From: Yosry Ahmed <yosry.ahmed@linux.dev>
To: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Ken Hofsass <hofsass@google.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Yosry Ahmed <yosry.ahmed@linux.dev>
Subject: [PATCH 2/3] KVM: selftests: Use TEST_ASSERT_EQ() in debug_regs
Date: Fri, 21 Nov 2025 19:32:03 +0000 [thread overview]
Message-ID: <20251121193204.952988-3-yosry.ahmed@linux.dev> (raw)
In-Reply-To: <20251121193204.952988-1-yosry.ahmed@linux.dev>
The test currently uses calls of TEST_ASSERT() that combine all checked
conditions for every test case. This makes it unclear which value is
incorrect without visually parsing the output.
The only useful content in the error message is the test case,
especially for test cases running in loops where even the line number of
the failed assertion does not provide full information.
Switch to using TEST_ASSERT_EQ(), and print the test case currently
being asserted to keep the information intact. The test output is a lot
more verbose now, but debuggability trumps conciseness (right?).
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
---
tools/testing/selftests/kvm/x86/debug_regs.c | 66 +++++++-------------
1 file changed, 24 insertions(+), 42 deletions(-)
diff --git a/tools/testing/selftests/kvm/x86/debug_regs.c b/tools/testing/selftests/kvm/x86/debug_regs.c
index 2d814c1d1dc4..563e52217cdd 100644
--- a/tools/testing/selftests/kvm/x86/debug_regs.c
+++ b/tools/testing/selftests/kvm/x86/debug_regs.c
@@ -104,20 +104,19 @@ int main(void)
run = vcpu->run;
/* Test software BPs - int3 */
+ pr_info("Testing INT3\n");
memset(&debug, 0, sizeof(debug));
debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
vcpu_guest_debug_set(vcpu, &debug);
vcpu_run(vcpu);
- TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
- run->debug.arch.exception == BP_VECTOR &&
- run->debug.arch.pc == CAST_TO_RIP(sw_bp),
- "INT3: exit %d exception %d rip 0x%llx (should be 0x%llx)",
- run->exit_reason, run->debug.arch.exception,
- run->debug.arch.pc, CAST_TO_RIP(sw_bp));
+ TEST_ASSERT_EQ(run->exit_reason, KVM_EXIT_DEBUG);
+ TEST_ASSERT_EQ(run->debug.arch.exception, BP_VECTOR);
+ TEST_ASSERT_EQ(run->debug.arch.pc, CAST_TO_RIP(sw_bp));
vcpu_skip_insn(vcpu, 1);
/* Test instruction HW BP over DR[0-3] */
for (i = 0; i < 4; i++) {
+ pr_info("Testing INS_HW_BP DR[%d]\n", i);
memset(&debug, 0, sizeof(debug));
debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP;
debug.arch.debugreg[i] = CAST_TO_RIP(hw_bp);
@@ -125,21 +124,17 @@ int main(void)
vcpu_guest_debug_set(vcpu, &debug);
vcpu_run(vcpu);
target_dr6 = 0xffff0ff0 | (1UL << i);
- TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
- run->debug.arch.exception == DB_VECTOR &&
- run->debug.arch.pc == CAST_TO_RIP(hw_bp) &&
- run->debug.arch.dr6 == target_dr6,
- "INS_HW_BP (DR%d): exit %d exception %d rip 0x%llx "
- "(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
- i, run->exit_reason, run->debug.arch.exception,
- run->debug.arch.pc, CAST_TO_RIP(hw_bp),
- run->debug.arch.dr6, target_dr6);
+ TEST_ASSERT_EQ(run->exit_reason, KVM_EXIT_DEBUG);
+ TEST_ASSERT_EQ(run->debug.arch.exception, DB_VECTOR);
+ TEST_ASSERT_EQ(run->debug.arch.pc, CAST_TO_RIP(hw_bp));
+ TEST_ASSERT_EQ(run->debug.arch.dr6, target_dr6);
}
/* Skip "nop" */
vcpu_skip_insn(vcpu, 1);
/* Test data access HW BP over DR[0-3] */
for (i = 0; i < 4; i++) {
+ pr_info("Testing DATA_HW_BP DR[%d]\n", i);
memset(&debug, 0, sizeof(debug));
debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP;
debug.arch.debugreg[i] = CAST_TO_RIP(guest_value);
