From e0ad0b477c36fde6b0923670647495d07bf42f94 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 20 Aug 2014 10:08:23 +0200 Subject: [PATCH] KVM: emulate: warn on invalid or uninitialized exception numbers These were reported when running Jailhouse on AMD processors. Initialize ctxt->exception.vector with an invalid exception number, and warn if it remained invalid even though the emulator got an X86EMUL_PROPAGATE_FAULT return code. Signed-off-by: Paolo Bonzini --- arch/x86/kvm/emulate.c | 5 ++++- arch/x86/kvm/x86.c | 1 + 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 4fbf4b598f92..e5bf13003cd2 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -527,6 +527,7 @@ static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg) static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec, u32 error, bool valid) { + WARN_ON(vec > 0x1f); ctxt->exception.vector = vec; ctxt->exception.error_code = error; ctxt->exception.error_code_valid = valid; @@ -4827,8 +4828,10 @@ writeback: ctxt->eip = ctxt->_eip; done: - if (rc == X86EMUL_PROPAGATE_FAULT) + if (rc == X86EMUL_PROPAGATE_FAULT) { + WARN_ON(ctxt->exception.vector > 0x1f); ctxt->have_exception = true; + } if (rc == X86EMUL_INTERCEPTED) return EMULATION_INTERCEPTED; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 737b4bdac41c..cd718c01cdf1 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5248,6 +5248,7 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, ctxt->interruptibility = 0; ctxt->have_exception = false; + ctxt->exception.vector = -1; ctxt->perm_ok = false; ctxt->ud = emulation_type & EMULTYPE_TRAP_UD; -- 2.39.2