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 X-Spam-Level: X-Spam-Status: No, score=-11.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AEA9EC2BBD1 for ; Thu, 17 Sep 2020 16:47:56 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id F1B5421D7B for ; Thu, 17 Sep 2020 16:47:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="RMfY/5wb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F1B5421D7B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:45774 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kIx4c-00084h-UM for qemu-devel@archiver.kernel.org; Thu, 17 Sep 2020 12:47:54 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56272) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kIx3f-0007Az-UX for qemu-devel@nongnu.org; Thu, 17 Sep 2020 12:46:55 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:51129 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kIx3d-0003TO-E9 for qemu-devel@nongnu.org; Thu, 17 Sep 2020 12:46:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600361211; 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: in-reply-to:in-reply-to:references:references; bh=MVBdWjTL0qbbnnHx4Pq910SY+VQTNVPxgmO0+InTW3g=; b=RMfY/5wb3Wus66VLJ3vuYzKc97dOiMIRIahX3QLZZPqaHyb/DY4cBiUGNgQ3EKIigo+9/f 2/D9MeZTA8AZfi5IZDoh9grTiJCVPal/OyIQnf44d09ormrs9G/Q5EQ5x67uLSSfCvXvEn 8v+reYl1vvp7LBk5rPRghx9/7zWBMcQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-266-a-6vknJcOmmUSmp6HQvp-A-1; Thu, 17 Sep 2020 12:46:45 -0400 X-MC-Unique: a-6vknJcOmmUSmp6HQvp-A-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BC5B81091066; Thu, 17 Sep 2020 16:46:43 +0000 (UTC) Received: from work-vm (ovpn-114-108.ams2.redhat.com [10.36.114.108]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5997260BEC; Thu, 17 Sep 2020 16:46:37 +0000 (UTC) Date: Thu, 17 Sep 2020 17:46:35 +0100 From: "Dr. David Alan Gilbert" To: Tom Lendacky Subject: Re: [PATCH v3 3/5] sev/i386: Allow AP booting under SEV-ES Message-ID: <20200917164635.GQ2793@work-vm> References: <9d964b7575471f45c522eea9ea3a7d84ed4d7d2b.1600205384.git.thomas.lendacky@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9d964b7575471f45c522eea9ea3a7d84ed4d7d2b.1600205384.git.thomas.lendacky@amd.com> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Received-SPF: pass client-ip=205.139.110.61; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/17 08:56:18 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -50 X-Spam_score: -5.1 X-Spam_bar: ----- X-Spam_report: (-5.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-2.997, 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_H2=-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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Brijesh Singh , Eduardo Habkost , kvm@vger.kernel.org, "Michael S. Tsirkin" , Connor Kuehl , Marcelo Tosatti , qemu-devel@nongnu.org, Paolo Bonzini , Jiri Slaby , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Tom Lendacky (thomas.lendacky@amd.com) wrote: > From: Tom Lendacky > > When SEV-ES is enabled, it is not possible modify the guests register > state after it has been initially created, encrypted and measured. > > Normally, an INIT-SIPI-SIPI request is used to boot the AP. However, the > hypervisor cannot emulate this because it cannot update the AP register > state. For the very first boot by an AP, the reset vector CS segment > value and the EIP value must be programmed before the register has been > encrypted and measured. > > Signed-off-by: Tom Lendacky > --- > accel/kvm/kvm-all.c | 64 ++++++++++++++++++++++++++++++++++++++++++ > accel/stubs/kvm-stub.c | 5 ++++ > hw/i386/pc_sysfw.c | 10 ++++++- > include/sysemu/kvm.h | 16 +++++++++++ > include/sysemu/sev.h | 3 ++ > target/i386/kvm.c | 2 ++ > target/i386/sev.c | 51 +++++++++++++++++++++++++++++++++ > 7 files changed, 