[PATCH 074/128] KVM: selftests: Add proper helper for advancing RIP in debug_regs

Sean Christopherson
2022-05-04T22:53:56Z

Replace MOVE_RIP+SET_RIP with a proper helper, vcpu_skip_insn(), that is
more descriptive, doesn't subtly access local variables, and provides
type safety.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
.../testing/selftests/kvm/x86_64/debug_regs.c | 25 ++++++++++---------
1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/debug_regs.c b/tools/testing/selftests/kvm/x86_64/debug_regs.c
index b999c9753fc3..487d0ae3e75f 100644
--- a/tools/testing/selftests/kvm/x86_64/debug_regs.c
+++ b/tools/testing/selftests/kvm/x86_64/debug_regs.c
@@ -65,19 +65,21 @@ static void guest_code(void)
}

#define CAST_TO_RIP(v) ((unsigned long long)&(v))
-#define SET_RIP(v) do { \
- vcpu_regs_get(vm, vcpu->id, &regs); \
- regs.rip = (v); \
- vcpu_regs_set(vm, vcpu->id, &regs); \
- } while (0)
-#define MOVE_RIP(v) SET_RIP(regs.rip + (v));
+
+static void vcpu_skip_insn(struct kvm_vcpu *vcpu, int insn_len)
+{
+ struct kvm_regs regs;
+
+ vcpu_regs_get(vcpu->vm, vcpu->id, &regs);
+ regs.rip += insn_len;
+ vcpu_regs_set(vcpu->vm, vcpu->id, &regs);
+}

int main(void)
{
struct kvm_guest_debug debug;
unsigned long long target_dr6, target_rip;
struct kvm_vcpu *vcpu;
- struct kvm_regs regs;
struct kvm_run *run;
struct kvm_vm *vm;
struct ucall uc;
@@ -112,7 +114,7 @@ int main(void)
"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));
- MOVE_RIP(1);
+ vcpu_skip_insn(vcpu, 1);

/* Test instruction HW BP over DR[0-3] */
for (i = 0; i < 4; i++) {
@@ -134,7 +136,7 @@ int main(void)
run->debug.arch.dr6, target_dr6);
}
/* Skip "nop" */
- MOVE_RIP(1);
+ vcpu_skip_insn(vcpu, 1);

/* Test data access HW BP over DR[0-3] */
for (i = 0; i < 4; i++) {
@@ -156,15 +158,14 @@ int main(void)
run->debug.arch.pc, CAST_TO_RIP(write_data),
run->debug.arch.dr6, target_dr6);
/* Rollback the 4-bytes "mov" */
- MOVE_RIP(-7);
+ vcpu_skip_insn(vcpu, -7);
}
/* Skip the 4-bytes "mov" */
- MOVE_RIP(7);
+ vcpu_skip_insn(vcpu, 7);

/* Test single step */
target_rip = CAST_TO_RIP(ss_start);
target_dr6 = 0xffff4ff0ULL;
- vcpu_regs_get(vm, vcpu->id, &regs);
for (i = 0; i < (sizeof(ss_size) / sizeof(ss_size[0])); i++) {
target_rip += ss_size[i];
memset(&debug, 0, sizeof(debug));
--
2.36.0.464.gb9c8b46e94-goog