kvm: vmx: Skip all SYSCALL MSRs in setup_msrs() when !EFER.SCE (84c8c5b8) · Commits · 戴 / test

Like IA32_STAR, IA32_LSTAR and IA32_FMASK only need to contain guest values on VM-entry when the guest is in long mode and EFER.SCE is set. Signed-off-by:

Jim Mattson <jmattson@google.com> Reviewed-by:

Peter Shier <pshier@google.com> Reviewed-by:

Marc Orr <marcorr@google.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/vmx.c

+8 −8

Original line number	Diff line number	Diff line
		@@ -1375,19 +1375,19 @@ static void setup_msrs(struct vcpu_vmx *vmx)

		save_nmsrs = 0;
		#ifdef CONFIG_X86_64
		if (is_long_mode(&vmx->vcpu)) {
		index = __find_msr_index(vmx, MSR_SYSCALL_MASK);
		/*
		* The SYSCALL MSRs are only needed on long mode guests, and only
		* when EFER.SCE is set.
		*/
		if (is_long_mode(&vmx->vcpu) && (vmx->vcpu.arch.efer & EFER_SCE)) {
		index = __find_msr_index(vmx, MSR_STAR);
		if (index >= 0)
		move_msr_up(vmx, index, save_nmsrs++);
		index = __find_msr_index(vmx, MSR_LSTAR);
		if (index >= 0)
		move_msr_up(vmx, index, save_nmsrs++);
		/*
		* MSR_STAR is only needed on long mode guests, and only
		* if efer.sce is enabled.
		*/
		index = __find_msr_index(vmx, MSR_STAR);
		if ((index >= 0) && (vmx->vcpu.arch.efer & EFER_SCE))
		index = __find_msr_index(vmx, MSR_SYSCALL_MASK);
		if (index >= 0)
		move_msr_up(vmx, index, save_nmsrs++);
		}
		#endif

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