150 insertions(+), 1 deletion(-) > > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index 63ef6af9a1..20725b0368 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -39,6 +39,7 @@ > #include "qemu/main-loop.h" > #include "trace.h" > #include "hw/irq.h" > +#include "sysemu/kvm.h" > #include "sysemu/sev.h" > #include "qapi/visitor.h" > #include "qapi/qapi-types-common.h" > @@ -120,6 +121,12 @@ struct KVMState > /* memory encryption */ > void *memcrypt_handle; > int (*memcrypt_encrypt_data)(void *handle, uint8_t *ptr, uint64_t len); > + int (*memcrypt_save_reset_vector)(void *handle, void *flash_ptr, > + uint64_t flash_size, uint32_t *addr); > + > + unsigned int reset_cs; > + unsigned int reset_ip; uint32_t's ? > + bool reset_valid; > > /* For "info mtree -f" to tell if an MR is registered in KVM */ > int nr_as; > @@ -239,6 +246,62 @@ int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len) > return 1; > } > > +void kvm_memcrypt_set_reset_vector(CPUState *cpu) > +{ > + X86CPU *x86; > + CPUX86State *env; > + > + /* Only update if we have valid reset information */ > + if (!kvm_state->reset_valid) { > + return; > + } > + > + /* Do not update the BSP reset state */ > + if (cpu->cpu_index == 0) { > + return; > + } > + > + x86 = X86_CPU(cpu); > + env = &x86->env; > + > + cpu_x86_load_seg_cache(env, R_CS, 0xf000, kvm_state->reset_cs, 0xffff, > + DESC_P_MASK | DESC_S_MASK | DESC_CS_MASK | > + DESC_R_MASK | DESC_A_MASK); > + > + env->eip = kvm_state->reset_ip; > +} > + > +int kvm_memcrypt_save_reset_vector(void *flash_ptr, uint64_t flash_size) > +{ > + CPUState *cpu; > + uint32_t addr; > + int ret; > + > + if (kvm_memcrypt_enabled() && > + kvm_state->memcrypt_save_reset_vector) { > + > + addr = 0; > + ret = kvm_state->memcrypt_save_reset_vector(kvm_state->memcrypt_handle, > + flash_ptr, flash_size, > + &addr); > + if (ret) { > + return ret; > + } > + > + if (addr) { > + kvm_state->reset_cs = addr & 0xffff0000; > + kvm_state->reset_ip = addr & 0x0000ffff; > + kvm_state->reset_valid = true; > + > + CPU_FOREACH(cpu) { > + kvm_memcrypt_set_reset_vector(cpu); > + } > + } > + } > + > + return 0; > +} > + > /* Called with KVMMemoryListener.slots_lock held */ > static KVMSlot *kvm_get_free_slot(KVMMemoryListener *kml) > { > @@ -2193,6 +2256,7 @@ static int kvm_init(MachineState *ms) > } > > kvm_state->memcrypt_encrypt_data = sev_encrypt_data; > + kvm_state->memcrypt_save_reset_vector = sev_es_save_reset_vector; > } > > ret = kvm_arch_init(ms, s); > diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c > index 82f118d2df..3aece9b513 100644 > --- a/accel/stubs/kvm-stub.c > +++ b/accel/stubs/kvm-stub.c > @@ -114,6 +114,11 @@ int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len) > return 1; > } > > +int kvm_memcrypt_save_reset_vector(void *flash_ptr, uint64_t flash_size) > +{ > + return -ENOSYS; > +} > + > #ifndef CONFIG_USER_ONLY > int kvm_irqchip_add_msi_route(KVMState *s, int vector, PCIDevice *dev) > { > diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c > index b6c0822fe3..321ff94261 100644 > --- a/hw/i386/pc_sysfw.c > +++ b/hw/i386/pc_sysfw.c > @@ -156,7 +156,8 @@ static void pc_system_flash_map(PCMachineState *pcms, > PFlashCFI01 *system_flash; > MemoryRegion *flash_mem; > void *flash_ptr; > - int ret, flash_size; > + uint64_t flash_size; > + int ret; > > assert(PC_MACHINE_GET_CLASS(pcms)->pci_enabled); > > @@ -204,6 +205,13 @@ static void pc_system_flash_map(PCMachineState *pcms, > if (kvm_memcrypt_enabled()) { > flash_ptr = memory_region_get_ram_ptr(flash_mem); > flash_size = memory_region_size(flash_mem); > + > + ret = kvm_memcrypt_save_reset_vector(flash_ptr, flash_size); > + if (ret) { > + error_report("failed to locate and/or save reset vector"); > + exit(1); > + } > + > ret = kvm_memcrypt_encrypt_data(flash_ptr, flash_size); > if (ret) { > error_report("failed to encrypt pflash rom"); > diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h > index b4174d941c..f74cfa85ab 100644 > --- a/include/sysemu/kvm.h > +++ b/include/sysemu/kvm.h > @@ -247,6 +247,22 @@ bool kvm_memcrypt_enabled(void); > */ > int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len); > > +/** > + * kvm_memcrypt_set_reset_vector - sets the CS/IP value for the AP if SEV-ES > + * is active. > + */ > +void kvm_memcrypt_set_reset_vector(CPUState *cpu); > + > +/** > + * kvm_memcrypt_save_reset_vector - locates and saves the reset vector to be > + * used as the initial CS/IP value for APs > + * if SEV-ES is active. > + * > + * Return: 1 SEV-ES is active and failed to locate a valid reset vector > + * 0 SEV-ES is not active or successfully located and saved the > + * reset vector address > + */ > +int kvm_memcrypt_save_reset_vector(void *flash_prt, uint64_t flash_size); > > #ifdef NEED_CPU_H > #include "cpu.h" > diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h > index 98c1ec8d38..5198e5a621 100644 > --- a/include/sysemu/sev.h > +++ b/include/sysemu/sev.h > @@ -18,4 +18,7 @@ > > void *sev_guest_init(const char *id); > int sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len); > +int sev_es_save_reset_vector(void *handle, void *flash_ptr, > + uint64_t flash_size, uint32_t *addr); > + > #endif > diff --git a/target/i386/kvm.c b/target/i386/kvm.c > index 6f18d940a5..10eaba8943 100644 > --- a/target/i386/kvm.c > +++ b/target/i386/kvm.c > @@ -1912,6 +1912,8 @@ void kvm_arch_reset_vcpu(X86CPU *cpu) > } > /* enabled by default */ > env->poll_control_msr = 1; > + > + kvm_memcrypt_set_reset_vector(CPU(cpu)); > } > > void kvm_arch_do_init_vcpu(X86CPU *cpu) > diff --git a/target/i386/sev.c b/target/i386/sev.c > index 5055b1fe00..6ddefc65fa 100644 > --- a/target/i386/sev.c > +++ b/target/i386/sev.c > @@ -70,6 +70,19 @@ struct SevGuestState { > #define DEFAULT_GUEST_POLICY 0x1 /* disable debug */ > #define DEFAULT_SEV_DEVICE "/dev/sev" > > +/* SEV Information Block GUID = 00f771de-1a7e-4fcb-890e-68c77e2fb44e */ > +#define SEV_INFO_BLOCK_GUID \ > + "\xde\x71\xf7\x00\x7e\x1a\xcb\x4f\x89\x0e\x68\xc7\x7e\x2f\xb4\x4e" > + > +typedef struct __attribute__((__packed__)) SevInfoBlock { > + /* SEV-ES Reset Vector Address */ > + uint32_t reset_addr; > + > + /* SEV Information Block size and GUID */ > + uint16_t size; > + char guid[16]; > +} SevInfoBlock; > + Is that all signed off and happy from the OVMF guys? > static SevGuestState *sev_guest; > static Error *sev_mig_blocker; > > @@ -833,6 +846,44 @@ sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len) > return 0; > } > > +int > +sev_es_save_reset_vector(void *handle, void *flash_ptr, uint64_t flash_size, > + uint32_t *addr) > +{ > + SevInfoBlock *info; > + > + assert(handle); > + > + /* > + * Initialize the address to zero. An address of zero with a successful > + * return code indicates that SEV-ES is not active. > + */ > + *addr = 0; > + if (!sev_es_enabled()) { > + return 0; > + } > + > + /* > + * Extract the AP reset vector for SEV-ES guests by locating the SEV GUID. > + * The SEV GUID is located 32 bytes from the end of the flash. Use this > + * address to base the SEV information block. It surprises me a bit it's at a fixed offset. Dave > + */ > + info = flash_ptr + flash_size - 0x20 - sizeof(*info); > + if (memcmp(info->guid, SEV_INFO_BLOCK_GUID, 16)) { > + error_report("SEV information block not found in pflash rom"); > + return 1; > + } > + > + if (!info->reset_addr) { > + error_report("SEV-ES reset address is zero"); > + return 1; > + } > + > + *addr = info->reset_addr; > + > + return 0; > +} > + > static void > sev_register_types(void) > { > -- > 2.28.0 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK