git: f565b4d6303f - main - bhyve: add helper struct for qemus acpi table loader
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Date: Tue, 25 Apr 2023 06:30:02 UTC
The branch main has been updated by corvink:
URL: https://cgit.FreeBSD.org/src/commit/?id=f565b4d6303f4798a2cb0dc51ef88de9e4a24047
commit f565b4d6303f4798a2cb0dc51ef88de9e4a24047
Author: Corvin Köhne <corvink@FreeBSD.org>
AuthorDate: 2022-04-06 09:10:36 +0000
Commit: Corvin Köhne <corvink@FreeBSD.org>
CommitDate: 2023-04-25 06:29:25 +0000
bhyve: add helper struct for qemus acpi table loader
The hypervisor is aware of all system properties. For the guest bios
it's hard and complex to detect all system properties. For that reason,
it would be better if the hypervisor creates acpi tables instead of the
guest. Therefore, the hypervisor has to send the acpi tables to the
guest. At the moment, bhyve just copies the acpi tables into the guest
memory. This approach has some restrictions. You have to keep sure that
the guest doesn't overwrite them accidentally. Additionally, the size of
acpi tables is limited.
Providing a plain copy of all acpi tables by fwcfg isn't possible. Acpi
tables have to point to each other. So, if the guest copies the acpi
tables into memory by it's own, it has to patch the tables. Due to
different layouts for different acpi tables, there's no generic way to
do that. For that reason, qemu created a table loader interface. It
contains commands for the guest for loading specific blobs into guest
memory and patching those blobs.
This commit adds a qemu_loader class which handles the creation of qemu
loader commands. At the moment, the WRITE_POINTER command isn't
implement. It won't be required by bhyve's acpi table generation yet.
Reviewed by: markj
MFC after: 1 week
Sponsored by: Beckhoff Automation GmbH & Co. KG
Differential Revision: https://reviews.freebsd.org/D38438
---
usr.sbin/bhyve/Makefile | 1 +
usr.sbin/bhyve/qemu_loader.c | 274 +++++++++++++++++++++++++++++++++++++++++++
usr.sbin/bhyve/qemu_loader.h | 77 ++++++++++++
3 files changed, 352 insertions(+)
diff --git a/usr.sbin/bhyve/Makefile b/usr.sbin/bhyve/Makefile
index e211a58defd9..7f67c5bf0489 100644
--- a/usr.sbin/bhyve/Makefile
+++ b/usr.sbin/bhyve/Makefile
@@ -65,6 +65,7 @@ SRCS= \
ps2kbd.c \
ps2mouse.c \
qemu_fwcfg.c \
+ qemu_loader.c \
rfb.c \
rtc.c \
smbiostbl.c \
diff --git a/usr.sbin/bhyve/qemu_loader.c b/usr.sbin/bhyve/qemu_loader.c
new file mode 100644
index 000000000000..b0e1197a4b6b
--- /dev/null
+++ b/usr.sbin/bhyve/qemu_loader.c
@@ -0,0 +1,274 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2022 Beckhoff Automation GmbH & Co. KG
+ * Author: Corvin Köhne <c.koehne@beckhoff.com>
+ */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/endian.h>
+#include <sys/queue.h>
+
+#include <machine/vmm.h>
+
+#include <err.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <vmmapi.h>
+
+#include "qemu_fwcfg.h"
+#include "qemu_loader.h"
+
+struct qemu_loader_entry {
+ uint32_t cmd_le;
+ union {
+ struct {
+ uint8_t name[QEMU_FWCFG_MAX_NAME];
+ uint32_t alignment_le;
+ uint8_t zone;
+ } alloc;
+ struct {
+ uint8_t dest_name[QEMU_FWCFG_MAX_NAME];
