_dom0_inclusive;
 
 extern unsigned int iommu_dev_iotlb_timeout;
 
@@ -51,6 +52,7 @@ void arch_iommu_domain_destroy(struct domain *d);
 int arch_iommu_domain_init(struct domain *d);
 int arch_iommu_populate_page_table(struct domain *d);
 void arch_iommu_check_autotranslated_hwdom(struct domain *d);
+void arch_iommu_hwdom_init(struct domain *d);
 
 int iommu_construct(struct domain *d);
 
-- 
2.18.0


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