This patch adds support for parsing through multiple AMD container
binaries concatenated together. It is a feature already present in Linux.
Link to linux patch:
http://lkml.kernel.org/r/1370463236-2115-3-git-send-email-jacob.shin@xxxxxxx
Other changes introduced:
- Define HDR_SIZE's explicitly for code clarity.
Changes in V3
- Change approach that used AMD_MAX_CONT_APPEND to handle edge case
- No need of a 'found' variable
- return 0 for success and not AMD_UCODE_APPLY_SUCCESS as someone
could just as easily break things by redefining it as bool
- No need of 'header' in container_fast_forward
- Handle more corner cases in container_fast_forward
- Fix code style issues
Changes in V2
- per Jan suggestion
- return bool_t from find_equiv_cpu_id
=> drop the respective initializers of equiv_cpu_id in the callers
- Reduce number of casts by using void * for passing raw binary whenever
possible
- Need size_left >= size check in container_fast_forward
- Use error value returned from container_fast_forward in
cpu_request_microcode
- If changing code around 'error = save_error', make sure the behavior
for single container files does not change
- per Boris suggestion
- No need use pointer type for tot_size
=> We can remove this from the caller too as it is unnecessary
- if ( mpbuf->len + CONT_HDR_SIZE >= *tot_size ) check can be
removed
- Fix logic
- if the first container is corrupted for some reason and returns error
then we return pre-maturely. Instead, now we at least (try to) forward
to next container and look for patches there as well
- Using AMD_MAX_CONT_APPEND as loop condition check simply because I
wanted to avoid using a while (1) which would also work just as well
- This check makes some logical sense too as there are only 2 available
AMD containers out there now. So if we did not find correct patch by then,
we might as well stop trying.
Signed-off-by: Aravind Gopalakrishnan <aravind.gopalakrishnan@xxxxxxx>
---
xen/arch/x86/microcode_amd.c | 150 +++++++++++++++++++++++++++++++++++-------
1 file changed, 128 insertions(+), 22 deletions(-)
diff --git a/xen/arch/x86/microcode_amd.c b/xen/arch/x86/microcode_amd.c
index e83f4b6..8a7fa4a 100644
--- a/xen/arch/x86/microcode_amd.c
+++ b/xen/arch/x86/microcode_amd.c
@@ -29,6 +29,9 @@
#define pr_debug(x...) ((void)0)
+#define CONT_HDR_SIZE 12
+#define SECTION_HDR_SIZE 8
+
struct __packed equiv_cpu_entry {
uint32_t installed_cpu;
uint32_t fixed_errata_mask;
@@ -124,30 +127,41 @@ static bool_t verify_patch_size(uint32_t patch_size)
return (patch_size <= max_size);
}
+static bool_t find_equiv_cpu_id(const struct equiv_cpu_entry *equiv_cpu_table,
+ unsigned int current_cpu_id,
+ unsigned int *equiv_cpu_id)
+{
+ unsigned int i;
+
+ if ( !equiv_cpu_table )
+ return 0;
+
+ for ( i = 0; equiv_cpu_table[i].installed_cpu != 0; i++ )
+ {
+ if ( current_cpu_id == equiv_cpu_table[i].installed_cpu )
+ {
+ *equiv_cpu_id = equiv_cpu_table[i].equiv_cpu & 0xffff;
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
static bool_t microcode_fits(const struct microcode_amd *mc_amd, int cpu)
{
struct ucode_cpu_info *uci = &per_cpu(ucode_cpu_info, cpu);
const struct microcode_header_amd *mc_header = mc_amd->mpb;
const struct equiv_cpu_entry *equiv_cpu_table = mc_amd->equiv_cpu_table;
unsigned int current_cpu_id;
- unsigned int equiv_cpu_id = 0x0;
- unsigned int i;
+ unsigned int equiv_cpu_id;
/* We should bind the task to the CPU */
BUG_ON(cpu != raw_smp_processor_id());
current_cpu_id = cpuid_eax(0x00000001);
- for ( i = 0; equiv_cpu_table[i].installed_cpu != 0; i++ )
- {
- if ( current_cpu_id == equiv_cpu_table[i].installed_cpu )
- {
- equiv_cpu_id = equiv_cpu_table[i].equiv_cpu & 0xffff;
- break;
- }
- }
-
- if ( !equiv_cpu_id )
+ if ( !find_equiv_cpu_id(equiv_cpu_table, current_cpu_id, &equiv_cpu_id) )
return 0;
if ( (mc_header->processor_rev_id) != equiv_cpu_id )
@@ -236,7 +250,14 @@ static int get_ucode_from_buffer_amd(
mpbuf = (const struct mpbhdr *)&bufp[off];
if ( mpbuf->type != UCODE_UCODE_TYPE )
{
- printk(KERN_ERR "microcode: Wrong microcode payload type field\n");
+ /*
+ * In a situation where ucode update has succeeded;
+ * but there is a subsequent container file being parsed,
+ * then, there is no need of this ERR message to be printed.
+ */
+ if ( *(const uint32_t *)buf != UCODE_MAGIC )
+ printk(KERN_ERR "microcode: Wrong microcode payload type field\n");
+
return -EINVAL;
}
@@ -260,7 +281,7 @@ static int get_ucode_from_buffer_amd(
}
memcpy(mc_amd->mpb, mpbuf->data, mpbuf->len);
- *offset = off + mpbuf->len + 8;
+ *offset = off + mpbuf->len + SECTION_HDR_SIZE;
pr_debug("microcode: CPU%d size %zu, block size %u offset %zu equivID %#x rev %#x\n",
raw_smp_processor_id(), bufsize, mpbuf->len, off,
@@ -272,14 +293,13 @@ static int get_ucode_from_buffer_amd(
static int install_equiv_cpu_table(
struct microcode_amd *mc_amd,
- const uint32_t *buf,
+ const void *data,
size_t *offset)
{
+ uint32_t *buf = (uint32_t *) (data + *offset);
const struct mpbhdr *mpbuf = (const struct mpbhdr *)&buf[1];
- /* No more data */
- if ( mpbuf->len + 12 >= *offset )
- return -EINVAL;
+ *offset += mpbuf->len + CONT_HDR_SIZE; /* add header length */
if ( mpbuf->type != UCODE_EQUIV_CPU_TABLE_TYPE )
{
@@ -303,7 +323,33 @@ static int install_equiv_cpu_table(
memcpy(mc_amd->equiv_cpu_table, mpbuf->data, mpbuf->len);
mc_amd->equiv_cpu_table_size = mpbuf->len;
- *offset = mpbuf->len + 12; /* add header length */
+ return 0;
+}
+
+static int container_fast_forward(const void *data, size_t size_left, size_t
*offset)
+{
+ size_t size;
+
+ while ( size_left )
+ {
+ if ( size_left < SECTION_HDR_SIZE )
+ return -EINVAL;
+
+ if ( *(const uint32_t *)(data + *offset) == UCODE_MAGIC &&
+ *(const uint32_t *)(data + *offset + 4) ==
+ UCODE_EQUIV_CPU_TABLE_TYPE )
+ break;
+
+ size = *(uint32_t *)(data + *offset + 4) + SECTION_HDR_SIZE;
+ if ( size_left < size )
+ return -EINVAL;
+
+ size_left -= size;
+ *offset += size;
+ }
+
+ if ( !size_left )
+ return -EINVAL;
return 0;
}
@@ -311,14 +357,18 @@ static int install_equiv_cpu_table(
static int cpu_request_microcode(int cpu, const void *buf, size_t bufsize)
{
struct microcode_amd *mc_amd, *mc_old;
- size_t offset = bufsize;
+ size_t offset = 0;
size_t last_offset, applied_offset = 0;
int error = 0, save_error = 1;
struct ucode_cpu_info *uci = &per_cpu(ucode_cpu_info, cpu);
+ unsigned int current_cpu_id;
+ unsigned int equiv_cpu_id;
/* We should bind the task to the CPU */
BUG_ON(cpu != raw_smp_processor_id());
+ current_cpu_id = cpuid_eax(0x00000001);
+
if ( *(const uint32_t *)buf != UCODE_MAGIC )
{
printk(KERN_ERR "microcode: Wrong microcode patch file magic\n");
@@ -334,7 +384,40 @@ static int cpu_request_microcode(int cpu, const void *buf,
size_t bufsize)
goto out;
}
- error = install_equiv_cpu_table(mc_amd, buf, &offset);
+ /*
+ * Multiple container file support:
+ * 1. check if this container file has equiv_cpu_id match
+ * 2. If not, fast-fwd to next container file
+ */
+ while ( offset < bufsize )
+ {
+ error = install_equiv_cpu_table(mc_amd, buf, &offset);
+
+ if ( !error &&
+ find_equiv_cpu_id(mc_amd->equiv_cpu_table, current_cpu_id,
+ &equiv_cpu_id) )
+ break;
+
+ /*
+ * Could happen as we advance 'offset' early
+ * in install_equiv_cpu_table
+ */
+ if ( offset > bufsize )
+ {
+ printk(KERN_ERR "microcode: Microcode buffer overrun\n");
+ return -EINVAL;
+ }
+
+ error = container_fast_forward(buf, bufsize - offset, &offset);
+ if ( error )
+ {
+ printk(KERN_ERR "microcode: CPU%d incorrect or corrupt container
file\n"
+ "microcode: Failed to update patch level. "
+ "Current lvl:%#x\n", cpu, uci->cpu_sig.rev);
+ goto out;
+ }
+ }
+
if ( error )
{
xfree(mc_amd);
@@ -379,12 +462,35 @@ static int cpu_request_microcode(int cpu, const void
*buf, size_t bufsize)
save_error = get_ucode_from_buffer_amd(
mc_amd, buf, bufsize, &applied_offset);
- if ( save_error )
+ /*
+ * If there happens to be multiple container files and if patch
+ * update succeeded on an earlier container itself, a stale error
+ * val is returned from get_ucode_from_buffer_amd. Since we already
+ * succeeded in patch application, force error = 0
+ */
+ if ( offset < bufsize )
+ error = 0;
+ else if ( save_error )
error = save_error;
}
if ( save_error )
{
+ /*
+ * By the time 'microcode_init' runs, we have already updated the
+ * patch level on all (currently) running cpus.
+ * But, get_ucode_from_buffer_amd will return -EINVAL as
+ * if ( mpbuf->type != UCODE_UCODE_TYPE ) fails in this case:
+ * Multiple containers are present && update succeeded with the
+ * first container file itself.
+ *
+ * Only this time, there is no 'applied_offset' as well.
+ * So, 'save_error' = 1. But error = -EINVAL.
+ * Hence, this check is necessary to return 0 for success.
+ */
+ if ( (error != save_error) && (offset < bufsize) )
+ error = 0;
+
xfree(mc_amd);
uci->mc.mc_amd = mc_old;
}
