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 0D254C28B20 for ; Wed, 2 Apr 2025 14:55:23 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tzzUa-0001ik-1i; Wed, 02 Apr 2025 10:55:00 -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 1tzzUY-0001iR-OF for qemu-devel@nongnu.org; Wed, 02 Apr 2025 10:54:58 -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 1tzzUW-00013j-I4 for qemu-devel@nongnu.org; Wed, 02 Apr 2025 10:54:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1743605694; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=zFQFFt3eYGni+Iy/Ebc0glNqyUlJyXnj5Hi35jIZM2Y=; b=Ve4qkvkmJgi0oXeJYEdssrAcMmdbmuF8eT6bgcKs2hEP/eCUB18CrL+HWVzDyNEb81YtTj mJmvf7HnNkFKQ0291RgBbAraDRAPeTVo3eHBsgYHERtKSD78gvXt/PtquE0A3PlrYt6Wmg C4HfR7u9h8hAXE9z00lbhgsHkJZUsU4= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-217-V12LjXPwMK2OYocQQUao6w-1; Wed, 02 Apr 2025 10:54:49 -0400 X-MC-Unique: V12LjXPwMK2OYocQQUao6w-1 X-Mimecast-MFC-AGG-ID: V12LjXPwMK2OYocQQUao6w_1743605688 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (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 mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 684701955DCD; Wed, 2 Apr 2025 14:54:48 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.12]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id B11221955BC2; Wed, 2 Apr 2025 14:54:45 +0000 (UTC) Date: Wed, 2 Apr 2025 15:54:42 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Xiaoyao Li Cc: Paolo Bonzini , "Michael S. Tsirkin" , Markus Armbruster , Francesco Lavra , Marcelo Tosatti , qemu-devel@nongnu.org, Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , Rick Edgecombe Subject: Re: [PATCH v8 05/55] i386/tdx: Get tdx_capabilities via KVM_TDX_CAPABILITIES Message-ID: References: <20250401130205.2198253-1-xiaoyao.li@intel.com> <20250401130205.2198253-6-xiaoyao.li@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.2.13 (2024-03-09) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 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: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.153, 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, 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 Wed, Apr 02, 2025 at 10:52:38PM +0800, Xiaoyao Li wrote: > On 4/2/2025 7:00 PM, Daniel P. Berrangé wrote: > > On Tue, Apr 01, 2025 at 09:01:15AM -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 VCPU scope > > > in preparation. > > > > > > Signed-off-by: Xiaoyao Li > > > --- > > > Changes in v7: > > > - refine and unifiy the error handling; (Daniel) > > > > > > Changes in v6: > > > - Pass CPUState * to tdx_vcpu_ioctl(); > > > - update commit message to remove platform scope thing; > > > - dump hw_error when it's non-zero to help debug; > > > > > > Changes in v4: > > > - use {} to initialize struct kvm_tdx_cmd, to avoid memset(); > > > - remove tdx_platform_ioctl() because no user; > > > > > > Changes in v3: > > > - rename __tdx_ioctl() to tdx_ioctl_internal() > > > - Pass errp in get_tdx_capabilities(); > > > > > > changes in v2: > > > - Make the error message more clear; > > > > > > changes in v1: > > > - 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 | 107 ++++++++++++++++++++++++++++++++++++- > > > 3 files changed, 108 insertions(+), 3 deletions(-) > > > > > > diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c > > > index 1af4710556ad..b4fa35405fe1 100644 > > > --- a/target/i386/kvm/kvm.c > > > +++ b/target/i386/kvm/kvm.c > > > @@ -1779,8 +1779,6 @@ 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 88565e8dbac1..ed1e61fb8ba9 100644 > > > --- a/target/i386/kvm/kvm_i386.h > > > +++ b/target/i386/kvm/kvm_i386.h > > > @@ -13,6 +13,8 @@ > > > #include "system/kvm.h" > > > +#define KVM_MAX_CPUID_ENTRIES 100 > > > + > > > /* always false if !CONFIG_KVM */ > > > #define kvm_pit_in_kernel() \ > > > (kvm_irqchip_in_kernel() && !kvm_irqchip_is_split()) > > > diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c > > > index 4ff94860815d..c67be5e618e2 100644 > > > --- a/target/i386/kvm/tdx.c > > > +++ b/target/i386/kvm/tdx.c > > > @@ -10,17 +10,122 @@ > > > */ > > > #include "qemu/osdep.h" > > > +#include "qemu/error-report.h" > > > +#include "qapi/error.h" > > > #include "qom/object_interfaces.