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, 0 insertions, 44 deletions

diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 0e0a9022a7..58cf0de6c0 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -3141,50 +3141,6 @@ void async_exception_cleanup(struct vcpu *curr)
                 break;
     ASSERT(trap <= VCPU_TRAP_LAST);
 
-    /* inject vMCE to PV_Guest including DOM0. */
-    if ( trap == VCPU_TRAP_MCE )
-    {
-        gdprintk(XENLOG_DEBUG, "MCE: Return from vMCE# trap!\n");
-        if ( curr->vcpu_id == 0 )
-        {
-            struct domain *d = curr->domain;
-
-            if ( !d->arch.vmca_msrs->nr_injection )
-            {
-                printk(XENLOG_WARNING "MCE: ret from vMCE#, "
-                       "no injection node\n");
-                goto end;
-            }
-
-            d->arch.vmca_msrs->nr_injection--;
-            if ( !list_empty(&d->arch.vmca_msrs->impact_header) )
-            {
-                struct bank_entry *entry;
-
-                entry = list_entry(d->arch.vmca_msrs->impact_header.next,
-                                   struct bank_entry, list);
-                gdprintk(XENLOG_DEBUG, "MCE: delete last injection node\n");
-                list_del(&entry->list);
-            }
-            else
-                printk(XENLOG_ERR "MCE: didn't found last injection node\n");
-
-            /* further injection */
-            if ( d->arch.vmca_msrs->nr_injection > 0 &&
-                 guest_has_trap_callback(d, 0, TRAP_machine_check) &&
-                 !test_and_set_bool(curr->mce_pending) )
-            {
-                int cpu = smp_processor_id();
-
-                cpumask_copy(curr->cpu_affinity_tmp, curr->cpu_affinity);
-                printk(XENLOG_DEBUG "MCE: CPU%d set affinity, old %d\n",
-                       cpu, curr->processor);
-                vcpu_set_affinity(curr, cpumask_of(cpu));
-            }
-        }
-    }
-
-end:
     /* Restore previous asynchronous exception mask. */
     curr->async_exception_mask = curr->async_exception_state(trap).old_mask;
 }