KVM: x86 emulator: fix LIDT/LGDT in long mode (510425ff) · Commits · 戴 / test

The operand size for these instructions is 8 bytes in long mode, even without a REX prefix. Set it explicitly. Triggered while booting Linux with emulate_invalid_guest_state=1. Signed-off-by:

Avi Kivity <avi@redhat.com>

arch/x86/kvm/emulate.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -2997,6 +2997,8 @@ static int em_lgdt(struct x86_emulate_ctxt *ctxt)
		struct desc_ptr desc_ptr;
		int rc;

		if (ctxt->mode == X86EMUL_MODE_PROT64)
		ctxt->op_bytes = 8;
		rc = read_descriptor(ctxt, ctxt->src.addr.mem,
		&desc_ptr.size, &desc_ptr.address,
		ctxt->op_bytes);
		@@ -3024,6 +3026,8 @@ static int em_lidt(struct x86_emulate_ctxt *ctxt)
		struct desc_ptr desc_ptr;
		int rc;

		if (ctxt->mode == X86EMUL_MODE_PROT64)
		ctxt->op_bytes = 8;
		rc = read_descriptor(ctxt, ctxt->src.addr.mem,
		&desc_ptr.size, &desc_ptr.address,
		ctxt->op_bytes);

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