From patchwork Mon Jun 28 17:31:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Edmondson X-Patchwork-Id: 12348389 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT 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 25D4AC11F64 for ; Mon, 28 Jun 2021 17:41:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0CEB861C67 for ; Mon, 28 Jun 2021 17:41:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234555AbhF1RnZ (ORCPT ); Mon, 28 Jun 2021 13:43:25 -0400 Received: from forward3-smtp.messagingengine.com ([66.111.4.237]:47081 "EHLO forward3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232719AbhF1RnY (ORCPT ); Mon, 28 Jun 2021 13:43:24 -0400 X-Greylist: delayed 539 seconds by postgrey-1.27 at vger.kernel.org; Mon, 28 Jun 2021 13:43:24 EDT Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailforward.nyi.internal (Postfix) with ESMTP id B0F1019408F3; Mon, 28 Jun 2021 13:32:03 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute1.internal (MEProxy); Mon, 28 Jun 2021 13:32:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:date:from :in-reply-to:message-id:mime-version:references:subject:to :x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm3; bh=GWKq2EyJGwGZbgi4ujs6lIVnpbb6K31l1aQySTXp12c=; b=hC/hWktO AKMbHlUg1ay7CUnrkVH9nFt3Dg3L+QPhHGGNmKdG6a3y1xQ+KBCEZBbcBK68kvpf WdM9rn2uhZt3fNnVy0iOHszi+GXQAcHKhItX9PczqhtJE9g4ER2nH4lF2lgjmSwP fvgs2UCKohL4878EUKTUU+75qcCvjuC2LsTC7fCukKNAaLg5bkhLccwzubJGXhsP bAgueFkxavCy4K+mGHuBx4e+7JKfEd1mCgU9j6N7zLOimIr1JJNuWW+HF1wrnyim T94Mqi/zUqH8t3xv62tMDNhUTJkyRNXpdsDzY3Opvxp6dHiLTf6I4xJgeMLQ/ABo YwQcGD/njiVgrg== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrfeehgedguddufecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd enucfjughrpefhvffufffkofgjfhgggfestdekredtredttdenucfhrhhomhepffgrvhhi ugcugfgumhhonhgushhonhcuoegurghvihgurdgvughmohhnughsohhnsehorhgrtghlvg drtghomheqnecuggftrfgrthhtvghrnhepudefteejgfefhfdtjefhhedtffethfetkeeh gfelheffhfeihfeglefgjedtheeknecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrg hmpehmrghilhhfrhhomhepuggrvhhiugdrvggumhhonhgushhonhesohhrrggtlhgvrdgt ohhm X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Mon, 28 Jun 2021 13:31:59 -0400 (EDT) Received: from localhost (disaster-area.hh.sledj.net [local]) by disaster-area.hh.sledj.net (OpenSMTPD) with ESMTPA id 9a1db742; Mon, 28 Jun 2021 17:31:52 +0000 (UTC) From: David Edmondson To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, Thomas Gleixner , Borislav Petkov , Vitaly Kuznetsov , Joerg Roedel , Ingo Molnar , Sean Christopherson , Wanpeng Li , Jim Mattson , "H. Peter Anvin" , Paolo Bonzini , x86@kernel.org, David Edmondson , Joao Martins Subject: [PATCH 2/2] KVM: x86: On emulation failure, convey the exit reason to userspace Date: Mon, 28 Jun 2021 18:31:52 +0100 Message-Id: <20210628173152.2062988-3-david.edmondson@oracle.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210628173152.2062988-1-david.edmondson@oracle.com> References: <20210628173152.2062988-1-david.edmondson@oracle.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org To aid in debugging. Suggested-by: Joao Martins Signed-off-by: David Edmondson --- arch/x86/kvm/x86.c | 23 +++++++++++++++++------ include/uapi/linux/kvm.h | 2 ++ 2 files changed, 19 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8166ad113fb2..48ef0dc68faf 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7455,7 +7455,7 @@ void kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip) } EXPORT_SYMBOL_GPL(kvm_inject_realmode_interrupt); -static void prepare_emulation_failure_exit(struct kvm_vcpu *vcpu) +static void prepare_emulation_failure_exit(struct kvm_vcpu *vcpu, uint64_t flags) { struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt; u32 insn_size = ctxt->fetch.end - ctxt->fetch.data; @@ -7466,7 +7466,8 @@ static void prepare_emulation_failure_exit(struct kvm_vcpu *vcpu) run->emulation_failure.ndata = 0; run->emulation_failure.flags = 0; - if (insn_size) { + if (insn_size && + (flags & KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES)) { run->emulation_failure.ndata = 3; run->emulation_failure.flags |= KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES; @@ -7476,6 +7477,14 @@ static void prepare_emulation_failure_exit(struct kvm_vcpu *vcpu) memcpy(run->emulation_failure.insn_bytes, ctxt->fetch.data, insn_size); } + + if (flags & KVM_INTERNAL_ERROR_EMULATION_FLAG_EXIT_REASON) { + run->emulation_failure.ndata = 4; + run->emulation_failure.flags |= + KVM_INTERNAL_ERROR_EMULATION_FLAG_EXIT_REASON; + run->emulation_failure.exit_reason = + static_call(kvm_x86_get_exit_reason)(vcpu); + } } static int handle_emulation_failure(struct kvm_vcpu *vcpu, int emulation_type) @@ -7492,16 +7501,18 @@ static int handle_emulation_failure(struct kvm_vcpu *vcpu, int emulation_type) if (kvm->arch.exit_on_emulation_error || (emulation_type & EMULTYPE_SKIP)) { - prepare_emulation_failure_exit(vcpu); + prepare_emulation_failure_exit( + vcpu, + KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES | + KVM_INTERNAL_ERROR_EMULATION_FLAG_EXIT_REASON); return 0; } kvm_queue_exception(vcpu, UD_VECTOR); if (!is_guest_mode(vcpu) && static_call(kvm_x86_get_cpl)(vcpu) == 0) { - vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; - vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION; - vcpu->run->internal.ndata = 0; + prepare_emulation_failure_exit( + vcpu, KVM_INTERNAL_ERROR_EMULATION_FLAG_EXIT_REASON); return 0; } diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 68c9e6d8bbda..3e4126652a67 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -282,6 +282,7 @@ struct kvm_xen_exit { /* Flags that describe what fields in emulation_failure hold valid data. */ #define KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES (1ULL << 0) +#define KVM_INTERNAL_ERROR_EMULATION_FLAG_EXIT_REASON (1ULL << 1) /* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */ struct kvm_run { @@ -404,6 +405,7 @@ struct kvm_run { __u64 flags; __u8 insn_size; __u8 insn_bytes[15]; + __u64 exit_reason; } emulation_failure; /* KVM_EXIT_OSI */ struct {