From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by mx.groups.io with SMTP id smtpd.web11.96040.1673633848082644437 for ; Fri, 13 Jan 2023 10:17:28 -0800 Authentication-Results: mx.groups.io; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=hhGozOus; spf=pass (domain: kernel.org, ip: 139.178.84.217, mailfrom: ardb@kernel.org) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 10784622DA for ; Fri, 13 Jan 2023 18:17:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 02DB3C4339C for ; Fri, 13 Jan 2023 18:17:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673633846; bh=2zt1D0WkkskMOK0GYplJHioCRPNOKgvrMlF6jK6c7fY=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=hhGozOusAoikpCxk1O+3zD5R29MKrU6eOJWLUjMfjBTfYP66d0Tunefxlzsgm8o/w aF4VkUi5anxRTRUr/J47f7MDhgra1lrUra0MT8benRWo5dyZqvOEk5/NMizmgJYCay r3bb939q2/Vfsg8QCxz+5y/8FXkivPPkDBruDQbpuzELJdiDHysYo3OaLMHAHUuO/6 ScVAZEmQ4LmMTs01RHUxCUJOYl5J5JrEJsdBwSIjxB1Q9h5iqnmVWlfTVa6QToUduq Br+tA1ME/71YwfU3M+DmETERyNnyQj/sdN9e1Rrk8znV1/sAqBTtuQAWEus3mGcTn8 QbudCYW7lF9TQ== Received: by mail-lf1-f53.google.com with SMTP id d30so29322529lfv.8 for ; Fri, 13 Jan 2023 10:17:25 -0800 (PST) X-Gm-Message-State: AFqh2ko9TOiT+nNtXdhQf2z/gruIdcKArlXYQsYcPSU+RD6ICa0YgnC1 nWKaxLdNK4CymnQZcVRW7DS1GxgkUEQYHWgP5s0= X-Google-Smtp-Source: AMrXdXtAQC189esz+FEuEDqXM+pU5DM7V+8adrbBeL1UXtKeBq+EQOfFW2ONtlX5651QLe/i/MZ0vs3r5X8pZ/q1bTU= X-Received: by 2002:ac2:4a72:0:b0:4b6:f37c:c123 with SMTP id q18-20020ac24a72000000b004b6f37cc123mr5760052lfp.539.1673633843862; Fri, 13 Jan 2023 10:17:23 -0800 (PST) MIME-Version: 1.0 References: <20230113171125.2846306-1-dionnaglaze@google.com> In-Reply-To: <20230113171125.2846306-1-dionnaglaze@google.com> From: "Ard Biesheuvel" Date: Fri, 13 Jan 2023 19:17:11 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] x86/efi: Safely enable unaccepted memory in UEFI To: Dionna Glaze , linux-efi Cc: linux-kernel@vger.kernel.org, x86@kernel.org, jiewen.yao@intel.com, devel@edk2.groups.io, "Min M. Xu" , Gerd Hoffmann , James Bottomley , Tom Lendacky , Erdem Aktas , "Kirill A. Shutemov" , Dave Hansen Content-Type: text/plain; charset="UTF-8" (cc linux-efi) On Fri, 13 Jan 2023 at 18:11, Dionna Glaze wrote: > > This patch depends on Kirill A. Shutemov's series > > [PATCHv8 00/14] mm, x86/cc: Implement support for unaccepted memory > > The UEFI v2.9 specification includes a new memory type to be used in > environments where the OS must accept memory that is provided from its > host. Before the introduction of this memory type, all memory was > accepted eagerly in the firmware. In order for the firmware to safely > stop accepting memory on the OS's behalf, the OS must affirmatively > indicate support to the firmware. > > Enabling unaccepted memory requires calling a 0-argument enablement > protocol before ExitBootServices. This call is only made if the kernel > is compiled with UNACCEPTED_MEMORY=y > > The naming of the protocol guid is dependent on the standardization of > the protocol, which is being discussed. Acceptance is contingent on > the kernel community's approval. > > Cc: Ard Biescheuvel > Cc: "Min M. Xu" > Cc: Gerd Hoffmann > Cc: James Bottomley > Cc: Tom Lendacky > Cc: Jiewen Yao > Cc: Erdem Aktas > Cc: "Kirill A. Shutemov" > Cc: Dave Hansen > > Signed-off-by: Dionna