From nobody Sun Sep 14 14:53:53 2025 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 971F128CF77 for ; Thu, 4 Sep 2025 06:55:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756968919; cv=none; b=c9OKHPmM+0HRi/m1ngaqP/OXOQfndAnVh6xREXu7c50dka/7XF6b6eTwthyZmvXMP4TP3Cp/gx6es/lkES1PsAiKDqh2vXtnwVhuuism1MbonSB14L3EGG5fw/3/PSsGXcy0Q3vrNgmb+akmkgFz6RaTw671/SIvJpdUgGxEZ84= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756968919; c=relaxed/simple; bh=fl5WFH2pE48prKI9Xye9Kp56WYjFCfdYw5kFeG22K4o=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Y55//ZnCHlXAu17i3fM8xoUCf4QQ0m9jv9DD8E9NWMuIQ3faZx+rmBfudATbbBX5FYZCSdmJxNCu9qr73kXHbqvur5zRqdtocZVaY5l4SWBLCqf1xLkH4MsLOR1EQ6mEZfQLdZfP725xK/eIZ/AJy0g6E6husd3KBW9Ckh0JobI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--sagis.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=qu/EDxFo; arc=none smtp.client-ip=209.85.214.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--sagis.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="qu/EDxFo" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-24c9e2213f8so9977255ad.2 for ; Wed, 03 Sep 2025 23:55:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1756968917; x=1757573717; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=mbSK0q2wvsUvwJsHeMu0UEX5HMzL8ImDejpjGFji5HE=; b=qu/EDxFoOV4ELyAERC3Qntxd6bkNghnA2r0qmvIeUWNwki4V2b8pm+py5zhzI3oufK 7vHYBNuY1oXYfm67uH/mvuOlDFMNZfJ44f3BSqG4HjxvMuUoeJZhXI3gYNkO/IsafBXw NOht/T8ybr7z+drBQI66MvRu/wvQzKFsrxmipxFRZ77fadmsNpGx/Ev0XVh2oAMLfAQa lVPVZ8dvXALSnhePNPzKvkXsmldLPt7cHpctWI3quH8s2PuLEuMrlqRrLi1/s+nEWEXc 5fL7+Gq76WMOzvvfYhxxBlg7bO6gM/yPIsKzqp2el/PxEgfKRJSxUlvSAJtOi/NY13Ag B92Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756968917; x=1757573717; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=mbSK0q2wvsUvwJsHeMu0UEX5HMzL8ImDejpjGFji5HE=; b=FrRrVif69LHzcUdbNVw01IQgM6MudVUBDUrjHlwpTOLKX+2RwYTep+0S7fWleOVdmt 658PATY0YaTmVL1D5RICNjFaXg1cPLk8GedssckCHep9+Gr8MRkyx1O/V1fSXWKoxs3T /KM7CLvjETDRh+ws1ose8TP/h8vhPeSrnNpeB7qNNFaaru8jQY2gAKJAqD+Ani8QfeJo f4dAmKflWlE0XVXImZuE6F3VkJqQJ6zgiLVD0x4Kosugi1QjFeEUmu2zsvdAk1q7ARot IltVcUNmaR3jy5IMgwOaySrmofdf5aHmkkOdqYmokh7yK/nx8jrqkILvspWB5Cs3md1c 1jEg== X-Gm-Message-State: AOJu0YyeLt64VYODPg+LIICB0xPkcXFwdsm1DuqYpf+adw7q5qg58OAn d3+XSFxM3c6nbM3b1rS+92P/Cg3VAc0m4/i9FBTAuJcLIz8x5g2yZyvMKz1F3SwLYm5fUqP45di D5Q== X-Google-Smtp-Source: AGHT+IEIVmyBAsxeMnfR2DE0V7+2eEBlwFJC8ibSKdd/uSqU1DT1NSlXejdciIy1eX1XFGzYaP5WdMeUOQ== X-Received: from pfau2.prod.google.com ([2002:a05:6a00:aa82:b0:76e:1da7:f2ba]) (user=sagis job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:244c:b0:243:c23c:85cc with SMTP id adf61e73a8af0-243d6ddb139mr26453840637.7.1756968917074; Wed, 03 Sep 2025 23:55:17 -0700 (PDT) Date: Wed, 3 Sep 2025 23:54:39 -0700 In-Reply-To: <20250904065453.639610-1-sagis@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250904065453.639610-1-sagis@google.com> X-Mailer: git-send-email 2.51.0.338.gd7d06c2dae-goog Message-ID: <20250904065453.639610-10-sagis@google.com> Subject: [PATCH v10 09/21] KVM: selftests: Set up TDX boot code region From: Sagi Shahar To: linux-kselftest@vger.kernel.org, Paolo Bonzini , Shuah Khan , Sean Christopherson , Ackerley Tng , Ryan Afranji , Andrew Jones , Isaku Yamahata , Erdem Aktas , Rick Edgecombe , Sagi Shahar , Roger Wang , Binbin Wu , Oliver Upton , "Pratik R. Sampat" , Reinette Chatre , Ira Weiny , Chao Gao , Chenyi Qiang Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add memory for TDX boot code in a separate memslot. Use virt_map() to get identity map in this memory region to allow for seamless transition from paging disabled to paging enabled code. Copy