kvm: x86: Fix xstate_required_size() to follow XSTATE alignment rule

mainline inclusion
from mainline-v5.17-rc1
commit cc04b6a2
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I5RQLJ


CVE: NA

Intel-SIG: commit cc04b6a2 kvm: x86: Fix xstate_required_size() to follow XSTATE alignment rule.

--------------------------------

CPUID.0xD.1.EBX enumerates the size of the XSAVE area (in compacted
format) required by XSAVES. If CPUID.0xD.i.ECX[1] is set for a state
component (i), this state component should be located on the next
64-bytes boundary following the preceding state component in the
compacted layout.

Fix xstate_required_size() to follow the alignment rule. AMX is the
first state component with 64-bytes alignment to catch this bug.

Signed-off-by: Jing Liu <jing2.liu@intel.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20220105123532.12586-4-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Lin Wang <lin.x.wang@intel.com>