diff options
author | Michal Luczaj <mhal@rbox.co> | 2023-07-28 02:12:58 +0200 |
---|---|---|
committer | Sean Christopherson <seanjc@google.com> | 2023-08-02 13:33:20 -0700 |
commit | 0de704d2d6c82c7498fa1b8df66903f8139e3de2 (patch) | |
tree | 74a66deef7d82bdcec527f4206bdecde2b5ec852 /tools/testing/selftests | |
parent | 60c4063b475215321fc63ab253c9a840bb664f35 (diff) |
KVM: selftests: Extend x86's sync_regs_test to check for exception races
Attempt to set the to-be-queued exception to be both pending and injected
_after_ KVM_CAP_SYNC_REGS's kvm_vcpu_ioctl_x86_set_vcpu_events() squashes
the pending exception (if there's also an injected exception). Buggy KVM
versions will eventually yell loudly about having impossible state when
processing queued excpetions, e.g.
WARNING: CPU: 0 PID: 1115 at arch/x86/kvm/x86.c:10095 kvm_check_and_inject_events+0x220/0x500 [kvm]
arch/x86/kvm/x86.c:kvm_check_and_inject_events():
WARN_ON_ONCE(vcpu->arch.exception.injected &&
vcpu->arch.exception.pending);
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://lore.kernel.org/r/20230728001606.2275586-3-mhal@rbox.co
[sean: split to separate patch, massage changelog and comment]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'tools/testing/selftests')
-rw-r--r-- | tools/testing/selftests/kvm/x86_64/sync_regs_test.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/sync_regs_test.c b/tools/testing/selftests/kvm/x86_64/sync_regs_test.c index e4ff2eaad7cd..7e5b13869e2e 100644 --- a/tools/testing/selftests/kvm/x86_64/sync_regs_test.c +++ b/tools/testing/selftests/kvm/x86_64/sync_regs_test.c @@ -82,6 +82,28 @@ static void compare_vcpu_events(struct kvm_vcpu_events *left, #define INVALID_SYNC_FIELD 0x80000000 /* + * Set an exception as pending *and* injected while KVM is processing events. + * KVM is supposed to ignore/drop pending exceptions if userspace is also + * requesting that an exception be injected. + */ +static void *race_events_inj_pen(void *arg) +{ + struct kvm_run *run = (struct kvm_run *)arg; + struct kvm_vcpu_events *events = &run->s.regs.events; + + for (;;) { + WRITE_ONCE(run->kvm_dirty_regs, KVM_SYNC_X86_EVENTS); + WRITE_ONCE(events->flags, 0); + WRITE_ONCE(events->exception.injected, 1); + WRITE_ONCE(events->exception.pending, 1); + + pthread_testcancel(); + } + + return NULL; +} + +/* * Set an invalid exception vector while KVM is processing events. KVM is * supposed to reject any vector >= 32, as well as NMIs (vector 2). */ @@ -311,6 +333,7 @@ int main(int argc, char *argv[]) race_sync_regs(race_sregs_cr4); race_sync_regs(race_events_exc); + race_sync_regs(race_events_inj_pen); return 0; } |