From nobody Thu Oct 2 01:01:44 2025 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 C4C0E3218BA for ; Thu, 25 Sep 2025 17:29:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758821373; cv=none; b=puti/Am2roBipnELQjRyAl0lrZWlz5l4IqjLVgRX/XUxPrtFJJ9aSbzlyo+5RQojTPk68j67cfXffM1dtvwv6yDBMpp/FAfjPvonEJrYaN1tcJja9m8cZz5a9nZ3aZWsLQ/y+AHk7XLg6mpfbiWfupBP5JZwA03AaZ1xTpXrVrs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758821373; c=relaxed/simple; bh=dQKO09oJCnocRjFNIJDtEll6Y8mthajh35gt3qwwu5Y=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=EA85f1pWYksI6iqG5MGRYj89l/9Kv7RtERHEqD1wuER06AWHweXaYNVHHGsNmMSW5j0gDUNARzFRTI8HgZ8N8FV0hExz1YlCz4sTQpMNQ9QkV24KkTvgFoo3nEe2gV+Ti80Hu883QD4PluOSLOHaRk9scdlOJ+7Q2WpEr2GUEw8= 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=cyZW/fdB; arc=none smtp.client-ip=209.85.216.74 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="cyZW/fdB" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-32ec69d22b2so1192062a91.1 for ; Thu, 25 Sep 2025 10:29:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1758821371; x=1759426171; 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=ThwYPhcmkCcqvioAtkivdQwxT8TbijxWH5xfKoaQ6zM=; b=cyZW/fdBOJExph9ZXQLzSsO3znwutoIZ6isNvl8JN9BHU9paLFBSxxsNdJyEprLARn 5YQQTZ5+jfoaGt7rwll9s09kSDQzJBUD9YrlGs+UAE3MIrikGCJwwuchnOlIe6tMsQk5 rLFwBa6umtZIrtT4FeWQl3dBSSAU0pLVI1vrGFAen3LCXCEJV8dhIL7CA4Mb668BOl8d Aji12W4TsDQb/i0bCjyAzmYKWwa/rPbjQQdJRkglDSzq30c9y2Zcn2mWjeoyyUna4P3l z3Pyc3O/deyiE51rVZl1gTTDVS6lrLoyNBmaU+aa9BR4l1IZ+qkrjgCOOdYbfLiDmubO nhKw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758821371; x=1759426171; 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=ThwYPhcmkCcqvioAtkivdQwxT8TbijxWH5xfKoaQ6zM=; b=AUfJkQo8goarDr5ZOYR/Q4VBW2MshPfX5JFLb/yPutzM09ECXwk8jjgsVrIDtTqsJ6 rBr/yLZtqJoSmH9XdOdE/0IZPSOyx8kqNMv34Tsb+eeWU0AFWnmWsejMEgfbwtHb5QJe 4jBs3P/YJa91PhwtXIRawRd9hSA2zNvkNoX49o+GKkhViZnV764BmMy6nq3xe1D529V5 EsXc7BSKR4geVL/sM5qGO/NY44hDdUUEj4D3XWezwDIAYxkhlSzr48paabvkcinIKQIk a/3GjVFxQdywAuAWMDxdBYdPB03RMoXrvItW+Ys488oiFUUyi8a4LTPaPWIowinfZ20Y K9dw== X-Gm-Message-State: AOJu0YzMaEjnWr+RYWiJVonJPpEolLmErcsRDJJx3wkaXZGGPy4CZAYR 8LiaGMrmIyvtBeGpfntUjYag4ZvHQ+sNqjtSKDSp30ylzo1J3mHmJL048xZuxkl0RJJ0tSrSozK yEg== X-Google-Smtp-Source: AGHT+IHM1CN9rSt/1jalfBqV4Qi3jOCHo0SnGbk6lWEtgzzPfwzmrVSoUXtYNBHsHrzpTPor0m+ksolOYw== X-Received: from pjbmr16.prod.google.com ([2002:a17:90b:2390:b0:330:8b1f:c4e7]) (user=sagis job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:1b4f:b0:330:4a1d:223c with SMTP id 98e67ed59e1d1-3342a23af2fmr5505597a91.15.1758821371197; Thu, 25 Sep 2025 10:29:31 -0700 (PDT) Date: Thu, 25 Sep 2025 10:28:48 -0700 In-Reply-To: <20250925172851.606193-1-sagis@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250925172851.606193-1-sagis@google.com> X-Mailer: git-send-email 2.51.0.536.g15c5d4f767-goog Message-ID: <20250925172851.606193-21-sagis@google.com> Subject: [PATCH v11 20/21] KVM: selftests: Add ucall support for TDX 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" From: Ackerley Tng ucalls for non-Coco VMs work by having the guest write to the rdi register, then perform an io instruction to exit to the host. The host then reads rdi using kvm_get_regs(). CPU registers can't be read using kvm_get_regs() for TDX, so TDX guests use MMIO to pass the struct ucall's hva to the host. MMIO was chosen because it is one of the simplest (hence unlikely to fail) mechanisms that support passing 8 bytes