[RFC v6 25/25] intel_iommu: modify x-scalable-mode to be string option

[Liu Yi L]

Intel VT-d 3.0 introduces scalable mode, and it has a bunch of capabilities
related to scalable mode translation, thus there are multiple combinations.
While this vIOMMU implementation wants simplify it for user by providing
typical combinations. User could config it by "x-scalable-mode" option. The
usage is as below:

"-device intel-iommu,x-scalable-mode=["legacy"|"modern"|"off"]"

 - "legacy": gives support for SL page table
 - "modern": gives support for FL page table, pasid, virtual command
 - "off": no scalable mode support
 -  if not configured, means no scalable mode support, if not proper
    configured, will throw error

Note: this patch is supposed to be merged when  the whole vSVA patch series
were merged.

Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Yi Sun <yi.y.sun@linux.intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
---
rfcv5 (v2) -> rfcv6:
*) reports want_nested to VFIO;
*) assert iommu_set/unset_iommu_context() if vIOMMU is not scalable modern.

 hw/i386/intel_iommu.c          | 39 +++++++++++++++++++++++++++++++++++----
 hw/i386/intel_iommu_internal.h |  3 +++
 include/hw/i386/intel_iommu.h  |  2 ++
 3 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index ef16f18..a504dc4 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -4043,7 +4043,7 @@ static Property vtd_properties[] = {
     DEFINE_PROP_UINT8("aw-bits", IntelIOMMUState, aw_bits,
                       VTD_HOST_ADDRESS_WIDTH),
     DEFINE_PROP_BOOL("caching-mode", IntelIOMMUState, caching_mode, FALSE),
-    DEFINE_PROP_BOOL("x-scalable-mode", IntelIOMMUState, scalable_mode, FALSE),
+    DEFINE_PROP_STRING("x-scalable-mode", IntelIOMMUState, scalable_mode_str),
     DEFINE_PROP_BOOL("dma-drain", IntelIOMMUState, dma_drain, true),
     DEFINE_PROP_END_OF_LIST(),
 };
@@ -4413,6 +4413,7 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, 
PCIBus *bus, int devfn)
 static int vtd_dev_get_iommu_attr(PCIBus *bus, void *opaque, int32_t devfn,
                                    IOMMUAttr attr, void *data)
 {
+    IntelIOMMUState *s = opaque;
     int ret = 0;
 
     assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
@@ -4422,8 +4423,7 @@ static int vtd_dev_get_iommu_attr(PCIBus *bus, void 
*opaque, int32_t devfn,
     {
         bool *pdata = data;
 
-        /* return false until vSVA is ready */
-        *pdata = false;
+        *pdata = s->scalable_modern ? true : false;
         break;
     }
     default:
@@ -4517,6 +4517,8 @@ static int vtd_dev_set_iommu_context(PCIBus *bus, void 
*opaque,
     VTDHostIOMMUContext *vtd_dev_icx;
 
     assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
+    /* only modern scalable supports set_ioimmu_context */
+    assert(s->scalable_modern);
 
     vtd_bus = vtd_find_add_bus(s, bus);
 
@@ -4551,6 +4553,8 @@ static void vtd_dev_unset_iommu_context(PCIBus *bus, void 
*opaque, int devfn)
     VTDHostIOMMUContext *vtd_dev_icx;
 
     assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
+    /* only modern scalable supports unset_ioimmu_context */
+    assert(s->scalable_modern);
 
     vtd_bus = vtd_find_add_bus(s, bus);
 
@@ -4778,8 +4782,13 @@ static void vtd_init(IntelIOMMUState *s)
     }
 
     /* TODO: read cap/ecap from host to decide which cap to be exposed. */
-    if (s->scalable_mode) {
+    if (s->scalable_mode && !s->scalable_modern) {
         s->ecap |= VTD_ECAP_SMTS | VTD_ECAP_SRS | VTD_ECAP_SLTS;
+    } else if (s->scalable_mode && s->scalable_modern) {
+        s->ecap |= VTD_ECAP_SMTS | VTD_ECAP_SRS | VTD_ECAP_PASID |
+                   VTD_ECAP_FLTS | VTD_ECAP_PSS(VTD_PASID_SS) |
+                   VTD_ECAP_VCS;
+        s->vccap |= VTD_VCCAP_PAS;
     }
 
     if (!s->cap_finalized) {
@@ -4920,6 +4929,28 @@ static bool vtd_decide_config(IntelIOMMUState *s, Error 
**errp)
         return false;
     }
 
+    if (s->scalable_mode_str &&
+        (strcmp(s->scalable_mode_str, "off") &&
+         strcmp(s->scalable_mode_str, "modern") &&
+         strcmp(s->scalable_mode_str, "legacy"))) {
+        error_setg(errp, "Invalid x-scalable-mode config,"
+                         "Please use \"modern\", \"legacy\" or \"off\"");
+        return false;
+    }
+
+    if (s->scalable_mode_str &&
+        !strcmp(s->scalable_mode_str, "legacy")) {
+        s->scalable_mode = true;
+        s->scalable_modern = false;
+    } else if (s->scalable_mode_str &&
+        !strcmp(s->scalable_mode_str, "modern")) {
+        s->scalable_mode = true;
+        s->scalable_modern = true;
+    } else {
+        s->scalable_mode = false;
+        s->scalable_modern = false;
+    }
+
     return true;
 }
 
diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
index 9530e0d..e7c5815 100644
--- a/hw/i386/intel_iommu_internal.h
+++ b/hw/i386/intel_iommu_internal.h
@@ -199,8 +199,11 @@
 #define VTD_ECAP_PSS(val)           (((val) & 0x1fULL) << 35)
 #define VTD_ECAP_PASID              (1ULL << 40)
 #define VTD_ECAP_SMTS               (1ULL << 43)
+#define VTD_ECAP_VCS                (1ULL << 44)
 #define VTD_ECAP_SLTS               (1ULL << 46)
+#define VTD_ECAP_FLTS               (1ULL << 47)
 
+#define VTD_PASID_SS                (19)
 #define VTD_GET_PSS(val)            (((val) >> 35) & 0x1f)
 #define VTD_ECAP_PSS_MASK           (0x1fULL << 35)
 
diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
index 1aab882..fd64364 100644
--- a/include/hw/i386/intel_iommu.h
+++ b/include/hw/i386/intel_iommu.h
@@ -263,6 +263,8 @@ struct IntelIOMMUState {
 
     bool caching_mode;              /* RO - is cap CM enabled? */
     bool scalable_mode;             /* RO - is Scalable Mode supported? */
+    char *scalable_mode_str;        /* RO - admin's Scalable Mode config */
+    bool scalable_modern;           /* RO - is modern SM supported? */
 
     dma_addr_t root;                /* Current root table pointer */
     bool root_scalable;             /* Type of root table (scalable or not) */
-- 
2.7.4