From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, Sean Christopherson <seanjc@google.com>,
Manali Shukla <manali.shukla@amd.com>
Subject: [kvm-unit-tests PATCH v3 1/9] nVMX: Add "nop" after setting EFLAGS.TF to guarantee single-step #DB
Date: Wed, 5 Oct 2022 23:52:04 +0000 [thread overview]
Message-ID: <20221005235212.57836-2-seanjc@google.com> (raw)
In-Reply-To: <20221005235212.57836-1-seanjc@google.com>
Add a "nop" after enabling single-stepping in vmx_l2_db_test() to ensure
a #DB is generated in the scope of the function even if the helper is
inlined. Enabling single-step #DBs have a one-instruction delay, e.g. if
the function were inlined and the caller generated a "terminal" VM-Exit
immediately after invoking the helper, then no #DB would be generated.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
x86/vmx_tests.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
index aa2ecbb..3e3d699 100644
--- a/x86/vmx_tests.c
+++ b/x86/vmx_tests.c
@@ -10745,6 +10745,7 @@ static void vmx_l2_bp_test(void)
static void vmx_l2_db_test(void)
{
write_rflags(read_rflags() | X86_EFLAGS_TF);
+ asm volatile("nop");
}
static uint64_t usermode_callback(void)
--
2.38.0.rc1.362.ged0d419d3c-goog
next prev parent reply other threads:[~2022-10-05 23:52 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-05 23:52 [kvm-unit-tests PATCH v3 0/9] x86: n{VMX,SVM} exception tests Sean Christopherson
2022-10-05 23:52 ` Sean Christopherson [this message]
2022-10-05 23:52 ` [kvm-unit-tests PATCH v3 2/9] x86: Move helpers to generate misc exceptions to processor.h Sean Christopherson
2022-10-05 23:52 ` [kvm-unit-tests PATCH v3 3/9] nVMX: Move #OF test to generic exceptions test Sean Christopherson
2022-10-05 23:52 ` [kvm-unit-tests PATCH v3 4/9] nVMX: Drop one-off INT3=>#BP test Sean Christopherson
2022-10-05 23:52 ` [kvm-unit-tests PATCH v3 5/9] x86: nSVM: Add an exception test framework and tests Sean Christopherson
2022-10-05 23:52 ` [kvm-unit-tests PATCH v3 6/9] x86: nSVM: Move #BP test to exception test framework Sean Christopherson
2022-10-05 23:52 ` [kvm-unit-tests PATCH v3 7/9] x86: nSVM: Move #OF " Sean Christopherson
2022-10-05 23:52 ` [kvm-unit-tests PATCH v3 8/9] x86: nSVM: Move part of #NM " Sean Christopherson
2022-10-05 23:52 ` [kvm-unit-tests PATCH v3 9/9] nVMX: Move #NM test to generic " Sean Christopherson
2022-10-12 4:17 ` [kvm-unit-tests PATCH v3 0/9] x86: n{VMX,SVM} exception tests Manali Shukla
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