KVM: selftests: restore special vmmcall code layout needed by the harness

Commit 8fda37cf3d ("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: 8fda37cf3d ("KVM: selftests: Stuff RAX/RCX with 'safe' values in vmmcall()/vmcall()"
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20221130181147.9911-1-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2022-11-30 13:11:47 -05:00
parent 02d9a04da4
commit 129c48cde6

View file

@ -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();