From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4E308EE4996 for ; Mon, 21 Aug 2023 08:47:37 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qY0Ya-0000Rw-9X; Mon, 21 Aug 2023 04:46:40 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qY0YZ-0000Ro-2G for qemu-devel@nongnu.org; Mon, 21 Aug 2023 04:46:39 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qY0YW-0004NU-CL for qemu-devel@nongnu.org; Mon, 21 Aug 2023 04:46:38 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1692607595; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=KinkQpWMVM+Uw33LLiNw2lBPP3gHnMZJKG8+W5k8YU8=; b=Asa5XlrCKVKJdeCTaSnx6DpQbuvlvjNqVjUMaxnVgeoWGIokI3/aQG8UJyLiFt7D4zjpta 3i+KuRmHvrehB9rtagNUi8cZuvqSfNc9p5XCE0SBcK7rzbQqG0qAs1/3NPAKmEqf9HbocN S5zSuDLJ3bBELbFRGKJEuyfkf+SSAEk= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-27-l1npuk_pOWCIVxQBVZ_igw-1; Mon, 21 Aug 2023 04:46:31 -0400 X-MC-Unique: l1npuk_pOWCIVxQBVZ_igw-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C27A68030A9; Mon, 21 Aug 2023 08:46:30 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.139]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1FE66492C13; Mon, 21 Aug 2023 08:46:27 +0000 (UTC) Date: Mon, 21 Aug 2023 09:46:26 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Xiaoyao Li Cc: Paolo Bonzini , Richard Henderson , "Michael S. Tsirkin" , Marcel Apfelbaum , Igor Mammedov , Ani Sinha , Peter Xu , David Hildenbrand , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , Cornelia Huck , Eric Blake , Markus Armbruster , Marcelo Tosatti , Gerd Hoffmann , qemu-devel@nongnu.org, kvm@vger.kernel.org, Eduardo Habkost , Laszlo Ersek , Isaku Yamahata , erdemaktas@google.com, Chenyi Qiang Subject: Re: [PATCH v2 06/58] i386/tdx: Get tdx_capabilities via KVM_TDX_CAPABILITIES Message-ID: References: <20230818095041.1973309-1-xiaoyao.li@intel.com> <20230818095041.1973309-7-xiaoyao.li@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230818095041.1973309-7-xiaoyao.li@intel.com> User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, Aug 18, 2023 at 05:49:49AM -0400, Xiaoyao Li wrote: > KVM provides TDX capabilities via sub command KVM_TDX_CAPABILITIES of > IOCTL(KVM_MEMORY_ENCRYPT_OP). Get the capabilities when initializing > TDX context. It will be used to validate user's setting later. > > Since there is no interface reporting how many cpuid configs contains in > KVM_TDX_CAPABILITIES, QEMU chooses to try starting with a known number > and abort when it exceeds KVM_MAX_CPUID_ENTRIES. > > Besides, introduce the interfaces to invoke TDX "ioctls" at different > scope (KVM, VM and VCPU) in preparation. > > Signed-off-by: Xiaoyao Li > --- > changes from v1: > - Make the error message more clear; > > changes from RFC v4: > - start from nr_cpuid_configs = 6 for the loop; > - stop the loop when nr_cpuid_configs exceeds KVM_MAX_CPUID_ENTRIES; > --- > target/i386/kvm/kvm.c | 2 - > target/i386/kvm/kvm_i386.h | 2 + > target/i386/kvm/tdx.c | 93 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 95 insertions(+), 2 deletions(-) > > diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c > index d6b988d6c2d1..ec5c07bffd38 100644 > --- a/target/i386/kvm/kvm.c > +++ b/target/i386/kvm/kvm.c > @@ -1751,8 +1751,6 @@ static int hyperv_init_vcpu(X86CPU *cpu) > > static Error *invtsc_mig_blocker; > > -#define KVM_MAX_CPUID_ENTRIES 100 > - > static void kvm_init_xsave(CPUX86State *env) > { > if (has_xsave2) { > diff --git a/target/i386/kvm/kvm_i386.h b/target/i386/kvm/kvm_i386.h > index ea3a5b174ac0..769eadbba56c 100644 > --- a/target/i386/kvm/kvm_i386.h > +++ b/target/i386/kvm/kvm_i386.h > @@ -13,6 +13,8 @@ > > #include "sysemu/kvm.h" > > +#define KVM_MAX_CPUID_ENTRIES 100 > + > #define kvm_apic_in_kernel() (kvm_irqchip_in_kernel()) > > #ifdef CONFIG_KVM > diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c > index 77e33ae01147..255c47a2a553 100644 > --- a/target/i386/kvm/tdx.c > +++ b/target/i386/kvm/tdx.c > @@ -12,14 +12,107 @@ > */ > > #include "qemu/osdep.h" > +#include "qemu/error-report.h" > #include "qapi/error.h" > #include "qom/object_interfaces.h" > +#include "sysemu/kvm.h" > > #include "hw/i386/x86.h" > +#include "kvm_i386.h" > #include "tdx.h" > > +static struct kvm_tdx_capabilities *tdx_caps; > + > +enum tdx_ioctl_level{ > + TDX_PLATFORM_IOCTL, > + TDX_VM_IOCTL, > + TDX_VCPU_IOCTL, > +}; > + > +static int __tdx_ioctl(void *state, enum tdx_ioctl_level level, int cmd_id, > + __u32 flags, void *data) Names with an initial double underscore are reserved for us by the platform implementation, so shouldn't be used in userspace app code. > +{ > + struct kvm_tdx_cmd tdx_cmd; > + int r; > + > + memset(&tdx_cmd, 0x0, sizeof(tdx_cmd)); > + > + tdx_cmd.id = cmd_id; > + tdx_cmd.flags = flags; > + tdx_cmd.data = (__u64)(unsigned long)data; > + > + switch (level) { > + case TDX_PLATFORM_IOCTL: > + r = kvm_ioctl(kvm_state, KVM_MEMORY_ENCRYPT_OP, &tdx_cmd); > + break; > + case TDX_VM_IOCTL: > + r = kvm_vm_ioctl(kvm_state, KVM_MEMORY_ENCRYPT_OP, &tdx_cmd); > + break; > + case TDX_VCPU_IOCTL: > + r = kvm_vcpu_ioctl(state, KVM_MEMORY_ENCRYPT_OP, &tdx_cmd); > + break; > + default: > + error_report("Invalid tdx_ioctl_level %d", level); > + exit(1); > + } > + > + return r; > +} > + > +static inline int tdx_platform_ioctl(int cmd_id, __u32 flags, void *data) > +{ > + return __tdx_ioctl(NULL, TDX_PLATFORM_IOCTL, cmd_id, flags, data); > +} > + > +static inline int tdx_vm_ioctl(int cmd_id, __u32 flags, void *data) > +{ > + return __tdx_ioctl(NULL, TDX_VM_IOCTL, cmd_id, flags, data); > +} > + > +static inline int tdx_vcpu_ioctl(void *vcpu_fd, int cmd_id, __u32 flags, > + void *data) > +{ > + return __tdx_ioctl(vcpu_fd, TDX_VCPU_IOCTL, cmd_id, flags, data); > +} > + > +static void get_tdx_capabilities(void) Pass in 'Error **errp' > +{ > + struct kvm_tdx_capabilities *caps; > + /* 1st generation of TDX reports 6 cpuid configs */ > + int nr_cpuid_configs = 6; > + int r, size; It is preferrable to use 'size_t' for memory allocation sizes. > + > + do { > + size = sizeof(struct kvm_tdx_capabilities) + > + nr_cpuid_configs * sizeof(struct kvm_tdx_cpuid_config); > + caps = g_malloc0(size); > + caps->nr_cpuid_configs = nr_cpuid_configs; > + > + r = tdx_vm_ioctl(KVM_TDX_CAPABILITIES, 0, caps); > + if (r == -E2BIG) { > + g_free(caps); > + nr_cpuid_configs *= 2; > + if (nr_cpuid_configs > KVM_MAX_CPUID_ENTRIES) { > + error_report("KVM TDX seems broken that number of CPUID entries in kvm_tdx_capabilities exceeds limit"); Include the limit in the error message, so if we ever need to change the limit, it'll be clear what limit the QEMU version was built with. Also use error_setg(errp, ...); > + exit(1); Return -1 > + } > + } else if (r < 0) { > + g_free(caps); > + error_report("KVM_TDX_CAPABILITIES failed: %s", strerror(-r)); Use error_setg_errno(errp, ...) instead of calling strerror yourself; > + exit(1); Return -1 > + } > + } > + while (r == -E2BIG); > + > + tdx_caps = caps; Return 0 > +} > + > int tdx_kvm_init(MachineState *ms, Error **errp) > { > + if (!tdx_caps) { > + get_tdx_capabilities(); Pass 'errp' into this method, and check return value for failure > + } > + > return 0; > } > > -- > 2.34.1 > With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|