From: Dan Carpenter <dan.carpenter@oracle.com>
To: jroedel@suse.de
Cc: kvm@vger.kernel.org
Subject: [bug report] x86/sev: Split up runtime #VC handler for correct state tracking
Date: Wed, 4 Aug 2021 12:57:25 +0300 [thread overview]
Message-ID: <20210804095725.GA8011@kili> (raw)
Hello Joerg Roedel,
The patch be1a5408868a: "x86/sev: Split up runtime #VC handler for
correct state tracking" from Jun 18, 2021, leads to the following
static checker warning:
arch/x86/kernel/kvm.c:153 kvm_async_pf_task_wait_schedule()
warn: sleeping in atomic context
arch/x86/kernel/sev.c
1416 * Handle #DB before calling into !noinstr code to avoid recursive #DB.
1417 */
1418 if (vc_is_db(error_code)) {
1419 exc_debug(regs);
1420 return;
1421 }
1422
1423 irq_state = irqentry_nmi_enter(regs);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
preempt disabled inside irqentry_nmi_enter().
1424
1425 instrumentation_begin();
1426
1427 if (!vc_raw_handle_exception(regs, error_code)) {
^^^^^^^^^^^^^^^^^^^^^^^^
These sleeping in atomic static checker warnings come with a lot of
caveats because the call tree is very long and it's easy to have false
positives.
--> vc_raw_handle_exception()
--> vc_forward_exception()
--> exc_page_fault()
Page faults always sleep right?
1428 /* Show some debug info */
1429 show_regs(regs);
1430
1431 /* Ask hypervisor to sev_es_terminate */
1432 sev_es_terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
1433
1434 /* If that fails and we get here - just panic */
1435 panic("Returned from Terminate-Request to Hypervisor\n");
1436 }
1437
1438 instrumentation_end();
1439 irqentry_nmi_exit(regs, irq_state);
1440 }
regards,
dan carpenter
next reply other threads:[~2021-08-04 9:57 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-04 9:57 Dan Carpenter [this message]
2021-08-04 12:38 ` [bug report] x86/sev: Split up runtime #VC handler for correct state tracking Joerg Roedel
2021-08-04 12:58 ` Dan Carpenter
2021-08-04 13:35 ` Joerg Roedel
2021-08-04 13:42 ` Dan Carpenter
2021-08-04 14:23 ` Joerg Roedel
2021-08-06 8:35 ` Dan Carpenter
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