From: Kai Huang <kai.huang@intel.com>
To: linux-sgx@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org
Cc: seanjc@google.com, jarkko@kernel.org, luto@kernel.org,
dave.hansen@intel.com, haitao.huang@intel.com,
pbonzini@redhat.com, bp@alien8.de, tglx@linutronix.de,
mingo@redhat.com, hpa@zytor.com, jmattson@google.com,
joro@8bytes.org, vkuznets@redhat.com, wanpengli@tencent.com,
corbet@lwn.net, Andy Lutomirski <luto@amacapital.net>,
Kai Huang <kai.huang@intel.com>
Subject: [RFC PATCH v3 27/27] KVM: x86: Add capability to grant VM access to privileged SGX attribute
Date: Tue, 26 Jan 2021 22:32:45 +1300 [thread overview]
Message-ID: <14d540efe5cdbd4dd5df1ea17b999b6089654d11.1611634586.git.kai.huang@intel.com> (raw)
In-Reply-To: <cover.1611634586.git.kai.huang@intel.com>
From: Sean Christopherson <sean.j.christopherson@intel.com>
Add a capability, KVM_CAP_SGX_ATTRIBUTE, that can be used by userspace
to grant a VM access to a priveleged attribute, with args[0] holding a
file handle to a valid SGX attribute file.
The SGX subsystem restricts access to a subset of enclave attributes to
provide additional security for an uncompromised kernel, e.g. to prevent
malware from using the PROVISIONKEY to ensure its nodes are running
inside a geniune SGX enclave and/or to obtain a stable fingerprint.
To prevent userspace from circumventing such restrictions by running an
enclave in a VM, KVM restricts guest access to privileged attributes by
default.
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
---
Documentation/virt/kvm/api.rst | 23 +++++++++++++++++++++++
arch/x86/kvm/cpuid.c | 2 +-
arch/x86/kvm/x86.c | 22 ++++++++++++++++++++++
include/uapi/linux/kvm.h | 1 +
4 files changed, 47 insertions(+), 1 deletion(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index c136e254b496..47c7c7c33025 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -6037,6 +6037,29 @@ KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR exit notifications which user space
can then handle to implement model specific MSR handling and/or user notifications
to inform a user that an MSR was not handled.
+7.22 KVM_CAP_SGX_ATTRIBUTE
+----------------------
+
+:Architectures: x86
+:Target: VM
+:Parameters: args[0] is a file handle of a SGX attribute file in securityfs
+:Returns: 0 on success, -EINVAL if the file handle is invalid or if a requested
+ attribute is not supported by KVM.
+
+KVM_CAP_SGX_ATTRIBUTE enables a userspace VMM to grant a VM access to one or
+more priveleged enclave attributes. args[0] must hold a file handle to a valid
+SGX attribute file corresponding to an attribute that is supported/restricted
+by KVM (currently only PROVISIONKEY).
+
+The SGX subsystem restricts access to a subset of enclave attributes to provide
+additional security for an uncompromised kernel, e.g. use of the PROVISIONKEY
+is restricted to deter malware from using the PROVISIONKEY to obtain a stable
+system fingerprint. To prevent userspace from circumventing such restrictions
+by running an enclave in a VM, KVM prevents access to privileged attributes by
+default.
+
+See Documentation/x86/sgx/2.Kernel-internals.rst for more details.
+
8. Other capabilities.
======================
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 04b2f5de2d7b..ad00a1af1545 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -833,7 +833,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
* expected to derive it from supported XCR0.
