Commit 95504c7c authored by Maxim Levitsky's avatar Maxim Levitsky Committed by Paolo Bonzini
Browse files

KVM: x86: SVM: don't save SVM state to SMRAM when VM is not long mode capable 



When the guest CPUID doesn't have support for long mode, 32 bit SMRAM
layout is used and it has no support for preserving EFER and/or SVM
state.

Note that this isn't relevant to running 32 bit guests on VM which is
long mode capable - such VM can still run 32 bit guests in compatibility
mode.

Signed-off-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20221025124741.228045-23-mlevitsk@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent dd5045fe

arch/x86/kvm/svm/svm.c

+8 −0
Original line number Diff line number Diff line
@@ -4410,6 +4410,14 @@ static int svm_enter_smm(struct kvm_vcpu *vcpu, union kvm_smram *smram) 
	if (!is_guest_mode(vcpu))

		return 0;



	/*

	 * 32-bit SMRAM format doesn't preserve EFER and SVM state.  Userspace is

	 * responsible for ensuring nested SVM and SMIs are mutually exclusive.

	 */



	if (!guest_cpuid_has(vcpu, X86_FEATURE_LM))

		return 1;



	smram->smram64.svm_guest_flag = 1;

	smram->smram64.svm_guest_vmcb_gpa = svm->nested.vmcb12_gpa;