PR unikraft#908

arch/arm/arm64/include/uk/asm/paging.h

@@ -104,6 +104,10 @@ struct ukarch_pagetable {
 #define PAGE_ATTR_SHAREABLE_IS		(1 << PAGE_ATTR_SHAREABLE_SHIFT)
 #define PAGE_ATTR_SHAREABLE_OS		(2 << PAGE_ATTR_SHAREABLE_SHIFT)
 
+/* Page fault error code bits */
+#define ARM64_PF_ESR_WnR		0x0000040UL
+#define ARM64_PF_ESR_ISV		0x1000000UL
+
 #define ARM64_PADDR_BITS		48
 #define ARM64_VADDR_BITS		48
 
@@ -173,6 +177,31 @@ static inline __paddr_t PT_Lx_PTE_PADDR(__pte_t pte, unsigned int lvl)
 	return paddr;
 }
 
+static inline __paddr_t PT_Lx_PTE_SET_PADDR(__pte_t pte, unsigned int lvl,
+					     __paddr_t paddr)
+{
+	static __u64 pte_lx_map_paddr_mask[] = {
+		PTE_L0_PAGE_PADDR_MASK,
+		PTE_L1_BLOCK_PADDR_MASK,
+		PTE_L2_BLOCK_PADDR_MASK
+	};
+
+	if (PAGE_Lx_IS(pte, lvl)) {
+#ifdef CONFIG_LIBUKDEBUG
+		UK_ASSERT(lvl <= PT_MAP_LEVEL_MAX);
+#endif /* CONFIG_LIBUKDEBUG */
+		paddr &= pte_lx_map_paddr_mask[lvl];
+		pte &= ~pte_lx_map_paddr_mask[lvl];
+	} else {
+#ifdef CONFIG_LIBUKDEBUG
+		UK_ASSERT(lvl > PAGE_LEVEL && lvl < PT_LEVELS);
+#endif /* CONFIG_LIBUKDEBUG */
+		paddr &= PTE_Lx_TABLE_PADDR_MASK;
+		pte &= ~PTE_Lx_TABLE_PADDR_MASK;
+	}
+	return pte | paddr;
+}
+
 static inline int ukarch_paddr_range_isvalid(__paddr_t start, __paddr_t end)
 {
 #ifdef CONFIG_LIBUKDEBUG

lib/ukvmem/Config.uk

@@ -4,8 +4,7 @@ menuconfig LIBUKVMEM
 	select LIBUKDEBUG
 	select LIBUKALLOC
 	select LIBISRLIB
-	# ARM architecture is not yet compatible
-	depends on ARCH_X86_64
+	select PAGING
 	help
 		This library implements virtual address management by
 		providing methods for working with virtual address space

lib/ukvmem/Makefile.uk

@@ -15,6 +15,8 @@ endif
 ifeq ($(CONFIG_HAVE_PAGING),y)
 LIBUKVMEM_SRCS-$(CONFIG_ARCH_X86_64) += \
 	$(LIBUKVMEM_BASE)/arch/x86_64/pagefault.c|isr
+LIBUKVMEM_SRCS-$(CONFIG_ARCH_ARM_64) += \
+	$(LIBUKVMEM_BASE)/arch/arm/pagefault64.c|isr
 endif
 
 ifneq ($(filter y,$(CONFIG_LIBUKVMEM_TEST) $(CONFIG_LIBUKTEST_ALL)),)

lib/ukvmem/arch/arm/pagefault64.c

@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/* Copyright (c) 2023, Unikraft GmbH and The Unikraft Authors.
+ * Licensed under the BSD-3-Clause License (the "License").
+ * You may not use this file except in compliance with the License.
+ */
+
+#include "../../vmem.h"
+
+#include <uk/assert.h>
+#include <uk/arch/traps.h>
+#include <uk/arch/types.h>
+#include <uk/print.h>
+#include <uk/config.h>
+
+static int vmem_arch_pagefault(void *data)
+{
+	struct ukarch_trap_ctx *ctx = (struct ukarch_trap_ctx *)data;
+	__vaddr_t vaddr = (__vaddr_t)ctx->far;
+	const char *faultstr[] __maybe_unused = {
+		"read", "write", "exec"
+	};
+	unsigned int faulttype;
+	unsigned long dfsc;
+	int rc;
+
+	if (ctx->esr & ARM64_PF_ESR_WnR)
+		faulttype = UK_VMA_FAULT_WRITE;
+	else if (ctx->esr & ARM64_PF_ESR_ISV)
+		faulttype = UK_VMA_FAULT_EXEC;
+	else
+		faulttype = UK_VMA_FAULT_READ;
+
+	dfsc = ctx->esr & ESR_ISS_ABRT_FSC_MASK;
+	if (dfsc >= ESR_ISS_ABRT_FSC_TRANS_L0 &&
+	    dfsc <= ESR_ISS_ABRT_FSC_TRANS_L3)
+		faulttype |= UK_VMA_FAULT_NONPRESENT;
+	else
+		faulttype |= UK_VMA_FAULT_MISCONFIG;
+
+	rc = vmem_pagefault(vaddr, faulttype, ctx->regs);
+	if (unlikely(rc < 0)) {
+		uk_pr_debug("Cannot handle %s page fault at 0x%"__PRIvaddr
+			    " (ec: 0x%x): %d\n",
+			    faultstr[faulttype & UK_VMA_FAULT_ACCESSTYPE],
+			    vaddr, ctx->esr, rc);
+
+		return UK_EVENT_NOT_HANDLED;
+	}
+
+	return UK_EVENT_HANDLED;
+}
+
+UK_EVENT_HANDLER_PRIO(UKARCH_TRAP_PAGE_FAULT, vmem_arch_pagefault,
+		      CONFIG_LIBUKVMEM_PAGEFAULT_HANDLER_PRIO);