From nobody Sun Oct 5 21:42:53 2025 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (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 ED3E52BE05B for ; Tue, 29 Jul 2025 22:55:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753829747; cv=none; b=io+qcB/5EyPNhauOdtm9KBlZS89aSEZjScMYn7XxToVg2XlLPouyijX8mJJsPRJipV8zB+EmOzNfEariR3BpleKlxXWmb3IpVy01uHF3dXB/wgBEzbY1nOu4HhRMSw2ZTSUO9OVQ4xO/AnYgsYxDEH0zs+ieDaRKGqRSFbwN9Ls= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753829747; c=relaxed/simple; bh=Sh/IfRFoYWaPKcCYaCpo6wz2Cjf9m+WXMtg9Zp0+6jw=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=pZbjYTYbPZgriRaHezmdKgdB3zfYA+bri8NJRzhiDxUHnWQAKXt6TxKkBQQpNA1HHUZBi6m+qyjbT5bzXoJgfUy0K5zuvDKLW51Tng5ya200PvqwNtmoMgJ0gKwP7RFvO8Xzvik+v7Iij7m5PkyBmGeBNBeJiuVkkzfGxlbnYOY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=cKRnjelS; arc=none smtp.client-ip=209.85.216.73 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--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="cKRnjelS" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-31eac278794so3523797a91.3 for ; Tue, 29 Jul 2025 15:55:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1753829745; x=1754434545; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=oV6gYTik8qRY3StGmPp/EUp2dAdw3D3Ak3GOGxl25v8=; b=cKRnjelS6OV9vgJoIZLd+O5acA0gMGTkpcZtVyrN+D/d4GiiBajbgsdYJzSx8R5l2g N/MnUjUc3uhfYYtg/fwQEAewo98CB4AB+rUhbpGXPBUV3lX7bX88K2wCOKPbFHIyCxv6 k0FhRKkflKaYwR71mFRfKvuY98NBrqHzvShNX5jscybxsTVxEsQ6I1l7NNTNiBQfCgdG vwJp6qZbXB/09a6Lz1BPOy6lys2kNrGPfyyDfx3s8efumI3Cb8MLn+rQ9qks4Qaqan2C lywJTS7kG+UplQbTmzTmF+Fvj5vU52NQ19Yqx2dM7NhcCxXpe7CDQZExPgIMmsOH0p2N pyjQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1753829745; x=1754434545; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=oV6gYTik8qRY3StGmPp/EUp2dAdw3D3Ak3GOGxl25v8=; b=C16Xwz//kjvVAMO0FrxBFcTv/iGOwopTEwNUadzw8Mj9N5RpeP5G7Ebj65VGgd57Zk q4ZhBqbaPcy7xtuQwUKyQuAHtsFcyv2Og0JGhUzqrDYb3m0Ue4WZFIdkh13WS7WXrJtm rmT1aAlfzA6KANU6aE/Pzyq8dwrg4WgeDpq0J2wqB/Svh+VzcCvd+6OI8CrtD0kGqNSK wVu4fIwFSEHelIGFUwoSaVZmKILRYaM8KXeIk0XlEMGKlTcgiUBNcbdLWlsghNb/7+sp dL+JrJHKvml1wWyRA1E6RCl6QOlNT9PWiSqq9q3+9sN7HP1Ez+FlGwXrjJTz/mzsCPVP IRIQ== X-Forwarded-Encrypted: i=1; AJvYcCWsU2dLIMoVoB3IbZR9Tg9mi+/dNwHtUxQfFHK90fBbtKtzhWJs/0lNNLdUjASH+Zi5X+rDGEmGd6Nsohk=@vger.kernel.org X-Gm-Message-State: AOJu0YwdJkJDOPeenQFqMKmwpYSwp1Vv4+AXEFpyIAK7uZTMoUPsgd48 FOApMkjuNr+luoEDoBr8QyOsht8ePftLQWETy3C2NqoBE+ADyZ4K/lSYRkxzCybTggwOu0jrLh1 Ghx0Sdw== X-Google-Smtp-Source: AGHT+IFUKuUgGE8Xp/j1VSO4HB6WlF8z7V2tvMpDcnp8m/G+j0eEa4knj1wWJuc7IsYN2X0Q+kKp6nFysik= X-Received: from pjbpv8.prod.google.com ([2002:a17:90b:3c88:b0:31e:998f:7b79]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:52c3:b0:31c:15d9:8ae with SMTP id 98e67ed59e1d1-31f5de68c89mr1509857a91.33.1753829745204; Tue, 29 Jul 2025 15:55:45 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 29 Jul 2025 15:54:40 -0700 In-Reply-To: <20250729225455.670324-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250729225455.670324-1-seanjc@google.com> X-Mailer: git-send-email 2.50.1.552.g942d659e1b-goog Message-ID: <20250729225455.670324-10-seanjc@google.com> Subject: [PATCH v17 09/24] KVM: x86: Enable KVM_GUEST_MEMFD for all 64-bit builds From: Sean Christopherson To: Paolo Bonzini , Marc Zyngier , Oliver Upton , Sean Christopherson Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, Ira Weiny , Gavin Shan , Shivank Garg , Vlastimil Babka , Xiaoyao Li , David Hildenbrand , Fuad Tabba , Ackerley Tng , Tao Chan , James Houghton Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Fuad Tabba Enable KVM_GUEST_MEMFD for all KVM x86 64-bit builds, i.e. for "default" VM types when running on 64-bit KVM. This will allow using guest_memfd to back non-private memory for all VM shapes, by supporting mmap() on guest_memfd. Opportunistically clean up various conditionals that become tautologies once x86 selects KVM_GUEST_MEMFD more broadly. Specifically, because SW protected VMs, SEV, and TDX are all 64-bit only, private memory no longer needs to take explicit dependencies on KVM_GUEST_MEMFD, because it is effectively