From patchwork Tue Jan 16 06:08:54 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 10166061 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id D991F603B5 for ; Tue, 16 Jan 2018 06:13:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DA3E82811E for ; Tue, 16 Jan 2018 06:13:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CE492281C3; Tue, 16 Jan 2018 06:13:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 5D7DD281F9 for ; Tue, 16 Jan 2018 06:13:10 +0000 (UTC) Received: from localhost ([::1]:40188 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ebKUf-0001wO-8l for patchwork-qemu-devel@patchwork.kernel.org; Tue, 16 Jan 2018 01:13:09 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38755) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ebKRG-0007AC-On for qemu-devel@nongnu.org; Tue, 16 Jan 2018 01:09:43 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ebKRD-00013r-Tu for qemu-devel@nongnu.org; Tue, 16 Jan 2018 01:09:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:30264) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ebKR5-00010K-Mj; Tue, 16 Jan 2018 01:09:27 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E429C356CA; Tue, 16 Jan 2018 06:09:26 +0000 (UTC) Received: from lemon.usersys.redhat.com (ovpn-12-35.pek2.redhat.com [10.72.12.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7B02B5D96E; Tue, 16 Jan 2018 06:09:20 +0000 (UTC) From: Fam Zheng To: qemu-devel@nongnu.org Date: Tue, 16 Jan 2018 14:08:54 +0800 Message-Id: <20180116060901.17413-3-famz@redhat.com> In-Reply-To: <20180116060901.17413-1-famz@redhat.com> References: <20180116060901.17413-1-famz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Tue, 16 Jan 2018 06:09:26 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v6 2/9] util: Introduce vfio helpers X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Fam Zheng , qemu-block@nongnu.org, Markus Armbruster , Max Reitz , Keith Busch , alex.williamson@redhat.com, Stefan Hajnoczi , Paolo Bonzini , Karl Rister Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP This is a library to manage the host vfio interface, which could be used to implement userspace device driver code in QEMU such as NVMe or net controllers. Signed-off-by: Fam Zheng Message-Id: <20180110091846.10699-3-famz@redhat.com> Reviewed-by: Stefan Hajnoczi --- include/qemu/vfio-helpers.h | 33 ++ util/Makefile.objs | 1 + util/trace-events | 11 + util/vfio-helpers.c | 726 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 771 insertions(+) create mode 100644 include/qemu/vfio-helpers.h create mode 100644 util/vfio-helpers.c diff --git a/include/qemu/vfio-helpers.h b/include/qemu/vfio-helpers.h new file mode 100644 index 0000000000..ce7e7b057f --- /dev/null +++ b/include/qemu/vfio-helpers.h @@ -0,0 +1,33 @@ +/* + * QEMU VFIO helpers + * + * Copyright 2016 - 2018 Red Hat, Inc. + * + * Authors: + * Fam Zheng + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#ifndef QEMU_VFIO_HELPERS_H +#define QEMU_VFIO_HELPERS_H +#include "qemu/typedefs.h" + +typedef struct QEMUVFIOState QEMUVFIOState; + +QEMUVFIOState *qemu_vfio_open_pci(const char *device, Error **errp); +void qemu_vfio_close(QEMUVFIOState *s); +int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size, + bool temporary, uint64_t *iova_list); +int qemu_vfio_dma_reset_temporary(QEMUVFIOState *s); +void qemu_vfio_dma_unmap(QEMUVFIOState *s, void *host); +void *qemu_vfio_pci_map_bar(QEMUVFIOState *s, int index, + uint64_t offset, uint64_t size, + Error **errp); +void qemu_vfio_pci_unmap_bar(QEMUVFIOState *s, int index, void *bar, + uint64_t offset, uint64_t size); +int qemu_vfio_pci_init_irq(QEMUVFIOState *s, EventNotifier *e, + int irq_type, Error **errp); + +#endif diff --git a/util/Makefile.objs b/util/Makefile.objs index 2973b0a323..3fb611631f 100644 --- a/util/Makefile.objs +++ b/util/Makefile.objs @@ -46,3 +46,4 @@ util-obj-y += qht.o util-obj-y += range.o util-obj-y += stats64.o util-obj-y += systemd.o +util-obj-$(CONFIG_LINUX) += vfio-helpers.o diff --git a/util/trace-events b/util/trace-events index 025499f83f..2f57bf2337 100644 --- a/util/trace-events +++ b/util/trace-events @@ -59,3 +59,14 @@ lockcnt_futex_wake(const void *lockcnt) "lockcnt %p waking up one waiter" # util/qemu-thread-posix.c qemu_mutex_locked(void *lock) "locked mutex %p" qemu_mutex_unlocked(void *lock) "unlocked mutex %p" + +# util/vfio-helpers.c +qemu_vfio_dma_reset_temporary(void *s) "s %p" +qemu_vfio_ram_block_added(void *s, void *p, size_t size) "s %p host %p size 0x%zx" +qemu_vfio_ram_block_removed(void *s, void *p, size_t size) "s %p host %p size 0x%zx" +qemu_vfio_find_mapping(void *s, void *p) "s %p host %p" +qemu_vfio_new_mapping(void *s, void *host, size_t size, int index, uint64_t iova) "s %p host %p size %zu index %d iova 0x%"PRIx64 +qemu_vfio_do_mapping(void *s, void *host, size_t size, uint64_t iova) "s %p host %p size %zu iova 0x%"PRIx64 +qemu_vfio_dma_map(void *s, void *host, size_t size, bool temporary, uint64_t *iova) "s %p host %p size %zu temporary %d iova %p" +qemu_vfio_dma_map_invalid(void *s, void *mapping_host, size_t mapping_size, void *host, size_t size) "s %p mapping %p %zu requested %p %zu" +qemu_vfio_dma_unmap(void *s, void *host) "s %p host %p" diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c new file mode 100644 index 0000000000..0660aaf2f7 --- /dev/null +++ b/util/vfio-helpers.c @@ -0,0 +1,726 @@ +/* + * VFIO utility + * + * Copyright 2016 - 2018 Red Hat, Inc. + * + * Authors: + * Fam Zheng + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include +#include +#include "qapi/error.h" +#include "exec/ramlist.h" +#include "exec/cpu-common.h" +#include "trace.h" +#include "qemu/queue.h" +#include "qemu/error-report.h" +#include "standard-headers/linux/pci_regs.h" +#include "qemu/event_notifier.h" +#include "qemu/vfio-helpers.h" +#include "trace.h" + +#define QEMU_VFIO_DEBUG 0 + +#define QEMU_VFIO_IOVA_MIN 0x10000ULL +/* XXX: Once VFIO exposes the iova bit width in the IOMMU capability interface, + * we can use a runtime limit; alternatively it's also possible to do platform + * specific detection by reading sysfs entries. Until then, 39 is a safe bet. + **/ +#define QEMU_VFIO_IOVA_MAX (1ULL << 39) + +typedef struct { + /* Page aligned addr. */ + void *host; + size_t size; + uint64_t iova; +} IOVAMapping; + +struct QEMUVFIOState { + QemuMutex lock; + + /* These fields are protected by BQL */ + int container; + int group; + int device; + RAMBlockNotifier ram_notifier; + struct vfio_region_info config_region_info, bar_region_info[6]; + + /* These fields are protected by @lock */ + /* VFIO's IO virtual address space is managed by splitting into a few + * sections: + * + * --------------- <= 0 + * |xxxxxxxxxxxxx| + * |-------------| <= QEMU_VFIO_IOVA_MIN + * | | + * | Fixed | + * | | + * |-------------| <= low_water_mark + * | | + * | Free | + * | | + * |-------------| <= high_water_mark + * | | + * | Temp | + * | | + * |-------------| <= QEMU_VFIO_IOVA_MAX + * |xxxxxxxxxxxxx| + * |xxxxxxxxxxxxx| + * --------------- + * + * - Addresses lower than QEMU_VFIO_IOVA_MIN are reserved as invalid; + * + * - Fixed mappings of HVAs are assigned "low" IOVAs in the range of + * [QEMU_VFIO_IOVA_MIN, low_water_mark). Once allocated they will not be + * reclaimed - low_water_mark never shrinks; + * + * - IOVAs in range [low_water_mark, high_water_mark) are free; + * + * - IOVAs in range [high_water_mark, QEMU_VFIO_IOVA_MAX) are volatile + * mappings. At each qemu_vfio_dma_reset_temporary() call, the whole area + * is recycled. The caller should make sure I/O's depending on these + * mappings are completed before calling. + **/ + uint64_t low_water_mark; + uint64_t high_water_mark; + IOVAMapping *mappings; + int nr_mappings; +}; + +/** + * Find group file by PCI device address as specified @device, and return the + * path. The returned string is owned by caller and should be g_free'ed later. + */ +static char *sysfs_find_group_file(const char *device, Error **errp) +{ + char *sysfs_link; + char *sysfs_group; + char *p; + char *path = NULL; + + sysfs_link = g_strdup_printf("/sys/bus/pci/devices/%s/iommu_group", device); + sysfs_group = g_malloc(PATH_MAX); + if (readlink(sysfs_link, sysfs_group, PATH_MAX - 1) == -1) { + error_setg_errno(errp, errno, "Failed to find iommu group sysfs path"); + goto out; + } + p = strrchr(sysfs_group, '/'); + if (!p) { + error_setg(errp, "Failed to find iommu group number"); + goto out; + } + + path = g_strdup_printf("/dev/vfio/%s", p + 1); +out: + g_free(sysfs_link); + g_free(sysfs_group); + return path; +} + +static inline void assert_bar_index_valid(QEMUVFIOState *s, int index) +{ + assert(index >= 0 && index < ARRAY_SIZE(s->bar_region_info)); +} + +static int qemu_vfio_pci_init_bar(QEMUVFIOState *s, int index, Error **errp) +{ + assert_bar_index_valid(s, index); + s->bar_region_info[index] = (struct vfio_region_info) { + .index = VFIO_PCI_BAR0_REGION_INDEX + index, + .argsz = sizeof(struct vfio_region_info), + }; + if (ioctl(s->device, VFIO_DEVICE_GET_REGION_INFO, &s->bar_region_info[index])) { + error_setg_errno(errp, errno, "Failed to get BAR region info"); + return -errno; + } + + return 0; +} + +/** + * Map a PCI bar area. + */ +void *qemu_vfio_pci_map_bar(QEMUVFIOState *s, int index, + uint64_t offset, uint64_t size, + Error **errp) +{ + void *p; + assert_bar_index_valid(s, index); + p = mmap(NULL, MIN(size, s->bar_region_info[index].size - offset), + PROT_READ | PROT_WRITE, MAP_SHARED, + s->device, s->bar_region_info[index].offset + offset); + if (p == MAP_FAILED) { + error_setg_errno(errp, errno, "Failed to map BAR region"); + p = NULL; + } + return p; +} + +/** + * Unmap a PCI bar area. + */ +void qemu_vfio_pci_unmap_bar(QEMUVFIOState *s, int index, void *bar, + uint64_t offset, uint64_t size) +{ + if (bar) { + munmap(bar, MIN(size, s->bar_region_info[index].size - offset)); + } +} + +/** + * Initialize device IRQ with @irq_type and and register an event notifier. + */ +int qemu_vfio_pci_init_irq(QEMUVFIOState *s, EventNotifier *e, + int irq_type, Error **errp) +{ + int r; + struct vfio_irq_set *irq_set; + size_t irq_set_size; + struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info) }; + + irq_info.index = irq_type; + if (ioctl(s->device, VFIO_DEVICE_GET_IRQ_INFO, &irq_info)) { + error_setg_errno(errp, errno, "Failed to get device interrupt info"); + return -errno; + } + if (!