Ilya Voronin sent a diff to misc to limit MSR_INT_PEN_MSG use to < AMD family 17h prompted by a problem with an AWS t3a instance.
https://marc.info/?l=openbsd-misc&m=162120066715633&w=2 Digging some more the 16h bkdgs have it as RAZ/non-functional as well. Bits are documented in 15h. BKDG for AMD Family 16h Models 00h-0Fh Processors MSRC001_0055 Interrupt Pending 63:0 RAZ. BKDG for AMD Family 16h Models 30h-3Fh Processors MSRC001_0055 Interrupt Pending 63:0 RAZ PPR for AMD Family 17h Model 71h B0 MSRC001_0055 [Reserved.] (Core::X86::Msr::IntPend) Read-only. Reset: Fixed,0000_0000_0000_0000h. Change the test to use extended family id while here. Index: sys/arch/amd64/amd64/lapic.c =================================================================== RCS file: /cvs/src/sys/arch/amd64/amd64/lapic.c,v retrieving revision 1.57 diff -u -p -r1.57 lapic.c --- sys/arch/amd64/amd64/lapic.c 6 Sep 2020 20:50:00 -0000 1.57 +++ sys/arch/amd64/amd64/lapic.c 19 May 2021 09:16:37 -0000 @@ -299,8 +299,7 @@ lapic_set_lvt(void) * Family 0Fh Processors" * #32559 revision 3.00 */ - if ((cpu_id & 0x00000f00) == 0x00000f00 && - (cpu_id & 0x0fff0000) >= 0x00040000) { + if (ci->ci_family >= 0xf && ci->ci_family < 0x16) { uint64_t msr; msr = rdmsr(MSR_INT_PEN_MSG); Index: sys/arch/i386/i386/lapic.c =================================================================== RCS file: /cvs/src/sys/arch/i386/i386/lapic.c,v retrieving revision 1.47 diff -u -p -r1.47 lapic.c --- sys/arch/i386/i386/lapic.c 30 Jul 2018 14:19:12 -0000 1.47 +++ sys/arch/i386/i386/lapic.c 19 May 2021 09:19:41 -0000 @@ -160,8 +160,7 @@ lapic_set_lvt(void) * Family 0Fh Processors" * #32559 revision 3.00 */ - if ((cpu_id & 0x00000f00) == 0x00000f00 && - (cpu_id & 0x0fff0000) >= 0x00040000) { + if (ci->ci_family >= 0xf && ci->ci_family < 0x16) { uint64_t msr; msr = rdmsr(MSR_INT_PEN_MSG);
