Re: [PATCH v8 07/10] ACPI ERST: create ACPI ERST table for pc/x86 machines

["Michael S. Tsirkin" <mst@redhat.com>]

On Sat, Oct 23, 2021 at 07:52:21AM +0530, Ani Sinha wrote:
> 
> 
> On Fri, 22 Oct 2021, Eric DeVolder wrote:
> 
> > Ani, inline below.
> > eric
> >
> > On 10/22/21 05:18, Ani Sinha wrote:
> > >
> > >
> > > On Fri, 15 Oct 2021, Eric DeVolder wrote:
> > >
> > > > This change exposes ACPI ERST support for x86 guests.
> > > >
> > > > Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
> > > > ---
> > > >   hw/i386/acpi-build.c   | 9 +++++++++
> > > >   hw/i386/acpi-microvm.c | 9 +++++++++
> > > >   include/hw/acpi/erst.h | 5 +++++
> > > >   3 files changed, 23 insertions(+)
> > > >
> > > > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> > > > index 81418b7..9c2f9d9 100644
> > > > --- a/hw/i386/acpi-build.c
> > > > +++ b/hw/i386/acpi-build.c
> > > > @@ -43,6 +43,7 @@
> > > >   #include "sysemu/tpm.h"
> > > >   #include "hw/acpi/tpm.h"
> > > >   #include "hw/acpi/vmgenid.h"
> > > > +#include "hw/acpi/erst.h"
> > > >   #include "sysemu/tpm_backend.h"
> > > >   #include "hw/rtc/mc146818rtc_regs.h"
> > > >   #include "migration/vmstate.h"
> > > > @@ -2499,6 +2500,7 @@ void acpi_build(AcpiBuildTables *tables,
> > > > MachineState *machine)
> > > >       GArray *tables_blob = tables->table_data;
> > > >       AcpiSlicOem slic_oem = { .id = NULL, .table_id = NULL };
> > > >       Object *vmgenid_dev;
> > > > +    Object *erst_dev;
> > > >       char *oem_id;
> > > >       char *oem_table_id;
> > > >
> > > > @@ -2560,6 +2562,13 @@ void acpi_build(AcpiBuildTables *tables,
> > > > MachineState *machine)
> > > >                       ACPI_DEVICE_IF(x86ms->acpi_dev), x86ms->oem_id,
> > > >                       x86ms->oem_table_id);
> > > >
> > > > +    erst_dev = find_erst_dev();
> > > > +    if (erst_dev) {
> > > > +        acpi_add_table(table_offsets, tables_blob);
> > > > +        build_erst(tables_blob, tables->linker, erst_dev,
> > > > +                   x86ms->oem_id, x86ms->oem_table_id);
> > > > +    }
> > > > +
> > >
> > > This needs to be ifdef'd between CONFIG_ERST.
> > ok
> >
> > >
> > >
> > > >       vmgenid_dev = find_vmgenid_dev();
> > > >       if (vmgenid_dev) {
> > > >           acpi_add_table(table_offsets, tables_blob);
> > > > diff --git a/hw/i386/acpi-microvm.c b/hw/i386/acpi-microvm.c
> > >
> > > I do not think we need to include this for microvm machines. They are
> > > supposed to have minimal ACPUI support. So lets not bloat it unless there
> > > is a specific requirement to support ERST on microvms as well.
> > Would it be ok if I ifdef this on CONFIG_ERST also?
> 
> I think we should not touch microvm machine unless you can justify why you
> need ERST support there.

OTOH why not? No idea... CC microvm maintainers and let them decide.

> >
> > >
> > >
> > > > index 196d318..662c8ad 100644
> > > > --- a/hw/i386/acpi-microvm.c
> > > > +++ b/hw/i386/acpi-microvm.c
> > > > @@ -30,6 +30,7 @@
> > > >   #include "hw/acpi/bios-linker-loader.h"
> > > >   #include "hw/acpi/generic_event_device.h"
> > > >   #include "hw/acpi/utils.h"
> > > > +#include "hw/acpi/erst.h"
> > > >   #include "hw/i386/fw_cfg.h"
> > > >   #include "hw/i386/microvm.h"
> > > >   #include "hw/pci/pci.h"
> > > > @@ -158,6 +159,7 @@ static void acpi_build_microvm(AcpiBuildTables
> > > > *tables,
> > > >       X86MachineState *x86ms = X86_MACHINE(mms);
> > > >       GArray *table_offsets;
> > > >       GArray *tables_blob = tables->table_data;
> > > > +    Object *erst_dev;
> > > >       unsigned dsdt, xsdt;
> > > >       AcpiFadtData pmfadt = {
> > > >           /* ACPI 5.0: 4.1 Hardware-Reduced ACPI */
> > > > @@ -207,6 +209,13 @@ static void acpi_build_microvm(AcpiBuildTables
> > > > *tables,
> > > >                       ACPI_DEVICE_IF(x86ms->acpi_dev), x86ms->oem_id,
> > > >                       x86ms->oem_table_id);
> > > >
> > > > +    erst_dev = find_erst_dev();
> > > > +    if (erst_dev) {
> > > > +        acpi_add_table(table_offsets, tables_blob);
> > > > +        build_erst(tables_blob, tables->linker, erst_dev,
> > > > +                   x86ms->oem_id, x86ms->oem_table_id);
> > > > +    }
> > > > +
> > >
> > >
> > >
> > > >       xsdt = tables_blob->len;
> > > >       build_xsdt(tables_blob, tables->linker, table_offsets,
> > > > x86ms->oem_id,
> > > >                  x86ms->oem_table_id);
> > > > diff --git a/include/hw/acpi/erst.h b/include/hw/acpi/erst.h
> > > > index 9d63717..b747fe7 100644
> > > > --- a/include/hw/acpi/erst.h
> > > > +++ b/include/hw/acpi/erst.h
> > > > @@ -16,4 +16,9 @@ void build_erst(GArray *table_data, BIOSLinker *linker,
> > > > Object *erst_dev,
> > > >
> > > >   #define TYPE_ACPI_ERST "acpi-erst"
> > > >
> > > > +/* returns NULL unless there is exactly one device */
> > > > +static inline Object *find_erst_dev(void)
> > > > +{
> > > > +    return object_resolve_path_type("", TYPE_ACPI_ERST, NULL);
> > > > +}
> > > >   #endif
> > > > --
> > > > 1.8.3.1
> > > >
> > > >
> >