Commit 40269c03 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86: Explicitly zero kvm_caps during vendor module load 



Zero out all of kvm_caps when loading a new vendor module to ensure that
KVM can't inadvertently rely on global initialization of a field, and add
a comment above the definition of kvm_caps to call out that all fields
needs to be explicitly computed during vendor module load.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Reviewed-by: default avatarXiaoyao Li <xiaoyao.li@intel.com>
Message-ID: <20240423165328.2853870-4-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 555485bd

arch/x86/kvm/x86.c

+7 −0
Original line number Diff line number Diff line
@@ -92,6 +92,11 @@ 
#define MAX_IO_MSRS 256

#define KVM_MAX_MCE_BANKS 32



/*

 * Note, kvm_caps fields should *never* have default values, all fields must be

 * recomputed from scratch during vendor module load, e.g. to account for a

 * vendor module being reloaded with different module parameters.

 */

struct kvm_caps kvm_caps __read_mostly;

EXPORT_SYMBOL_GPL(kvm_caps);
@@ -9755,6 +9760,8 @@ int kvm_x86_vendor_init(struct kvm_x86_init_ops *ops) 
		return -EIO;

	}



	memset(&kvm_caps, 0, sizeof(kvm_caps));



	x86_emulator_cache = kvm_alloc_emulator_cache();

	if (!x86_emulator_cache) {

		pr_err("failed to allocate cache for x86 emulator\n");