git: 29578470314c - main - bhyve: add basl support for checksums
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Date: Tue, 15 Nov 2022 07:28:09 UTC
The branch main has been updated by corvink:
URL: https://cgit.FreeBSD.org/src/commit/?id=29578470314c09d4ae3163f151da7d4684fb1428
commit 29578470314c09d4ae3163f151da7d4684fb1428
Author: Corvin Köhne <corvink@FreeBSD.org>
AuthorDate: 2022-04-06 09:10:39 +0000
Commit: Corvin Köhne <corvink@FreeBSD.org>
CommitDate: 2022-11-15 07:27:10 +0000
bhyve: add basl support for checksums
The qemu ACPI table loader patches the ACPI tables. After patching them,
checksums aren't correct any more. It has to calculate a new checksum
for the ACPI table. For that reason, basl has to keep track of checksums
and has to cause the qemu loader to create new checksums for the tables.
The qemu ACPI table loader isn't supported yet. However, the address of
all tables is unknown as long as bhyve hasn't finished ACPI table
creation. So, the checksum of tables which include pointer to other
tables are unknown too. This requires tracking of checksums too.
Reviewed by: jhb
Approved by: manu (mentor)
MFC after: 2 weeks
Sponsored by: Beckhoff Automation GmbH & Co. KG
Differential Revision: https://reviews.freebsd.org/D36990
---
usr.sbin/bhyve/basl.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++
usr.sbin/bhyve/basl.h | 4 ++
2 files changed, 116 insertions(+)
diff --git a/usr.sbin/bhyve/basl.c b/usr.sbin/bhyve/basl.c
index b03c936bd517..77f26a930b94 100644
--- a/usr.sbin/bhyve/basl.c
+++ b/usr.sbin/bhyve/basl.c
@@ -21,6 +21,13 @@
#include "basl.h"
+struct basl_table_checksum {
+ STAILQ_ENTRY(basl_table_checksum) chain;
+ uint32_t off;
+ uint32_t start;
+ uint32_t len;
+};
+
struct basl_table_length {
STAILQ_ENTRY(basl_table_length) chain;
uint32_t off;
@@ -35,6 +42,8 @@ struct basl_table {
uint32_t len;
uint32_t off;
uint32_t alignment;
+ STAILQ_HEAD(basl_table_checksum_list,
+ basl_table_checksum) checksums;
STAILQ_HEAD(basl_table_length_list, basl_table_length) lengths;
};
static STAILQ_HEAD(basl_table_list, basl_table) basl_tables = STAILQ_HEAD_INITIALIZER(
@@ -109,6 +118,64 @@ basl_finish_install_guest_tables(struct basl_table *const table)
return (0);
}
+static int
+basl_finish_patch_checksums(struct basl_table *const table)
+{
+ struct basl_table_checksum *checksum;
+
+ STAILQ_FOREACH(checksum, &table->checksums, chain) {
+ uint8_t *gva, *checksum_gva;
+ uint64_t gpa;
+ uint32_t len;
+ uint8_t sum;
+
+ len = checksum->len;
+ if (len == BASL_TABLE_CHECKSUM_LEN_FULL_TABLE) {
+ len = table->len;
+ }
+
+ assert(checksum->off < table->len);
+ assert(checksum->start < table->len);
+ assert(checksum->start + len <= table->len);
+
+ /*
+ * Install ACPI tables directly in guest memory for use by
+ * guests which do not boot via EFI. EFI ROMs provide a pointer
+ * to the firmware generated ACPI tables instead, but it doesn't
+ * hurt to install the tables always.
+ */
+ gpa = BHYVE_ACPI_BASE + table->off + checksum->start;
+ if ((gpa < BHYVE_ACPI_BASE) ||
+ (gpa < BHYVE_ACPI_BASE + table->off)) {
+ warnx("%s: invalid gpa (off 0x%8x start 0x%8x)",
+ __func__, table->off, checksum->start);
+ return (EFAULT);
+ }
+
+ gva = vm_map_gpa(table->ctx, gpa, len);
+ if (gva == NULL) {
+ warnx("%s: could not map gpa [ 0x%16lx, 0x%16lx ]",
+ __func__, gpa, gpa + len);
+ return (ENOMEM);
+ }
+
+ checksum_gva = gva + checksum->off;
+ if (checksum_gva < gva) {
+ warnx("%s: invalid checksum offset 0x%8x", __func__,
+ checksum->off);
+ return (EFAULT);
+ }
+
+ sum = 0;
+ for (uint32_t i = 0; i < len; ++i) {
+ sum += *(gva + i);
+ }
+ *checksum_gva = -sum;
+ }
+
+ return (0);
+}
+
static int
basl_finish_set_length(struct basl_table *const table)
{
@@ -135,10 +202,21 @@ basl_finish(void)
return (EINVAL);
}
+ /*
+ * We have to install all tables before we can patch them. Therefore,
+ * use two loops. The first one installs all tables and the second one
+ * patches them.
+ */
STAILQ_FOREACH(table, &basl_tables, chain) {
BASL_EXEC(basl_finish_set_length(table));
BASL_EXEC(basl_finish_install_guest_tables(table));
}
+ STAILQ_FOREACH(table, &basl_tables, chain) {
+ /*
+ * Calculate the checksum as last step!
+ */
+ BASL_EXEC(basl_finish_patch_checksums(table));
+ }
return (0);
}
@@ -149,6 +227,27 @@ basl_init(void)
return (0);
}
+static int
+basl_table_add_checksum(struct basl_table *const table, const uint32_t off,
+ const uint32_t start, const uint32_t len)
+{
+ struct basl_table_checksum *checksum;
+
+ checksum = calloc(1, sizeof(struct basl_table_checksum));
+ if (checksum == NULL) {
+ warnx("%s: failed to allocate checksum", __func__);
+ return (ENOMEM);
+ }
+
+ checksum->off = off;
+ checksum->start = start;
+ checksum->len = len;
+
+ STAILQ_INSERT_TAIL(&table->checksums, checksum, chain);
+
+ return (0);
+}
+
static int
basl_table_add_length(struct basl_table *const table, const uint32_t off,
const uint8_t size)
@@ -200,6 +299,18 @@ basl_table_append_bytes(struct basl_table *const table, const void *const bytes,
return (0);
}
+int
+basl_table_append_checksum(struct basl_table *const table, const uint32_t start,
+ const uint32_t len)
+{
+ assert(table != NULL);
+
+ BASL_EXEC(basl_table_add_checksum(table, table->len, start, len));
+ BASL_EXEC(basl_table_append_int(table, 0, 1));
+
+ return (0);
+}
+
int
basl_table_append_gas(struct basl_table *const table, const uint8_t space_id,
const uint8_t bit_width, const uint8_t bit_offset,
@@ -263,6 +374,7 @@ basl_table_create(struct basl_table **const table, struct vmctx *ctx,
new_table->alignment = alignment;
new_table->off = off;
+ STAILQ_INIT(&new_table->checksums);
STAILQ_INIT(&new_table->lengths);
STAILQ_INSERT_TAIL(&basl_tables, new_table, chain);
diff --git a/usr.sbin/bhyve/basl.h b/usr.sbin/bhyve/basl.h
index 95c5fd916761..b478780cb74d 100644
--- a/usr.sbin/bhyve/basl.h
+++ b/usr.sbin/bhyve/basl.h
@@ -20,6 +20,8 @@
#define BASL_TABLE_ALIGNMENT 0x10
#define BASL_TABLE_ALIGNMENT_FACS 0x40
+#define BASL_TABLE_CHECKSUM_LEN_FULL_TABLE (-1)
+
#define BASL_EXEC(x) \
do { \
const int error = (x); \
@@ -39,6 +41,8 @@ int basl_finish(void);
int basl_init(void);
int basl_table_append_bytes(struct basl_table *table, const void *bytes,
uint32_t len);
+int basl_table_append_checksum(struct basl_table *table, uint32_t start,
+ uint32_t len);
int basl_table_append_gas(struct basl_table *table, uint8_t space_id,
uint8_t bit_width, uint8_t bit_offset, uint8_t access_width,
uint64_t address);