From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f198.google.com (mail-pg1-f198.google.com [209.85.215.198]) (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 5546453A8A3 for ; Thu, 1 Oct 2026 19:39:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.198 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790883544; cv=none; b=d1sFyQ6rmx/kfIhcG6gL/vY08QnRzROKqSGGUd0y+keokp7Mn3D9eYu13Yhaa+FwXYhb/XUxFd6YhMixr5NN+88yKJ9kM9Q0lzG1ev3+VkTx93PRERClMsN1xcV/7yhIlXUpswbYnDD43WUrSGX17GoyAhRbSmgz8AJyCjB53LI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790883544; c=relaxed/simple; bh=OmYZrXMHQ6GNkHyoPspDJgmPZLZO4fxyA+WIizMm9Pk=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=moeq7SGeiVUqAO7Ku1s0o4nKMiMeeXQkO3azs4/7Q8+ENKqY1GuJXOHI2tTobadz1li3rZvBXhOJAd5DJSASDsvV7Ks9SNxg8KCpUq8G7QrndVZExk7VzrNtK34fIqWUf5pYEM32CR/czuiE/Z2dUTfGYahoTVoHwowqJuMJsss= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--wyihan.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=H5FkwgRG; arc=none smtp.client-ip=209.85.215.198 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--wyihan.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="H5FkwgRG" Received: by mail-pg1-f198.google.com with SMTP id 41be03b00d2f7-cbedbd182f5so831429a12.1 for ; Thu, 01 Oct 2026 12:39:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1790883540; x=1791488340; darn=lists.linux.dev; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=8PMxTCtqUELQe4eKRYkBdJgosWLyHcswIgZCsHoG0ME=; b=H5FkwgRGf8XXtBgJocJLmzvnbTIfAyWYV+j+JARGI/BMnegYtwa78XHd7afToaL1ZA rWaYozfK3Dbas7E69Gx2QvE2nLA/LJX2gcSA+H1iFJirrkTSgahUdZC1Jdch1Hjhexij 4QILKZcGl0XWutY/FCC4LzP2do5/uefjSs+AIo5Drq+lKstmjQ9NNmGTEl2vpKSa4JA2 3Rr6Z+oRQc0xLTB7GH8ZcaELuALlISdBVZsqpC4aLdRC1/f8E99ZQoBgUR7ruhcPn/u9 6lIMD13cf+7r6qzhwybyxvFNaVgYldx1Mwl4YHkkov5ZnemOhsoHI6DiEfDY+m2Hz9AW 8jQg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790883540; x=1791488340; h=content-type: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:content-type; bh=8PMxTCtqUELQe4eKRYkBdJgosWLyHcswIgZCsHoG0ME=; b=EXZ+EkAmI+YbxzJUZWa5et3+sJ9YX1umP+wW041vg+MIjJud57Ollv8TuTiNcKnsb6 47q6WMf0ChAgXBjbZea8Pv8d8WtjCkATMDAPWNR8OFdDKKS7d7IDNqnWy091jtxcQ4xM JZ1H0ExnS2uZFIMXdAd0DtqEf/nW2F9mC0Jk4NoFrhugO4sdxFF2xeZWjL8Y/pWceVnZ agxjngNlvihVRiZEN0FTr5lrlGIeHyyniGV/t6pRz026RPHRSIHSHQOk7K9nq3ZtvsAQ GcEViAlA44bIcaoPN4Cjkw91J4ArlZwwTqHpzWPgP9us0rNpjiQrZnVV/OKrDY5oeAKM EynA== X-Forwarded-Encrypted: i=1; AKwUvBzIfVVEzaIu7QbBXZzYWudMOLV8eLzU1SvdyoJ0V6Dl9R7FvKyIV+3Nt0RNC19/wg/GMsvixyA2xlQS@lists.linux.dev X-Gm-Message-State: AFuF++nY5Fr2zlboWaG0qhEFvXnIJ+uHLrpfT9R+BpePPhRcUuwQ8ZLS asdm6iq5muK1U51PGe3/CYjiBNqVcZtBW1aI83/K4lKwzs5WOcaAY+XrmTsT6xZ49hsYCUsKFaK Qkg/zxw== X-Received: from pgww6.prod.google.com ([2002:a05:6a02:2c86:b0:cc7:9f0d:787f]) (user=wyihan job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:700d:b0:3dd:a9a9:396b with SMTP id adf61e73a8af0-3deacdbf75amr3057879637.47.1790883539784; Thu, 01 Oct 2026 12:38:59 -0700 (PDT) Date: Thu, 01 Oct 2026 19:37:47 +0000 In-Reply-To: <20261001-tdx-selftests-v15-0-7c62a5d8a992@google.