linux/arch/x86/power
Borislav Petkov f9e14dbbd4 x86/cpu: Load microcode during restore_processor_state()
When resuming from system sleep state, restore_processor_state()
restores the boot CPU MSRs. These MSRs could be emulated by microcode.
If microcode is not loaded yet, writing to emulated MSRs leads to
unchecked MSR access error:

  ...
  PM: Calling lapic_suspend+0x0/0x210
  unchecked MSR access error: WRMSR to 0x10f (tried to write 0x0...0) at rIP: ... (native_write_msr)
  Call Trace:
    <TASK>
    ? restore_processor_state
    x86_acpi_suspend_lowlevel
    acpi_suspend_enter
    suspend_devices_and_enter
    pm_suspend.cold
    state_store
    kobj_attr_store
    sysfs_kf_write
    kernfs_fop_write_iter
    new_sync_write
    vfs_write
    ksys_write
    __x64_sys_write
    do_syscall_64
    entry_SYSCALL_64_after_hwframe
   RIP: 0033:0x7fda13c260a7

To ensure microcode emulated MSRs are available for restoration, load
the microcode on the boot CPU before restoring these MSRs.

  [ Pawan: write commit message and productize it. ]

Fixes: e2a1256b17 ("x86/speculation: Restore speculation related MSRs during S3 resume")
Reported-by: Kyle D. Pelton <kyle.d.pelton@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Tested-by: Kyle D. Pelton <kyle.d.pelton@intel.com>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215841
Link: https://lore.kernel.org/r/4350dfbf785cd482d3fafa72b2b49c83102df3ce.1650386317.git.pawan.kumar.gupta@linux.intel.com
2022-04-19 19:37:05 +02:00
..
cpu.c x86/cpu: Load microcode during restore_processor_state() 2022-04-19 19:37:05 +02:00
hibernate_32.c mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
hibernate_64.c mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
hibernate_asm_32.S x86: Prepare asm files for straight-line-speculation 2021-12-08 12:25:37 +01:00
hibernate_asm_64.S x86: Prepare asm files for straight-line-speculation 2021-12-08 12:25:37 +01:00
hibernate.c PM: hibernate: x86: Use crc32 instead of md5 for hibernation e820 integrity check 2021-04-21 19:03:37 +02:00
Makefile clang-lto for v5.12-rc1 (part2) 2021-02-23 15:13:45 -08:00