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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 163A3C4363C for ; Wed, 19 May 2021 01:21:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D9F9B6139A for ; Wed, 19 May 2021 01:21:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232223AbhESBWa (ORCPT ); Tue, 18 May 2021 21:22:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232192AbhESBW3 (ORCPT ); Tue, 18 May 2021 21:22:29 -0400 Received: from mail-yb1-xb36.google.com (mail-yb1-xb36.google.com [IPv6:2607:f8b0:4864:20::b36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C4194C06175F for ; Tue, 18 May 2021 18:21:10 -0700 (PDT) Received: by mail-yb1-xb36.google.com with SMTP id r8so15838848ybb.9 for ; Tue, 18 May 2021 18:21:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=OvP6C5u3es07lieekWZCHmsvTzfV4S8Srcbhv371jMA=; b=vYAUByKH56C6E8+Ulqe5d0IvuL+D8d4ZvGoi9bVIt9UR/uTxiimyOfuNDH05F8VDd/ uLXOlxOWJ8Hy0jf5i9gwaKNU5GIzYpvxwQF1Mg93gAL6wCCcaWaKE91/jfFRAdq4hSko RmSyUok6sLrdi6EgLJ9wJHJh55W2RBq7Pv1auDMRwgHhl/z/4neLd2pZtZtYj+uqvoaT qDXAjQtwwE/H+jub8+bEwv3cPaW9tUJX9DK+JyHlX+2f+rWPO1id4Bmr6bw/57cDxPcF R+vGjs9WKcXnn7Pv8z1+4BQlUjPIuvG07NZ9kqIlTg4US5aodYLSvd2YDOPH+vTO50f9 ZzQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=OvP6C5u3es07lieekWZCHmsvTzfV4S8Srcbhv371jMA=; b=gKBunfwuKn/h3u0kytSMzkxCYSo0S+x6gI1YjSdDs7U7hib6iXkYnheF3Xa/SyRCqh xhraLrvy+aHbr6ncMTCTgad+qeMvfr/OMkOiFDu7GcU2UNKq7tJRO80/QdOwBTyhibum /iBZ81PlZiWiGmiv3ao3ENSfhUuPx7aN1eeGQ2zPCXKxChzbrzRbOyWHDHhzYlX1RxPw Sjqqy7C1U38OvzVMFcvs61rNPKfjS+EwJB0UY5NQvoV6aWVLtSnPJPx272PBGKmcnFHu B5Nx3xqc5SGrjDFGUGJttHSum7qJp5lp6VQLI5dZxxPeHFmiOmxtXFVYHY9S9Bw08+rV Qqbg== X-Gm-Message-State: AOAM533fcMof4UE5OGSjKD436L1JjhyQYlFlCeXUdy0MxCBdXSEWM0v8 Cs4lXY8SoYuCKOtANQTfdvn5stOfe/7T4sU+r/8rzzZ/JWs= X-Google-Smtp-Source: ABdhPJxnY+/S3J2IYeK1sXB5g2pZk/QbdpHYhsqwQP12KHrtA2zp9X6jF2w/jRPhnT6OhWZuOiNSQOE7q4aQ57HlUlQ= X-Received: by 2002:a25:addc:: with SMTP id d28mr11853584ybe.448.1621387269819; Tue, 18 May 2021 18:21:09 -0700 (PDT) MIME-Version: 1.0 References: <97588756-5c12-2913-05a7-938eb7a510c8@intel.com> <20210519011712.1334416-1-sathyanarayanan.kuppuswamy@linux.intel.com> In-Reply-To: <20210519011712.1334416-1-sathyanarayanan.kuppuswamy@linux.intel.com> From: Sathyanarayanan Kuppuswamy Natarajan Date: Tue, 18 May 2021 18:20:58 -0700 Message-ID: Subject: Re: [RFC v2-fix-v3 1/1] x86/tdx: Wire up KVM hypercalls To: Kuppuswamy Sathyanarayanan Cc: Peter Zijlstra , Andy Lutomirski , Dave Hansen , Tony Luck , Andi Kleen , Kirill Shutemov , Dan Williams , Raj Ashok , Sean Christopherson , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sorry, I have missed to include a change log. * Removed tdx-kvm.c and implemented tdx_kvm_hypercall*() functions in tdx.h * Exported __tdx_hypercall_vendor_kvm() symbol for kvm.ko. * Fixed commit log as per Dave's suggestion. * Added Reviewed-by from Dave * Added FRAME_BEGIN/FRAME_END for __tdx_hypercall_vendor_kvm() to