diff options
| author | Philip Guenther <guenther@cvs.openbsd.org> | 2019-05-28 18:17:02 +0000 |
|---|---|---|
| committer | Philip Guenther <guenther@cvs.openbsd.org> | 2019-05-28 18:17:02 +0000 |
| commit | 9346d4a4d60a7c5f07f6457f818fa50d79dbfbbd (patch) | |
| tree | 1e28096638238012a318cd153793be6ca32f6106 /sys | |
| parent | ae2b6f2415ab8e5ee4725e0542759715291fb4e6 (diff) | |
Skip doing MDS mitigation on vmm entry if the new firmware is present,
as it enhances the L1D_FLUSH MSR to flush MDS too
ok mlarkin@
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/arch/amd64/amd64/cpu.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/sys/arch/amd64/amd64/cpu.c b/sys/arch/amd64/amd64/cpu.c index e14c8eaa9b0..8d51216ba0b 100644 --- a/sys/arch/amd64/amd64/cpu.c +++ b/sys/arch/amd64/amd64/cpu.c @@ -1,4 +1,4 @@ -/* $OpenBSD: cpu.c,v 1.136 2019/05/18 18:11:46 guenther Exp $ */ +/* $OpenBSD: cpu.c,v 1.137 2019/05/28 18:17:01 guenther Exp $ */ /* $NetBSD: cpu.c,v 1.1 2003/04/26 18:39:26 fvdl Exp $ */ /*- @@ -299,14 +299,23 @@ replacemds(void) } if (handler != NULL) { - printf("cpu0: using %s MDS workaround\n", type); + printf("cpu0: using %s MDS workaround%s\n", type, ""); s = splhigh(); codepatch_call(CPTAG_MDS, handler); codepatch_call(CPTAG_MDS_VMM, vmm_handler); splx(s); - } else if (has_verw) - printf("cpu0: using %s MDS workaround\n", "VERW"); - else { + } else if (has_verw) { + /* The new firmware enhances L1D_FLUSH MSR to flush MDS too */ + if (cpu_info_primary.ci_vmm_cap.vcc_vmx.vmx_has_l1_flush_msr == 1) { + s = splhigh(); + codepatch_nop(CPTAG_MDS_VMM); + splx(s); + type = " (except on vmm entry)"; + } else { + type = ""; + } + printf("cpu0: using %s MDS workaround%s\n", "VERW", type); + } else { s = splhigh(); codepatch_nop(CPTAG_MDS); codepatch_nop(CPTAG_MDS_VMM); |