(irq_info.flags & VFIO_IRQ_INFO_EVENTFD)) { + error_setg(errp, "Device interrupt doesn't support eventfd"); + return -EINVAL; + } + + irq_set_size = sizeof(*irq_set) + sizeof(int); + irq_set = g_malloc0(irq_set_size); + + /* Get to a known IRQ state */ + *irq_set = (struct vfio_irq_set) { + .argsz = irq_set_size, + .flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER, + .index = irq_info.index, + .start = 0, + .count = 1, + }; + + *(int *)&irq_set->data = event_notifier_get_fd(e); + r = ioctl(s->device, VFIO_DEVICE_SET_IRQS, irq_set); + g_free(irq_set); + if (r) { + error_setg_errno(errp, errno, "Failed to setup device interrupt"); + return -errno; + } + return 0; +} + +static int qemu_vfio_pci_read_config(QEMUVFIOState *s, void *buf, + int size, int ofs) +{ + int ret; + + do { + ret = pread(s->device, buf, size, s->config_region_info.offset + ofs); + } while (ret == -1 && errno == EINTR); + return ret == size ? 0 : -errno; +} + +static int qemu_vfio_pci_write_config(QEMUVFIOState *s, void *buf, int size, int ofs) +{ + int ret; + + do { + ret = pwrite(s->device, buf, size, s->config_region_info.offset + ofs); + } while (ret == -1 && errno == EINTR); + return ret == size ? 0 : -errno; +} + +static int qemu_vfio_init_pci(QEMUVFIOState *s, const char *device, + Error **errp) +{ + int ret; + int i; + uint16_t pci_cmd; + struct vfio_group_status group_status = { .argsz = sizeof(group_status) }; + struct vfio_iommu_type1_info iommu_info = { .argsz = sizeof(iommu_info) }; + struct vfio_device_info device_info = { .argsz = sizeof(device_info) }; + char *group_file = NULL; + + /* Create a new container */ + s->container = open("/dev/vfio/vfio", O_RDWR); + + if (s->container == -1) { + error_setg_errno(errp, errno, "Failed to open /dev/vfio/vfio"); + return -errno; + } + if (ioctl(s->container, VFIO_GET_API_VERSION) != VFIO_API_VERSION) { + error_setg(errp, "Invalid VFIO version"); + ret = -EINVAL; + goto fail_container; + } + + if (!ioctl(s->container, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU)) { + error_setg_errno(errp, errno, "VFIO IOMMU check failed"); + ret = -EINVAL; + goto fail_container; + } + + /* Open the group */ + group_file = sysfs_find_group_file(device, errp); + if (!group_file) { + ret = -EINVAL; + goto fail_container; + } + + s->group = open(group_file, O_RDWR); + if (s->group == -1) { + error_setg_errno(errp, errno, "Failed to open VFIO group file: %s", + group_file); + g_free(group_file); + ret = -errno; + goto fail_container; + } + g_free(group_file); + + /* Test the group is viable and available */ + if (ioctl(s->group, VFIO_GROUP_GET_STATUS, &group_status)) { + error_setg_errno(errp, errno, "Failed to get VFIO group status"); + ret = -errno; + goto fail; + } + + if (!(group_status.flags & VFIO_GROUP_FLAGS_VIABLE)) { + error_setg(errp, "VFIO group is not viable"); + ret = -EINVAL; + goto fail; + } + + /* Add the group to the container */ + if (ioctl(s->group, VFIO_GROUP_SET_CONTAINER, &s->container)) { + error_setg_errno(errp, errno, "Failed to add group to VFIO container"); + ret = -errno; + goto fail; + } + + /* Enable the IOMMU model we want */ + if (ioctl(s->container, VFIO_SET_IOMMU, VFIO_TYPE1_IOMMU)) { + error_setg_errno(errp, errno, "Failed to set VFIO IOMMU type"); + ret = -errno; + goto fail; + } + + /* Get additional IOMMU info */ + if (ioctl(s->container, VFIO_IOMMU_GET_INFO, &iommu_info)) { + error_setg_errno(errp, errno, "Failed to get IOMMU info"); + ret = -errno; + goto fail; + } + + s->device = ioctl(s->group, VFIO_GROUP_GET_DEVICE_FD, device); + + if (s->device < 0) { + error_setg_errno(errp, errno, "Failed to get device fd"); + ret = -errno; + goto fail; + } + + /* Test and setup the device */ + if (ioctl(s->device, VFIO_DEVICE_GET_INFO, &device_info)) { + error_setg_errno(errp, errno, "Failed to get device info"); + ret = -errno; + goto fail; + } + + if (device_info.num_regions < VFIO_PCI_CONFIG_REGION_INDEX) { + error_setg(errp, "Invalid device regions"); + ret = -EINVAL; + goto fail; + } + + s->config_region_info = (struct vfio_region_info) { + .index = VFIO_PCI_CONFIG_REGION_INDEX, + .argsz = sizeof(struct vfio_region_info), + }; + if (ioctl(s->device, VFIO_DEVICE_GET_REGION_INFO, &s->config_region_info)) { + error_setg_errno(errp, errno, "Failed to get config region info"); + ret = -errno; + goto fail; + } + + for (i = 0; i < 6; i++) { + ret = qemu_vfio_pci_init_bar(s, i, errp); + if (ret) { + goto fail; + } + } + + /* Enable bus master */ + ret = qemu_vfio_pci_read_config(s, &pci_cmd, sizeof(pci_cmd), PCI_COMMAND); + if (ret) { + goto fail; + } + pci_cmd |= PCI_COMMAND_MASTER; + ret = qemu_vfio_pci_write_config(s, &pci_cmd, sizeof(pci_cmd), PCI_COMMAND); + if (ret) { + goto fail; + } + return 0; +fail: + close(s->group); +fail_container: + close(s->container); + return ret; +} + +static void qemu_vfio_ram_block_added(RAMBlockNotifier *n, + void *host, size_t size) +{ + QEMUVFIOState *s = container_of(n, QEMUVFIOState, ram_notifier); + trace_qemu_vfio_ram_block_added(s, host, size); + qemu_vfio_dma_map(s, host, size, false, NULL); +} + +static void qemu_vfio_ram_block_removed(RAMBlockNotifier *n, + void *host, size_t size) +{ + QEMUVFIOState *s = container_of(n, QEMUVFIOState, ram_notifier); + if (host) { + trace_qemu_vfio_ram_block_removed(s, host, size); + qemu_vfio_dma_unmap(s, host); + } +} + +static int qemu_vfio_init_ramblock(const char *block_name, void *host_addr, + ram_addr_t offset, ram_addr_t length, + void *opaque) +{ + int ret; + QEMUVFIOState *s = opaque; + + if (!host_addr) { + return 0; + } + ret = qemu_vfio_dma_map(s, host_addr, length, false, NULL); + if (ret) { + fprintf(stderr, "qemu_vfio_init_ramblock: failed %p %ld\n", + host_addr, length); + } + return 0; +} + +static void qemu_vfio_open_common(QEMUVFIOState *s) +{ + s->ram_notifier.ram_block_added = qemu_vfio_ram_block_added; + s->ram_notifier.ram_block_removed = qemu_vfio_ram_block_removed; + ram_block_notifier_add(&s->ram_notifier); + s->low_water_mark = QEMU_VFIO_IOVA_MIN; + s->high_water_mark = QEMU_VFIO_IOVA_MAX; + qemu_ram_foreach_block(qemu_vfio_init_ramblock, s); + qemu_mutex_init(&s->lock); +} + +/** + * Open a PCI device, e.g. "0000:00:01.0". + */ +QEMUVFIOState *qemu_vfio_open_pci(const char *device, Error **errp) +{ + int r; + QEMUVFIOState *s = g_new0(QEMUVFIOState, 1); + + r = qemu_vfio_init_pci(s, device, errp); + if (r) { + g_free(s); + return NULL; + } + qemu_vfio_open_common(s); + return s; +} + +static void qemu_vfio_dump_mapping(IOVAMapping *m) +{ + if (QEMU_VFIO_DEBUG) { + printf(" vfio mapping %p %lx to %lx\n", m->host, m->size, m->iova); + } +} + +static void qemu_vfio_dump_mappings(QEMUVFIOState *s) +{ + int i; + + if (QEMU_VFIO_DEBUG) { + printf("vfio mappings\n"); + for (i = 0; i < s->nr_mappings; ++i) { + qemu_vfio_dump_mapping(&s->mappings[i]); + } + } +} + +/** + * Find the mapping entry that contains [host, host + size) and set @index