This is a note to let you know that I've just added the patch titled
x86/microcode: Attempt late loading only when new microcode is present
to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-microcode-attempt-late-loading-only-when-new-microcode-is-present.patch
and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2613f36ed965d0e5a595a1d931fd3b480e82d6fd Mon Sep 17 00:00:00 2001
From: Borislav Petkov <bp@xxxxxxx>
Date: Wed, 14 Mar 2018 19:36:14 +0100
Subject: x86/microcode: Attempt late loading only when new microcode is present
From: Borislav Petkov <bp@xxxxxxx>
commit 2613f36ed965d0e5a595a1d931fd3b480e82d6fd upstream.
Return UCODE_NEW from the scanning functions to denote that new microcode
was found and only then attempt the expensive synchronization dance.
Reported-by: Emanuel Czirai <xftroxgpx@xxxxxxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Emanuel Czirai <xftroxgpx@xxxxxxxxxxxxxx>
Tested-by: Ashok Raj <ashok.raj@xxxxxxxxx>
Tested-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Link: https://lkml.kernel.org/r/20180314183615.17629-1-bp@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/microcode.h | 1 +
arch/x86/kernel/cpu/microcode/amd.c | 34 +++++++++++++++++++++-------------
arch/x86/kernel/cpu/microcode/core.c | 8 +++-----
arch/x86/kernel/cpu/microcode/intel.c | 4 +++-
4 files changed, 28 insertions(+), 19 deletions(-)
--- a/arch/x86/include/asm/microcode.h
+++ b/arch/x86/include/asm/microcode.h
@@ -39,6 +39,7 @@ struct device;
enum ucode_state {
UCODE_OK = 0,
+ UCODE_NEW,
UCODE_UPDATED,
UCODE_NFOUND,
UCODE_ERROR,
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -339,7 +339,7 @@ int __init save_microcode_in_initrd_amd(
return -EINVAL;
ret = load_microcode_amd(true, x86_family(cpuid_1_eax), desc.data, desc.size);
- if (ret != UCODE_OK)
+ if (ret > UCODE_UPDATED)
return -EINVAL;
return 0;
@@ -683,27 +683,35 @@ static enum ucode_state __load_microcode
static enum ucode_state
load_microcode_amd(bool save, u8 family, const u8 *data, size_t size)
{
+ struct ucode_patch *p;
enum ucode_state ret;
/* free old equiv table */
free_equiv_cpu_table();
ret = __load_microcode_amd(family, data, size);
-
- if (ret != UCODE_OK)
+ if (ret != UCODE_OK) {
cleanup();
+ return ret;
+ }
-#ifdef CONFIG_X86_32
- /* save BSP's matching patch for early load */
- if (save) {
- struct ucode_patch *p = find_patch(0);
- if (p) {
- memset(amd_ucode_patch, 0, PATCH_MAX_SIZE);
- memcpy(amd_ucode_patch, p->data, min_t(u32, ksize(p->data),
- PATCH_MAX_SIZE));
- }
+ p = find_patch(0);
+ if (!p) {
+ return ret;
+ } else {
+ if (boot_cpu_data.microcode == p->patch_id)
+ return ret;
+
+ ret = UCODE_NEW;
}
-#endif
+
+ /* save BSP's matching patch for early load */
+ if (!save)
+ return ret;
+
+ memset(amd_ucode_patch, 0, PATCH_MAX_SIZE);
+ memcpy(amd_ucode_patch, p->data, min_t(u32, ksize(p->data), PATCH_MAX_SIZE));
+
return ret;
}
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -607,7 +607,7 @@ static ssize_t reload_store(struct devic
return size;
tmp_ret = microcode_ops->request_microcode_fw(bsp, µcode_pdev->dev, true);
- if (tmp_ret != UCODE_OK)
+ if (tmp_ret != UCODE_NEW)
return size;
get_online_cpus();
@@ -691,10 +691,8 @@ static enum ucode_state microcode_init_c
if (system_state != SYSTEM_RUNNING)
return UCODE_NFOUND;
- ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev,
- refresh_fw);
-
- if (ustate == UCODE_OK) {
+ ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev, refresh_fw);
+ if (ustate == UCODE_NEW) {
pr_debug("CPU%d updated upon init\n", cpu);
apply_microcode_on_target(cpu);
}
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -862,6 +862,7 @@ static enum ucode_state generic_load_mic
unsigned int leftover = size;
unsigned int curr_mc_size = 0, new_mc_size = 0;
unsigned int csig, cpf;
+ enum ucode_state ret = UCODE_OK;
while (leftover) {
struct microcode_header_intel mc_header;
@@ -903,6 +904,7 @@ static enum ucode_state generic_load_mic
new_mc = mc;
new_mc_size = mc_size;
mc = NULL; /* trigger new vmalloc */
+ ret = UCODE_NEW;
}
ucode_ptr += mc_size;
@@ -932,7 +934,7 @@ static enum ucode_state generic_load_mic
pr_debug("CPU%d found a matching microcode update with version 0x%x (current=0x%x)\n",
cpu, new_rev, uci->cpu_sig.rev);
- return UCODE_OK;
+ return ret;
}
static int get_ucode_fw(void *to, const void *from, size_t n)
Patches currently in stable-queue which might be from bp@xxxxxxx are
queue-4.15/x86-microcode-intel-check-microcode-revision-before-updating-sibling-threads.patch
queue-4.15/x86-microcode-attempt-late-loading-only-when-new-microcode-is-present.patch
queue-4.15/x86-microcode-propagate-return-value-from-updating-functions.patch
queue-4.15/x86-cpu-check-cpu-feature-bits-after-microcode-upgrade.patch
queue-4.15/x86-microcode-intel-writeback-and-invalidate-caches-before-updating-microcode.patch
queue-4.15/x86-microcode-intel-look-into-the-patch-cache-first.patch
queue-4.15/edac-mv64x60-fix-an-error-handling-path.patch
queue-4.15/x86-microcode-request-microcode-on-the-bsp.patch
queue-4.15/x86-microcode-get-rid-of-struct-apply_microcode_ctx.patch
queue-4.15/x86-microcode-fix-cpu-synchronization-routine.patch
queue-4.15/x86-microcode-synchronize-late-microcode-loading.patch
queue-4.15/x86-microcode-do-not-upload-microcode-if-cpus-are-offline.patch
queue-4.15/x86-cpu-add-a-microcode-loader-callback.patch