+ uint8_t src_name[QEMU_FWCFG_MAX_NAME];
+ uint32_t off_le;
+ uint8_t size;
+ } add_pointer;
+ struct {
+ uint8_t name[QEMU_FWCFG_MAX_NAME];
+ uint32_t off_le;
+ uint32_t start_le;
+ uint32_t len_le;
+ } add_checksum;
+ struct {
+ uint8_t dest_name[QEMU_FWCFG_MAX_NAME];
+ uint8_t src_name[QEMU_FWCFG_MAX_NAME];
+ uint32_t dest_off_le;
+ uint32_t src_off_le;
+ uint8_t size;
+ } write_pointer;
+
+ /* padding */
+ uint8_t pad[124];
+ };
+} __packed;
+
+enum qemu_loader_command {
+ QEMU_LOADER_CMD_ALLOC = 0x1,
+ QEMU_LOADER_CMD_ADD_POINTER = 0x2,
+ QEMU_LOADER_CMD_ADD_CHECKSUM = 0x3,
+ QEMU_LOADER_CMD_WRITE_POINTER = 0x4,
+};
+
+struct qemu_loader_element {
+ STAILQ_ENTRY(qemu_loader_element) chain;
+ struct qemu_loader_entry entry;
+};
+
+struct qemu_loader {
+ uint8_t fwcfg_name[QEMU_FWCFG_MAX_NAME];
+ STAILQ_HEAD(qemu_loader_list, qemu_loader_element) list;
+};
+
+int
+qemu_loader_alloc(struct qemu_loader *const loader, const uint8_t *name,
+ const uint32_t alignment, const enum qemu_loader_zone zone)
+{
+ struct qemu_loader_element *element;
+
+ if (strlen(name) >= QEMU_FWCFG_MAX_NAME)
+ return (EINVAL);
+
+ element = calloc(1, sizeof(struct qemu_loader_element));
+ if (element == NULL) {
+ warnx("%s: failed to allocate command", __func__);
+ return (ENOMEM);
+ }
+
+ element->entry.cmd_le = htole32(QEMU_LOADER_CMD_ALLOC);
+ strncpy(element->entry.alloc.name, name, QEMU_FWCFG_MAX_NAME);
+ element->entry.alloc.alignment_le = htole32(alignment);
+ element->entry.alloc.zone = zone;
+
+ /*
+ * The guest always works on copies of the fwcfg item, which where
+ * loaded into guest memory. Loading a fwcfg item is caused by ALLOC.
+ * For that reason, ALLOC should be scheduled in front of any other
+ * commands.
+ */
+ STAILQ_INSERT_HEAD(&loader->list, element, chain);
+
+ return (0);
+}
+
+int
+qemu_loader_add_checksum(struct qemu_loader *const loader, const uint8_t *name,
+ const uint32_t off, const uint32_t start, const uint32_t len)
+{
+ struct qemu_loader_element *element;
+
+ if (strlen(name) >= QEMU_FWCFG_MAX_NAME)
+ return (EINVAL);
+
+ element = calloc(1, sizeof(struct qemu_loader_element));
+ if (element == NULL) {
+ warnx("%s: failed to allocate command", __func__);
+ return (ENOMEM);
+ }
+
+ element->entry.cmd_le = htole32(QEMU_LOADER_CMD_ADD_CHECKSUM);
+ strncpy(element->entry.add_checksum.name, name, QEMU_FWCFG_MAX_NAME);
+ element->entry.add_checksum.off_le = htole32(off);
+ element->entry.add_checksum.start_le = htole32(start);
+ element->entry.add_checksum.len_le = htole32(len);
+
+ STAILQ_INSERT_TAIL(&loader->list, element, chain);
+
+ return (0);
+}
+
+int
+qemu_loader_add_pointer(struct qemu_loader *const loader,
+ const uint8_t *dest_name, const uint8_t *src_name, const uint32_t off,
+ const uint8_t size)
+{
+ struct qemu_loader_element *element;
+
+ if (strlen(dest_name) >= QEMU_FWCFG_MAX_NAME ||
+ strlen(src_name) >= QEMU_FWCFG_MAX_NAME)
+ return (EINVAL);
+
+ element = calloc(1, sizeof(struct qemu_loader_element));
+ if (element == NULL) {
+ warnx("%s: failed to allocate command", __func__);
+ return (ENOMEM);
+ }
+
+ element->entry.cmd_le = htole32(QEMU_LOADER_CMD_ADD_POINTER);
+ strncpy(element->entry.add_pointer.dest_name, dest_name,
