x86/vmce: fill MSR_IA32_MCG_STATUS on all vcpus in broadcast case

x86/vmce: fill MSR_IA32_MCG_STATUS on all vcpus in broadcast case

The current implementation only fills MC MSRs on vcpu0 and leaves MC
MSRs on other vcpus empty in the broadcast case. When guest reads 0
from MSR_IA32_MCG_STATUS on vcpuN (N > 0), it may think it's not
possible to recover the execution on that vcpu and then get panic,
although MSR_IA32_MCG_STATUS filled on vcpu0 may imply the injected
vMCE is actually recoverable. To avoid such unnecessary guest panic,
set MSR_IA32_MCG_STATUS on vcpuN (N > 0) to MCG_STATUS_MCIP|MCG_STATUS_RIPV.

In addition, fill_vmsr_data(mc_bank, ...) is changed to return -EINVAL
rather than 0, if an invalid domain ID is contained in mc_bank.

Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>