Re: [kvm-unit-test RFC] x86: Memory instructions test case

[Paolo Bonzini <pbonzini@redhat.com>]

On 04/11/2015 22:21, Eduardo Habkost wrote:
> Quickly hacked test case for memory instructions (clflush, mfence,
> sfence, lfence, clflushopt, clwb, pcommit), that simply checks for #UD
> exceptions.
> 
> This was useful to test TCG handling of those instructions.
> 
> The "fake clwb" part will probably break once a new instruction use
> those opcodes.
> 
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
>  config/config-x86-common.mak |  2 +
>  config/config-x86_64.mak     |  2 +-
>  x86/memory.c                 | 88 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 91 insertions(+), 1 deletion(-)
>  create mode 100644 x86/memory.c
> 
> diff --git a/config/config-x86-common.mak b/config/config-x86-common.mak
> index c2f9908..b89684d 100644
> --- a/config/config-x86-common.mak
> +++ b/config/config-x86-common.mak
> @@ -108,6 +108,8 @@ $(TEST_DIR)/vmx.elf: $(cstart.o) $(TEST_DIR)/vmx.o $(TEST_DIR)/vmx_tests.o
>  
>  $(TEST_DIR)/debug.elf: $(cstart.o) $(TEST_DIR)/debug.o
>  
> +$(TEST_DIR)/memory.elf: $(cstart.o) $(TEST_DIR)/memory.o
> +
>  arch_clean:
>  	$(RM) $(TEST_DIR)/*.o $(TEST_DIR)/*.flat $(TEST_DIR)/*.elf \
>  	$(TEST_DIR)/.*.d lib/x86/.*.d
> diff --git a/config/config-x86_64.mak b/config/config-x86_64.mak
> index 7d4eb34..ec4bded 100644
> --- a/config/config-x86_64.mak
> +++ b/config/config-x86_64.mak
> @@ -7,7 +7,7 @@ tests = $(TEST_DIR)/access.flat $(TEST_DIR)/apic.flat \
>  	  $(TEST_DIR)/emulator.flat $(TEST_DIR)/idt_test.flat \
>  	  $(TEST_DIR)/xsave.flat $(TEST_DIR)/rmap_chain.flat \
>  	  $(TEST_DIR)/pcid.flat $(TEST_DIR)/debug.flat \
> -	  $(TEST_DIR)/ioapic.flat
> +	  $(TEST_DIR)/ioapic.flat $(TEST_DIR)/memory.flat
>  tests += $(TEST_DIR)/svm.flat
>  tests += $(TEST_DIR)/vmx.flat
>  tests += $(TEST_DIR)/tscdeadline_latency.flat
> diff --git a/x86/memory.c b/x86/memory.c
> new file mode 100644
> index 0000000..cd1eb46
> --- /dev/null
> +++ b/x86/memory.c
> @@ -0,0 +1,88 @@
> +/*
> + * Test for x86 cache and memory instructions
> + *
> + * Copyright (c) 2015 Red Hat Inc
> + *
> + * Authors:
> + *  Eduardo Habkost <ehabkost@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.
> + */
> +
> +#include "libcflat.h"
> +#include "desc.h"
> +#include "processor.h"
> +
> +static long target;
> +static volatile int ud;
> +static volatile int isize;
> +
> +static void handle_ud(struct ex_regs *regs)
> +{
> +	ud = 1;
> +	regs->rip += isize;
> +}
> +
> +int main(int ac, char **av)
> +{
> +	struct cpuid cpuid7, cpuid1;
> +	int xfail;
> +
> +	setup_idt();
> +	handle_exception(UD_VECTOR, handle_ud);
> +
> +	cpuid1 = cpuid(1);
> +	cpuid7 = cpuid_indexed(7, 0);
> +
> +	/* 3-byte instructions: */
> +	isize = 3;
> +
> +	xfail = !(cpuid1.d & (1U << 19)); /* CLFLUSH */
> +	ud = 0;
> +	asm volatile("clflush (%0)" : : "b" (&target));
> +	report_xfail("clflush", xfail, ud == 0);
> +
> +	xfail = !(cpuid1.d & (1U << 25)); /* SSE */
> +	ud = 0;
> +	asm volatile("sfence");
> +	report_xfail("sfence", xfail, ud == 0);
> +
> +	xfail = !(cpuid1.d & (1U << 26)); /* SSE2 */
> +	ud = 0;
> +	asm volatile("lfence");
> +	report_xfail("lfence", xfail, ud == 0);
> +
> +	ud = 0;
> +	asm volatile("mfence");
> +	report_xfail("mfence", xfail, ud == 0);
> +
> +	/* 4-byte instructions: */
> +	isize = 4;
> +
> +	xfail = !(cpuid7.b & (1U << 23)); /* CLFLUSHOPT */
> +	ud = 0;
> +	/* clflushopt (%rbx): */
> +	asm volatile(".byte 0x66, 0x0f, 0xae, 0x3b" : : "b" (&target));
> +	report_xfail("clflushopt", xfail, ud == 0);
> +
> +	xfail = !(cpuid7.b & (1U << 24)); /* CLWB */
> +	ud = 0;
> +	/* clwb (%rbx): */
> +	asm volatile(".byte 0x66, 0x0f, 0xae, 0x33" : : "b" (&target));
> +	report_xfail("clwb", xfail, ud == 0);
> +
> +	ud = 0;
> +	/* clwb requires a memory operand, the following is NOT a valid
> +	 * CLWB instruction (modrm == 0xF0).
> +	 */
> +	asm volatile(".byte 0x66, 0x0f, 0xae, 0xf0");
> +	report("fake clwb", ud);
> +
> +	xfail = !(cpuid7.b & (1U << 22)); /* PCOMMIT */
> +	ud = 0;
> +	/* pcommit: */
> +	asm volatile(".byte 0x66, 0x0f, 0xae, 0xf8");
> +	report_xfail("pcommit", xfail, ud == 0);
> +
> +	return report_summary();
> +}
> 

Applied, thanks.

Paolo