*/
entry->eax &= SGX_ATTR_DEBUG | SGX_ATTR_MODE64BIT |
- /* PROVISIONKEY | */ SGX_ATTR_EINITTOKENKEY |
+ SGX_ATTR_PROVISIONKEY | SGX_ATTR_EINITTOKENKEY |
SGX_ATTR_KSS;
entry->ebx &= 0;
break;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5ca7b181a3ae..3d1b4113a57b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -74,6 +74,8 @@
#include <asm/tlbflush.h>
#include <asm/intel_pt.h>
#include <asm/emulate_prefix.h>
+#include <asm/sgx.h>
+#include <asm/sgx_arch.h>
#include <clocksource/hyperv_timer.h>
#define CREATE_TRACE_POINTS
@@ -3767,6 +3769,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_X86_USER_SPACE_MSR:
case KVM_CAP_X86_MSR_FILTER:
case KVM_CAP_ENFORCE_PV_FEATURE_CPUID:
+#ifdef CONFIG_X86_SGX_KVM
+ case KVM_CAP_SGX_ATTRIBUTE:
+#endif
r = 1;
break;
case KVM_CAP_SYNC_REGS:
@@ -5295,6 +5300,23 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
kvm->arch.user_space_msr_mask = cap->args[0];
r = 0;
break;
+#ifdef CONFIG_X86_SGX_KVM
+ case KVM_CAP_SGX_ATTRIBUTE: {
+ unsigned long allowed_attributes = 0;
+
+ r = sgx_set_attribute(&allowed_attributes, cap->args[0]);
+ if (r)
+ break;
+
+ /* KVM only supports the PROVISIONKEY privileged attribute. */
+ if ((allowed_attributes & SGX_ATTR_PROVISIONKEY) &&
+ !(allowed_attributes & ~SGX_ATTR_PROVISIONKEY))
+ kvm->arch.sgx_provisioning_allowed = true;
+ else
+ r = -EINVAL;
+ break;
+ }
+#endif
default:
r = -EINVAL;
break;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 374c67875cdb..e17bda18a9b4 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1058,6 +1058,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_ENFORCE_PV_FEATURE_CPUID 190
#define KVM_CAP_SYS_HYPERV_CPUID 191
#define KVM_CAP_DIRTY_LOG_RING 192
+#define KVM_CAP_SGX_ATTRIBUTE 200
#ifdef KVM_CAP_IRQ_ROUTING
--
2.29.2
next prev parent reply other threads:[~2021-01-26 15:23 UTC|newest]
Thread overview: 156+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-26 10:10 [RFC PATCH v3 00/27] KVM SGX virtualization support Kai Huang
2021-01-26 9:29 ` Kai Huang
2021-01-26 9:30 ` [RFC PATCH v3 01/27] x86/cpufeatures: Add SGX1 and SGX2 sub-features Kai Huang
2021-01-26 15:34 ` Dave Hansen
2021-01-26 23:18 ` Kai Huang
2021-01-30 13:20 ` Jarkko Sakkinen
2021-02-01 0:01 ` Kai Huang
2021-02-02 17:17 ` Jarkko Sakkinen
2021-02-03 1:09 ` Kai Huang
2021-02-02 17:56 ` Paolo Bonzini
2021-02-02 18:00 ` Dave Hansen
2021-02-02 18:03 ` Paolo Bonzini
2021-02-02 18:42 ` Sean Christopherson
2021-02-03 1:05 ` Kai Huang
2021-01-30 13:11 ` Jarkko Sakkinen
2021-01-26 9:30 ` [RFC PATCH v3 02/27] x86/cpufeatures: Make SGX_LC feature bit depend on SGX bit Kai Huang
2021-01-26 15:35 ` Dave Hansen
2021-01-30 13:22 ` Jarkko Sakkinen
2021-02-01 0:08 ` Kai Huang
2021-01-26 9:30 ` [RFC PATCH v3 03/27] x86/sgx: Remove a warn from sgx_free_epc_page() Kai Huang
2021-01-26 15:39 ` Dave Hansen
2021-01-26 16:30 ` Sean Christopherson
2021-01-27 1:08 ` Kai Huang
2021-01-27 1:12 ` Dave Hansen
2021-01-27 1:26 ` Kai Huang
2021-02-01 0:11 ` Kai Huang
2021-02-03 10:03 ` Jarkko Sakkinen
2021-01-26 9:30 ` [RFC PATCH v3 04/27] x86/sgx: Wipe out EREMOVE " Kai Huang
2021-01-26 16:04 ` Dave Hansen
2021-01-27 1:25 ` Kai Huang
2021-02-02 18:00 ` Paolo Bonzini
2021-02-02 19:25 ` Kai Huang