Glaze > --- > drivers/firmware/efi/libstub/x86-stub.c | 36 +++++++++++++++++++++++++ > include/linux/efi.h | 1 + > 2 files changed, 37 insertions(+) > > diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c > index a0bfd31358ba..5e9ebfbb49e6 100644 > --- a/drivers/firmware/efi/libstub/x86-stub.c > +++ b/drivers/firmware/efi/libstub/x86-stub.c > @@ -26,6 +26,17 @@ const efi_dxe_services_table_t *efi_dxe_table; > u32 image_offset __section(".data"); > static efi_loaded_image_t *image = NULL; > > +union memory_acceptance_protocol { > + struct { > + efi_status_t (__efiapi *allow_unaccepted_memory)( > + union memory_acceptance_protocol *); > + }; > + struct { > + u32 allow_unaccepted_memory; > + } mixed_mode; > +}; > +typedef union memory_acceptance_protocol memory_acceptance_protocol_t; > + Please put the typedef first, and use the defined type in the function prototype, not the union. > static efi_status_t > preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom) > { > @@ -310,6 +321,29 @@ setup_memory_protection(unsigned long image_base, unsigned long image_size) > #endif > } > > + > +static void setup_unaccepted_memory(void) > +{ > +#ifdef CONFIG_UNACCEPTED_MEMORY Please drop the #ifdef > + efi_guid_t mem_acceptance_proto = EFI_MEMORY_ACCEPTANCE_PROTOCOL_GUID; > + memory_acceptance_protocol_t *proto; > + efi_status_t status; > + ... and here, do if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) return; > + /* > + * Enable unaccepted memory before calling exit boot services in order > + * for the UEFI to not accept all memory on EBS. > + */ > + status = efi_bs_call(locate_protocol, &mem_acceptance_proto, NULL, > + (void **)&proto); > + if (status != EFI_SUCCESS) > + return; > + > + status = efi_call_proto(proto, allow_unaccepted_memory); > + if (status != EFI_SUCCESS) > + efi_err("Memory acceptance protocol failed\n"); > +#endif > +} > + > static const efi_char16_t apple[] = L"Apple"; > > static void setup_quirks(struct boot_params *boot_params, > @@ -899,6 +933,8 @@ asmlinkage unsigned long efi_main(efi_handle_t handle, > > setup_quirks(boot_params, bzimage_addr, buffer_end - buffer_start); > > + setup_unaccepted_memory(); > + > status = exit_boot(boot_params, handle); > if (status != EFI_SUCCESS) { > efi_err("exit_boot() failed!\n"); > diff --git a/include/linux/efi.h b/include/linux/efi.h > index 4b27519143f5..bfc0e4f2aba5 100644 > --- a/include/linux/efi.h > +++ b/include/linux/efi.h > @@ -391,6 +391,7 @@ void efi_native_runtime_setup(void); > #define EFI_RT_PROPERTIES_TABLE_GUID EFI_GUID(0xeb66918a, 0x7eef, 0x402a, 0x84, 0x2e, 0x93, 0x1d, 0x21, 0xc3, 0x8a, 0xe9) > #define EFI_DXE_SERVICES_TABLE_GUID EFI_GUID(0x05ad34ba, 0x6f02, 0x4214, 0x95, 0x2e, 0x4d, 0xa0, 0x39, 0x8e, 0x2b, 0xb9) > #define EFI_SMBIOS_PROTOCOL_GUID EFI_GUID(0x03583ff6, 0xcb36, 0x4940, 0x94, 0x7e, 0xb9, 0xb3, 0x9f, 0x4a, 0xfa, 0xf7) > +#define EFI_MEMORY_ACCEPTANCE_PROTOCOL_GUID EFI_GUID(0xc5a010fe, 0x38a7, 0x4531, 0x8a, 0x4a, 0x05, 0x00, 0xd2, 0xfd, 0x16, 0x49) > > #define EFI_IMAGE_SECURITY_DATABASE_GUID EFI_GUID(0xd719b2cb, 0x3d3a, 0x4596, 0xa3, 0xbc, 0xda, 0xd0, 0x0e, 0x67, 0x65, 0x6f) > #define EFI_SHIM_LOCK_GUID EFI_GUID(0x605dab50, 0xe046, 0x4300, 0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23) > -- > 2.39.0.314.g84b9a713c41-goog >