linux-kernel - Re: [PATCH] x86/efistub: Add options for forcing Apple set

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Message-ID: <52B0B784-2FB5-4B7D-8FB6-A7B694EDDFC3@live.com>
Date: Tue, 11 Feb 2025 16:05:12 +0000
From: Aditya Garg <gargaditya08@...e.com>
To: Lukas Wunner <lukas@...ner.de>
CC: Lleyton Gray <lleyton@...alabs.com>, Ard Biesheuvel <ardb@...nel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>
Subject: Re: [PATCH] x86/efistub: Add options for forcing Apple set_os
 protocol

Hi Lukas

> On 11 Feb 2025, at 1:28 AM, Lukas Wunner <lukas@...ner.de> wrote:
> 
> Hi Aditya,
> 
> sorry for the delay!
> 
> On Wed, Jan 01, 2025 at 11:39:13AM +0000, Aditya Garg wrote:
>> We have had issues with other people unable to use their eGPU if their
>> Mac doesn't have the apple set os quirk. We probably could do dual VGA
>> checks suggested by Lukas, but will it work with GPU hotplug?
> 
> FWIW, below would be my suggestion for replacing the DMI-based quirk
> with one that is based on the number of GPUs.
> 
> It should invoke the apple_set_os protocol both on dual GPU laptops
> as well as ones with an eGPU, hence my expectation is that it should
> fix the issue reported by Lleyton.
> 
> The quirk is not applied e.g. on single GPU MacBook Airs, hence
> should avoid regressing those.
> 
> The patch is compile-tested only.
> 
> It performs one additional 16-bit config space read for every PCI
> device in the system.  If anyone objects to that and wants it
> constrained to Apple systems, that could be changed easily.
> 
> Thanks,
> 
> Lukas
> 
> -- >8 --
> 
> diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
> index 863910e9eefc..3092a6e5166f 100644
> --- a/drivers/firmware/efi/libstub/x86-stub.c
> +++ b/drivers/firmware/efi/libstub/x86-stub.c
> @@ -27,6 +27,7 @@ const efi_system_table_t *efi_system_table;
> const efi_dxe_services_table_t *efi_dxe_table;
> static efi_loaded_image_t *image = NULL;
> static efi_memory_attribute_protocol_t *memattr;
> +static unsigned int nr_gpus;
> 
> typedef union sev_memory_acceptance_protocol sev_memory_acceptance_protocol_t;
> union sev_memory_acceptance_protocol {
> @@ -39,6 +40,23 @@ union sev_memory_acceptance_protocol {
> } mixed_mode;
> };
> 
> +static void update_nr_gpus(efi_pci_io_protocol_t *pci)
> +{
> + efi_status_t status;
> + u16 class;
> +
> + status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
> + PCI_CLASS_DEVICE, 1, &class);
> +
> + if (status != EFI_SUCCESS) {
> + efi_err("Failed to read device class\n");
> + return;
> + }
> +
> + if (class >> 8 == PCI_BASE_CLASS_DISPLAY)
> + nr_gpus++;
> +}
> +
> static efi_status_t
> preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
> {
> @@ -150,6 +168,8 @@ static void setup_efi_pci(struct boot_params *params)
> params->hdr.setup_data = (unsigned long)rom;
> 
> data = (struct setup_data *)rom;
> +
> + update_nr_gpus(pci);
> }
> }
> 
> @@ -203,37 +223,6 @@ static void retrieve_apple_device_properties(struct boot_params *boot_params)
> }
> }
> 
> -static bool apple_match_product_name(void)
> -{
> - static const char type1_product_matches[][15] = {
> - "MacBookPro11,3",
> - "MacBookPro11,5",
> - "MacBookPro13,3",
> - "MacBookPro14,3",
> - "MacBookPro15,1",
> - "MacBookPro15,3",
> - "MacBookPro16,1",
> - "MacBookPro16,4",
> - };
> - const struct efi_smbios_type1_record *record;
> - const u8 *product;
> -
> - record = (struct efi_smbios_type1_record *)efi_get_smbios_record(1);
> - if (!record)
> - return false;
> -
> - product = efi_get_smbios_string(record, product_name);
> - if (!product)
> - return false;
> -
> - for (int i = 0; i < ARRAY_SIZE(type1_product_matches); i++) {
> - if (!strcmp(product, type1_product_matches[i]))
> - return true;
> - }
> -
> - return false;
> -}
> -
> static void apple_set_os(void)
> {
> struct {
> @@ -243,7 +232,7 @@ static void apple_set_os(void)
> } *set_os;
> efi_status_t status;
> 
> - if (!efi_is_64bit() || !apple_match_product_name())
> + if (!efi_is_64bit() || nr_gpus < 2)
> return;
> 
> status = efi_bs_call(locate_protocol, &APPLE_SET_OS_PROTOCOL_GUID, NULL,

This patch does not enable the os set protocol on my MacBook Pro 16 inch 2019

journalctl -k: https://pastebin.com/7etWy0D5