Em Thu, 8 Aug 2024 10:11:07 +0200
Igor Mammedov <imamm...@redhat.com> escreveu:
> On Wed, 7 Aug 2024 15:25:47 +0100
> Jonathan Cameron <jonathan.came...@huawei.com> wrote:
>
> > On Tue, 6 Aug 2024 16:31:13 +0200
> > Igor Mammedov <imamm...@redhat.com> wrote:
> >
> > > On Fri, 2 Aug 2024 23:44:01 +0200
> > > Mauro Carvalho Chehab <mchehab+hua...@kernel.org> wrote:
> > >
> > > > Provide a generic interface for error injection via GHESv2.
> > > >
> > > > This patch is co-authored:
> > > > - original ghes logic to inject a simple ARM record by Shiju Jose;
> > > > - generic logic to handle block addresses by Jonathan Cameron;
> > > > - generic GHESv2 error inject by Mauro Carvalho Chehab;
> > > >
> > > > Co-authored-by: Jonathan Cameron <jonathan.came...@huawei.com>
> > > > Co-authored-by: Shiju Jose <shiju.j...@huawei.com>
> > > > Co-authored-by: Mauro Carvalho Chehab <mchehab+hua...@kernel.org>
> > > > Cc: Jonathan Cameron <jonathan.came...@huawei.com>
> > > > Cc: Shiju Jose <shiju.j...@huawei.com>
> > > > Signed-off-by: Mauro Carvalho Chehab <mchehab+hua...@kernel.org>
> > > > ---
> > > > hw/acpi/ghes.c | 159 ++++++++++++++++++++++++++++++++++++++---
> > > > hw/acpi/ghes_cper.c | 2 +-
> > > > include/hw/acpi/ghes.h | 3 +
> > > > 3 files changed, 152 insertions(+), 12 deletions(-)
> > > >
> > > > diff --git a/hw/acpi/ghes.c b/hw/acpi/ghes.c
> > > > index a745dcc7be5e..e125c9475773 100644
> > > > --- a/hw/acpi/ghes.c
> > > > +++ b/hw/acpi/ghes.c
> > > > @@ -395,23 +395,22 @@ void acpi_ghes_add_fw_cfg(AcpiGhesState *ags,
> > > > FWCfgState *s,
> > > > ags->present = true;
> > > > }
> > > >
> > > > +static uint64_t ghes_get_state_start_address(void)
> > >
> > > ghes_get_hardware_errors_address() might better reflect what address it
> > > will return
> > >
> > > > +{
> > > > + AcpiGedState *acpi_ged_state =
> > > > + ACPI_GED(object_resolve_path_type("", TYPE_ACPI_GED, NULL));
> > > > + AcpiGhesState *ags = &acpi_ged_state->ghes_state;
> > > > +
> > > > + return le64_to_cpu(ags->ghes_addr_le);
> > > > +}
> > > > +
> > > > int acpi_ghes_record_errors(uint8_t source_id, uint64_t
> > > > physical_address)
> > > > {
> > > > uint64_t error_block_addr, read_ack_register_addr,
> > > > read_ack_register = 0;
> > > > - uint64_t start_addr;
> > > > + uint64_t start_addr = ghes_get_state_start_address();
> > > > bool ret = -1;
> > > > - AcpiGedState *acpi_ged_state;
> > > > - AcpiGhesState *ags;
> > > > -
> > > > assert(source_id < ACPI_HEST_SRC_ID_RESERVED);
> > > >
> > > > - acpi_ged_state = ACPI_GED(object_resolve_path_type("",
> > > > TYPE_ACPI_GED,
> > > > - NULL));
> > > > - g_assert(acpi_ged_state);
> > > > - ags = &acpi_ged_state->ghes_state;
> > > > -
> > > > - start_addr = le64_to_cpu(ags->ghes_addr_le);
> > > > -
> > > > if (physical_address) {
> > > > start_addr += source_id * sizeof(uint64_t);
> > >
> > > above should be a separate patch
> > >
> > > >
> > > > @@ -448,9 +447,147 @@ int acpi_ghes_record_errors(uint8_t source_id,
> > > > uint64_t physical_address)
> > > > return ret;
> > > > }
> > > >
> > > > +/*
> > > > + * Error register block data layout
> > > > + *
> > > > + * | +---------------------+ ges.ghes_addr_le
> > > > + * | |error_block_address0 |
> > > > + * | +---------------------+
> > > > + * | |error_block_address1 |
> > > > + * | +---------------------+ --+--
