From patchwork Mon Nov 13 02:23:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= X-Patchwork-Id: 13453570 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 92BEB18B08 for ; Mon, 13 Nov 2023 02:32:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=digikod.net header.i=@digikod.net header.b="vrln9/b4" Received: from smtp-42ac.mail.infomaniak.ch (smtp-42ac.mail.infomaniak.ch [IPv6:2001:1600:4:17::42ac]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D16C10E6 for ; Sun, 12 Nov 2023 18:32:29 -0800 (PST) Received: from smtp-3-0001.mail.infomaniak.ch (unknown [10.4.36.108]) by smtp-3-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4STCtJ0ZdVzMpvZk; Mon, 13 Nov 2023 02:24:24 +0000 (UTC) Received: from unknown by smtp-3-0001.mail.infomaniak.ch (Postfix) with ESMTPA id 4STCtG6J2GzMpnPd; Mon, 13 Nov 2023 03:24:22 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=digikod.net; s=20191114; t=1699842263; bh=oVoPkAWjPfqZGemyyPZ53MkaSuuZZCG0BkbPtJbgAiE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vrln9/b46q/IyvbLiM7gr/pjSy6nNAlaXyCcWrkwCHL76184CKYv4PInqVYTmM3XU usQOOb2erA5xMR73/PzeYEi/AVI+wGVine2Q4AcSnr9lSM8X4meSz+MPB7uM5eZm7x SS5OjADjVFHRajKr3cVBhD/5XC7T3gtprqTK5mks= From: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= To: Borislav Petkov , Dave Hansen , "H . Peter Anvin" , Ingo Molnar , Kees Cook , Paolo Bonzini , Sean Christopherson , Thomas Gleixner , Vitaly Kuznetsov , Wanpeng Li Cc: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= , Alexander Graf , Chao Peng , "Edgecombe, Rick P" , Forrest Yuan Yu , James Gowans , James Morris , John Andersen , "Madhavan T . Venkataraman" , Marian Rotariu , =?utf-8?q?Mihai_Don=C8=9Bu?= , =?utf-8?b?TmljdciZ?= =?utf-8?b?b3IgQ8OuyJt1?= , Thara Gopinath , Trilok Soni , Wei Liu , Will Deacon , Yu Zhang , Zahra Tarkhani , =?utf-8?q?=C8=98tefan_=C8=98icler?= =?utf-8?q?u?= , dev@lists.cloudhypervisor.org, kvm@vger.kernel.org, linux-hardening@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, x86@kernel.org, xen-devel@lists.xenproject.org Subject: [RFC PATCH v2 08/19] KVM: x86: Extend kvm_vm_set_mem_attributes() with a mask Date: Sun, 12 Nov 2023 21:23:15 -0500 Message-ID: <20231113022326.24388-9-mic@digikod.net> In-Reply-To: <20231113022326.24388-1-mic@digikod.net> References: <20231113022326.24388-1-mic@digikod.net> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Infomaniak-Routing: alpha Enable to only update a subset of attributes. This is needed to be able to use the XArray for different use cases and make sure they don't interfere (see a following commit). Cc: Chao Peng Cc: Kees Cook Cc: Madhavan T. Venkataraman Cc: Sean Christopherson Cc: Yu Zhang Signed-off-by: Mickaël Salaün --- Changes since v1: * New patch --- arch/x86/kvm/mmu/mmu.c | 2 +- include/linux/kvm_host.h | 2 +- virt/kvm/kvm_main.c | 27 +++++++++++++++++++-------- 3 files changed, 21 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 4d378d308762..d7010e09440d 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -7283,7 +7283,7 @@ static bool hugepage_has_attrs(struct kvm *kvm, struct kvm_memory_slot *slot, for (gfn = start; gfn < end; gfn += KVM_PAGES_PER_HPAGE(level - 1)) { if (hugepage_test_mixed(slot, gfn, level - 1) || - attrs != kvm_get_memory_attributes(kvm, gfn)) + !(attrs & kvm_get_memory_attributes(kvm, gfn))) return false; } return true; diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 85b8648fd892..de68390ab0f2 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -2397,7 +2397,7 @@ bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm, bool kvm_arch_post_set_memory_attributes(struct kvm *kvm, struct kvm_gfn_range *range); int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end, - unsigned long attributes); + unsigned long attributes, unsigned long mask); 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 0096ccfbb609..e2c178db17d5 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2436,7 +2436,7 @@ static int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm, #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES /* * Returns true if _all_ gfns in the range [@start, @end) have attributes - * matching @attrs. + * matching the @attrs bitmask. */ bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end, unsigned long attrs) @@ -2459,7 +2459,8 @@ bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end, entry = xas_next(&xas); } while (xas_retry(&xas, entry)); - if (xas.xa_index != index || xa_to_value(entry) != attrs) { + if (xas.xa_index != index || + (xa_to_value(entry) & attrs) != attrs) { has_attrs = false; break; } @@ -2553,7 +2554,7 @@ static bool kvm_pre_set_memory_attributes(struct kvm *kvm, /* Set @attributes for the gfn range [@start, @end). */ int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end, - unsigned long attributes) + unsigned long attributes, unsigned long mask) { struct kvm_mmu_notifier_range pre_set_range = { .start = start, @@ -2572,11 +2573,8 @@ int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end, .may_block = true, }; unsigned long i; - void *entry; int r = 0; - entry = attributes ? xa_mk_value(attributes) : NULL; - lockdep_assert_held(&kvm->slots_arch_lock); /* Nothing to do if the entire range as the desired attributes. */ @@ -2596,6 +2594,16 @@ int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end, kvm_handle_gfn_range(kvm, &pre_set_range); for (i = start; i < end; i++) { + unsigned long value = 0; + void *entry; + + entry = xa_load(&kvm->mem_attr_array, i); + if (xa_is_value(entry)) + value = xa_to_value(entry) & ~mask; + + value |= attributes & mask; + entry = value ? xa_mk_value(value) : NULL; + r = xa_err(xa_store(&kvm->mem_attr_array, i, entry, GFP_KERNEL_ACCOUNT)); KVM_BUG_ON(r, kvm); @@ -2609,12 +2617,14 @@ static int kvm_vm_ioctl_set_mem_attributes(struct kvm *kvm, struct kvm_memory_attributes *attrs) { int r; + unsigned long attrs_mask; gfn_t start, end; /* flags is currently not used. */ if (attrs->flags) return -EINVAL; - if (attrs->attributes & ~kvm_supported_mem_attributes(kvm)) + attrs_mask = kvm_supported_mem_attributes(kvm); + if (attrs->attributes & ~attrs_mask) return -EINVAL; if (attrs->size == 0 || attrs->address + attrs->size < attrs->address) return -EINVAL; @@ -2632,7 +2642,8 @@ static int kvm_vm_ioctl_set_mem_attributes(struct kvm *kvm, BUILD_BUG_ON(sizeof(attrs->attributes) != sizeof(unsigned long)); mutex_lock(&kvm->slots_arch_lock); - r = kvm_vm_set_mem_attributes(kvm, start, end, attrs->attributes); + r = kvm_vm_set_mem_attributes(kvm, start, end, attrs->attributes, + attrs_mask); mutex_unlock(&kvm->slots_arch_lock); return r; }