[Qemu-devel] [PATCH v3 0/2] Add QEMU support for Intel local MCE

[Haozhong Zhang]

This is v3 of LMCE patch series. Previous ones can be found at
 v2: https://lists.nongnu.org/archive/html/qemu-devel/2015-12/msg01731.html
 v1: https://lists.nongnu.org/archive/html/qemu-devel/2015-12/msg01651.html
 v0: https://lists.nongnu.org/archive/html/qemu-devel/2015-12/msg01498.html

Changes in v3:
 * LMCE can be enabled only for non-intel guests.
 * LMCE is disabled by default and a cpu option 'lmce=on/off' is added
   to explicitly enable/disable LMCE.
 * LMCE is disabled if KVM does not support (even though 'lmce=on').
 * VM on LMCE-enabled QEMU can be only migrated to LMCE-enabled QEMU.
 * MCG_LMCE_P is not included in MCE_CAP_DEF and instead added to
   env->mcg_cap if LMCE is enabled.
 * Code style fix.

This QEMU patch series along with the corresponding KVM patch (sent
via another email with title "[PATCH v1] Add KVM support for Intel
local MCE") enables Intel local MCE feature for guest.

Intel Local MCE (LMCE) is a feature on Intel Skylake Server CPU that
can deliver MCE to a single processor thread instead of broadcasting
to all threads, which can reduce software's load when processing MCE
on machines with a large number of processor threads.

The technical details of LMCE can be found in Intel SDM Vol 3, Chapter
"Machine-Check Architecture" (search for 'LMCE'). Basically,
 * The capability of LMCE is indicated by bit 27 (MCG_LMCE_P) of
   MSR_IA32_MCG_CAP.
 * LMCE is enabled by setting bit 20 (MSR_IA32_FEATURE_CONTROL_LMCE)
   of MSR_IA32_FEATURE_CONTROL and bit 0 (MCG_EXT_CTL_LMCE_EN) of
   MSR_IA32_MCG_EXT_CTL.
 * Software can determine if a MCE is local to the current processor
   thread by checking bit 2 (MCG_STATUS_LMCE) of MSR_IA32_MCG_STATUS.

Haozhong Zhang (2):
  target-i386: KVM: add basic Intel LMCE support
  target-i386: add migration support for Intel LMCE

 include/hw/i386/pc.h  |  7 ++++++-
 target-i386/cpu.c     | 27 +++++++++++++++++++++++++++
 target-i386/cpu.h     | 18 +++++++++++++++++-
 target-i386/kvm.c     | 35 +++++++++++++++++++++++++++++++----
 target-i386/machine.c | 24 ++++++++++++++++++++++++
 5 files changed, 105 insertions(+), 6 deletions(-)

-- 
2.8.3