> > > > + * | | ............. | GHES_ADDRESS_SIZE
> > > > + * | +---------------------+ --+--
> > > > + * | |error_block_addressN |
> > > > + * | +---------------------+
> > > > + * | | read_ack0 |
> > > > + * | +---------------------+ --+--
> > > > + * | | read_ack1 | GHES_ADDRESS_SIZE
> > > > + * | +---------------------+ --+--
> > > > + * | | ............. |
> > > > + * | +---------------------+
> > > > + * | | read_ackN |
> > > > + * | +---------------------+ --+--
> > > > + * | | CPER | |
> > > > + * | | .... | GHES_MAX_RAW_DATA_LENGT
> > > > + * | | CPER | |
> > > > + * | +---------------------+ --+--
> > > > + * | | .......... |
> > > > + * | +---------------------+
> > > > + * | | CPER |
> > > > + * | | .... |
> > > > + * | | CPER |
> > > > + * | +---------------------+
> > > > + */
> > >
> > > no need to duplicate docs/specs/acpi_hest_ghes.rst,
> > > I'd just reffer to it and maybe add short comment as to why it's
> > > mentioned.
> > >
> > > > +/* Map from uint32_t notify to entry offset in GHES */
> > > > +static const uint8_t error_source_to_index[] = { 0xff, 0xff, 0xff,
> > > > 0xff,
> > > > + 0xff, 0xff, 0xff, 1,
> > > > 0};
> > > > +
> > > > +static bool ghes_get_addr(uint32_t notify, uint64_t *error_block_addr,
> > > > + uint64_t *read_ack_addr)
> > > > +{
> > > > + uint64_t base;
> > > > +
> > > > + if (notify >= ACPI_GHES_NOTIFY_RESERVED) {
> > > > + return false;
> > > > + }
> > > > +
> > > > + /* Find and check the source id for this new CPER */
> > > > + if (error_source_to_index[notify] == 0xff) {
> > > > + return false;
> > > > + }
> > > > +
> > > > + base = ghes_get_state_start_address();
> > > > +
> > > > + *read_ack_addr = base +
> > > > + ACPI_GHES_ERROR_SOURCE_COUNT * sizeof(uint64_t) +
> > > > + error_source_to_index[notify] * sizeof(uint64_t);
> > > > +
> > > > + /* Could also be read back from the error_block_address register */
> > > > + *error_block_addr = base +
> > > > + ACPI_GHES_ERROR_SOURCE_COUNT * sizeof(uint64_t) +
> > > > + ACPI_GHES_ERROR_SOURCE_COUNT * sizeof(uint64_t) +
> > > > + error_source_to_index[notify] * ACPI_GHES_MAX_RAW_DATA_LENGTH;
> > > > +
> > > > + return true;
> > > > +}
> > >
> > > I don't like all this pointer math, which is basically a reverse
> > > engineered
> > > QEMU actions on startup + guest provided etc/hardware_errors address.
> > >
> > > For once, it assumes error_source_to_index[] matches order in which HEST
> > > error sources were described, which is fragile.
> > >
> > > 2nd: migration-wive it's disaster, since old/new HEST/hardware_errors
> > > tables
> > > in RAM migrated from older version might not match above assumptions
> > > of target QEMU.
> > >
> > > I see 2 ways to rectify it:
> > > 1st: preferred/cleanest would be to tell QEMU (via fw_cfg) address of
> > > HEST table
> > > in guest RAM, like we do with etc/hardware_errors, see
> > > build_ghes_error_table()
> > > ...
> > > tell firmware to write hardware_errors GPA into
> > > and then fetch from HEST table in RAM, the guest patched error/ack
> > > addresses
> > > for given source_id
> > >
> > > code-wise: relatively simple once one wraps their own head over
> > > how this whole APEI thing works in QEMU
> > > workflow is described in docs/specs/acpi_hest_ghes.rst
> > > look to me as sufficient to grasp it.
