Commit 2e6b9bd4 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: SVM: Use "standard" stgi() helper when disabling SVM 

Now that kvm_rebooting is guaranteed to be true prior to disabling SVM
in an emergency, use the existing stgi() helper instead of open coding
STGI.  In effect, eat faults on STGI if and only if kvm_rebooting==true.

Link: https://lore.kernel.org/r/20230721201859.2307736-19-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 6ae44e01

arch/x86/kvm/svm/svm.c

+3 −10
Original line number Diff line number Diff line
@@ -588,17 +588,10 @@ static inline void kvm_cpu_svm_disable(void) 
	rdmsrl(MSR_EFER, efer);

	if (efer & EFER_SVME) {

		/*

		 * Force GIF=1 prior to disabling SVM to ensure INIT and NMI

		 * aren't blocked, e.g. if a fatal error occurred between CLGI

		 * and STGI.  Note, STGI may #UD if SVM is disabled from NMI

		 * context between reading EFER and executing STGI.  In that

		 * case, GIF must already be set, otherwise the NMI would have

		 * been blocked, so just eat the fault.

		 * Force GIF=1 prior to disabling SVM, e.g. to ensure INIT and

		 * NMI aren't blocked.

		 */

		asm_volatile_goto("1: stgi\n\t"

				  _ASM_EXTABLE(1b, %l[fault])

				  ::: "memory" : fault);

fault:

		stgi();

		wrmsrl(MSR_EFER, efer & ~EFER_SVME);

	}

}