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_VM_IOCTL, > > > + TDX_VCPU_IOCTL, > > > +}; > > > + > > > +static int tdx_ioctl_internal(enum tdx_ioctl_level level, void *state, > > > + int cmd_id, __u32 flags, void *data, > > > + Error **errp) > > > +{ > > > + struct kvm_tdx_cmd tdx_cmd = {}; > > > + int r; > > > + > > > + const char *tdx_ioctl_name[] = { > > > + [KVM_TDX_CAPABILITIES] = "KVM_TDX_CAPABILITIES", > > > + [KVM_TDX_INIT_VM] = "KVM_TDX_INIT_VM", > > > + [KVM_TDX_INIT_VCPU] = "KVM_TDX_INIT_VCPU", > > > + [KVM_TDX_INIT_MEM_REGION] = "KVM_TDX_INIT_MEM_REGION", > > > + [KVM_TDX_FINALIZE_VM] = "KVM_TDX_FINALIZE_VM", > > > + [KVM_TDX_GET_CPUID] = "KVM_TDX_GET_CPUID", > > > + }; > > > + > > > + tdx_cmd.id = cmd_id; > > > + tdx_cmd.flags = flags; > > > + tdx_cmd.data = (__u64)(unsigned long)data; > > > + > > > + switch (level) { > > > + 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_setg(errp, "Invalid tdx_ioctl_level %d", level); > > > + return -EINVAL; > > > + } > > > + > > > + if (r < 0) { > > > + error_setg_errno(errp, -r, "TDX ioctl %s failed, hw_errors: 0x%llx", > > > + tdx_ioctl_name[cmd_id], tdx_cmd.hw_error); > > > + } > > > + return r; > > > +} > > > + > > > +static inline int tdx_vm_ioctl(int cmd_id, __u32 flags, void *data, > > > + Error **errp) > > > +{ > > > + return tdx_ioctl_internal(TDX_VM_IOCTL, NULL, cmd_id, flags, data, errp); > > > +} > > > + > > > +static inline int tdx_vcpu_ioctl(CPUState *cpu, int cmd_id, __u32 flags, > > > + void *data, Error **errp) > > > +{ > > > + return tdx_ioctl_internal(TDX_VCPU_IOCTL, cpu, cmd_id, flags, data, errp); > > > +} > > > + > > > +static int get_tdx_capabilities(Error **errp) > > > +{ > > > + struct kvm_tdx_capabilities *caps; > > > + /* 1st generation of TDX reports 6 cpuid configs */ > > > + int nr_cpuid_configs = 6; > > > + size_t size; > > > + int r; > > > + > > > + do { > > > + Error *local_err = NULL; > > > + size = sizeof(struct kvm_tdx_capabilities) + > > > + nr_cpuid_configs * sizeof(struct kvm_cpuid_entry2); > > > + caps = g_malloc0(size); > > > + caps->cpuid.nent = nr_cpuid_configs; > > > + > > > + r = tdx_vm_ioctl(KVM_TDX_CAPABILITIES, 0, caps, &local_err); > > > + 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: %d", > > > + KVM_MAX_CPUID_ENTRIES); > > > + error_propagate(errp, local_err); > > > + return r; > > > + } > > > + error_free(local_err); > > > > IIRC, you'll need 'local_err = NULL' here, otherwise next time around > > the loop 'local_err' will be pointing to a free'd error object which > > 'error_setg' will think is still valid & won't overwrite. > > it's set to NULL at the beginning of the do loop. Oh yes, i missed that, your code is fine as is then. > (It looks I need to declare Error *local_err outside the do loop.) Nah, it is fine within the loop given nothing outside needs it. > > > > + } else if (r < 0) { > > > + g_free(caps); > > > + error_propagate(errp, local_err); > > > + return r; > > > + } > > > + } while (r == -E2BIG); > > > + > > > + tdx_caps = caps; > > > + > > > + return 0; > > > +} > > > + > > > > > > With regards, > > Daniel > 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 :|