+ QEMU_FWCFG_MAX_NAME);
+ strncpy(element->entry.add_pointer.src_name, src_name,
+ QEMU_FWCFG_MAX_NAME);
+ element->entry.add_pointer.off_le = htole32(off);
+ element->entry.add_pointer.size = size;
+
+ STAILQ_INSERT_TAIL(&loader->list, element, chain);
+
+ return (0);
+}
+
+int
+qemu_loader_create(struct qemu_loader **const new_loader,
+ const uint8_t *fwcfg_name)
+{
+ struct qemu_loader *loader;
+
+ if (new_loader == NULL || strlen(fwcfg_name) >= QEMU_FWCFG_MAX_NAME) {
+ return (EINVAL);
+ }
+
+ loader = calloc(1, sizeof(struct qemu_loader));
+ if (loader == NULL) {
+ warnx("%s: failed to allocate loader", __func__);
+ return (ENOMEM);
+ }
+
+ strncpy(loader->fwcfg_name, fwcfg_name, QEMU_FWCFG_MAX_NAME);
+ STAILQ_INIT(&loader->list);
+
+ *new_loader = loader;
+
+ return (0);
+}
+
+static const uint8_t *
+qemu_loader_get_zone_name(const enum qemu_loader_zone zone)
+{
+ switch (zone) {
+ case QEMU_LOADER_ALLOC_HIGH:
+ return ("HIGH");
+ case QEMU_LOADER_ALLOC_FSEG:
+ return ("FSEG");
+ default:
+ return ("Unknown");
+ }
+}
+
+static void __unused
+qemu_loader_dump_entry(const struct qemu_loader_entry *const entry)
+{
+ switch (le32toh(entry->cmd_le)) {
+ case QEMU_LOADER_CMD_ALLOC:
+ printf("CMD_ALLOC\n\r");
+ printf(" name : %s\n\r", entry->alloc.name);
+ printf(" alignment: %8x\n\r",
+ le32toh(entry->alloc.alignment_le));
+ printf(" zone : %s\n\r",
+ qemu_loader_get_zone_name(entry->alloc.zone));
+ break;
+ case QEMU_LOADER_CMD_ADD_POINTER:
+ printf("CMD_ADD_POINTER\n\r");
+ printf(" dest_name: %s\n\r", entry->add_pointer.dest_name);
+ printf(" src_name : %s\n\r", entry->add_pointer.src_name);
+ printf(" off : %8x\n\r",
+ le32toh(entry->add_pointer.off_le));
+ printf(" size : %8x\n\r", entry->add_pointer.size);
+ break;
+ case QEMU_LOADER_CMD_ADD_CHECKSUM:
+ printf("CMD_ADD_CHECKSUM\n\r");
+ printf(" name : %s\n\r", entry->add_checksum.name);
+ printf(" off : %8x\n\r",
+ le32toh(entry->add_checksum.off_le));
+ printf(" start : %8x\n\r",
+ le32toh(entry->add_checksum.start_le));
+ printf(" length : %8x\n\r",
+ le32toh(entry->add_checksum.len_le));
+ break;
+ case QEMU_LOADER_CMD_WRITE_POINTER:
+ printf("CMD_WRITE_POINTER\n\r");
+ printf(" dest_name: %s\n\r", entry->write_pointer.dest_name);
+ printf(" src_name : %s\n\r", entry->write_pointer.src_name);
+ printf(" dest_off : %8x\n\r",
+ le32toh(entry->write_pointer.dest_off_le));
+ printf(" src_off : %8x\n\r",
+ le32toh(entry->write_pointer.src_off_le));
+ printf(" size : %8x\n\r", entry->write_pointer.size);
+ break;
+ default:
+ printf("UNKNOWN\n\r");
+ break;
+ }
+}
+
+int
+qemu_loader_finish(struct qemu_loader *const loader)
+{
+ struct qemu_loader_element *element;
+ struct qemu_loader_entry *data;
+ size_t len = 0;
+
+ STAILQ_FOREACH(element, &loader->list, chain) {
+ len += sizeof(struct qemu_loader_entry);
+ }
+ if (len == 0) {
+ warnx("%s: bios loader empty", __func__);
+ return (EFAULT);
+ }
+
+ data = calloc(1, len);
+ if (data == NULL) {
+ warnx("%s: failed to allocate fwcfg data", __func__);
+ return (ENOMEM);
+ }
+
+ int i = 0;
+ STAILQ_FOREACH(element, &loader->list, chain) {
+ memcpy(&data[i], &element->entry,