2021-02-02 19:02 ` Dave Hansen
2021-01-26 9:30 ` [RFC PATCH v3 05/27] x86/sgx: Add SGX_CHILD_PRESENT hardware error code Kai Huang
2021-01-26 15:49 ` Dave Hansen
2021-01-27 0:00 ` Kai Huang
2021-01-27 0:21 ` Dave Hansen
2021-01-27 0:52 ` Kai Huang
2021-01-26 9:30 ` [RFC PATCH v3 06/27] x86/sgx: Introduce virtual EPC for use by KVM guests Kai Huang
2021-01-26 16:19 ` Dave Hansen
2021-01-27 0:16 ` Kai Huang
2021-01-27 0:27 ` Dave Hansen
2021-01-27 0:48 ` Kai Huang
2021-01-30 14:41 ` Jarkko Sakkinen
2021-01-26 9:30 ` [RFC PATCH v3 07/27] x86/cpu/intel: Allow SGX virtualization without Launch Control support Kai Huang
2021-01-26 16:26 ` Dave Hansen
2021-01-26 17:00 ` Sean Christopherson
2021-01-26 23:54 ` Kai Huang
2021-01-26 23:56 ` Kai Huang
2021-01-27 0:18 ` Dave Hansen
2021-01-27 2:02 ` Kai Huang
2021-01-27 17:13 ` Sean Christopherson
2021-01-30 14:42 ` Jarkko Sakkinen
2021-02-01 5:38 ` Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 08/27] x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled Kai Huang
2021-01-26 17:03 ` Dave Hansen
2021-01-26 18:10 ` Andy Lutomirski
2021-01-26 23:25 ` Kai Huang
2021-01-30 14:45 ` Jarkko Sakkinen
2021-02-01 5:40 ` Kai Huang
2021-02-01 15:25 ` Dave Hansen
2021-02-01 17:23 ` Sean Christopherson
2021-02-02 0:12 ` Kai Huang
2021-02-02 23:10 ` Jarkko Sakkinen
2021-02-02 23:07 ` Jarkko Sakkinen
2021-02-02 17:32 ` Jarkko Sakkinen
2021-02-02 18:20 ` Sean Christopherson
2021-02-02 23:16 ` Jarkko Sakkinen
2021-02-03 0:49 ` Kai Huang
2021-02-03 22:02 ` Jarkko Sakkinen
2021-02-03 22:59 ` Sean Christopherson
2021-02-04 1:39 ` Jarkko Sakkinen
2021-02-04 2:59 ` Kai Huang
2021-02-04 3:05 ` Jarkko Sakkinen
2021-02-04 3:09 ` Jarkko Sakkinen
2021-02-04 3:20 ` Kai Huang
2021-02-04 14:51 ` Jarkko Sakkinen
2021-02-04 22:41 ` Dave Hansen
2021-02-04 22:56 ` Kai Huang
2021-02-05 2:08 ` Jarkko Sakkinen
2021-02-05 3:00 ` Huang, Kai
2021-02-02 18:49 ` Kai Huang
2021-02-02 23:17 ` Jarkko Sakkinen
2021-01-26 9:31 ` [RFC PATCH v3 09/27] x86/sgx: Expose SGX architectural definitions to the kernel Kai Huang
2021-01-30 14:46 ` Jarkko Sakkinen
2021-01-26 9:31 ` [RFC PATCH v3 10/27] x86/sgx: Move ENCLS leaf definitions to sgx_arch.h Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 11/27] x86/sgx: Add SGX2 ENCLS leaf definitions (EAUG, EMODPR and EMODT) Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 12/27] x86/sgx: Add encls_faulted() helper Kai Huang
2021-01-30 14:48 ` Jarkko Sakkinen
2021-01-26 9:31 ` [RFC PATCH v3 13/27] x86/sgx: Add helper to update SGX_LEPUBKEYHASHn MSRs Kai Huang
2021-01-30 14:49 ` Jarkko Sakkinen
2021-02-01 1:17 ` Kai Huang
2021-02-01 21:22 ` Dave Hansen
2021-01-26 9:31 ` [RFC PATCH v3 14/27] x86/sgx: Add helpers to expose ECREATE and EINIT to KVM Kai Huang
2021-01-30 14:51 ` Jarkko Sakkinen
2021-02-01 0:17 ` Kai Huang
2021-02-02 17:20 ` Jarkko Sakkinen
2021-02-02 20:35 ` Kai Huang
2021-02-04 3:53 ` Kai Huang
2021-02-05 0:32 ` Sean Christopherson
2021-02-05 1:39 ` Huang, Kai
2021-01-26 9:31 ` [RFC PATCH v3 15/27] x86/sgx: Move provisioning device creation out of SGX driver Kai Huang
2021-01-30 14:52 ` Jarkko Sakkinen
2021-01-26 9:31 ` [RFC PATCH v3 16/27] KVM: VMX: Convert vcpu_vmx.exit_reason to a union Kai Huang
2021-01-30 15:00 ` Jarkko Sakkinen
