iommufd fault queue

examples/iopf.c

@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+/*
+ * This file is part of libvfn.
+ *
+ * Copyright (C) 2022 The libvfn Authors. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <inttypes.h>
+
+#include <sys/mman.h>
+
+#include <linux/iommufd.h>
+
+#include <vfn/vfio.h>
+#include <vfn/iommu.h>
+#include <vfn/iommu/iommufd.h>
+#include <vfn/support.h>
+
+#include "ccan/err/err.h"
+#include "ccan/opt/opt.h"
+#include "ccan/str/str.h"
+
+#include "common.h"
+
+#define REG_ADDR 0x0
+#define REG_CMD  0x8
+
+#define IOVA_BASE 0xfef00000
+
+static struct opt_table opts[] = {
+	OPT_SUBTABLE(opts_base, NULL),
+	OPT_ENDTABLE,
+};
+
+struct vfio_pci_device pdev;
+
+int main(int argc, char **argv)
+{
+	void *bar0;
+	uint64_t iova = IOVA_BASE;
+	ssize_t len;
+	void *vaddr;
+
+	struct iommufd_fault_queue fq;
+
+	struct iommu_hwpt_pgfault pgfault;
+	struct iommu_hwpt_page_response pgresp = {
+		.code = IOMMUFD_PAGE_RESP_SUCCESS,
+	};
+
+	opt_register_table(opts, NULL);
+	opt_parse(&argc, argv, opt_log_stderr_exit);
+
+	if (show_usage)
+		opt_usage_and_exit(NULL);
+
+	if (streq(bdf, ""))
+		opt_usage_exit_fail("missing --device parameter");
+
+	opt_free_table();
+
+	if (vfio_pci_open(&pdev, bdf))
+		err(1, "failed to open pci device");
+
+	if (iommufd_alloc_fault_queue(&fq))
+		err(1, "could not allocate fault queue");
+
+	if (iommufd_set_fault_queue(pdev.dev.ctx, &fq, pdev.dev.fd))
+		err(1, "could not associate fault queue with device/ioas");
+
+	bar0 = vfio_pci_map_bar(&pdev, 0, 0x1000, 0, PROT_READ | PROT_WRITE);
+	if (!bar0)
+		err(1, "failed to map bar");
+
+	len = pgmap(&vaddr, 0x1000);
+	if (len < 0)
+		err(1, "could not allocate aligned memory");
+
+	memset(vaddr, 0x42, 0x1000);
+
+	mmio_lh_write64(bar0 + REG_ADDR, iova);
+	mmio_write32(bar0 + REG_CMD, 0x3);
+
+	/* wait for page fault */
+	while (read(fq.fault_fd, &pgfault, sizeof(pgfault)) == 0)
+		;
+
+	printf("handling page fault on addr 0x%llx\n", pgfault.addr);
+
+	if (iommu_map_vaddr(pdev.dev.ctx, vaddr, 0x1000, &iova, IOMMU_MAP_FIXED_IOVA))
+		err(1, "failed to map page");
+
+	pgresp.cookie = pgfault.cookie;
+
+	if (write(fq.fault_fd, &pgresp, sizeof(pgresp)) < 0)
+		err(1, "failed to write page response");
+
+	while (mmio_read32(bar0 + REG_CMD) & 0x1)
+		;
+
+	memset(vaddr, 0x0, 0x1000);
+
+	mmio_write32(bar0 + REG_CMD, 0x1);
+
+	while (mmio_read32(bar0 + REG_CMD) & 0x1)
+		;
+
+	for (int i = 0; i < 0x1000; i++) {
+		uint8_t byte = *(uint8_t *)(vaddr + i);
+
+		if (byte != 0x42)
+			errx(1, "unexpected byte 0x%"PRIx8, byte);
+	}
+
+	return 0;
+}

examples/meson.build

@@ -16,10 +16,14 @@ examples = {
   'regs': ['regs.c'],
 }
 
+if config_host.get('HAVE_IOMMU_FAULT_QUEUE_ALLOC', false)
+  examples += {'iopf': ['iopf.c']}
+endif
+
 foreach example, sources : examples
   executable(example, [example_sources, sources],
     dependencies: [libnvme],
     link_with: [ccan_lib, vfn_lib],
-    include_directories: [ccan_inc, vfn_inc],
+    include_directories: [ccan_inc, vfn_inc, linux_headers],
   )
 endforeach

