kvm: vmx: Document the need for MSR_STAR in i386 builds (898a811f) · Commits · 戴 / test

Add a comment explaining why MSR_STAR must be included in vmx_msr_index[] even for i386 builds. The elided comment has not been relevant since move_msr_up() was introduced in commit ("KVM: VMX: Avoid saving and restoring msrs on lightweight vmexit"). Signed-off-by:

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

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

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/vmx.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -373,8 +373,11 @@ static const struct kvm_vmx_segment_field {
		u64 host_efer;

		/*
		* Keep MSR_STAR at the end, as setup_msrs() will try to optimize it
		* away by decrementing the array size.
		* Though SYSCALL is only supported in 64-bit mode on Intel CPUs, kvm
		* will emulate SYSCALL in legacy mode if the vendor string in guest
		* CPUID.0:{EBX,ECX,EDX} is "AuthenticAMD" or "AMDisbetter!" To
		* support this emulation, IA32_STAR must always be included in
		* vmx_msr_index[], even in i386 builds.
		*/
		const u32 vmx_msr_index[] = {
		#ifdef CONFIG_X86_64

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