x86: vMCE emulation

This patch provides virtual MCE support to guest. It emulates a simple
and clean MCE MSRs interface to guest by faking caps to guest if needed
and masking caps if unnecessary:
1. Providing a well-defined MCG_CAP to guest, filter out un-necessary
   caps and provide only guest needed caps;
2. Disabling MCG_CTL to avoid model specific;
3. Sticking all 1's to MCi_CTL to guest to avoid model specific;
4. Enabling CMCI cap but never really inject to guest to prevent
   polling periodically;
5. Masking MSCOD field of MCi_STATUS to avoid model specific;
6. Keeping natural semantics by per-vcpu instead of per-domain
   variables;
7. Using bank1 and reserving bank0 to work around 'bank0 quirk' of some
   very old processors;
8. Cleaning some vMCE# injection logic which shared by Intel and AMD
   but useless under new vMCE implement;
9. Keeping compatilbe w/ old xen version which has been backported to
   SLES11 SP2, so that old vMCE would not blocked when migrate to new
   vMCE;

Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>

- make printing consistent (and non-exploitable)
- fix return values of intel_mce_{rd,wr}msr() for out of range banks
- miscellaneous cleanup

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Committed-by: Jan Beulich <jbeulich@suse.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index b407a0470b..cb51252ac5 100644
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -1066,7 +1066,7 @@ long arch_do_domctl(
                 evc->syscall32_callback_eip    = 0;
                 evc->syscall32_disables_events = 0;
             }
-            evc->mcg_cap = v->arch.mcg_cap;
+            evc->mcg_cap = v->arch.vmce.mcg_cap;
         }
         else
         {