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| author |   Paolo Bonzini <pbonzini@redhat.com> | 2020-05-06 05:59:39 -0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-05-08 07:44:31 -0400 |
| commit | 45981dedf555bd66d86ccb51e4049d9f7ec45bd5 (patch) | |
| tree | b900146bb6cabb366b4cdb1219704caf7d5006b9 /tools/testing/selftests/kvm | |
| parent | KVM: x86, SVM: isolate vcpu->arch.dr6 from vmcb->save.dr6 (diff) | |
| download | wireguard-linux-45981dedf555bd66d86ccb51e4049d9f7ec45bd5.tar.xz wireguard-linux-45981dedf555bd66d86ccb51e4049d9f7ec45bd5.zip | |
KVM: VMX: pass correct DR6 for GD userspace exit
When KVM_EXIT_DEBUG is raised for the disabled-breakpoints case (DR7.GD),
DR6 was incorrectly copied from the value in the VM. Instead,
DR6.BD should be set in order to catch this case.
On AMD this does not need any special code because the processor triggers
a #DB exception that is intercepted. However, the testcase would fail
without the previous patch because both DR6.BS and DR6.BD would be set.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'tools/testing/selftests/kvm')
| -rw-r--r-- | tools/testing/selftests/kvm/x86_64/debug_regs.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/debug_regs.c b/tools/testing/selftests/kvm/x86_64/debug_regs.c index 077f25d61d1a..8162c58a1234 100644 --- a/tools/testing/selftests/kvm/x86_64/debug_regs.c +++ b/tools/testing/selftests/kvm/x86_64/debug_regs.c @@ -11,10 +11,13 @@ #define VCPU_ID 0 +#define DR6_BD (1 << 13) +#define DR7_GD (1 << 13) + /* For testing data access debug BP */ uint32_t guest_value; -extern unsigned char sw_bp, hw_bp, write_data, ss_start; +extern unsigned char sw_bp, hw_bp, write_data, ss_start, bd_start; static void guest_code(void) { @@ -43,6 +46,8 @@ static void guest_code(void) "rdmsr\n\t" : : : "rax", "ecx"); + /* DR6.BD test */ + asm volatile("bd_start: mov %%dr0, %%rax" : : : "rax"); GUEST_DONE(); } @@ -165,6 +170,23 @@ int main(void) target_dr6); } + /* Finally test global disable */ + CLEAR_DEBUG(); + debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP; + debug.arch.debugreg[7] = 0x400 | DR7_GD; + APPLY_DEBUG(); + vcpu_run(vm, VCPU_ID); + 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); + /* Disable all debug controls, run to the end */ CLEAR_DEBUG(); APPLY_DEBUG(); |