On Sun, 8 Oct 2023 01:47:39 +0530
<[email protected]> wrote:
> From: Ankit Agrawal <[email protected]>
>
> ACPI spec provides a scheme to associate "Generic Initiators" [1]
> (e.g. heterogeneous processors and accelerators, GPUs, and I/O devices with
> integrated compute or DMA engines GPUs) with Proximity Domains. This is
> achieved using Generic Initiator Affinity Structure in SRAT. During bootup,
> Linux kernel parse the ACPI SRAT to determine the PXM ids and create a NUMA
> node for each unique PXM ID encountered. Qemu currently do not implement
> these structures while building SRAT.
>
> Add GI structures while building VM ACPI SRAT. The association between
> devices and PXM are stored using acpi-generic-initiator object. Lookup
> presence of all such objects and use them to build these structures.
>
> The structure needs a PCI device handle [2] that consists of the device BDF.
> The vfio-pci-nohotplug device corresponding to the acpi-generic-initiator
> object is located to determine the BDF.
>
> [1] ACPI Spec 6.5, Section 5.2.16.6
> [2] ACPI Spec 6.5, Table 5.66
>
> Signed-off-by: Ankit Agrawal <[email protected]>
> ---
> hw/acpi/acpi-generic-initiator.c | 78 ++++++++++++++++++++++++
> hw/arm/virt-acpi-build.c | 3 +
> hw/vfio/pci.c | 2 -
> hw/vfio/pci.h | 2 +
> include/hw/acpi/acpi-generic-initiator.h | 22 +++++++
> 5 files changed, 105 insertions(+), 2 deletions(-)
>
> diff --git a/hw/acpi/acpi-generic-initiator.c
> b/hw/acpi/acpi-generic-initiator.c
> index 6406736090..1ae79639be 100644
> --- a/hw/acpi/acpi-generic-initiator.c
> +++ b/hw/acpi/acpi-generic-initiator.c
> @@ -72,3 +72,81 @@ static void acpi_generic_initiator_class_init(ObjectClass
> *oc, void *data)
> NULL, acpi_generic_initiator_set_node, NULL,
> NULL);
> }
> +
> +static int acpi_generic_initiator_list(Object *obj, void *opaque)
> +{
> + GSList **list = opaque;
> +
> + if (object_dynamic_cast(obj, TYPE_ACPI_GENERIC_INITIATOR)) {
> + *list = g_slist_append(*list, ACPI_GENERIC_INITIATOR(obj));
> + }
> +
> + object_child_foreach(obj, acpi_generic_initiator_list, opaque);
> + return 0;
> +}
> +
> +/*
> + * Identify Generic Initiator objects and link them into the list which is
> + * returned to the caller.
> + *
> + * Note: it is the caller's responsibility to free the list to avoid
> + * memory leak.
> + */
> +static GSList *acpi_generic_initiator_get_list(void)
> +{
> + GSList *list = NULL;
> +
> + object_child_foreach(object_get_root(), acpi_generic_initiator_list,
> &list);
> + return list;
> +}
> +
> +/*
> + * ACPI spec, Revision 6.5
> + * 5.2.16.6 Generic Initiator Affinity Structure
> + */
> +static void build_srat_generic_initiator_affinity(GArray *table_data, int
> node,
> + PCIDeviceHandle *handle,
> + GenericAffinityFlags flags)
> +{
> + build_append_int_noprefix(table_data, 5, 1); /* Type */
> + build_append_int_noprefix(table_data, 32, 1); /* Length */
> + build_append_int_noprefix(table_data, 0, 1); /* Reserved */
> + build_append_int_noprefix(table_data, 1, 1); /* Device Handle Type */
> + build_append_int_noprefix(table_data, node, 4); /* Proximity Domain */
> + build_append_int_noprefix(table_data, handle->segment, 2);
> + build_append_int_noprefix(table_data, handle->bdf, 2);
> + build_append_int_noprefix(table_data, handle->res0, 4);
> + build_append_int_noprefix(table_data, handle->res1, 8);
Why are we storing reserved fields in the PCIDeviceHandle? This
function is already specific to building a PCI Device Handle, so we
could just loop build_append_byte() with a fixed zero value here.
