The branch stable/14 has been updated by jtl: URL: https://cgit.FreeBSD.org/src/commit/?id=40b2111cfaa1ea9c7ae3487e536e8f75debba700
commit 40b2111cfaa1ea9c7ae3487e536e8f75debba700 Author: Loic Prylli <[email protected]> AuthorDate: 2025-10-06 17:59:41 +0000 Commit: Jonathan T. Looney <[email protected]> CommitDate: 2025-10-28 19:24:31 +0000 x86: Add a way to inject artificial MCA events for testing Reviewed by: glebius Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D52942 (cherry picked from commit 1c2fc62e4a9689961169be7836038acd5f757be1) --- sys/x86/x86/mca.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/sys/x86/x86/mca.c b/sys/x86/x86/mca.c index efe1524eb0e7..a167854e8bbb 100644 --- a/sys/x86/x86/mca.c +++ b/sys/x86/x86/mca.c @@ -125,6 +125,17 @@ SYSCTL_INT(_hw_mca, OID_AUTO, erratum383, CTLFLAG_RDTUN, &workaround_erratum383, 0, "Is the workaround for Erratum 383 on AMD Family 10h processors enabled?"); +#ifdef DIAGNOSTIC +static uint64_t fake_status; +SYSCTL_U64(_hw_mca, OID_AUTO, fake_status, CTLFLAG_RW, + &fake_status, 0, + "Insert artificial MCA with given status (testing purpose only)"); +static int fake_bank; +SYSCTL_INT(_hw_mca, OID_AUTO, fake_bank, CTLFLAG_RW, + &fake_bank, 0, + "Bank to use for artificial MCAs (testing purpose only)"); +#endif + static STAILQ_HEAD(, mca_internal) mca_freelist; static int mca_freecount; static STAILQ_HEAD(, mca_internal) mca_records; @@ -783,8 +794,24 @@ mca_check_status(enum scan_mode mode, uint64_t mcg_cap, int bank, bool mce, recover; status = rdmsr(mca_msr_ops.status(bank)); - if (!(status & MC_STATUS_VAL)) + if (!(status & MC_STATUS_VAL)) { +#ifdef DIAGNOSTIC + /* + * Check if we have a pending artificial event to generate. + * Note that this is potentially racy with the sysctl. The + * tradeoff is deemed acceptable given the test nature + * of the code. + */ + if (fake_status && bank == fake_bank) { + status = fake_status; + fake_status = 0; + } + if (!(status & MC_STATUS_VAL)) + return (0); +#else return (0); +#endif + } recover = *recoverablep; mce = mca_is_mce(mcg_cap, status, &recover);
