From 7d6362d56bfc5018b59da98e6d1a295a4cbf899b Mon Sep 17 00:00:00 2001 From: Angel Pons Date: Thu, 11 May 2023 16:53:47 +0200 Subject: mb/prodrive/hermes: Ensure VMX setting is applied VMX is enabled through a bit in the IA32_FEATURE_CONTROL MSR, which can be locked. The MSR remains locked after a non-power cycle reset, though. If the MSR is locked, coreboot bails out and leaves VMX in the state it was found. Because of this, changes to the VMX enable option in the BMC only take effect after the system is power cycled. This behaviour is highly undesirable because users are likely not aware that a power cycle is required for changes to VMX state to take effect. So, if VMX is supported, the IA32_FEATURE_CONTROL MSR is locked and the current VMX state does not match the requested state, then issue a full reset. This will power cycle the system and unlock the MSR, so that the desired VMX state can be programmed into the MSR. This is checked early to avoid needlessly doing time-consuming operations (running FSP) twice if we know we will need to power cycle the system anyway. Note that a user may change the VMX setting after the newly-added check but before the setting is read in ramstage to program the MSR, but this is a non-issue as firmware settings need a reset to take effect anyway. TEST: Toggle VMX setting in BMC and reboot without power cycle, observe coreboot automatically issues a power cycle reset because the MSR is locked and the VMX state differs. Verify that the system boots properly with VMX in the correct state after having power cycled. Change-Id: Id9061ba896a7062da45a86fb26eeb58927184dcb Signed-off-by: Angel Pons Reviewed-on: https://review.coreboot.org/c/coreboot/+/75141 Tested-by: build bot (Jenkins) Reviewed-by: Lean Sheng Tan --- src/mainboard/prodrive/hermes/romstage.c | 37 +++++++++++++++++++++++++++++++- 1 file changed, 36 insertions(+), 1 deletion(-) (limited to 'src') diff --git a/src/mainboard/prodrive/hermes/romstage.c b/src/mainboard/prodrive/hermes/romstage.c index 985342678a..a479bd51af 100644 --- a/src/mainboard/prodrive/hermes/romstage.c +++ b/src/mainboard/prodrive/hermes/romstage.c @@ -1,7 +1,12 @@ /* SPDX-License-Identifier: GPL-2.0-only */ +#include +#include +#include +#include #include #include +#include #include "eeprom.h" @@ -40,14 +45,44 @@ static const struct cnl_mb_cfg baseboard_mem_cfg = { .ect = 0, }; +static bool vmx_needs_full_reset(const bool enable_vmx) +{ + const uint32_t feature_flag = cpu_get_feature_flags_ecx(); + + if (!(feature_flag & (CPUID_VMX | CPUID_SMX))) { + /* CPU does not support VMX, no reset needed */ + return false; + } + + const msr_t msr = rdmsr(IA32_FEATURE_CONTROL); + + const bool msr_locked = msr.lo & (1 << 0); + const bool vmx_enabled = msr.lo & (1 << 2); + + /* Reset if the MSR is locked and VMX state does not match requested state */ + return msr_locked && (vmx_enabled != enable_vmx); +} + void mainboard_memory_init_params(FSPM_UPD *memupd) { + const struct eeprom_board_settings *board_cfg = get_board_settings(); + + /* + * IA32_FEATURE_CONTROL is only unlocked by a full reset. + * Check early to avoid wasting time if we need to reset. + */ + const bool enable_vmx = !board_cfg->vtx_disabled; + if (vmx_needs_full_reset(enable_vmx)) { + printk(BIOS_INFO, "IA32_FEATURE_CONTROL locked; full reset needed to %s VMX\n", + enable_vmx ? "enable" : "disable"); + full_reset(); + } + memupd->FspmConfig.UserBd = BOARD_TYPE_SERVER; memupd->FspmTestConfig.SmbusSpdWriteDisable = 0; cannonlake_memcfg_init(&memupd->FspmConfig, &baseboard_mem_cfg); /* Tell FSP-M about the desired primary video adapter so that GGC is set up properly */ - const struct eeprom_board_settings *board_cfg = get_board_settings(); if (board_cfg && board_cfg->primary_video == PRIMARY_VIDEO_INTEL) memupd->FspmConfig.PrimaryDisplay = 0; /* iGPU is primary */ -- cgit v1.2.3