linux_dsm_epyc7002/arch/x86
Thomas Lendacky 912139cfbf x86/microcode/amd: Don't falsely trick the late loading mechanism
The load_microcode_amd() function searches for microcode patches and
attempts to apply a microcode patch if it is of different level than the
currently installed level.

While the processor won't actually load a level that is less than
what is already installed, the logic wrongly returns UCODE_NEW thus
signaling to its caller reload_store() that a late loading should be
attempted.

If the file-system contains an older microcode revision than what is
currently running, such a late microcode reload can result in these
misleading messages:

  x86/CPU: CPU features have changed after loading microcode, but might not take effect.
  x86/CPU: Please consider either early loading through initrd/built-in or a potential BIOS update.

These messages were issued on a system where SME/SEV are not
enabled by the BIOS (MSR C001_0010[23] = 0b) because during boot,
early_detect_mem_encrypt() is called and cleared the SME and SEV
features in this case.

However, after the wrong late load attempt, get_cpu_cap() is called and
reloads the SME and SEV feature bits, resulting in the messages.

Update the microcode level check to not attempt microcode loading if the
current level is greater than(!) and not only equal to the current patch
level.

 [ bp: massage commit message. ]

Fixes: 2613f36ed9 ("x86/microcode: Attempt late loading only when new microcode is present")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/154894518427.9406.8246222496874202773.stgit@tlendack-t1.amdoffice.net
2019-01-31 16:54:32 +01:00
..
boot x86/boot/compressed/64: Set EFER.LME=1 in 32-bit trampoline before returning to long mode 2019-01-29 21:58:59 +01:00
configs PCI: consolidate PCI config entry in drivers/pci 2018-11-23 11:45:34 +09:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-12-27 13:53:32 -08:00
entry x86/entry/64/compat: Fix stack switching for XEN PV 2019-01-18 00:39:33 +01:00
events Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-12-26 17:03:51 -08:00
hyperv x86/hyper-v: Add HvFlushGuestAddressList hypercall support 2018-12-21 11:28:39 +01:00
ia32 Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
include x86/cpu: Add Atom Tremont (Jacobsville) 2019-01-29 16:37:35 +01:00
kernel x86/microcode/amd: Don't falsely trick the late loading mechanism 2019-01-31 16:54:32 +01:00
kvm jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
lib x86/kaslr: Fix incorrect i8254 outb() parameters 2019-01-11 21:35:47 +01:00
math-emu Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
mm x86/fault: Fix sign-extend unintended sign extension 2019-01-29 21:58:59 +01:00
net bpf: Add bpf_line_info support 2018-12-09 13:54:38 -08:00
oprofile x86/oprofile: Fix bogus GCC-8 warning in nmi_setup() 2018-02-21 09:54:17 +01:00
pci pci-v4.21-changes 2019-01-05 17:57:34 -08:00
platform Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-12-26 18:42:51 -08:00
power mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
purgatory kbuild: move bin2c back to scripts/ from scripts/basic/ 2018-07-18 01:18:05 +09:00
ras
realmode x86-64/realmode: Add instruction suffix 2018-02-20 09:33:41 +01:00
tools x86: Clean up 'sizeof x' => 'sizeof(x)' 2018-10-29 07:13:28 +01:00
um Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
video
xen Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-12-26 17:03:51 -08:00
.gitignore
Kbuild KVM: x86: Allow Qemu/KVM to use PVH entry point 2018-12-13 13:41:49 -05:00
Kconfig x86/Kconfig: Select PCI_LOCKLESS_CONFIG if PCI is enabled 2019-01-22 17:06:28 +01:00
Kconfig.cpu x86/cpu: Create Hygon Dhyana architecture support file 2018-09-27 16:14:05 +02:00
Kconfig.debug x86/kconfig: Remove redundant 'default n' lines from all x86 Kconfig's 2018-10-17 08:39:42 +02:00
Makefile jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
Makefile_32.cpu
Makefile.um x86, powerpc: Remove -funit-at-a-time compiler option entirely 2018-12-09 11:55:32 +01:00