sp1/amd64: mmu: Introduce virtual fuck regions

Signed-off-by: Ian Moffett <ian@mirocom.org>

usr/src/sp1/amd64/cpu/cpu_mmu.c

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2026, Mirocom Laboratories
+ * All rights reserved.
+ *
+ * The following sources are CONFIDENTIAL and PROPRIETARY
+ * property of Mirocom Laboratories. Unauthorized copying,
+ * use, distribution or modification of this file, in whole
+ * and in part, is strictly prohibited without the prior written
+ * consent from Mirocom Laboratories.
+ */
+
+#include <sys/cdefs.h>
+#include <mu/mmu.h>
+
+void
+mu_mmu_readvfr(struct mmu_vfr *res)
+{
+    if (res == NULL) {
+        return;
+    }
+
+    __asmv(
+        "mov %%cr3, %0"
+        : "=r" (res->cr3)
+        :
+        : "memory"
+    );
+}
+
+void
+mu_mmu_writevfr(struct mmu_vfr *vfr)
+{
+    if (vfr == NULL) {
+        return;
+    }
+
+    __asmv(
+        "mov %0, %%cr3"
+        :
+        : "r" (vfr->cr3)
+        : "memory"
+    );
+}

usr/src/sp1/head/amd64/vfr.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2026, Mirocom Laboratories
+ * All rights reserved.
+ *
+ * The following sources are CONFIDENTIAL and PROPRIETARY
+ * property of Mirocom Laboratories. Unauthorized copying,
+ * use, distribution or modification of this file, in whole
+ * and in part, is strictly prohibited without the prior written
+ * consent from Mirocom Laboratories.
+ */
+
+#ifndef _MACHINE_VFR_H_
+#define _MACHINE_VFR_H_ 1
+
+#include <sys/types.h>
+
+/*
+ * Virtual fuck region for AMD64
+ */
+struct mmu_vfr {
+    uint64_t cr3;
+};
+
+#endif  /* !_MACHINE_VFR_H_ */

usr/src/sp1/head/mu/mmu.h

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2026, Mirocom Laboratories
+ * All rights reserved.
+ *
+ * The following sources are CONFIDENTIAL and PROPRIETARY
+ * property of Mirocom Laboratories. Unauthorized copying,
+ * use, distribution or modification of this file, in whole
+ * and in part, is strictly prohibited without the prior written
+ * consent from Mirocom Laboratories.
+ */
+
+#ifndef _MU_MMU_H_
+#define _MU_MMU_H_ 1
+
+/*
+ * Each running SP1 process is to have a virtual fuck region
+ * which logically isolates their address space with the help
+ * of the platform memory management unit.
+ */
+#include <machine/vfr.h>    /* shared; virtual fuck region~ */
+
+/*
+ * Obtain the current VFR in-use
+ *
+ * @res: Result is written here
+ */
+void mu_mmu_readvfr(struct mmu_vfr *res);
+
+/*
+ * Write a new VFR to the processor
+ *
+ * @vfr: Virtual fuck region to set
+ */
+void mu_mmu_writevfr(struct mmu_vfr *vfr);
+
+#endif  /* !_MU_MMU_H_ */