> > > (but my view is very biased given my prior knowledge,
> > > aka: docs/comments/examples wrt acpi patching are good
> > > enough)
> > > (if it's not clear how to do it, ask me for pointers)
> >
> > Hi Igor, I think I follow what you mean but maybe this question will reveal
> > otherwise. HEST is currently in ACPI_BUILD_TABLE_FILE.
> > Would you suggest splitting it to it's own file, or using table_offsets
> > to get the offset in ACPI_BUILD_TABLE_FILE GPA?
> yep, offset taken right before HEST is to be created
> doc comment for bios_linker_loader_write_pointer() explains how it works
>
> we need something like:
> bios_linker_loader_write_pointer(linker,
> ACPI_HEST_TABLE_ADDR_FW_CFG_FILE, 0, sizeof(uint64_t),
> ACPI_BUILD_TABLE_FILE, hest_offset_within_ACPI_BUILD_TABLE_FILE);
>
> to register new file see:
> a08a64627 ACPI: Record the Generic Error Status Block address
> and to avoid copy past error maybe
> 136fc6aa2 ACPI: Avoid infinite recursion when dump-vmstat
> for this needs to be limited to new machine types and keep
> old ones without this new feature. (I'd use hw_compat_ machinery for that)
Not sure if I got it. The code, after this patch from my v6:
https://lore.kernel.org/qemu-devel/5710c364d7ef6cdab6b2f1e127ef191bdf84e8c2.1723119423.git.mchehab+hua...@kernel.org/T/#u
Already stores two of the three address offsets via
bios_linker_loader_add_pointer(), e. g. it is similar to the
code below (I simplified the code to make the example clearer):
<snip>
/* From hw/arm/virt-acpi-build.c */
static
void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
{
...
if (vms->ras) {
build_ghes_error_table(tables->hardware_errors, tables->linker);
acpi_add_table(table_offsets, tables_blob);
/* internally, call build_ghes_v2() for SEA and GED notification
sources */
acpi_build_hest(tables_blob, tables->linker, vms->oem_id,
vms->oem_table_id);
}
...
}
/* From hw/acpi/ghes.c */
static void build_ghes_v2(GArray *table_data,
enum AcpiGhesNotifyType notify,
BIOSLinker *linker)
{
uint64_t address_offset, ack_offset, block_addr_offset, cper_offset;
enum AcpiHestSourceId source_id;
/*
* Get offsets for either SEA or GED notification - easy to extend
* to all mechanisms like MCE and SCI to better support x86
*/
assert(!acpi_hest_address_offset(notify, &block_addr_offset, &ack_offset,
&cper_offset, &source_id));
bios_linker_loader_add_pointer(linker, ACPI_BUILD_TABLE_FILE,
address_offset + GAS_ADDR_OFFSET,
sizeof(uint64_t),
ACPI_GHES_ERRORS_FW_CFG_FILE,
block_addr_offset);
bios_linker_loader_add_pointer(linker, ACPI_BUILD_TABLE_FILE,
address_offset + GAS_ADDR_OFFSET,
sizeof(uint64_t),
ACPI_GHES_ERRORS_FW_CFG_FILE,
ack_offset);
/* Current code ignores &cper_offset when creating HEST */
}
void ghes_record_cper_errors(AcpiGhesCper *cper, Error **errp,
enum AcpiGhesNotifyType notify)
{
uint64_t cper_addr, read_ack_start_addr;
assert(!ghes_get_hardware_errors_address(notify, NULL, &read_ack_start_addr,
&cper_addr, NULL));
/*
* Use cpu_physical_memory_read/write() to
* - read/store at read_ack_start_addr
* - Write cper block GArray at cper_addr
*/
}
</snip>
We may also store cper_offset there via bios_linker_loader_add_pointer()
and/or use bios_linker_loader_write_pointer(), but I can't see how the
data stored there can be retrieved, nor any advantage of using it instead
of the current code, as, in the end, we'll have 3 addresses that will be
used:
- an address where a pointer to CPER record will be stored;
- an address where the ack will be stored;
- an address where the actual CPER record will be stored.
And those are calculated on a single function and are all stored at the
ACPI table files.
What am I missing?
Thanks,
Mauro
