From nobody Fri Oct 31 16:24:01 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=gmail.com ARC-Seal: i=1; a=rsa-sha256; t=1748375805; cv=none; d=zohomail.com; s=zohoarc; b=dOlghqyjlciQz9a/uANgZ1ixyrys7S4Xuag+Hh93k01u2mAdN8l7lp30JlC9WI2RWMS4fXfA7Kz8KN3nSFqVJoHS1HZmyUNPIUAjHqv1eRwGJN8KZkPKGP8whB+zk6dz7IpTmcqZdOcDormJjQz+lpnnov0ThSZpI68CuUbvQJ8= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1748375805; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=PW4Ul/brgurN+ahlG/LjWsE4mRdaFGlUa4ZnyTf/6ck=; b=eqlqW+xf53DBmMOGR9UCiQ2xWZBdb/LU+j+djcdZRbbd0VzQc9wQtLF4hGnJFcqa2B4h1uSp2yGGm5UCE4xlrYxOT1ileR687NpZyRaVb9UpedOdNy8AU0jiodiw+vPCcv4CyuW+W+HRlRbssly1PMV7MduXkHXsZlilmT46I00= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1748375805668429.07707977170094; Tue, 27 May 2025 12:56:45 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.998702.1379432 (Exim 4.92) (envelope-from ) id 1uK0PQ-0006tn-OE; Tue, 27 May 2025 19:56:24 +0000 Received: by outflank-mailman (output) from mailman id 998702.1379432; Tue, 27 May 2025 19:56:24 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uK0PQ-0006tg-JR; Tue, 27 May 2025 19:56:24 +0000 Received: by outflank-mailman (input) for mailman id 998702; Tue, 27 May 2025 19:56:22 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uK0PO-0006fw-S7 for xen-devel@lists.xenproject.org; Tue, 27 May 2025 19:56:22 +0000 Received: from mail-lf1-x132.google.com (mail-lf1-x132.google.com [2a00:1450:4864:20::132]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id a9ee8c48-3b34-11f0-a2fe-13f23c93f187; Tue, 27 May 2025 21:56:22 +0200 (CEST) Received: by mail-lf1-x132.google.com with SMTP id 2adb3069b0e04-553280c345cso1315068e87.0 for ; Tue, 27 May 2025 12:56:22 -0700 (PDT) Received: from gmail.com (213-67-3-247-no600.tbcn.telia.com. [213.67.3.247]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-5532ee71af1sm4355e87.212.2025.05.27.12.56.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 May 2025 12:56:19 -0700 (PDT) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: a9ee8c48-3b34-11f0-a2fe-13f23c93f187 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1748375781; x=1748980581; darn=lists.xenproject.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=PW4Ul/brgurN+ahlG/LjWsE4mRdaFGlUa4ZnyTf/6ck=; b=bw/xY25X28E+cPcQavaGvMJAf8FI5XSin7ALy7NZHdn/AUSjuZjd4AATsf/QHh+c7v hNdJQV1Svwmvenii3WIOZ/+1bLWwB0p9FBbe6g+9efqpT1mMFSuQKih0dCYLIViwSw1G IV94JfpaseMJJdkI1NWZE7PJUNTJrpu8oeCJmWe885E3ppSr5ndmfzn01yiyyCOO53nJ +zM0y58S59wI0kupc+0IiF9K/sv89gxjnio6OsBe+5VgGRFcx4TxjR0CDoKt0vmejyHd GCvk0rKVexm+2uIos9t/FCdqVpDr5Jlgs2YYRW8RwJm25m3A/Ay2VPWX73WKf8Uc3qpW pzyw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1748375781; x=1748980581; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=PW4Ul/brgurN+ahlG/LjWsE4mRdaFGlUa4ZnyTf/6ck=; b=NIp+2Q5dkuRjdl/ugDSn7IJETKfLdPIZMt1dDRhBT//trBbqzWaVJsqtSCLbTl3d26 1W+9nzdjMrZcYbad5OEw5zdsiGfxtVjziH8MPZOD3p04vtfb0wS0nNVRR2Sq2mIhA+Zm P1jzWu5ml+OPEV29VSSs09ZynRMH9+1ZLMTwYwvfRufzvhLq8Gvmv3vYpAsYoRQIQ/4n H4eO4NmxW6wXojthmMDn1TapfGC/qU+s0/ZeUCKoOaJMDgh4IbLVa6YGSjInbqx3IkB5 