to + * the position. If no entry contains it, @index is the position _after_ which + * to insert the new mapping. IOW, it is the index of the largest element that + * is smaller than @host, or -1 if no entry is. + */ +static IOVAMapping *qemu_vfio_find_mapping(QEMUVFIOState *s, void *host, + int *index) +{ + IOVAMapping *p = s->mappings; + IOVAMapping *q = p ? p + s->nr_mappings - 1 : NULL; + IOVAMapping *mid; + trace_qemu_vfio_find_mapping(s, host); + if (!p) { + *index = -1; + return NULL; + } + while (true) { + mid = p + (q - p) / 2; + if (mid == p) { + break; + } + if (mid->host > host) { + q = mid; + } else if (mid->host < host) { + p = mid; + } else { + break; + } + } + if (mid->host > host) { + mid--; + } else if (mid < &s->mappings[s->nr_mappings - 1] + && (mid + 1)->host <= host) { + mid++; + } + *index = mid - &s->mappings[0]; + if (mid >= &s->mappings[0] && + mid->host <= host && mid->host + mid->size > host) { + assert(mid < &s->mappings[s->nr_mappings]); + return mid; + } + /* At this point *index + 1 is the right position to insert the new + * mapping.*/ + return NULL; +} + +/** + * Allocate IOVA and and create a new mapping record and insert it in @s. + */ +static IOVAMapping *qemu_vfio_add_mapping(QEMUVFIOState *s, + void *host, size_t size, + int index, uint64_t iova) +{ + int shift; + IOVAMapping m = {.host = host, .size = size, iova = iova}; + IOVAMapping *insert; + + assert(QEMU_IS_ALIGNED(size, getpagesize())); + assert(QEMU_IS_ALIGNED(s->low_water_mark, getpagesize())); + assert(QEMU_IS_ALIGNED(s->high_water_mark, getpagesize())); + trace_qemu_vfio_new_mapping(s, host, size, index, iova); + + assert(index >= 0); + s->nr_mappings++; + s->mappings = g_realloc_n(s->mappings, sizeof(s->mappings[0]), + s->nr_mappings); + insert = &s->mappings[index]; + shift = s->nr_mappings - index - 1; + if (shift) { + memmove(insert + 1, insert, shift * sizeof(s->mappings[0])); + } + *insert = m; + return insert; +} + +/* Do the DMA mapping with VFIO. */ +static int qemu_vfio_do_mapping(QEMUVFIOState *s, void *host, size_t size, + uint64_t iova) +{ + struct vfio_iommu_type1_dma_map dma_map = { + .argsz = sizeof(dma_map), + .flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE, + .iova = iova, + .vaddr = (uintptr_t)host, + .size = size, + }; + trace_qemu_vfio_do_mapping(s, host, size, iova); + + if (ioctl(s->container, VFIO_IOMMU_MAP_DMA, &dma_map)) { + error_report("VFIO_MAP_DMA: %d", -errno); + return -errno; + } + return 0; +} + +/** + * Undo the DMA mapping from @s with VFIO, and remove from mapping list. + */ +static void qemu_vfio_undo_mapping(QEMUVFIOState *s, IOVAMapping *mapping, + Error **errp) +{ + int index; + struct vfio_iommu_type1_dma_unmap unmap = { + .argsz = sizeof(unmap), + .flags = 0, + .iova = mapping->iova, + .size = mapping->size, + }; + + index = mapping - s->mappings; + assert(mapping->size > 0); + assert(QEMU_IS_ALIGNED(mapping->size, getpagesize())); + assert(index >= 0 && index < s->nr_mappings); + if (ioctl(s->container, VFIO_IOMMU_UNMAP_DMA, &unmap)) { + error_setg(errp, "VFIO_UNMAP_DMA failed: %d", -errno); + } + memmove(mapping, &s->mappings[index + 1], + sizeof(s->mappings[0]) * (s->nr_mappings - index - 1)); + s->nr_mappings--; + s->mappings = g_realloc_n(s->mappings, sizeof(s->mappings[0]), + s->nr_mappings); +} + +/* Check if the mapping list is (ascending) ordered. */ +static bool qemu_vfio_verify_mappings(QEMUVFIOState *s) +{ + int i; + if (QEMU_VFIO_DEBUG) { + for (i = 0; i < s->nr_mappings - 1; ++i) { + if (!