include/vfn/iommu/iommufd.h

@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later or MIT */
+
+/*
+ * This file is part of libvfn.
+ *
+ * Copyright (C) 2022 The libvfn Authors. All Rights Reserved.
+ *
+ * This library (libvfn) is dual licensed under the GNU Lesser General
+ * Public License version 2.1 or later or the MIT license. See the
+ * COPYING and LICENSE files for more information.
+ */
+
+#ifndef LIBVFN_IOMMU_IOMMUFD_H
+#define LIBVFN_IOMMU_IOMMUFD_H
+
+#ifdef IOMMU_FAULT_QUEUE_ALLOC
+struct iommufd_fault_queue {
+	int fault_id;
+	int fault_fd;
+};
+
+int iommufd_alloc_fault_queue(struct iommufd_fault_queue *fq);
+int iommufd_set_fault_queue(struct iommu_ctx *ctx, struct iommufd_fault_queue *fq, int devfd);
+#endif
+
+#endif /* LIBVFN_IOMMU_IOMMUFD_H */

include/vfn/iommu/meson.build

@@ -1,6 +1,7 @@
 vfn_iommu_headers = files([
   'context.h',
   'dma.h',
+  'iommufd.h',
 ])
 
 install_headers(vfn_iommu_headers, subdir: 'vfn/iommu')

meson.build

@@ -28,6 +28,8 @@ if get_option('debug')
   add_project_arguments(['-DDEBUG'], language: ['c', 'cpp'])
 endif
 
+linux_headers = include_directories(get_option('linux-headers'))
+
 ##
 ##  Programs
 ##  --------
@@ -36,6 +38,7 @@ endif
 perl = find_program('perl')
 trace_pl = find_program('scripts/trace.pl')
 
+
 ##
 ##  Compiler Configuration
 ##  ----------------------
@@ -64,8 +67,14 @@ config_host.set('NVME_AQ_QSIZE', get_option('aq_qsize'),
   description: 'admin command queue size')
 
 config_host.set('HAVE_VFIO_DEVICE_BIND_IOMMUFD',
-  cc.has_header_symbol('linux/vfio.h', 'VFIO_DEVICE_BIND_IOMMUFD'),
-  description: 'weather VFIO_DEVICE_BIND_IOMMUFD is defined in linux/vfio.h')
+  cc.has_header_symbol('linux/vfio.h', 'VFIO_DEVICE_BIND_IOMMUFD',
+    include_directories: linux_headers),
+  description: 'if VFIO_DEVICE_BIND_IOMMUFD is defined in linux/vfio.h')
+
+config_host.set('HAVE_IOMMU_FAULT_QUEUE_ALLOC',
+  cc.has_header_symbol('linux/iommufd.h', 'IOMMU_FAULT_QUEUE_ALLOC',
+    include_directories: linux_headers),
+  description: 'if IOMMU_FAULT_QUEUE_ALLOC is defined in linux/iommufd.h')
 
 subdir('internal')
 
@@ -74,6 +83,7 @@ add_project_arguments([
   ], language: 'c',
 )
 
+
 ##
 ##  Optional dependencies
 ##  ---------------------
@@ -171,4 +181,5 @@ summary_info += {'Debugging': get_option('debug')}
 summary_info += {'Documentation': build_docs}
 summary_info += {'Profiling': get_option('profiling')}
 summary_info += {'iommufd': config_host.get('HAVE_VFIO_DEVICE_BIND_IOMMUFD')}
+summary_info += {'iommufd fault queue': config_host.get('HAVE_IOMMU_FAULT_QUEUE_ALLOC')}
 summary(summary_info, bool_yn: true, section: 'Features')

meson_options.txt

@@ -12,3 +12,6 @@ option('docs', type: 'feature', value: 'auto',
 
 option('trace-events-file', type: 'string', value: 'config/trace-events-all',
   description: 'trace events file')
+
+option('linux-headers', type: 'string', value: '',
+  description: 'path to linux headers')