the boot code into the memory region and set up the reset vectors at this point. While it's possible to separate the memory allocation and boot code initialization into separate functions, having all the calculations for memory size and offsets in one place simplifies the code and avoids duplications. Handcode the reset vector as suggested by Sean Christopherson. Suggested-by: Sean Christopherson Co-developed-by: Erdem Aktas Signed-off-by: Erdem Aktas Signed-off-by: Sagi Shahar Reviewed-by: Binbin Wu --- tools/testing/selftests/kvm/Makefile.kvm | 1 + .../selftests/kvm/include/x86/tdx/tdx_util.h | 2 + .../selftests/kvm/lib/x86/tdx/tdx_util.c | 54 +++++++++++++++++++ 3 files changed, 57 insertions(+) create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selft= ests/kvm/Makefile.kvm index d11d02e17cc5..52c90f1c0484 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -31,6 +31,7 @@ LIBKVM_x86 +=3D lib/x86/sev.c LIBKVM_x86 +=3D lib/x86/svm.c LIBKVM_x86 +=3D lib/x86/ucall.c LIBKVM_x86 +=3D lib/x86/vmx.c +LIBKVM_x86 +=3D lib/x86/tdx/tdx_util.c LIBKVM_x86 +=3D lib/x86/tdx/td_boot.S =20 LIBKVM_arm64 +=3D lib/arm64/gic.c diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools= /testing/selftests/kvm/include/x86/tdx/tdx_util.h index 286d5e3c24b1..ec05bcd59145 100644 --- a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h +++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h @@ -11,4 +11,6 @@ static inline bool is_tdx_vm(struct kvm_vm *vm) return vm->type =3D=3D KVM_X86_TDX_VM; } =20 +void vm_tdx_setup_boot_code_region(struct kvm_vm *vm); + #endif // SELFTESTS_TDX_TDX_UTIL_H diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/tes= ting/selftests/kvm/lib/x86/tdx/tdx_util.c new file mode 100644 index 000000000000..a1cf12de9d56 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include + +#include "kvm_util.h" +#include "processor.h" +#include "tdx/td_boot.h" +#include "tdx/tdx_util.h" + +/* Arbitrarily selected to avoid overlaps with anything else */ +#define TD_BOOT_CODE_SLOT 20 + +#define X86_RESET_VECTOR 0xfffffff0ul +#define X86_RESET_VECTOR_SIZE 16 + +void vm_tdx_setup_boot_code_region(struct kvm_vm *vm) +{ + size_t total_code_size =3D TD_BOOT_CODE_SIZE + X86_RESET_VECTOR_SIZE; + vm_paddr_t boot_code_gpa =3D X86_RESET_VECTOR - TD_BOOT_CODE_SIZE; + vm_paddr_t alloc_gpa =3D round_down(boot_code_gpa, PAGE_SIZE); + size_t nr_pages =3D DIV_ROUND_UP(total_code_size, PAGE_SIZE); + vm_paddr_t gpa; + uint8_t *hva; + + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, + alloc_gpa, + TD_BOOT_CODE_SLOT, nr_pages, + KVM_MEM_GUEST_MEMFD); + + gpa =3D vm_phy_pages_alloc(vm, nr_pages, alloc_gpa, TD_BOOT_CODE_SLOT); + TEST_ASSERT(gpa =3D=3D alloc_gpa, "Failed vm_phy_pages_alloc\n"); + + virt_map(vm, alloc_gpa, alloc_gpa, nr_pages); + hva =3D addr_gpa2hva(vm, boot_code_gpa); + memcpy(hva, td_boot, TD_BOOT_CODE_SIZE); + + hva +=3D TD_BOOT_CODE_SIZE; + TEST_ASSERT(hva =3D=3D addr_gpa2hva(vm, X86_RESET_VECTOR), + "Expected RESET vector at hva 0x%lx, got %lx", + (unsigned long)addr_gpa2hva(vm, X86_RESET_VECTOR), (unsigned long)hv= a); + + /* + * Handcode "JMP rel8" at the RESET vector to jump back to the TD boot + * code, as there are only 16 bytes at the RESET vector before RIP will + * wrap back to zero. Insert a trailing int3 so that the vCPU crashes + * in case the JMP somehow falls through. Note! The target address is + * relative to the end of the instruction! + */ + TEST_ASSERT(TD_BOOT_CODE_SIZE + 2 <=3D 128, + "TD boot code not addressable by 'JMP rel8'"); + hva[0] =3D 0xeb; + hva[1] =3D 256 - 2 - TD_BOOT_CODE_SIZE; + hva[2] =3D 0xcc; +} --=20 2.51.0.338.gd7d06c2dae-goog