Re: [PATCH v5 06/10] ACPI ERST: build the ACPI ERST table

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 21 Jul 2021 11:12:41 -0500
Eric DeVolder <eric.devolder@oracle.com> wrote:

> On 7/20/21 8:16 AM, Igor Mammedov wrote:
> > On Wed, 30 Jun 2021 15:07:17 -0400
> > Eric DeVolder <eric.devolder@oracle.com> wrote:
> >   
> >> This code is called from the machine code (if ACPI supported)
> >> to generate the ACPI ERST table.  
> > should be along lines:
> > This builds ACPI ERST table /spec ref/ to inform OSMP
> > how to communicate with ... device.  
> 
> Like this?
> This builds the ACPI ERST table to inform OSMP how to communicate
                                 ^ [1]
> with the acpi-erst device.
> 

1) ACPI spec vX.Y, chapter foo

> 
> >   
> >>
> >> Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
> >> ---
> >>   hw/acpi/erst.c | 214 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >>   1 file changed, 214 insertions(+)
> >>
> >> diff --git a/hw/acpi/erst.c b/hw/acpi/erst.c
> >> index 6e9bd2e..1f1dbbc 100644
> >> --- a/hw/acpi/erst.c
> >> +++ b/hw/acpi/erst.c
> >> @@ -555,6 +555,220 @@ static const MemoryRegionOps erst_mem_ops = {
> >>   /*******************************************************************/
> >>   /*******************************************************************/
> >>   
> >> +/* ACPI 4.0: 17.4.1.2 Serialization Instruction Entries */
> >> +static void build_serialization_instruction_entry(GArray *table_data,
> >> +    uint8_t serialization_action,
> >> +    uint8_t instruction,
> >> +    uint8_t flags,
> >> +    uint8_t register_bit_width,
> >> +    uint64_t register_address,
> >> +    uint64_t value,
> >> +    uint64_t mask)  
> > like I mentioned in previous patch, It could be simplified
> > a lot if it's possible to use fixed 64-bit access with every
> > action and the same width mask.  
> See previous response.
lets see if it's a guest OS issue first, and then decide what to do with it.

> 
> >   
> >> +{
> >> +    /* ACPI 4.0: Table 17-18 Serialization Instruction Entry */
> >> +    struct AcpiGenericAddress gas;
> >> +
> >> +    /* Serialization Action */
> >> +    build_append_int_noprefix(table_data, serialization_action, 1);
> >> +    /* Instruction */
> >> +    build_append_int_noprefix(table_data, instruction         , 1);
> >> +    /* Flags */
> >> +    build_append_int_noprefix(table_data, flags               , 1);
> >> +    /* Reserved */
> >> +    build_append_int_noprefix(table_data, 0                   , 1);
> >> +    /* Register Region */
> >> +    gas.space_id = AML_SYSTEM_MEMORY;
> >> +    gas.bit_width = register_bit_width;
> >> +    gas.bit_offset = 0;
> >> +    switch (register_bit_width) {
> >> +    case 8:
> >> +        gas.access_width = 1;
> >> +        break;
> >> +    case 16:
> >> +        gas.access_width = 2;
> >> +        break;
> >> +    case 32:
> >> +        gas.access_width = 3;
> >> +        break;
> >> +    case 64:
> >> +        gas.access_width = 4;
> >> +        break;
> >> +    default:
> >> +        gas.access_width = 0;
> >> +        break;
> >> +    }
> >> +    gas.address = register_address;
> >> +    build_append_gas_from_struct(table_data, &gas);
> >> +    /* Value */
> >> +    build_append_int_noprefix(table_data, value  , 8);
> >> +    /* Mask */
> >> +    build_append_int_noprefix(table_data, mask   , 8);
> >> +}
> >> +
> >> +/* ACPI 4.0: 17.4.1 Serialization Action Table */
> >> +void build_erst(GArray *table_data, BIOSLinker *linker, Object *erst_dev,
> >> +    const char *oem_id, const char *oem_table_id)
> >> +{
> >> +    ERSTDeviceState *s = ACPIERST(erst_dev);  
> > 
> > globals are not welcomed in new code,
> > pass erst_dev as argument here (ex: find_vmgenid_dev)
> >   
> >> +    unsigned action;
> >> +    unsigned erst_start = table_data->len;
> >> +  
> >   
> >> +    s->bar0 = (hwaddr)pci_get_bar_addr(PCI_DEVICE(erst_dev), 0);
> >> +    trace_acpi_erst_pci_bar_0(s->bar0);
> >> +    s->bar1 = (hwaddr)pci_get_bar_addr(PCI_DEVICE(erst_dev), 1);  
> > 
> > just store pci_get_bar_addr(PCI_DEVICE(erst_dev), 0) in local variable,
> > Bar 1 is not used in this function so you don't need it here.  
> Corrected
> 
> > 
> >   
> >> +    trace_acpi_erst_pci_bar_1(s->bar1);
> >> +
> >> +    acpi_data_push(table_data, sizeof(AcpiTableHeader));
> >> +    /* serialization_header_length */  
> > comments documenting table entries should be verbatim copy from spec,
> > see build_amd_iommu() as example of preferred style.  
> Corrected
> 
> >   
> >> +    build_append_int_noprefix(table_data, 48, 4);
> >> +    /* reserved */
> >> +    build_append_int_noprefix(table_data,  0, 4);
> >> +    /*
> >> +     * instruction_entry_count - changes to the number of serialization
> >> +     * instructions in the ACTIONs below must be reflected in this
> >> +     * pre-computed value.
> >> +     */
> >> +    build_append_int_noprefix(table_data, 29, 4);  
> > a bit fragile as it can easily diverge from actual number later on.
> > maybe instead of building instruction entries in place, build it
> > in separate array and when done, use actual count to fill instruction_entry_count.
> > pseudo code could look like:
> > 
> >       /* prepare instructions in advance because ... */
> >       GArray table_instruction_data;
> >       build_serialization_instruction_entry(table_instruction_data,...);;
> >       ...
> >       build_serialization_instruction_entry(table_instruction_data,...);
> >       /* instructions count */
> >       build_append_int_noprefix(table_data, table_instruction_data.len/entry_size, 4);
> >       /* copy prepared in advance instructions */
> >       g_array_append_vals(table_data, table_instruction_data.data, table_instruction_data.len);  
> Corrected
> 
> >     
> >   
> >> +
> >> +#define MASK8  0x00000000000000FFUL
> >> +#define MASK16 0x000000000000FFFFUL
> >> +#define MASK32 0x00000000FFFFFFFFUL
> >> +#define MASK64 0xFFFFFFFFFFFFFFFFUL
> >> +
> >> +    for (action = 0; action < ACPI_ERST_MAX_ACTIONS; ++action) {  
> > I'd unroll this loop and just directly code entries in required order.
> > also drop reserved and nop actions/instructions or explain why they are necessary.  
> Unrolled. Dropped the NOP.