fix compiler warnings. On Tue, May 18, 2021 at 6:17 PM Kuppuswamy Sathyanarayanan wrote: > > From: "Kirill A. Shutemov" > > KVM hypercalls use the "vmcall" or "vmmcall" instructions. > Although the ABI is similar, those instructions no longer > function for TDX guests. Make vendor-specific TDVMCALLs > instead of VMCALL. This enables TDX guests to run with KVM > acting as the hypervisor. TDX guests running under other > hypervisors will continue to use those hypervisors' > hypercalls. > > Since KVM driver can be built as a kernel module, export > tdx_kvm_hypercall*() to make the symbols visible to kvm.ko. > > [Isaku Yamahata: proposed KVM VENDOR string] > Signed-off-by: Kirill A. Shutemov > Reviewed-by: Andi Kleen > Reviewed-by: Dave Hansen > Signed-off-by: Kuppuswamy Sathyanarayanan > --- > arch/x86/Kconfig | 5 +++ > arch/x86/include/asm/kvm_para.h | 21 ++++++++++ > arch/x86/include/asm/tdx.h | 68 +++++++++++++++++++++++++++++++++ > arch/x86/kernel/tdcall.S | 26 +++++++++++++ > 4 files changed, 120 insertions(+) > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 9e0e0ff76bab..15e66a99dd41 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -886,6 +886,11 @@ config INTEL_TDX_GUEST > run in a CPU mode that protects the confidentiality of TD memor= y > contents and the TD=E2=80=99s CPU state from other software, in= cluding VMM. > > +# This option enables KVM specific hypercalls in TDX guest. > +config INTEL_TDX_GUEST_KVM > + def_bool y > + depends on KVM_GUEST && INTEL_TDX_GUEST > + > endif #HYPERVISOR_GUEST > > source "arch/x86/Kconfig.cpu" > diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_p= ara.h > index 338119852512..2fa85481520b 100644 > --- a/arch/x86/include/asm/kvm_para.h > +++ b/arch/x86/include/asm/kvm_para.h > @@ -6,6 +6,7 @@ > #include > #include > #include > +#include > > extern void kvmclock_init(void); > > @@ -34,6 +35,10 @@ static inline bool kvm_check_and_clear_guest_paused(vo= id) > static inline long kvm_hypercall0(unsigned int nr) > { > long ret; > + > + if (is_tdx_guest()) > + return tdx_kvm_hypercall0(nr); > + > asm volatile(KVM_HYPERCALL > : "=3Da"(ret) > : "a"(nr) > @@ -44,6 +49,10 @@ static inline long kvm_hypercall0(unsigned int nr) > static inline long kvm_hypercall1(unsigned int nr, unsigned long p1) > { > long ret; > + > + if (is_tdx_guest()) > + return tdx_kvm_hypercall1(nr, p1); > + > asm volatile(KVM_HYPERCALL > : "=3Da"(ret) > : "a"(nr), "b"(p1) > @@ -55,6 +64,10 @@ static inline long kvm_hypercall2(unsigned int nr, uns= igned long p1, > unsigned long p2) > { > long ret; > + > + if (is_tdx_guest()) > + return tdx_kvm_hypercall2(nr, p1, p2); > + > asm volatile(KVM_HYPERCALL > : "=3Da"(ret) > : "a"(nr), "b"(p1), "c"(p2) > @@ -66,6 +79,10 @@ static inline long kvm_hypercall3(unsigned int nr, uns= igned long p1, > unsigned long p2, unsigned long p3) > { > long ret; > + > + if (is_tdx_guest()) > + return tdx_kvm_hypercall3(nr, p1, p2, p3); > + > asm