EYdhMpMd7CbZvOicFNRfBKBsXxvdNcGhdcdY1W31OaLNrFD1mlRi92LgZzqbovjzyY/X MEOA== X-Gm-Message-State: AOJu0YwC3B1Jy/3sVacn574JU/hr9Lgr8A1dK+fwPwu8+NiQxm0P2bHh hBK/wMJk2vNkF6hMBrp0aCgjeRe/8V+GvhdQ5k2ODJ0OsJBQtDzBzOHdnDMkDFN0i2k= X-Gm-Gg: ASbGnctaAUr7RSASOg/0jpGySVIqh67gh++EIhuN1BLglusxCHb94rUyiLGbMJA87R6 U/VtZa0N8IkZIXCSFsff0fJUQnl7iHv6pko+27j/x0rCUhSFkPGchGWQ0JtrriDykcq1askFUgO cKqDIqv3qsA370JTnh5Kdwf4EtzSiKEAaVWJf/7R0IMNILihLWQiY1XxaOGR2ykzNz6IOVTHN+p I4k/vp6STwr2t05zxBHkFzJYgKqax6X0MR016a8FMkgN3Xsa0fRFsJKFChK/DUikjk7BFzCWAzi i6Kg8cWwtUKRaChvAWKMr6P59Gdilqt4iIBACTVPx8gjyg9wxAna3293CgqQwPzBjV1TU4VXzt5 osk67u6bB7n8Uuh5uiHQpxK0= X-Google-Smtp-Source: AGHT+IHrDm2Qy6vp9VEqaHnRTakLi2LeAuU7KzcB3N2VPuRneBPy+2xU8AZM4IMeoq4oAeVXe0vaGA== X-Received: by 2002:a05:6512:68f:b0:54f:cc4e:a9ef with SMTP id 2adb3069b0e04-5521cba987cmr4748985e87.43.1748375781216; Tue, 27 May 2025 12:56:21 -0700 (PDT) From: "Edgar E. Iglesias" To: xen-devel@lists.xenproject.org Cc: sstabellini@kernel.org, julien@xen.org, bertrand.marquis@arm.com, michal.orzel@amd.com, Volodymyr_Babchuk@epam.com, edgar.iglesias@amd.com, Anthony PERARD , Juergen Gross Subject: [PATCH v1 1/3] xen/arm: Add a way to disable traps on unmapped MMIO Date: Tue, 27 May 2025 21:56:14 +0200 Message-ID: <20250527195616.874614-2-edgar.iglesias@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250527195616.874614-1-edgar.iglesias@gmail.com> References: <20250527195616.874614-1-edgar.iglesias@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @gmail.com) X-ZM-MESSAGEID: 1748375806415116600 Content-Type: text/plain; charset="utf-8" From: "Edgar E. Iglesias" Add a per-domain way to optionally disable traps on unmapped MMIO. Signed-off-by: Edgar E. Iglesias --- tools/libs/light/libxl_arm.c | 3 +++ xen/arch/arm/dom0less-build.c | 3 +++ xen/arch/arm/domain.c | 2 ++ xen/arch/arm/domain_build.c | 3 +++ xen/arch/arm/include/asm/domain.h | 2 ++ xen/arch/arm/io.c | 33 +++++++++++++++++++++++++++++-- xen/include/public/arch-arm.h | 9 +++++++++ 7 files changed, 53 insertions(+), 2 deletions(-) diff --git a/tools/libs/light/libxl_arm.c b/tools/libs/light/libxl_arm.c index 75c811053c..40cd005619 100644 --- a/tools/libs/light/libxl_arm.c +++ b/tools/libs/light/libxl_arm.c @@ -233,6 +233,9 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc, config->arch.sve_vl =3D d_config->b_info.arch_arm.sve_vl / 128U; } =20 + /* Trap accesses to unmapped MMIO. */ + config->arch.flags =3D XEN_ARM_TRAP_UNMAPPED_MMIO; + return 0; } =20 diff --git a/xen/arch/arm/dom0less-build.c b/xen/arch/arm/dom0less-build.c index a49764f0ad..e5e13e07d0 100644 --- a/xen/arch/arm/dom0less-build.c +++ b/xen/arch/arm/dom0less-build.c @@ -343,6 +343,9 @@ void __init arch_create_domUs(struct dt_device_node *no= de, panic("'sve' property found, but CONFIG_ARM64_SVE not selected\n"); #endif } + + /* Trap accesses to unmapped MMIO. */ + d_cfg->arch.flags =3D XEN_ARM_TRAP_UNMAPPED_MMIO; } =20 int __init init_intc_phandle(struct kernel_info *kinfo, const char *name, diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c index 45aeb8bddc..54c6ae7678 100644 --- a/xen/arch/arm/domain.c +++ b/xen/arch/arm/domain.c @@ -714,6 +714,8 @@ int arch_domain_create(struct domain *d, ioreq_domain_init(d); #endif =20 + d->arch.trap_unmapped_mmio =3D config->arch.flags & XEN_ARM_TRAP_UNMAP= PED_MMIO; + /* p2m_init relies on some value initialized by the IOMMU subsystem */ if ( (rc =3D iommu_domain_init(d, config->iommu_opts)) !