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Re: [Qemu-devel] [PATCH v2] Add ACPI tables for TPM
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [PATCH v2] Add ACPI tables for TPM |
Date: |
Wed, 30 Jul 2014 17:25:25 +0200 |
On Wed, Jul 30, 2014 at 11:13:07AM -0400, Stefan Berger wrote:
> "Michael S. Tsirkin" <address@hidden> wrote on 07/30/2014 11:07:28 AM:
>
>
> > > >If you need bios to allocate this memory, then we will
> > > >need a new allocation type for this, add it to linker
> > > >in bios and qemu.
> > >
> > > Why does the BIOS 'need' to allocate it? Why can it not just use the
> > > memory
> > > that QEMU allocates? Obviously I am using the 'pointer relocation' feature
> > > of the BIOS to bend the pointer in the TCPA table to this log area.
> >
> > You tell me - your patches make BIOS allocate it.
>
> No, the BIOS does not allocate it, it merely relocates the pointer.
Yes it does :)
You pushed the log as part of the table_data which bios
allocates memory for, and reads from QEMU.
> One example here:
>
> fadt->firmware_ctrl = cpu_to_le32(facs);
> /* FACS address to be filled by Guest linker */
> bios_linker_loader_add_pointer(linker, ACPI_BUILD_TABLE_FILE,
> ACPI_BUILD_TABLE_FILE,
> table_data, &fadt->firmware_ctrl,
> sizeof fadt->firmware_ctrl);
>
> similar example here:
>
> log_area_start_address = table_data->len + sizeof(*tcpa);
>
> [...]
> tcpa->log_area_start_address = cpu_to_le64(log_area_start_address);
>
> /* LASA address to be filled by Guest linker */
> bios_linker_loader_add_pointer(linker, ACPI_BUILD_TABLE_FILE,
> ACPI_BUILD_TABLE_FILE,
> table_data, &tcpa->log_area_start_address,
> sizeof(tcpa->log_area_start_address));
>
>
>
> Stefan
It relocates it to within the table that it allocated.
- Re: [Qemu-devel] [PATCH v2] Add ACPI tables for TPM, (continued)
- Re: [Qemu-devel] [PATCH v2] Add ACPI tables for TPM, Michael S. Tsirkin, 2014/07/30
- Re: [Qemu-devel] [PATCH v2] Add ACPI tables for TPM, Stefan Berger, 2014/07/30
- Re: [Qemu-devel] [PATCH v2] Add ACPI tables for TPM, Michael S. Tsirkin, 2014/07/30
- Re: [Qemu-devel] [PATCH v2] Add ACPI tables for TPM, Laszlo Ersek, 2014/07/30
- Re: [Qemu-devel] [PATCH v2] Add ACPI tables for TPM, Michael S. Tsirkin, 2014/07/30
Re: [Qemu-devel] [PATCH v2] Add ACPI tables for TPM, Stefan Berger, 2014/07/30