from guest to host. Signed-off-by: Ackerley Tng Co-developed-by: Sagi Shahar Signed-off-by: Sagi Shahar ---------------------------------------------- Changes from v10: * Removed ucall_arch_init() decleration from ucall.h. * Replace vm_type type check with is_tdx_vm(). * Move mmio info initialization under is_tdx_vm() case. --- .../selftests/kvm/include/ucall_common.h | 1 + .../testing/selftests/kvm/include/x86/ucall.h | 6 --- tools/testing/selftests/kvm/lib/x86/ucall.c | 46 +++++++++++++++++-- 3 files changed, 42 insertions(+), 11 deletions(-) diff --git a/tools/testing/selftests/kvm/include/ucall_common.h b/tools/tes= ting/selftests/kvm/include/ucall_common.h index d9d6581b8d4f..f5eebf690033 100644 --- a/tools/testing/selftests/kvm/include/ucall_common.h +++ b/tools/testing/selftests/kvm/include/ucall_common.h @@ -4,6 +4,7 @@ */ #ifndef SELFTEST_KVM_UCALL_COMMON_H #define SELFTEST_KVM_UCALL_COMMON_H +#include "kvm_util.h" #include "test_util.h" #include "ucall.h" =20 diff --git a/tools/testing/selftests/kvm/include/x86/ucall.h b/tools/testin= g/selftests/kvm/include/x86/ucall.h index d3825dcc3cd9..7e54ec2c1a45 100644 --- a/tools/testing/selftests/kvm/include/x86/ucall.h +++ b/tools/testing/selftests/kvm/include/x86/ucall.h @@ -2,12 +2,6 @@ #ifndef SELFTEST_KVM_UCALL_H #define SELFTEST_KVM_UCALL_H =20 -#include "kvm_util.h" - #define UCALL_EXIT_REASON KVM_EXIT_IO =20 -static inline void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa) -{ -} - #endif diff --git a/tools/testing/selftests/kvm/lib/x86/ucall.c b/tools/testing/se= lftests/kvm/lib/x86/ucall.c index 1265cecc7dd1..fae6f37b0bcd 100644 --- a/tools/testing/selftests/kvm/lib/x86/ucall.c +++ b/tools/testing/selftests/kvm/lib/x86/ucall.c @@ -5,11 +5,35 @@ * Copyright (C) 2018, Red Hat, Inc. */ #include "kvm_util.h" +#include "tdx/tdx.h" +#include "tdx/tdx_util.h" =20 #define UCALL_PIO_PORT ((uint16_t)0x1000) =20 +static uint8_t vm_type; +static vm_paddr_t host_ucall_mmio_gpa; +static vm_paddr_t ucall_mmio_gpa; + +void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa) +{ + vm_type =3D vm->type; + sync_global_to_guest(vm, vm_type); + + if (is_tdx_vm(vm)) { + host_ucall_mmio_gpa =3D ucall_mmio_gpa =3D mmio_gpa; + ucall_mmio_gpa |=3D vm->arch.s_bit; + } + + sync_global_to_guest(vm, ucall_mmio_gpa); +} + void ucall_arch_do_ucall(vm_vaddr_t uc) { + if (vm_type =3D=3D KVM_X86_TDX_VM) { + tdg_vp_vmcall_ve_request_mmio_write(ucall_mmio_gpa, 8, uc); + return; + } + /* * FIXME: Revert this hack (the entire commit that added it) once nVMX * preserves L2 GPRs across a nested VM-Exit. If a ucall from L2, e.g. @@ -46,11 +70,23 @@ void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu) { struct kvm_run *run =3D vcpu->run; =20 - if (run->exit_reason =3D=3D KVM_EXIT_IO && run->io.port =3D=3D UCALL_PIO_= PORT) { - struct kvm_regs regs; + switch (vm_type) { + case KVM_X86_TDX_VM: + if (vcpu->run->exit_reason =3D=3D KVM_EXIT_MMIO && + vcpu->run->mmio.phys_addr =3D=3D host_ucall_mmio_gpa && + vcpu->run->mmio.len =3D=3D 8 && vcpu->run->mmio.is_write) { + uint64_t data =3D *(uint64_t *)vcpu->run->mmio.data; + + return (void *)data; + } + return NULL; + default: + if (run->exit_reason =3D=3D KVM_EXIT_IO && run->io.port =3D=3D UCALL_PIO= _PORT) { + struct kvm_regs regs; =20 - vcpu_regs_get(vcpu, ®s); - return (void *)regs.rdi; + vcpu_regs_get(vcpu, ®s); + return (void *)regs.rdi; + } + return NULL; } - return NULL; } --=20 2.51.0.536.g15c5d4f767-goog