This test checks that single stepping through CPUID and RDMSR works.
Both instructions trigger VM exits and are emulated by the hypervisor.
Signed-off-by: Kyle Huey <khuey@xxxxxxxxxxxx>
---
x86/debug.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/x86/debug.c b/x86/debug.c
index d04de23..fb1fb0d 100644
--- a/x86/debug.c
+++ b/x86/debug.c
@@ -107,16 +107,47 @@ hw_bp2:
"popf\n\t"
: "=g" (start) : : "rax");
report("single step",
n == 3 &&
bp_addr[0] == start+1+6 && dr6[0] == 0xffff4ff0 &&
bp_addr[1] == start+1+6+1 && dr6[1] == 0xffff4ff0 &&
bp_addr[2] == start+1+6+1+1 && dr6[2] == 0xffff4ff0);
+ /*
+ * cpuid and rdmsr (among others) trigger VM exits and are then
+ * emulated. Test that single stepping works on emulated instructions.
+ */
+ n = 0;
+ set_dr6(0);
+ asm volatile(
+ "pushf\n\t"
+ "pop %%rax\n\t"
+ "or $(1<<8),%%rax\n\t"
+ "push %%rax\n\t"
+ "lea (%%rip),%0\n\t"
+ "popf\n\t"
+ "and $~(1<<8),%%rax\n\t"
+ "push %%rax\n\t"
+ "xor %%rax,%%rax\n\t"
+ "cpuid\n\t"
+ "movl $0x1a0,%%ecx\n\t"
+ "rdmsr\n\t"
+ "popf\n\t"
+ : "=g" (start) : : "rax", "ebx", "ecx", "edx");
+ report("single step emulated instructions",
+ n == 7 &&
+ bp_addr[0] == start+1+6 && dr6[0] == 0xffff4ff0 &&
+ bp_addr[1] == start+1+6+1 && dr6[1] == 0xffff4ff0 &&
+ bp_addr[2] == start+1+6+1+3 && dr6[2] == 0xffff4ff0 &&
+ bp_addr[3] == start+1+6+1+3+2 && dr6[3] == 0xffff4ff0 &&
+ bp_addr[4] == start+1+6+1+3+2+5 && dr6[4] == 0xffff4ff0 &&
+ bp_addr[5] == start+1+6+1+3+2+5+2 && dr6[4] == 0xffff4ff0 &&
+ bp_addr[6] == start+1+6+1+3+2+5+2+1 && dr6[4] == 0xffff4ff0);
+
n = 0;
set_dr1((void *)&value);
set_dr7(0x00d0040a);
asm volatile(
"mov $42,%%rax\n\t"
"mov %%rax,%0\n\t"
: "=m" (value) : : "rax");
--
2.10.2
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