=3D 0 ) goto fail; diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c index b189a7cfae..c3c8212260 100644 --- a/xen/arch/arm/domain_build.c +++ b/xen/arch/arm/domain_build.c @@ -2018,6 +2018,9 @@ void __init create_dom0(void) dom0_cfg.arch.tee_type =3D tee_get_type(); dom0_cfg.max_vcpus =3D dom0_max_vcpus(); =20 + /* Dom0 always traps on unmapped MMIO. */ + dom0_cfg.arch.flags |=3D XEN_ARM_TRAP_UNMAPPED_MMIO; + if ( iommu_enabled ) dom0_cfg.flags |=3D XEN_DOMCTL_CDF_iommu; =20 diff --git a/xen/arch/arm/include/asm/domain.h b/xen/arch/arm/include/asm/d= omain.h index a3487ca713..4d1a180ce2 100644 --- a/xen/arch/arm/include/asm/domain.h +++ b/xen/arch/arm/include/asm/domain.h @@ -121,6 +121,8 @@ struct arch_domain void *tee; #endif =20 + bool trap_unmapped_mmio; + } __cacheline_aligned; =20 struct arch_vcpu diff --git a/xen/arch/arm/io.c b/xen/arch/arm/io.c index 5a4b0e8f25..11ffa48969 100644 --- a/xen/arch/arm/io.c +++ b/xen/arch/arm/io.c @@ -21,6 +21,32 @@ =20 #include "decode.h" =20 +/* Handler for unmapped ranges. Writes ignored, reads return all ones. */ +static int unmapped_read(struct vcpu *v, mmio_info_t *info, register_t *r, + void *priv) +{ + uint64_t mask =3D GENMASK_ULL((1U << info->dabt.size) * 8 - 1, 0); + + /* Mask off upper bits. */ + *r =3D UINT64_MAX & mask; + return 1; +} + +static int unmapped_write(struct vcpu *v, mmio_info_t *info, register_t r, + void *priv) +{ + return 1; +} + +static const struct mmio_handler_ops unmapped_ops =3D { + .read =3D unmapped_read, + .write =3D unmapped_write +}; + +static const struct mmio_handler unmapped_handler =3D { + .ops =3D &unmapped_ops +}; + static enum io_state handle_read(const struct mmio_handler *handler, struct vcpu *v, mmio_info_t *info) @@ -178,8 +204,11 @@ enum io_state try_handle_mmio(struct cpu_user_regs *re= gs, rc =3D try_fwd_ioserv(regs, v, info); if ( rc =3D=3D IO_HANDLED ) return handle_ioserv(regs, v); - - return rc; + else if ( rc =3D=3D IO_UNHANDLED && !v->domain->arch.trap_unmapped= _mmio ) { + /* Fallback to the unmapped handler. */ + handler =3D &unmapped_handler; + } else + return rc; } =20 /* diff --git a/xen/include/public/arch-arm.h b/xen/include/public/arch-arm.h index e2412a1747..32b023504d 100644 --- a/xen/include/public/arch-arm.h +++ b/xen/include/public/arch-arm.h @@ -350,6 +350,15 @@ struct xen_arch_domainconfig { * */ uint32_t clock_frequency; + /* + * IN + * + * XEN_ARM_TRAP_UNMAPPED_MMIO enables trapping of memory accesses + * into unmapped ranges. When disabled, Xen will handle the access + * by reading 0xFFFFFFFF and ignoring writes. + */ +#define XEN_ARM_TRAP_UNMAPPED_MMIO (1U << 0) + uint32_t flags; }; #endif /* __XEN__ || __XEN_TOOLS__ */ =20 --=20 2.43.0