@@ -148,15 +143,10 @@ int main(void)
vcpu_guest_debug_set(vcpu, &debug);
vcpu_run(vcpu);
target_dr6 = 0xffff0ff0 | (1UL << i);
- TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
- run->debug.arch.exception == DB_VECTOR &&
- run->debug.arch.pc == CAST_TO_RIP(write_data) &&
- run->debug.arch.dr6 == target_dr6,
- "DATA_HW_BP (DR%d): exit %d exception %d rip 0x%llx "
- "(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
- i, run->exit_reason, run->debug.arch.exception,
- run->debug.arch.pc, CAST_TO_RIP(write_data),
- run->debug.arch.dr6, target_dr6);
+ TEST_ASSERT_EQ(run->exit_reason, KVM_EXIT_DEBUG);
+ TEST_ASSERT_EQ(run->debug.arch.exception, DB_VECTOR);
+ TEST_ASSERT_EQ(run->debug.arch.pc, CAST_TO_RIP(write_data));
+ TEST_ASSERT_EQ(run->debug.arch.dr6, target_dr6);
/* Rollback the 4-bytes "mov" */
vcpu_skip_insn(vcpu, -7);
}
@@ -167,6 +157,7 @@ int main(void)
target_rip = CAST_TO_RIP(ss_start);
target_dr6 = 0xffff4ff0ULL;
for (i = 0; i < ARRAY_SIZE(ss_size); i++) {
+ pr_info("Testing SINGLE_STEP (%d)\n", i);
target_rip += ss_size[i];
memset(&debug, 0, sizeof(debug));
debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP |
@@ -174,33 +165,24 @@ int main(void)
debug.arch.debugreg[7] = 0x00000400;
vcpu_guest_debug_set(vcpu, &debug);
vcpu_run(vcpu);
- TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
- run->debug.arch.exception == DB_VECTOR &&
- run->debug.arch.pc == target_rip &&
- run->debug.arch.dr6 == target_dr6,
- "SINGLE_STEP[%d]: exit %d exception %d rip 0x%llx "
- "(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
- i, run->exit_reason, run->debug.arch.exception,
- run->debug.arch.pc, target_rip, run->debug.arch.dr6,
- target_dr6);
+ TEST_ASSERT_EQ(run->exit_reason, KVM_EXIT_DEBUG);
+ TEST_ASSERT_EQ(run->debug.arch.exception, DB_VECTOR);
+ TEST_ASSERT_EQ(run->debug.arch.pc, target_rip);
+ TEST_ASSERT_EQ(run->debug.arch.dr6, target_dr6);
}
/* Finally test global disable */
+ pr_info("Testing DR7.GD\n");
memset(&debug, 0, sizeof(debug));
debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP;
debug.arch.debugreg[7] = 0x400 | DR7_GD;
vcpu_guest_debug_set(vcpu, &debug);
vcpu_run(vcpu);
target_dr6 = 0xffff0ff0 | DR6_BD;
- TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
- run->debug.arch.exception == DB_VECTOR &&
- run->debug.arch.pc == CAST_TO_RIP(bd_start) &&
- run->debug.arch.dr6 == target_dr6,
- "DR7.GD: exit %d exception %d rip 0x%llx "
- "(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
- run->exit_reason, run->debug.arch.exception,
- run->debug.arch.pc, target_rip, run->debug.arch.dr6,
- target_dr6);
+ TEST_ASSERT_EQ(run->exit_reason, KVM_EXIT_DEBUG);
+ TEST_ASSERT_EQ(run->debug.arch.exception, DB_VECTOR);
+ TEST_ASSERT_EQ(run->debug.arch.pc, CAST_TO_RIP(bd_start));
+ TEST_ASSERT_EQ(run->debug.arch.dr6, target_dr6);
/* Disable all debug controls, run to the end */
memset(&debug, 0, sizeof(debug));
--
2.52.0.rc2.455.g230fcf2819-goog
next prev parent reply other threads:[~2025-11-21 19:32 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-21 19:32 [PATCH 0/3] KVM: x86: Accelerate reading CR3 for guest debug Yosry Ahmed
2025-11-21 19:32 ` [PATCH 1/3] KVM: x86: Add CR3 to guest debug info Yosry Ahmed
2025-11-21 21:01 ` Sean Christopherson
2025-11-21 23:12 ` Yosry Ahmed
2025-11-24 14:45 ` Sean Christopherson
2025-11-24 15:35 ` Yosry Ahmed
2025-11-21 19:32 ` Yosry Ahmed [this message]
2025-11-21 19:32 ` [PATCH 3/3] KVM: selftests: Verify CR3 in debug_regs Yosry Ahmed
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