What about 'reserved"?

> 
> >   
> >> +        switch (action) {
> >> +        case ACPI_ERST_ACTION_BEGIN_WRITE_OPERATION:  
> > given these names will/should never be exposed outside of hw/acpi/erst.c
> > I'd drop ACPI_ERST_ACTION_/ACPI_ERST_INST_ prefixes (i.e. use names as defined in spec)
> > if it doesn't cause build issues.  
> These are in include/hw/acpi/erst.h which is included by hw/i386/acpi-build.c,
> which includes many other hardware files.
> Removing the prefix leaves a rather generic name.
> I'd prefer to leave them as it uniquely differentiates.
is there a reason to put them into erst.h and expose to outside world?
If not then it might be better to move them into erst.c

> 
> 
> >   
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_BEGIN_READ_OPERATION:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_BEGIN_CLEAR_OPERATION:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_END_OPERATION:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_SET_RECORD_OFFSET:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER      , 0, 32,
> >> +                s->bar0 + ERST_CSR_VALUE , 0, MASK32);
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_EXECUTE_OPERATION:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_VALUE , ERST_EXECUTE_OPERATION_MAGIC, MASK8);
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_CHECK_BUSY_STATUS:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_READ_REGISTER_VALUE , 0, 32,
> >> +                s->bar0 + ERST_CSR_VALUE, 0x01, MASK8);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_GET_COMMAND_STATUS:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_READ_REGISTER       , 0, 32,
> >> +                s->bar0 + ERST_CSR_VALUE, 0, MASK8);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_GET_RECORD_IDENTIFIER:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_READ_REGISTER       , 0, 64,
> >> +                s->bar0 + ERST_CSR_VALUE, 0, MASK64);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_SET_RECORD_IDENTIFIER:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER      , 0, 64,
> >> +                s->bar0 + ERST_CSR_VALUE , 0, MASK64);
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_GET_RECORD_COUNT:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_READ_REGISTER       , 0, 32,
> >> +                s->bar0 + ERST_CSR_VALUE, 0, MASK32);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_BEGIN_DUMMY_WRITE_OPERATION:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_RESERVED:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_GET_ERROR_LOG_ADDRESS_RANGE:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_READ_REGISTER       , 0, 64,
> >> +                s->bar0 + ERST_CSR_VALUE, 0, MASK64);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_GET_ERROR_LOG_ADDRESS_LENGTH:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_READ_REGISTER       , 0, 64,
> >> +                s->bar0 + ERST_CSR_VALUE, 0, MASK32);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_GET_ERROR_LOG_ADDRESS_RANGE_ATTRIBUTES:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_READ_REGISTER       , 0, 32,
> >> +                s->bar0 + ERST_CSR_VALUE, 0, MASK32);
> >> +            break;
> >> +        case ACPI_ERST_ACTION_GET_EXECUTE_OPERATION_TIMINGS:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_WRITE_REGISTER_VALUE, 0, 32,
> >> +                s->bar0 + ERST_CSR_ACTION, action, MASK8);
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_READ_REGISTER       , 0, 64,
> >> +                s->bar0 + ERST_CSR_VALUE, 0, MASK64);
> >> +        default:
> >> +            build_serialization_instruction_entry(table_data, action,
> >> +                ACPI_ERST_INST_NOOP, 0, 0, 0, action, 0);
> >> +            break;
> >> +        }
> >> +    }
> >> +    build_header(linker, table_data,
> >> +                 (void *)(table_data->data + erst_start),
> >> +                 "ERST", table_data->len - erst_start,
> >> +                 1, oem_id, oem_table_id);
> >> +}
> >> +
> >> +/*******************************************************************/
> >> +/*******************************************************************/
> >> +
> >>   static const VMStateDescription erst_vmstate  = {
> >>       .name = "acpi-erst",
> >>       .version_id = 1,  
> >   
>