From patchwork Thu Apr 4 18:50:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 13618141 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 8FB4F1332A1 for ; Thu, 4 Apr 2024 18:50:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712256643; cv=none; b=KoH5TIK8akXnXikFRxu1AEXIqyok5BEjkMiHJ2MCvNfhhsG4GTw9UUxemhT29WK1gPR/m3HbHqSC/9Q+QaPyv3bqVe+lLHXkqnowCUQQ2fY10cRf4JCVX80A3xNwMccKozTj5K8Z4wNURuFARFHE65eAB33GnHtA/jHSWo5WihE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712256643; c=relaxed/simple; bh=lH7jR8Jko64IRgmkF8sRM1H2UWKCIFsqlXz2X8glJ+Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=mxk1M0Qr+obnVzD3OCtVscfA+tXpwfxd9BO7AV9jxrAYR5d7bVm++NN8XmIVxSE4YbTCRgc4xgCDMt4qvy7tae5ZKjm/6Mmt6nI0C3EOSjwFylijlXcK7MB+624tdC9Z0w3SISOJTT4vE1C6V4YTS5fpH5a0QL2kQaO5LcaTAKk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=GU9GywVC; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GU9GywVC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1712256640; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BGuDZxdd8LJgYrU56BO8/CIic8VVHhfGx5lnP9x/JCo=; b=GU9GywVCPgKwSqd8rYgTe81RrxrItpsCnfxwVM3LQv2I/4bHv2OtyjkhFOdSGCFD9o2edA o6c/Z65pXMZ7piZr1GJhBm2A0xPsc6DjQkGxDgyBoYuCCjcDTcVbD8bp0Ol7EOjTJJGABy +qT1vtLDFUeIxMAqsm48kO/xLSH96wo= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-42-TU-jMcaSNrCubAMbdTs3rg-1; Thu, 04 Apr 2024 14:50:37 -0400 X-MC-Unique: TU-jMcaSNrCubAMbdTs3rg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id DA5EF8007A1; Thu, 4 Apr 2024 18:50:36 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id B2EF7200A386; Thu, 4 Apr 2024 18:50:36 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: seanjc@google.com, michael.roth@amd.com, isaku.yamahata@intel.com Subject: [PATCH 10/11] KVM: guest_memfd: Add hook for invalidating memory Date: Thu, 4 Apr 2024 14:50:32 -0400 Message-ID: <20240404185034.3184582-11-pbonzini@redhat.com> In-Reply-To: <20240404185034.3184582-1-pbonzini@redhat.com> References: <20240404185034.3184582-1-pbonzini@redhat.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.4 From: Michael Roth In some cases, like with SEV-SNP, guest memory needs to be updated in a platform-specific manner before it can be safely freed back to the host. Wire up arch-defined hooks to the .free_folio kvm_gmem_aops callback to allow for special handling of this sort when freeing memory in response to FALLOC_FL_PUNCH_HOLE operations and when releasing the inode, and go ahead and define an arch-specific hook for x86 since it will be needed for handling memory used for SEV-SNP guests. Signed-off-by: Michael Roth Message-Id: <20231230172351.574091-6-michael.roth@amd.com> Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm-x86-ops.h | 1 + arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/x86.c | 7 +++++++ include/linux/kvm_host.h | 4 ++++ virt/kvm/Kconfig | 4 ++++ virt/kvm/guest_memfd.c | 14 ++++++++++++++ 6 files changed, 31 insertions(+) diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index d26fcad13e36..c81990937ab4 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -140,6 +140,7 @@ KVM_X86_OP_OPTIONAL_RET0(vcpu_get_apicv_inhibit_reasons); KVM_X86_OP_OPTIONAL(get_untagged_addr) KVM_X86_OP_OPTIONAL(alloc_apic_backing_page) KVM_X86_OP_OPTIONAL_RET0(gmem_prepare) +KVM_X86_OP_OPTIONAL(gmem_invalidate) #undef KVM_X86_OP #undef KVM_X86_OP_OPTIONAL diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index f101fab0040e..59c7b95034fc 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1810,6 +1810,7 @@ struct kvm_x86_ops { gva_t (*get_untagged_addr)(struct kvm_vcpu *vcpu, gva_t gva, unsigned int flags); void *(*alloc_apic_backing_page)(struct kvm_vcpu *vcpu); int (*gmem_prepare)(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order); + void (*gmem_invalidate)(kvm_pfn_t start, kvm_pfn_t end); }; struct kvm_x86_nested_ops { diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 972524ddcfdb..83b8260443a3 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -13605,6 +13605,13 @@ int kvm_arch_gmem_prepare(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, int max_ord } #endif +#ifdef CONFIG_HAVE_KVM_GMEM_INVALIDATE +void kvm_arch_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end) +{ + static_call_cond(kvm_x86_gmem_invalidate)(start, end); +} +#endif + int kvm_spec_ctrl_test_value(u64 value) { /* diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 97d57ec59789..ab439706ea2f 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -2476,4 +2476,8 @@ long kvm_gmem_populate(struct kvm *kvm, gfn_t gfn, void __user *src, long npages void __user *src, int order, void *opaque), void *opaque); +#ifdef CONFIG_HAVE_KVM_GMEM_INVALIDATE +void kvm_arch_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end); +#endif + #endif diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index ca870157b2ed..754c6c923427 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -113,3 +113,7 @@ config KVM_GENERIC_PRIVATE_MEM config HAVE_KVM_GMEM_PREPARE bool depends on KVM_PRIVATE_MEM + +config HAVE_KVM_GMEM_INVALIDATE + bool + depends on KVM_PRIVATE_MEM diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index e7de97382a67..d6b92d9b935a 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -360,10 +360,24 @@ static int kvm_gmem_error_folio(struct address_space *mapping, struct folio *fol return MF_DELAYED; } +#ifdef CONFIG_HAVE_KVM_GMEM_INVALIDATE +static void kvm_gmem_free_folio(struct folio *folio) +{ + struct page *page = folio_page(folio, 0); + kvm_pfn_t pfn = page_to_pfn(page); + int order = folio_order(folio); + + kvm_arch_gmem_invalidate(pfn, pfn + (1ul << order)); +} +#endif + static const struct address_space_operations kvm_gmem_aops = { .dirty_folio = noop_dirty_folio, .migrate_folio = kvm_gmem_migrate_folio, .error_remove_folio = kvm_gmem_error_folio, +#ifdef CONFIG_HAVE_KVM_GMEM_INVALIDATE + .free_folio = kvm_gmem_free_folio, +#endif }; static int kvm_gmem_getattr(struct mnt_idmap *idmap, const struct path *path,