From: Andy Lutomirski <luto@kernel.org>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>, "X86 ML" <x86@kernel.org>,
"Jarkko Sakkinen" <jarkko.sakkinen@linux.intel.com>,
"Joerg Roedel" <joro@8bytes.org>,
"H. Peter Anvin" <hpa@zytor.com>,
"kvm list" <kvm@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-sgx@vger.kernel.org
Subject: Re: [RFC PATCH 08/21] KVM: x86: Add kvm_x86_ops hook to short circuit emulation
Date: Sat, 27 Jul 2019 10:38:03 -0700 [thread overview]
Message-ID: <CALCETrU_51Ae=F9HzUwsUuSkJ1or63p_eG+f3uKkBqFx=bheUA@mail.gmail.com> (raw)
In-Reply-To: <20190727055214.9282-9-sean.j.christopherson@intel.com>
On Fri, Jul 26, 2019 at 10:52 PM Sean Christopherson
<sean.j.christopherson@intel.com> wrote:
>
> Similar to the existing AMD #NPF case where emulation of the current
> instruction is not possible due to lack of information, virtualization
> of Intel SGX will introduce a scenario where emulation is not possible
> due to the VMExit occurring in an SGX enclave. And again similar to
> the AMD case, emulation can be initiated by kvm_mmu_page_fault(), i.e.
> outside of the control of the vendor-specific code.
>
> While the cause and architecturally visible behavior of the two cases
> is different, e.g. Intel SGX will inject a #UD whereas AMD #NPF is a
> clean resume or complete shutdown, the impact on the common emulation
> code is identical: KVM must stop emulation immediately and resume the
> guest.
>
> Replace the exisiting need_emulation_on_page_fault() with a more generic
> is_emulatable() kvm_x86_ops callback, which is called unconditionally
> by x86_emulate_instruction().
>
Having recently noticed that emulate_ud() is broken when the guest's
TF is set, I suppose I should ask: does your new code function
sensibly when TF is set?
Also, anyone want to fix that emulate_ud() bug? The test case is merged now:
# ./tools/testing/selftests/x86/syscall_arg_fault_32
[RUN] SYSENTER with invalid state
[OK] Seems okay
[RUN] SYSCALL with invalid state
[SKIP] Illegal instruction
[RUN] SYSENTER with TF and invalid state
[OK] Seems okay
[RUN] SYSCALL with TF and invalid state
[WARN] Got stuck single-stepping -- you probably have a KVM bug
next prev parent reply other threads:[~2019-07-27 17:38 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-27 5:51 [RFC PATCH 00/21] x86/sgx: KVM: Add SGX virtualization Sean Christopherson
2019-07-27 5:51 ` [RFC PATCH 01/21] x86/sgx: Add defines for SGX device minor numbers Sean Christopherson
2019-07-27 5:51 ` [RFC PATCH 02/21] x86/sgx: Move bus registration and device init to common code Sean Christopherson
2019-07-27 5:51 ` [RFC PATCH 03/21] x86/sgx: Move provisioning device " Sean Christopherson
2019-07-27 5:51 ` [RFC PATCH 04/21] x86/sgx: Add /dev/sgx/virt_epc device to allocate "raw" EPC for VMs Sean Christopherson
2019-07-27 17:44 ` Andy Lutomirski
2019-07-29 17:05 ` Sean Christopherson
2019-07-27 5:51 ` [RFC PATCH 05/21] x86/sgx: Expose SGX architectural definitions to the kernel Sean Christopherson
2019-07-27 5:51 ` [RFC PATCH 06/21] KVM: x86: Add SGX sub-features leaf to reverse CPUID table Sean Christopherson
2019-07-27 5:52 ` [RFC PATCH 07/21] KVM: x86: Add WARN_ON_ONCE(index!=0) in __do_cpuid_ent Sean Christopherson
2019-07-27 5:52 ` [RFC PATCH 08/21] KVM: x86: Add kvm_x86_ops hook to short circuit emulation Sean Christopherson
2019-07-27 17:38 ` Andy Lutomirski [this message]
2019-07-30 2:49 ` Sean Christopherson
2019-08-16 0:47 ` Andy Lutomirski
2019-08-19 22:01 ` Sean Christopherson
2019-08-20 1:34 ` Andy Lutomirski
2019-08-20 1:41 ` Sean Christopherson
2019-07-30 3:08 ` Sean Christopherson
2019-07-27 5:52 ` [RFC PATCH 09/21] KVM: VMX: Add basic handling of VM-Exit from SGX enclave Sean Christopherson
2019-07-27 5:52 ` [RFC PATCH 10/21] KVM: x86: Export kvm_mmu_gva_to_gpa_{read,write}() for VMX/SGX Sean Christopherson
2019-07-27 5:52 ` [RFC PATCH 11/21] KVM: x86: Export kvm_propagate_fault (as kvm_propagate_page_fault) Sean Christopherson
2019-07-27 5:52 ` [RFC PATCH 12/21] KVM: x86: Define new #PF SGX error code bit Sean Christopherson
2019-07-27 5:52 ` [RFC PATCH 13/21] x86/sgx: Move the intermediate EINIT helper into the driver Sean Christopherson
2019-07-27 5:52 ` [RFC PATCH 14/21] x86/sgx: Add helpers to expose ECREATE and EINIT to KVM Sean Christopherson
2019-07-27 5:52 ` [RFC PATCH 15/21] KVM: VMX: Add SGX ENCLS[ECREATE] handler to enforce CPUID restrictions Sean Christopherson
2019-07-27 5:52 ` [RFC PATCH 16/21] KVM: VMX: Edd emulation of SGX Launch Control LE hash MSRs Sean Christopherson
2019-07-27 5:52 ` [RFC PATCH 17/21] KVM: VMX: Add handler for ENCLS[EINIT] to support SGX Launch Control Sean Christopherson
2019-07-27 5:52 ` [RFC PATCH 18/21] KVM: x86: Invoke kvm_x86_ops->cpuid_update() after kvm_update_cpuid() Sean Christopherson
2019-07-27 5:52 ` [RFC PATCH 19/21] KVM: VMX: Enable SGX virtualization for SGX1, SGX2 and LC Sean Christopherson
2019-07-27 5:52 ` [RFC PATCH 20/21] x86/sgx: Export sgx_set_attribute() for use by KVM Sean Christopherson
2019-07-27 5:52 ` [RFC PATCH 21/21] KVM: x86: Add capability to grant VM access to privileged SGX attribute Sean Christopherson
2019-07-27 17:32 ` Andy Lutomirski
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