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20261001-tdx-selftests-v15-0-7c62a5d8a992@google.com> X-Developer-Key: i=wyihan@google.com; a=ed25519; pk=cRi0fKzS5BMxlHyHY2pJv3w/1zcgfYKr6EYGYppdMYc= X-Developer-Signature: v=1; a=ed25519-sha256; t=1790883521; l=2963; i=wyihan@google.com; s=20260319; h=from:subject:message-id; bh=1jhZF7MSEYmQ46gvcXXFj0gF9FxGyiWCS3GM6O8ekwE=; b=cCVqhBZTduk/xhTjJgvwm/ClTICdSU0FEwX9Q2XAkSN/UPg3vnXMFjPrhYwqS0SbIEuxLgkUB yI3hbduPE+8C3WKMNUuk75C9ugXAks5fAjUgIj/vygm+UQIsJoSLhBB X-Mailer: b4 0.14.3 Message-ID: <20261001-tdx-selftests-v15-20-7c62a5d8a992@google.com> Subject: [PATCH v15 20/23] KVM: selftests: Add a helper to issue TDVMCALLs from the TDX vm From: Lisa Wang To: Andrew Jones , Ackerley Tng , Binbin Wu , Chao Gao , Chenyi Qiang , Dave Hansen , Erdem Aktas , Ira Weiny , Isaku Yamahata , Kiryl Shutsemau , linux-kselftest@vger.kernel.org, Paolo Bonzini , "Pratik R. Sampat" , Reinette Chatre , Rick Edgecombe , Roger Wang , Ryan Afranji , Sagi Shahar , Sean Christopherson , Shuah Khan , Xiaoyao Li , Oliver Upton Cc: Jeremiah McReynolds , kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, x86@kernel.org, Lisa Wang Content-Type: text/plain; charset="utf-8" From: Erdem Aktas TDX VMs need to notify the host, e.g. ucall. Add tdvmcall() to allow VMs to issue TDG.VP.VMCALL with a single function call instead of open-coding TDVMCALL registers setup at every call site. The helper makes standard GHCI TDVMCALLs: the caller passes the GHCI sub-function and up to four arguments and returns the TDVMCALL status from R10. Co-developed-by: Sagi Shahar Signed-off-by: Sagi Shahar Co-developed-by: Lisa Wang Signed-off-by: Lisa Wang Signed-off-by: Erdem Aktas Reviewed-by: Ackerley Tng --- tools/testing/selftests/kvm/Makefile.kvm | 1 + tools/testing/selftests/kvm/include/x86/tdx/tdx.h | 9 ++++++ tools/testing/selftests/kvm/lib/x86/tdx/tdx.S | 39 +++++++++++++++++++++++ 3 files changed, 49 insertions(+) diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index 9464168e361a..495de8ef8166 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -34,6 +34,7 @@ LIBKVM_x86 += lib/x86/tdx/tdx_util.c LIBKVM_x86 += lib/x86/ucall.c LIBKVM_x86 += lib/x86/vmx.c LIBKVM_x86 += lib/x86/tdx/td_boot.S +LIBKVM_x86 += lib/x86/tdx/tdx.S LIBKVM_arm64 += lib/arm64/gic.c LIBKVM_arm64 += lib/arm64/gic_v3.c diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx.h new file mode 100644 index 000000000000..d41a1efc8a63 --- /dev/null +++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx.h @@ -0,0 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef SELFTEST_KVM_TDX_TDX_H +#define SELFTEST_KVM_TDX_TDX_H + +#include + +u64 __tdvmcall(u64 fn, u64 r12, u64 r13, u64 r14, u64 r15); + +#endif /* SELFTEST_KVM_TDX_TDX_H */ diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx.S b/tools/testing/selftests/kvm/lib/x86/tdx/tdx.S new file mode 100644 index 000000000000..e3f0f7f2232b --- /dev/null +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx.S @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +.globl __tdvmcall +/* + * u64 __tdvmcall(u64 fn, u64 r12, u64 r13, u64 r14, u64 r15) + */ +__tdvmcall: + push %r12 + push %r13 + push %r14 + push %r15 + + /* + * Map C ABI fast arguments to TDX GHCI payload registers + * RDI=fn, RSI=r12, RDX=r13, RCX=r14, R8=r15 + */ + mov %rdi, %r11 + mov %rsi, %r12 + mov %rdx, %r13 + mov %rcx, %r14 + mov %r8, %r15 + + mov $0, %rax /* TDCALL leaf 0: TDG.VP.VMCALL */ + mov $0xFC00, %rcx /* Expose R10-R15 */ + mov $0, %r10 /* Standard GHCI call */ + + /* TDCALL instruction */ + .byte 0x66, 0x0f, 0x01, 0xcc + + /* Extract status */ + mov %r10, %rax + + pop %r15 + pop %r14 + pop %r13 + pop %r12 + ret + +.section .note.GNU-stack,"",%progbits -- 2.56.0.rc1.315.gc6ed9934b7-goog