2021-02-01 0:32 ` Kai Huang
2021-02-02 17:24 ` Jarkko Sakkinen
2021-02-02 19:23 ` Kai Huang
2021-02-02 22:41 ` Jarkko Sakkinen
2021-02-03 0:42 ` Kai Huang
2021-02-01 17:12 ` Sean Christopherson
2021-02-02 22:38 ` Jarkko Sakkinen
2021-01-26 9:31 ` [RFC PATCH v3 17/27] KVM: x86: Export kvm_mmu_gva_to_gpa_{read,write}() for SGX (VMX) Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 18/27] KVM: x86: Define new #PF SGX error code bit Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 19/27] KVM: x86: Add support for reverse CPUID lookup of scattered features Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 20/27] KVM: x86: Add reverse-CPUID lookup support for scattered SGX features Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 21/27] KVM: VMX: Add basic handling of VM-Exit from SGX enclave Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 22/27] KVM: VMX: Frame in ENCLS handler for SGX virtualization Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 23/27] KVM: VMX: Add SGX ENCLS[ECREATE] handler to enforce CPUID restrictions Kai Huang
2021-02-03 0:52 ` Edgecombe, Rick P
2021-02-03 1:36 ` Sean Christopherson
2021-02-03 9:11 ` Kai Huang
2021-02-03 17:07 ` Sean Christopherson
2021-02-03 23:11 ` Kai Huang
2021-02-03 18:47 ` Edgecombe, Rick P
2021-02-03 19:36 ` Sean Christopherson
2021-02-03 23:29 ` Kai Huang
2021-02-03 23:36 ` Sean Christopherson
2021-02-03 23:45 ` Kai Huang
2021-02-03 23:59 ` Sean Christopherson
2021-02-04 0:11 ` Kai Huang
2021-02-04 2:01 ` Sean Christopherson
2021-01-26 9:31 ` [RFC PATCH v3 24/27] KVM: VMX: Add emulation of SGX Launch Control LE hash MSRs Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 25/27] KVM: VMX: Add ENCLS[EINIT] handler to support SGX Launch Control (LC) Kai Huang
2021-01-26 9:31 ` [RFC PATCH v3 26/27] KVM: VMX: Enable SGX virtualization for SGX1, SGX2 and LC Kai Huang
2021-01-26 9:32 ` Kai Huang [this message]
2021-02-02 22:21 ` [RFC PATCH v3 00/27] KVM SGX virtualization support Edgecombe, Rick P
2021-02-02 22:33 ` Sean Christopherson
2021-02-02 23:21 ` Dave Hansen
2021-02-02 23:56 ` Sean Christopherson
2021-02-03 0:43 ` Dave Hansen
2021-02-03 15:10 ` Dave Hansen
2021-02-03 17:36 ` Sean Christopherson
2021-02-03 17:43 ` Paolo Bonzini
2021-02-03 17:46 ` Dave Hansen
2021-02-03 23:09 ` Kai Huang
2021-02-03 23:32 ` Sean Christopherson
2021-02-03 23:37 ` Dave Hansen
2021-02-04 0:04 ` Kai Huang
2021-02-04 0:28 ` Sean Christopherson
2021-02-04 3:18 ` Kai Huang
2021-02-04 16:28 ` Sean Christopherson
2021-02-04 16:48 ` Dave Hansen
2021-02-05 12:32 ` Kai Huang
2021-02-05 16:51 ` Sean Christopherson
2021-02-02 22:36 ` Dave Hansen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=14d540efe5cdbd4dd5df1ea17b999b6089654d11.1611634586.git.kai.huang@intel.com \
--to=kai.huang@intel.com \
--cc=bp@alien8.de \
--cc=corbet@lwn.net \
--cc=dave.hansen@intel.com \
--cc=haitao.huang@intel.com \
--cc=hpa@zytor.com \
--cc=jarkko@kernel.org \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=kvm@vger.kernel.org \
--cc=linux-sgx@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=pbonzini@redhat.com \
--cc=seanjc@google.com \
--cc=tglx@linutronix.de \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).