[RFC PATCH 20/27] KVM: x86: Add per-VM flag to track CPUID paranoid mode

[Binbin Wu <binbin.wu@linux.intel.com>]

Add 'is_cpuid_paranoid_mode' to struct kvm_arch to indicate whether
CPUID paranoid verification is enabled for a VM.

When enabled, KVM will restrict the guest's CPUID configuration to only
known and supported bits, rejecting userspace-provided CPUID entries that
set unsupported or unrecognized features.  CPUID paranoid mode will be
unconditionally enforced for TDX guests, and optionally enabled for other
VM types via a new KVM capability that will be introduced in a subsequent
patch.

No functional change intended.

Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com>
---
 arch/x86/include/asm/kvm_host.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f6d79e8496c3..4f645f9dfb5a 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1485,6 +1485,9 @@ struct kvm_arch {
 	bool has_protected_state;
 	bool has_protected_eoi;
 	bool pre_fault_allowed;
+
+	bool is_cpuid_paranoid_mode;
+
 	struct hlist_head *mmu_page_hash;
 	struct list_head active_mmu_pages;
 	struct kvm_possible_nx_huge_pages possible_nx_huge_pages[KVM_NR_MMU_TYPES];
-- 
2.46.0