Re: [PATCH v2 00/35] acpi: refactor error prone build_header() and packed structures usage in ACPI tables

[Igor Mammedov]

On Tue, 13 Jul 2021 11:45:46 -0400
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> On Thu, Jul 08, 2021 at 11:45:42AM -0400, Igor Mammedov wrote:
> > v2:
> >   - drop test related patches, they will be sent as a separate series
> >   - fix bios_loader pointer initialization ordering when using TPM1.2
> >   - extend commit message of [1/35] and add extra comment about
> >     table length patching   
> 
> 
> So I think this is in good shape, and I really like the code size
> reduction. Given a rush to push things before the freeze, I'm inclined
> to just defer API rework to the next release. This kind of thing is
> better at the beginning of the cycle so we can iron out API kinks if any
> surface.

ok, I'll respin once another merge window is open.

As for tests part, that I dropped, should I repost it
for merging during soft-freeze or we postpone that as well?

> 
> > Highlights:
> >   * drop pointer arithmetic in ACPI tables code
> >   * use endian agnostic API
> >   * simplifies review of tables. /in most cases just line by line 
> > comparision with spec/
> > 
> > Series replaces build_header() with acpi_init_table()/acpi_table_composed()
> > API that hides pointer/offset arithmetic from user, to prevent
> > errors caused by it [1].
> > While doing above, it was necessary to split table header from
> > packed structure that was describing the table, which is
> > counter-productive since it still leaves packed structure drawbacks.
> > So that sort of forced me to rewrite tables that were composed with
> > help of packed structures to preferred build_append_int_noprefix() API.
> > In cases where refactoring to build_append_int_noprefix() was small,
> > it was squashed with acpi_init_table()/acpi_table_composed() patch.
> > Conversion reduced code size quite a bit despite me adding doc comments
> > for every table row.
> > 
> > 1) commits
> >    bb9feea43179 x86: acpi: use offset instead of pointer when using 
> > build_header()
> >    4d027afeb3a9 Virt: ACPI: fix qemu assert due to re-assigned table data 
> > address
> > 
> > Link to repo:
> >    
> > https://gitlab.com/imammedo/qemu/-/commits/acpi_build_header_refactoring_v2
> > 
> > CC: mst@redhat.com
> > 
> > 
> > 
> > Igor Mammedov (35):
> >   acpi: add helper routines to initialize ACPI tables
> >   acpi: build_rsdt: use acpi_init_table()/acpi_table_composed() instead
> >     of build_header()
> >   acpi: build_xsdt: use acpi_init_table()/acpi_table_composed() instead
> >     of build_header()
> >   acpi: build_slit: use acpi_init_table()/acpi_table_composed() instead
> >     of build_header()
> >   acpi: build_fadt: use acpi_init_table()/acpi_table_composed() instead
> >     of build_header()
> >   acpi: build_tpm2: use acpi_init_table()/acpi_table_composed() instead
> >     of build_header()
> >   acpi: acpi_build_hest: use acpi_init_table()/acpi_table_composed()
> >     instead of build_header()
> >   acpi: build_mcfg: use acpi_init_table()/acpi_table_composed() instead
> >     of build_header()
> >   acpi: build_hmat: use acpi_init_table()/acpi_table_composed() instead
> >     of build_header()
> >   acpi: nvdimm_build_nfit: use acpi_init_table()/acpi_table_composed()
> >     instead of build_header()
> >   acpi: nvdimm_build_ssdt: use acpi_init_table()/acpi_table_composed()
> >     instead of build_header()
> >   acpi: vmgenid_build_acpi: use acpi_init_table()/acpi_table_composed()
> >     instead of build_header()
> >   acpi: x86: build_dsdt: use acpi_init_table()/acpi_table_composed()
> >     instead of build_header()
> >   acpi: build_hpet: use acpi_init_table()/acpi_table_composed() instead
> >     of build_header()
> >   acpi: build_tpm_tcpa: use acpi_init_table()/acpi_table_composed()
> >     instead of build_header()
> >   acpi: arm/x86: build_srat: use acpi_init_table()/acpi_table_composed()
> >     instead of build_header()
> >   acpi: use build_append_int_noprefix() API to compose SRAT table
> >   acpi: build_dmar_q35: use acpi_init_table()/acpi_table_composed()
> >     instead of build_header()
> >   acpi: build_waet: use acpi_init_table()/acpi_table_composed() instead
> >     of build_header()
> >   acpi: build_amd_iommu: use acpi_init_table()/acpi_table_composed()
> >     instead of build_header()
> >   acpi: madt: arm/x86: use acpi_init_table()/acpi_table_composed()
> >     instead of build_header()
> >   acpi: x86: remove dead code
> >   acpi: x86: set enabled when composing _MAT entries
> >   acpi: x86: madt: use build_append_int_noprefix() API to compose MADT
> >     table
> >   acpi: arm/virt: madt: use build_append_int_noprefix() API to compose
> >     MADT table
> >   acpi: build_dsdt_microvm: use acpi_init_table()/acpi_table_composed()
> >     instead of build_header()
> >   acpi: arm: virt: build_dsdt: use
> >     acpi_init_table()/acpi_table_composed() instead of build_header()
> >   acpi: arm: virt: build_iort: use
> >     acpi_init_table()/acpi_table_composed() instead of build_header()
> >   acpi: arm/virt: convert build_iort() to endian agnostic
> >     build_append_FOO() API
> >   acpi: arm/virt: build_spcr: fix invalid cast
> >   acpi: arm/virt: build_spcr: use
> >     acpi_init_table()/acpi_table_composed() instead of build_header()
> >   acpi: arm/virt: build_gtdt: use
> >     acpi_init_table()/acpi_table_composed() instead of build_header()
> >   acpi: build_facs: use build_append_int_noprefix() API to compose table
> >   acpi: remove no longer used build_header()
> >   acpi: AcpiGenericAddress no longer used to map/access fields of MMIO,
> >     drop packed attribute
> > 
> >  include/hw/acpi/acpi-defs.h          | 528 +------------------------
> >  include/hw/acpi/acpi_dev_interface.h |   3 +-
> >  include/hw/acpi/aml-build.h          |  21 +-
> >  include/hw/i386/pc.h                 |   7 +-
> >  hw/acpi/acpi-x86-stub.c              |   3 +-
> >  hw/acpi/aml-build.c                  | 193 ++++++----
> >  hw/acpi/cpu.c                        |  17 +-
> >  hw/acpi/ghes.c                       |  10 +-
> >  hw/acpi/hmat.c                       |  14 +-
> >  hw/acpi/nvdimm.c                     |  64 ++--
> >  hw/acpi/pci.c                        |  18 +-
> >  hw/acpi/vmgenid.c                    |  16 +-
> >  hw/arm/virt-acpi-build.c             | 550 +++++++++++++++------------
> >  hw/i386/acpi-build.c                 | 284 ++++++++------
> >  hw/i386/acpi-common.c                | 158 ++++----
> >  hw/i386/acpi-microvm.c               |  13 +-
> >  16 files changed, 750 insertions(+), 1149 deletions(-)
> > 
> > -- 
> > 2.27.0  
>