Add support for handling #DE (divide error) exceptions in KVM selftests so that the fastops test can verify KVM correctly handles #DE when emulating DIV or IDIV on behalf of the guest. Morph #DE to 0xff (i.e. to -1) as a mostly-arbitrary vector to indicate #DE, so that '0' (the real #DE vector) can still be used to indicate "no exception". Signed-off-by: Sean Christopherson --- tools/testing/selftests/kvm/include/x86/processor.h | 6 ++++++ tools/testing/selftests/kvm/lib/x86/processor.c | 2 +- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/include/x86/processor.h b/tools/testing/selftests/kvm/include/x86/processor.h index 2efb05c2f2fb..5142d1bf15a2 100644 --- a/tools/testing/selftests/kvm/include/x86/processor.h +++ b/tools/testing/selftests/kvm/include/x86/processor.h @@ -1179,6 +1179,12 @@ struct idt_entry { void vm_install_exception_handler(struct kvm_vm *vm, int vector, void (*handler)(struct ex_regs *)); +/* + * Exception fixup morphs #DE to an arbitrary magic vector so that '0' can be + * used to signal "no expcetion". + */ +#define KVM_MAGIC_DE_VECTOR 0xff + /* If a toddler were to say "abracadabra". */ #define KVM_EXCEPTION_MAGIC 0xabacadabaULL diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c index d4c19ac885a9..3b63c99f7b96 100644 --- a/tools/testing/selftests/kvm/lib/x86/processor.c +++ b/tools/testing/selftests/kvm/lib/x86/processor.c @@ -557,7 +557,7 @@ static bool kvm_fixup_exception(struct ex_regs *regs) return false; if (regs->vector == DE_VECTOR) - return false; + regs->vector = KVM_MAGIC_DE_VECTOR; regs->rip = regs->r11; regs->r9 = regs->vector; -- 2.51.0.384.g4c02a37b29-goog