[Qemu-devel] [PATCH v4 5/8] intel_iommu: add OnOffAuto intr_eim as "eim" property

[Radim Krčmář]

The default (auto) emulates the current behavior.
A user can now control EIM like
  -device intel-iommu,intremap=on,eim=off

Reviewed-by: Igor Mammedov <imamm...@redhat.com>
Signed-off-by: Radim Krčmář <rkrc...@redhat.com>
---
v4:
 * r-b Igor
 * added an example to the commit message
v3:
 * use error_setg [Paolo]
 * shorten the code [Peter]
---
 hw/i386/intel_iommu.c         | 24 +++++++++++++++++++++---
 include/hw/i386/intel_iommu.h |  1 +
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 5b06b4091f36..17892b8c336b 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -2012,6 +2012,8 @@ static const MemoryRegionOps vtd_mem_ops = {
 
 static Property vtd_properties[] = {
     DEFINE_PROP_UINT32("version", IntelIOMMUState, version, 0),
+    DEFINE_PROP_ON_OFF_AUTO("eim", IntelIOMMUState, intr_eim,
+                            ON_OFF_AUTO_AUTO),
     DEFINE_PROP_END_OF_LIST(),
 };
 
@@ -2368,7 +2370,11 @@ static void vtd_init(IntelIOMMUState *s)
     s->ecap = VTD_ECAP_QI | VTD_ECAP_IRO;
 
     if (x86_iommu->intr_supported) {
-        s->ecap |= VTD_ECAP_IR | VTD_ECAP_EIM | VTD_ECAP_MHMV;
+        s->ecap |= VTD_ECAP_IR | VTD_ECAP_MHMV;
+        if (s->intr_eim == ON_OFF_AUTO_ON) {
+            s->ecap |= VTD_ECAP_EIM;
+        }
+        assert(s->intr_eim != ON_OFF_AUTO_AUTO);
     }
 
     vtd_reset_context_cache(s);
@@ -2449,8 +2455,10 @@ static AddressSpace *vtd_host_dma_iommu(PCIBus *bus, 
void *opaque, int devfn)
     return &vtd_as->as;
 }
 
-static bool vtd_check_config(X86IOMMUState *x86_iommu, Error **errp)
+static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
 {
+    X86IOMMUState *x86_iommu = X86_IOMMU_DEVICE(s);
+
     /* Currently Intel IOMMU IR only support "kernel-irqchip={off|split}" */
     if (x86_iommu->intr_supported && kvm_irqchip_in_kernel() &&
         !kvm_irqchip_is_split()) {
@@ -2458,6 +2466,16 @@ static bool vtd_check_config(X86IOMMUState *x86_iommu, 
Error **errp)
                          "kernel-irqchip=on, please use 'split|off'.");
         return false;
     }
+    if (s->intr_eim == ON_OFF_AUTO_ON && !x86_iommu->intr_supported) {
+        error_setg(errp, "eim=on cannot be selected without intremap=on");
+        return false;
+    }
+
+    if (s->intr_eim == ON_OFF_AUTO_AUTO) {
+        s->intr_eim = x86_iommu->intr_supported ?
+                                              ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF;
+    }
+
     return true;
 }
 
@@ -2471,7 +2489,7 @@ static void vtd_realize(DeviceState *dev, Error **errp)
     VTD_DPRINTF(GENERAL, "");
     x86_iommu->type = TYPE_INTEL;
 
-    if (!vtd_check_config(x86_iommu, errp)) {
+    if (!vtd_decide_config(s, errp)) {
         return;
     }
 
diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
index a42dbd745a70..b5ac60927b1f 100644
--- a/include/hw/i386/intel_iommu.h
+++ b/include/hw/i386/intel_iommu.h
@@ -289,6 +289,7 @@ struct IntelIOMMUState {
     dma_addr_t intr_root;           /* Interrupt remapping table pointer */
     uint32_t intr_size;             /* Number of IR table entries */
     bool intr_eime;                 /* Extended interrupt mode enabled */
+    OnOffAuto intr_eim;             /* Toggle for EIM cabability */
 };
 
 /* Find the VTD Address space associated with the given bus pointer,
-- 
2.10.0