> + build_append_int_noprefix(table_data, flags, 4); /* Flags */
> + build_append_int_noprefix(table_data, 0, 4); /* Reserved */
> +}
> +
> +void build_srat_generic_initiator(GArray *table_data)
> +{
> + GSList *gi_list, *list = acpi_generic_initiator_get_list();
> + for (gi_list = list; gi_list; gi_list = gi_list->next) {
> + AcpiGenericInitiator *gi = gi_list->data;
> + Object *o;
> + int count;
> +
> + if (gi->node == MAX_NODES) {
> + continue;
> + }
Why do we have uninitialized AcpiGenericInitiator objects lingering?
> +
> + o = object_resolve_path_type(gi->device, TYPE_VFIO_PCI_NOHOTPLUG,
> NULL);
TYPE_PCI_DEVICE? Maybe you could check hotpluggable from the device
class, but certainly the generic code should not be dependent on being
a vfio-pci-nohotplug device. The spec also supports an ACPI object
description, so should this be build_srat_generic_pci_initiator()?
> + if (!o) {
> + continue;
> + }
> +
> + for (count = 0; count < gi->node_count; count++) {
> + PCIDeviceHandle dev_handle = {0};
> + PCIDevice *pci_dev = PCI_DEVICE(o);
> +
> + dev_handle.bdf = pci_dev->devfn;
Where does the bus part of the bdf get filled in?
> + build_srat_generic_initiator_affinity(table_data,
> + gi->node + count,
> &dev_handle,
> + GEN_AFFINITY_ENABLED);
Seems like the code that built the AcpiGenericInitiator object should
supply the flags. In fact the flag GEN_AFFINITY_ENABLED might be a
better indicator to populate the SRAT with the GI than the node value.
Thanks,
Alex
> + }
> + }
> + g_slist_free(list);
> +}
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index 6b674231c2..7337d8076b 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -58,6 +58,7 @@
> #include "migration/vmstate.h"
> #include "hw/acpi/ghes.h"
> #include "hw/acpi/viot.h"
> +#include "hw/acpi/acpi-generic-initiator.h"
>
> #define ARM_SPI_BASE 32
>
> @@ -558,6 +559,8 @@ build_srat(GArray *table_data, BIOSLinker *linker,
> VirtMachineState *vms)
> }
> }
>
> + build_srat_generic_initiator(table_data);
> +
> if (ms->nvdimms_state->is_enabled) {
> nvdimm_build_srat(table_data);
> }
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index a205c6b113..5e2a7c650a 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -43,8 +43,6 @@
> #include "migration/blocker.h"
> #include "migration/qemu-file.h"
>
> -#define TYPE_VFIO_PCI_NOHOTPLUG "vfio-pci-nohotplug"
> -
> /* Protected by BQL */
> static KVMRouteChange vfio_route_change;
>
> diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
> index a2771b9ff3..74ac77a260 100644
> --- a/hw/vfio/pci.h
> +++ b/hw/vfio/pci.h
> @@ -118,6 +118,8 @@ typedef struct VFIOMSIXInfo {
> #define TYPE_VFIO_PCI "vfio-pci"
> OBJECT_DECLARE_SIMPLE_TYPE(VFIOPCIDevice, VFIO_PCI)
>
> +#define TYPE_VFIO_PCI_NOHOTPLUG "vfio-pci-nohotplug"
> +
> struct VFIOPCIDevice {
> PCIDevice pdev;
> VFIODevice vbasedev;
> diff --git a/include/hw/acpi/acpi-generic-initiator.h
> b/include/hw/acpi/acpi-generic-initiator.h
> index e67e6e23b1..e8e2670309 100644
> --- a/include/hw/acpi/acpi-generic-initiator.h
> +++ b/include/hw/acpi/acpi-generic-initiator.h
> @@ -27,4 +27,26 @@ typedef struct AcpiGenericInitiatorClass {
> ObjectClass parent_class;
> } AcpiGenericInitiatorClass;
>
> +/*
> + * ACPI 6.5: Table 5-68 Flags - Generic Initiator
> + */
> +typedef enum {
> + GEN_AFFINITY_NOFLAGS = 0,
> + GEN_AFFINITY_ENABLED = (1 << 0),
> + GEN_AFFINITY_ARCH_TRANS = (1 << 1),
> +} GenericAffinityFlags;
> +
> +/*
> + * ACPI 6.5: Table 5-66 Device Handle - PCI
> + * Device Handle definition
> + */
> +typedef struct PCIDeviceHandle {
> + uint16_t segment;
> + uint16_t bdf;
> + uint32_t res0;
> + uint64_t res1;
> +} PCIDeviceHandle;
> +
> +void build_srat_generic_initiator(GArray *table_data);
> +
> #endif