+ sizeof(struct qemu_loader_entry));
+ ++i;
+ }
+
+ return (qemu_fwcfg_add_file(loader->fwcfg_name, len, data));
+}
diff --git a/usr.sbin/bhyve/qemu_loader.h b/usr.sbin/bhyve/qemu_loader.h
new file mode 100644
index 000000000000..b6ce48ad0871
--- /dev/null
+++ b/usr.sbin/bhyve/qemu_loader.h
@@ -0,0 +1,77 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2022 Beckhoff Automation GmbH & Co. KG
+ * Author: Corvin Köhne <c.koehne@beckhoff.com>
+ */
+
+#pragma once
+
+#include "qemu_fwcfg.h"
+
+struct qemu_loader;
+
+/*
+ * Some guest bios like seabios assume the RSDP to be located in the FSEG. Bhyve
+ * only supports OVMF which has no such requirement.
+ */
+enum qemu_loader_zone {
+ QEMU_LOADER_ALLOC_HIGH = 1,
+ QEMU_LOADER_ALLOC_FSEG, /* 0x0F000000 - 0x100000 */
+};
+
+/**
+ * Loads a fwcfg item into guest memory. This command has to be issued before
+ * any subsequent command can be used.
+ *
+ * @param loader Qemu loader instance the command should be added to.
+ * @param name Name of the fwcfg item which should be allocated.
+ * @param alignment Alignment required by the data.
+ * @param zone Memory zone in which it should be loaded.
+ */
+int qemu_loader_alloc(struct qemu_loader *loader, const uint8_t *name,
+ uint32_t alignment, enum qemu_loader_zone zone);
+/**
+ * Calculates a checksum for @p name and writes it to @p name + @p off . The
+ * checksum calculation ranges from @p start to @p start + @p len. The checksum
+ * field is always one byte large and all bytes in the specified range,
+ * including the checksum, have to sum up to 0.
+ *
+ * @param loader Qemu loader instance the command should be added to.
+ * @param name Name of the fwcfg item which should be patched.
+ * @param off Offset into @p name .
+ * @param start Start offset of checksum calculation.
+ * @param len Length of the checksum calculation.
+ */
+int qemu_loader_add_checksum(struct qemu_loader *loader, const uint8_t *name,
+ uint32_t off, uint32_t start, uint32_t len);
+/**
+ * Adds the address of @p src_name to the value at @p dest_name + @p off . The
+ * size of the pointer is determined by @p dest_size and should be 1, 2, 4 or 8.
+ *
+ * @param loader Qemu loader instance the command should be added to.
+ * @param dest_name Name of the fwcfg item which should be patched.
+ * @param src_name Name of the fwcfg item which address should be written to
+ * @p dest_name + @p off.
+ * @param off Offset into @p dest_name .
+ * @param size Size of the pointer (1, 2, 4 or 8).
+ */
+int qemu_loader_add_pointer(struct qemu_loader *loader,
+ const uint8_t *dest_name, const uint8_t *src_name, uint32_t off,
+ uint8_t size);
+
+/**
+ * Creates a qemu loader instance.
+ *
+ * @param new_loader Returns the newly created qemu loader instance.
+ * @param fwcfg_name Name of the FwCfg item which represents the qemu loader
+ */
+int qemu_loader_create(struct qemu_loader **new_loader,
+ const uint8_t *fwcfg_name);
+/**
+ * Signals that all commands are written to the qemu loader. This function
+ * creates a proper FwCfg item and registers it.
+ *
+ * @param loader Qemu loader instance which should be finished.
+ */
+int qemu_loader_finish(struct qemu_loader *loader);