Commit 8fda37cf3d41 ("KVM: selftests: Stuff RAX/RCX with 'safe' values
in vmmcall()/vmcall()", 2022-11-21) broke the svm_nested_soft_inject_test
because it placed a "pop rbp" instruction after vmmcall. While this is
correct and mimics what is done in the VMX case, this particular test
expects a ud2 instruction right after the vmmcall, so that it can skip
over it in the L1 part of the test.
Inline a suitably-modified version of vmmcall() to restore the
functionality of the test.
Fixes: 8fda37cf3d41 ("KVM: selftests: Stuff RAX/RCX with 'safe' values in vmmcall()/vmcall()"
Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
.../kvm/x86_64/svm_nested_soft_inject_test.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/x86_64/svm_nested_soft_inject_test.c b/tools/testing/selftests/kvm/x86_64/svm_nested_soft_inject_test.c
index e497ace629c1..b34980d45648 100644
--- a/tools/testing/selftests/kvm/x86_64/svm_nested_soft_inject_test.c
+++ b/tools/testing/selftests/kvm/x86_64/svm_nested_soft_inject_test.c
@@ -41,8 +41,17 @@ static void guest_int_handler(struct ex_regs *regs)
static void l2_guest_code_int(void)
{
GUEST_ASSERT_1(int_fired == 1, int_fired);
- vmmcall();
- ud2();
+
+ /*
+ * Same as the vmmcall() function, but with a ud2 sneaked after the
+ * vmmcall. The caller injects an exception with the return address
+ * increased by 2, so the "pop rbp" must be after the ud2 and we cannot
+ * use vmmcall() directly.
+ */
+ __asm__ __volatile__("push %%rbp; vmmcall; ud2; pop %%rbp"
+ : : "a"(0xdeadbeef), "c"(0xbeefdead)
+ : "rbx", "rdx", "rsi", "rdi", "r8", "r9",
+ "r10", "r11", "r12", "r13", "r14", "r15");
GUEST_ASSERT_1(bp_fired == 1, bp_fired);
hlt();
--
2.31.1
