From patchwork Wed Apr 30 16:56:54 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fuad Tabba X-Patchwork-Id: 886093 Received: from mail-wm1-f73.google.com (mail-wm1-f73.google.com [209.85.128.73]) (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 BF4B7270EA1 for ; Wed, 30 Apr 2025 16:57:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746032245; cv=none; b=ZweKxIg6rztOnD9PUKn0Qp6n8gHO7Ow4DIG5Y8PuadZmeGKW+w4Xn/EfWu1+Gq9L2aFFy8jEC/YWTV5SJvuqjJ7aR51Ia+OTm85NCL9SwsmNYwrgAnLB3lWz4YF3vdci65xL93oa31vRHHAB2KblJOcTq6uGAoBjNZbxfvWaf+Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746032245; c=relaxed/simple; bh=XrKt/cQ1PJ4L8WD+acL5St80qFJz8v71jskxh3LK1WE=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=H6Lhbqnrgc5ZbB37hptpJ5E/Ft5Sa2+MWW+jJpbXQG0AmKV86j9MYiwLSX2HBmnRn5Hl4nNi/MaSBIL8oiTDs+WQFQ/3A2hq64c4Lu6eLLsbSWqRDjO2BeMUixlTpeWaPbrb2TtePG31vGxvkoo+0Iqg7qzJvT1VXytVR56xSYA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--tabba.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Ch2oQ6RN; arc=none smtp.client-ip=209.85.128.73 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--tabba.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Ch2oQ6RN" Received: by mail-wm1-f73.google.com with SMTP id 5b1f17b1804b1-43d6c65dc52so114215e9.1 for ; Wed, 30 Apr 2025 09:57:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1746032242; x=1746637042; 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=r8U8U1nhHclBviWvD96hvtWkHURwDxBT0dCfKidoius=; b=Ch2oQ6RNjM2pdVaWRzVFKWDiH6e+k3DqduHifO0ks8nBObuLR+t+zniR/gVGPDljoJ XJWGhfHutNC2cKnJhGM3p/5ZfUrgqze1QrRnLyeJgHkacRnK3h5CinxxtmdI9FSmg3/Y zrpHJMYlqxyoY0MAI9yvG4+0pXx5mGsvEUPERmu5WRMILZLRINzrOxrMwPL11GJMA/1F cS8ojRcl3zBqcrzmy83mYowcSbQ9qm4Ks1wDGNpQl3V/AGkoUe5RZAehnz0JZ7bPKcUE JsjFjZv0/Ak6abkELIIqaVwBEeQ1TyuFW4G5Ox9lKCt2087PJmUyMnJTwYasIcFLAdHa ypQg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1746032242; x=1746637042; 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=r8U8U1nhHclBviWvD96hvtWkHURwDxBT0dCfKidoius=; b=fWc8rmWoTZbvKDML/9lZ1lklAkmZG3mc04ITfTsY8T1y9mC3MmWHdNTVr/sa40V1mr Or2VE31jIuT5yLzWvXSgXsMmLtBrLAtkOdR8FWmNbmk/qV/O/rAMJ9+omB6C9Zu+BXS+ yhzuJB8K4m3IY8LsSvXIl3eTh1qs+pQrlwDAecL6V0Q5ZXMvLS887OHZzrCR4rkISJ3s /TiSY/ITNJ0miA+D/LfLdEOFIsb7gsL7rXd7hvxob3UXuInMdyOq5pWHpflFHSJSZpw5 e+l7X8RMB+dAKdx3/h9njmhuFD6qMAQS9ftPnrbYpyR5PCYpwL5jAzfXktmdlByVNbwH VE5Q== X-Forwarded-Encrypted: i=1; AJvYcCWimg77PWlflKk8e7RvjYa37L8Qp+kMofz0/i3kxEwI/Ae4t6s40pS9J9pFVhYypefvkD3vNsIiOke6Vz1v@vger.kernel.org X-Gm-Message-State: AOJu0YxBUxdhDZmlgQYJPQ6/0KDgJJhaYwQAf9aQwo8gJZiqSJJFOjgR J6Qd1iVeRo13m4sP0NbxxMbGWVMnMFphfnejOL/xLvzy+WpFVN30/TDd0EDLnRAoM1p7KwrrJA= = X-Google-Smtp-Source: AGHT+IH7GwjRIYej47ad9eSczR4IN/8XTDl2Y0w5DE8LJkqljmss+RSdA/meE0fu/iiOZNhdn1995hFeMQ== X-Received: from wmbep11.prod.google.com ([2002:a05:600c:840b:b0:43b:c7e5:66e0]) (user=tabba job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:1c12:b0:43d:4686:5cfb with SMTP id 5b1f17b1804b1-441b1f5fc52mr33367835e9.27.1746032242127; Wed, 