lcd/iommu: save the lcd struct pointer for lookup

In the Rx path, page fragments are mapped inside the isolated domain and passed
onto the kernel for consumption by upper layers. Let's save the lcd_struct so
that we can easily do a lookup.
Signed-off-by: Vikram Narayanan <vikram186@gmail.com>

lcd-domains/microkernel/iommu.c

@@ -21,6 +21,9 @@ struct region {
 	}
 };
 
+struct lcd *iommu_lcd;
+EXPORT_SYMBOL(iommu_lcd);
+
 /* XXX: We are indeed walking the ept *without* a lock!
  * HINT: A mutex is initialized during ept init and never used.
  * What are the consequences?
@@ -79,9 +82,10 @@ int lcd_iommu_map_page(struct lcd *lcd, gpa_t gpa, unsigned int order,
 			BUG_ON(ret != PAGE_SIZE);
 		}
 
+		if (0) {
 		printk("%s, mapping gpa:hpa %lx:%lx pair\n", __func__,
 		       gpa_val(ga), hpa_val(hpa));
-
+		}
 		/* map */
 		ret = iommu_map(lcd->domain, gpa_val(ga), hpa_val(hpa),
 				PAGE_SIZE, IOMMU_READ | IOMMU_WRITE);
@@ -124,7 +128,7 @@ int lcd_iommu_unmap_page(struct lcd *lcd, gpa_t gpa, unsigned int order)
 		}
 
 		ret = iommu_iova_to_phys(lcd->domain, gpa_val(ga));
-
+		if (0)
 		printk("%s, unmapping gpa:hpa %lx:%lx pair\n", __func__,
 		       gpa_val(ga), hpa_val(hpa));
 
@@ -133,6 +137,7 @@ int lcd_iommu_unmap_page(struct lcd *lcd, gpa_t gpa, unsigned int order)
 			ret = iommu_unmap(lcd->domain, gpa_val(ga), PAGE_SIZE);
 			/* bug if not a page */
 			BUG_ON(ret != PAGE_SIZE);
+
 		}
 	}
 	/* return success */
@@ -257,6 +262,8 @@ int lcd_iommu_map_domain(struct lcd *lcd, struct pci_dev *pdev)
 		goto fail_attach;
 	}
 
+	/* XXX: Grrr. this is ugly. devise a clean way to do this */
+	iommu_lcd = lcd;
 	return ret;
 
 fail_attach: