mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 02:09:42 +00:00
x86/microcode/AMD: Apply the patch early on every logical thread
commite7ad18d116
upstream. Currently, the patch application logic checks whether the revision needs to be applied on each logical CPU (SMT thread). Therefore, on SMT designs where the microcode engine is shared between the two threads, the application happens only on one of them as that is enough to update the shared microcode engine. However, there are microcode patches which do per-thread modification, see Link tag below. Therefore, drop the revision check and try applying on each thread. This is what the BIOS does too so this method is very much tested. Btw, change only the early paths. On the late loading paths, there's no point in doing per-thread modification because if is it some case like in the bugzilla below - removing a CPUID flag - the kernel cannot go and un-use features it has detected are there early. For that, one should use early loading anyway. [ bp: Fixes does not contain the oldest commit which did check for equality but that is good enough. ] Fixes:8801b3fcb5
("x86/microcode/AMD: Rework container parsing") Reported-by: Ștefan Talpalaru <stefantalpalaru@yahoo.com> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Ștefan Talpalaru <stefantalpalaru@yahoo.com> Cc: <stable@vger.kernel.org> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216211 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
3064c74198
commit
3ea7da6a97
1 changed files with 13 additions and 3 deletions
|
@ -441,7 +441,13 @@ apply_microcode_early_amd(u32 cpuid_1_eax, void *ucode, size_t size, bool save_p
|
|||
return ret;
|
||||
|
||||
native_rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy);
|
||||
if (rev >= mc->hdr.patch_id)
|
||||
|
||||
/*
|
||||
* Allow application of the same revision to pick up SMT-specific
|
||||
* changes even if the revision of the other SMT thread is already
|
||||
* up-to-date.
|
||||
*/
|
||||
if (rev > mc->hdr.patch_id)
|
||||
return ret;
|
||||
|
||||
if (!__apply_microcode_amd(mc)) {
|
||||
|
@ -523,8 +529,12 @@ void load_ucode_amd_ap(unsigned int cpuid_1_eax)
|
|||
|
||||
native_rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy);
|
||||
|
||||
/* Check whether we have saved a new patch already: */
|
||||
if (*new_rev && rev < mc->hdr.patch_id) {
|
||||
/*
|
||||
* Check whether a new patch has been saved already. Also, allow application of
|
||||
* the same revision in order to pick up SMT-thread-specific configuration even
|
||||
* if the sibling SMT thread already has an up-to-date revision.
|
||||
*/
|
||||
if (*new_rev && rev <= mc->hdr.patch_id) {
|
||||
if (!__apply_microcode_amd(mc)) {
|
||||
*new_rev = mc->hdr.patch_id;
|
||||
return;
|
||||
|
|
Loading…
Reference in a new issue