a prerequisite. Suggested-by: Sean Christopherson Signed-off-by: Fuad Tabba Reviewed-by: Xiaoyao Li Reviewed-by: David Hildenbrand Signed-off-by: Sean Christopherson --- arch/x86/include/asm/kvm_host.h | 4 +--- arch/x86/kvm/Kconfig | 12 ++++-------- include/linux/kvm_host.h | 9 ++------- virt/kvm/kvm_main.c | 4 ++-- 4 files changed, 9 insertions(+), 20 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_hos= t.h index 7b0f2b3e492d..50366a1ca192 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -2276,10 +2276,8 @@ void kvm_configure_mmu(bool enable_tdp, int tdp_forc= ed_root_level, int tdp_max_root_level, int tdp_huge_page_level); =20 =20 -#ifdef CONFIG_KVM_GUEST_MEMFD +#ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES #define kvm_arch_has_private_mem(kvm) ((kvm)->arch.has_private_mem) -#else -#define kvm_arch_has_private_mem(kvm) false #endif =20 #define kvm_arch_has_readonly_mem(kvm) (!(kvm)->arch.has_protected_state) diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index c763446d9b9f..4e43923656d0 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -47,6 +47,7 @@ config KVM_X86 select KVM_GENERIC_HARDWARE_ENABLING select KVM_GENERIC_PRE_FAULT_MEMORY select KVM_WERROR if WERROR + select KVM_GUEST_MEMFD if X86_64 =20 config KVM tristate "Kernel-based Virtual Machine (KVM) support" @@ -79,16 +80,11 @@ config KVM_WERROR =20 If in doubt, say "N". =20 -config KVM_X86_PRIVATE_MEM - select KVM_GENERIC_MEMORY_ATTRIBUTES - select KVM_GUEST_MEMFD - bool - config KVM_SW_PROTECTED_VM bool "Enable support for KVM software-protected VMs" depends on EXPERT depends on KVM_X86 && X86_64 - select KVM_X86_PRIVATE_MEM + select KVM_GENERIC_MEMORY_ATTRIBUTES help Enable support for KVM software-protected VMs. Currently, software- protected VMs are purely a development and testing vehicle for @@ -138,7 +134,7 @@ config KVM_INTEL_TDX bool "Intel Trust Domain Extensions (TDX) support" default y depends on INTEL_TDX_HOST - select KVM_X86_PRIVATE_MEM + select KVM_GENERIC_MEMORY_ATTRIBUTES select HAVE_KVM_ARCH_GMEM_POPULATE help Provides support for launching Intel Trust Domain Extensions (TDX) @@ -162,7 +158,7 @@ config KVM_AMD_SEV depends on KVM_AMD && X86_64 depends on CRYPTO_DEV_SP_PSP && !(KVM_AMD=3Dy && CRYPTO_DEV_CCP_DD=3Dm) select ARCH_HAS_CC_PLATFORM - select KVM_X86_PRIVATE_MEM + select KVM_GENERIC_MEMORY_ATTRIBUTES select HAVE_KVM_ARCH_GMEM_PREPARE select HAVE_KVM_ARCH_GMEM_INVALIDATE select HAVE_KVM_ARCH_GMEM_POPULATE diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 56ea8c862cfd..4d1c44622056 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -719,11 +719,7 @@ static inline int kvm_arch_vcpu_memslots_id(struct kvm= _vcpu *vcpu) } #endif =20 -/* - * Arch code must define kvm_arch_has_private_mem if support for guest_mem= fd is - * enabled. - */ -#if !defined(kvm_arch_has_private_mem) && !IS_ENABLED(CONFIG_KVM_GUEST_MEM= FD) +#ifndef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES static inline bool kvm_arch_has_private_mem(struct kvm *kvm) { return false; @@ -2505,8 +2501,7 @@ bool kvm_arch_post_set_memory_attributes(struct kvm *= kvm, =20 static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn) { - return IS_ENABLED(CONFIG_KVM_GUEST_MEMFD) && - kvm_get_memory_attributes(kvm, gfn) & KVM_MEMORY_ATTRIBUTE_PRIVATE; + return kvm_get_memory_attributes(kvm, gfn) & KVM_MEMORY_ATTRIBUTE_PRIVATE; } #else static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index aa86dfd757db..4f57cb92e109 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1588,7 +1588,7 @@ static int check_memory_region_flags(struct kvm *kvm, { u32 valid_flags =3D KVM_MEM_LOG_DIRTY_PAGES; =20 - if (kvm_arch_has_private_mem(kvm)) + if (IS_ENABLED(CONFIG_KVM_GUEST_MEMFD)) valid_flags |=3D KVM_MEM_GUEST_MEMFD; =20 /* Dirty logging private memory is not currently supported. */ @@ -4917,7 +4917,7 @@ static int kvm_vm_ioctl_check_extension_generic(struc= t kvm *kvm, long arg) #endif #ifdef CONFIG_KVM_GUEST_MEMFD case KVM_CAP_GUEST_MEMFD: - return !kvm || kvm_arch_has_private_mem(kvm); + return 1; #endif default: break; --=20 2.50.1.552.g942d659e1b-goog