30 Apr 2025 09:57:22 -0700 (PDT) Date: Wed, 30 Apr 2025 17:56:54 +0100 In-Reply-To: <20250430165655.605595-1-tabba@google.com> Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250430165655.605595-1-tabba@google.com> X-Mailer: git-send-email 2.49.0.967.g6a0df3ecc3-goog Message-ID: <20250430165655.605595-13-tabba@google.com> Subject: [PATCH v8 12/13] KVM: x86: KVM_X86_SW_PROTECTED_VM to support guest_memfd shared memory From: Fuad Tabba To: kvm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mm@kvack.org Cc: pbonzini@redhat.com, chenhuacai@kernel.org, mpe@ellerman.id.au, anup@brainfault.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, seanjc@google.com, viro@zeniv.linux.org.uk, brauner@kernel.org, willy@infradead.org, akpm@linux-foundation.org, xiaoyao.li@intel.com, yilun.xu@intel.com, chao.p.peng@linux.intel.com, jarkko@kernel.org, amoorthy@google.com, dmatlack@google.com, isaku.yamahata@intel.com, mic@digikod.net, vbabka@suse.cz, vannapurve@google.com, ackerleytng@google.com, mail@maciej.szmigiero.name, david@redhat.com, michael.roth@amd.com, wei.w.wang@intel.com, liam.merwick@oracle.com, isaku.yamahata@gmail.com, kirill.shutemov@linux.intel.com, suzuki.poulose@arm.com, steven.price@arm.com, quic_eberman@quicinc.com, quic_mnalajal@quicinc.com, quic_tsoni@quicinc.com, quic_svaddagi@quicinc.com, quic_cvanscha@quicinc.com, quic_pderrin@quicinc.com, quic_pheragu@quicinc.com, catalin.marinas@arm.com, james.morse@arm.com, yuzenghui@huawei.com, oliver.upton@linux.dev, maz@kernel.org, will@kernel.org, qperret@google.com, keirf@google.com, roypat@amazon.co.uk, shuah@kernel.org, hch@infradead.org, jgg@nvidia.com, rientjes@google.com, jhubbard@nvidia.com, fvdl@google.com, hughd@google.com, jthoughton@google.com, peterx@redhat.com, pankaj.gupta@amd.com, tabba@google.com The KVM_X86_SW_PROTECTED_VM type is meant for experimentation and does not have underlying support for protected guests. This makes it a good candidate for testing mapping shared memory. Therefore, only when the kconfig option for in-place shared memory is enabled (KVM_GMEM_SHARED_MEM), mark this type as supporting shared memory. This means that this memory is considered by guest_memfd to be shared with the host, which is now able to map and fault in guest_memfd memory belonging to this VM type. Signed-off-by: Fuad Tabba --- arch/x86/include/asm/kvm_host.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 709cc2a7ba66..1858dde449c3 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -2255,8 +2255,13 @@ void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, #ifdef CONFIG_KVM_GMEM #define kvm_arch_supports_gmem(kvm) ((kvm)->arch.supports_gmem) + +#define kvm_arch_gmem_supports_shared_mem(kvm) \ + (IS_ENABLED(CONFIG_KVM_GMEM_SHARED_MEM) && \ + ((kvm)->arch.vm_type == KVM_X86_SW_PROTECTED_VM)) #else #define kvm_arch_supports_gmem(kvm) false +#define kvm_arch_gmem_supports_shared_mem(kvm) false #endif #define kvm_arch_has_readonly_mem(kvm) (!(kvm)->arch.has_protected_state)