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Re: [Qemu-devel] [PATCH 23/31] ich9: implement SMI_LOCK
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH 23/31] ich9: implement SMI_LOCK |
Date: |
Mon, 11 May 2015 17:21:34 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 |
On 11/05/2015 17:17, Laszlo Ersek wrote:
> If I understand correctly, this makes SMI_LOCK lock down the GBL_SMI_EN
> bit (and my OVMF patch that relies on that / tests it is satisfied too).
>
> But, it doesn't seem to lock down APMC_EN. According to the ICH9 spec,
> it doesn't need to -- however when we discussed this earlier (see
> Message-Id: <address@hidden>), the idea was to lock down
> APMC_EN as well. (And I don't understand why the ICH9 spec / hw
> implementation doesn't lock APMC_EN; without that, APM_CNT won't
> necessarily trigger an SMI.)
I don't think it should. See here
<https://lists.gnu.org/archive/html/qemu-devel/2015-04/msg02758.html>
where I wrote explicitly "Even if the OS tries to maliciously set
APMC_EN to 0 (SMI_LOCK doesn't lock APMC_EN)...".
Paolo
- [Qemu-devel] [PATCH 16/31] hw/i386: remove smram_update, (continued)
- [Qemu-devel] [PATCH 16/31] hw/i386: remove smram_update, Paolo Bonzini, 2015/05/11
- [Qemu-devel] [PATCH 17/31] q35: implement high SMRAM, Paolo Bonzini, 2015/05/11
- [Qemu-devel] [PATCH 18/31] q35: fix ESMRAMC default, Paolo Bonzini, 2015/05/11
- [Qemu-devel] [PATCH 19/31] q35: add config space wmask for SMRAM and ESMRAMC, Paolo Bonzini, 2015/05/11
- [Qemu-devel] [PATCH 22/31] q35: implement TSEG, Paolo Bonzini, 2015/05/11
- [Qemu-devel] [PATCH 21/31] q35: add test for SMRAM.D_LCK, Paolo Bonzini, 2015/05/11
- [Qemu-devel] [PATCH 23/31] ich9: implement SMI_LOCK, Paolo Bonzini, 2015/05/11
- Re: [Qemu-devel] [PATCH 23/31] ich9: implement SMI_LOCK, Gerd Hoffmann, 2015/05/12
[Qemu-devel] [PATCH 24/31] hw/acpi: acpi_pm1_cnt_init(): take "disable_s3" and "disable_s4", Paolo Bonzini, 2015/05/11
[Qemu-devel] [PATCH 25/31] hw/acpi: move "etc/system-states" fw_cfg file from PIIX4 to core, Paolo Bonzini, 2015/05/11
[Qemu-devel] [PATCH 26/31] hw/acpi: piix4_pm_init(): take fw_cfg object no more, Paolo Bonzini, 2015/05/11
[Qemu-devel] [PATCH 28/31] vga: disable chain4_alias if KVM supports SMRAM, Paolo Bonzini, 2015/05/11
[Qemu-devel] [PATCH 29/31] pc_piix: rename kvm_enabled to smm_enabled, Paolo Bonzini, 2015/05/11
[Qemu-devel] [PATCH 27/31] target-i386: add support for SMBASE MSR and SMIs, Paolo Bonzini, 2015/05/11