(s->mappings[i].host < s->mappings[i + 1].host)) { + fprintf(stderr, "item %d not sorted!\n", i); + qemu_vfio_dump_mappings(s); + return false; + } + if (!(s->mappings[i].host + s->mappings[i].size <= + s->mappings[i + 1].host)) { + fprintf(stderr, "item %d overlap with next!\n", i); + qemu_vfio_dump_mappings(s); + return false; + } + } + } + return true; +} + +/* Map [host, host + size) area into a contiguous IOVA address space, and store + * the result in @iova if not NULL. The caller need to make sure the area is + * aligned to page size, and mustn't overlap with existing mapping areas (split + * mapping status within this area is not allowed). + */ +int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size, + bool temporary, uint64_t *iova) +{ + int ret = 0; + int index; + IOVAMapping *mapping; + uint64_t iova0; + + assert(QEMU_PTR_IS_ALIGNED(host, getpagesize())); + assert(QEMU_IS_ALIGNED(size, getpagesize())); + trace_qemu_vfio_dma_map(s, host, size, temporary, iova); + qemu_mutex_lock(&s->lock); + mapping = qemu_vfio_find_mapping(s, host, &index); + if (mapping) { + iova0 = mapping->iova + ((uint8_t *)host - (uint8_t *)mapping->host); + } else { + if (s->high_water_mark - s->low_water_mark + 1 < size) { + ret = -ENOMEM; + goto out; + } + if (!temporary) { + iova0 = s->low_water_mark; + mapping = qemu_vfio_add_mapping(s, host, size, index + 1, iova0); + if (!mapping) { + ret = -ENOMEM; + goto out; + } + assert(qemu_vfio_verify_mappings(s)); + ret = qemu_vfio_do_mapping(s, host, size, iova0); + if (ret) { + qemu_vfio_undo_mapping(s, mapping, NULL); + goto out; + } + s->low_water_mark += size; + qemu_vfio_dump_mappings(s); + } else { + iova0 = s->high_water_mark - size; + ret = qemu_vfio_do_mapping(s, host, size, iova0); + if (ret) { + goto out; + } + s->high_water_mark -= size; + } + } + if (iova) { + *iova = iova0; + } +out: + qemu_mutex_unlock(&s->lock); + return ret; +} + +/* Reset the high watermark and free all "temporary" mappings. */ +int qemu_vfio_dma_reset_temporary(QEMUVFIOState *s) +{ + struct vfio_iommu_type1_dma_unmap unmap = { + .argsz = sizeof(unmap), + .flags = 0, + .iova = s->high_water_mark, + .size = QEMU_VFIO_IOVA_MAX - s->high_water_mark, + }; + trace_qemu_vfio_dma_reset_temporary(s); + qemu_mutex_lock(&s->lock); + if (ioctl(s->container, VFIO_IOMMU_UNMAP_DMA, &unmap)) { + error_report("VFIO_UNMAP_DMA: %d", -errno); + qemu_mutex_unlock(&s->lock); + return -errno; + } + s->high_water_mark = QEMU_VFIO_IOVA_MAX; + qemu_mutex_unlock(&s->lock); + return 0; +} + +/* Unmapping the whole area that was previously mapped with + * qemu_vfio_dma_map(). */ +void qemu_vfio_dma_unmap(QEMUVFIOState *s, void *host) +{ + int index = 0; + IOVAMapping *m; + + if (!host) { + return; + } + + trace_qemu_vfio_dma_unmap(s, host); + qemu_mutex_lock(&s->lock); + m = qemu_vfio_find_mapping(s, host, &index); + if (!m) { + goto out; + } + qemu_vfio_undo_mapping(s, m, NULL); +out: + qemu_mutex_unlock(&s->lock); +} + +static void qemu_vfio_reset(QEMUVFIOState *s) +{ + ioctl(s->device, VFIO_DEVICE_RESET); +} + +/* Close and free the VFIO resources. */ +void qemu_vfio_close(QEMUVFIOState *s) +{ + int i; + + if (!s) { + return; + } + for (i = 0; i < s->nr_mappings; ++i) { + qemu_vfio_undo_mapping(s, &s->mappings[i], NULL); + } + ram_block_notifier_remove(&s->ram_notifier); + qemu_vfio_reset(s); + close(s->device); + close(s->group); + close(s->container); +}