fix vmce MCi_ADDR/MCi_MISC wrmsr bug

fix vmce MCi_ADDR/MCi_MISC wrmsr bug

This patch fixes a bug related to wrmsr vmce MCi_ADDR/MCi_MISC
registers, since they are not read-only.

Intel SDM recommanded os mce driver clear MCi_ADDR/MCi_MISC, so guest
MCE driver may clear MCi_ADDR/MCi_MISC registers. In such case, old
vmce wrmsr logic would generate a #GP fault in guest MCE context,
causing the guest to crash.

When wrmsr MCi_ADDR/MCi_MISC, writing all 1s will cause #GP.

Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Committed-by: Jan Beulich <jbeulich@suse.com>