volatile(KVM_HYPERCALL > : "=3Da"(ret) > : "a"(nr), "b"(p1), "c"(p2), "d"(p3) > @@ -78,6 +95,10 @@ static inline long kvm_hypercall4(unsigned int nr, uns= igned long p1, > unsigned long p4) > { > long ret; > + > + if (is_tdx_guest()) > + return tdx_kvm_hypercall4(nr, p1, p2, p3, p4); > + > asm volatile(KVM_HYPERCALL > : "=3Da"(ret) > : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4) > diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h > index 8ab4067afefc..3d8d977e52f0 100644 > --- a/arch/x86/include/asm/tdx.h > +++ b/arch/x86/include/asm/tdx.h > @@ -73,4 +73,72 @@ static inline void tdx_early_init(void) { }; > > #endif /* CONFIG_INTEL_TDX_GUEST */ > > +#ifdef CONFIG_INTEL_TDX_GUEST_KVM > +u64 __tdx_hypercall_vendor_kvm(u64 fn, u64 r12, u64 r13, u64 r14, > + u64 r15, struct tdx_hypercall_output *out)= ; > + > +/* Used by kvm_hypercall0() to trigger hypercall in TDX guest */ > +static inline long tdx_kvm_hypercall0(unsigned int nr) > +{ > + return __tdx_hypercall_vendor_kvm(nr, 0, 0, 0, 0, NULL); > +} > + > +/* Used by kvm_hypercall1() to trigger hypercall in TDX guest */ > +static inline long tdx_kvm_hypercall1(unsigned int nr, unsigned long p1) > +{ > + return __tdx_hypercall_vendor_kvm(nr, p1, 0, 0, 0, NULL); > +} > + > +/* Used by kvm_hypercall2() to trigger hypercall in TDX guest */ > +static inline long tdx_kvm_hypercall2(unsigned int nr, unsigned long p1, > + unsigned long p2) > +{ > + return __tdx_hypercall_vendor_kvm(nr, p1, p2, 0, 0, NULL); > +} > + > +/* Used by kvm_hypercall3() to trigger hypercall in TDX guest */ > +static inline long tdx_kvm_hypercall3(unsigned int nr, unsigned long p1, > + unsigned long p2, unsigned long p3) > +{ > + return __tdx_hypercall_vendor_kvm(nr, p1, p2, p3, 0, NULL); > +} > + > +/* Used by kvm_hypercall4() to trigger hypercall in TDX guest */ > +static inline long tdx_kvm_hypercall4(unsigned int nr, unsigned long p1, > + unsigned long p2, unsigned long p3, > + unsigned long p4) > +{ > + return __tdx_hypercall_vendor_kvm(nr, p1, p2, p3, p4, NULL); > +} > +#else > +static inline long tdx_kvm_hypercall0(unsigned int nr) > +{ > + return -ENODEV; > +} > + > +static inline long tdx_kvm_hypercall1(unsigned int nr, unsigned long p1) > +{ > + return -ENODEV; > +} > + > +static inline long tdx_kvm_hypercall2(unsigned int nr, unsigned long p1, > + unsigned long p2) > +{ > + return -ENODEV; > +} > + > +static inline long tdx_kvm_hypercall3(unsigned int nr, unsigned long p1, > + unsigned long p2, unsigned long p3) > +{ > + return -ENODEV; > +} > + > +static inline long tdx_kvm_hypercall4(unsigned int nr, unsigned long p1, > + unsigned long p2, unsigned long p3, > + unsigned long p4) > +{ > + return -ENODEV; > +} > +#endif /* CONFIG_INTEL_TDX_GUEST_KVM */ > + > #endif /* _ASM_X86_TDX_H */ > diff --git a/arch/x86/kernel/tdcall.S b/arch/x86/kernel/tdcall.S > index 2dfecdae38bb..27355fb80aeb 100644 > --- a/arch/x86/kernel/tdcall.S > +++ b/arch/x86/kernel/tdcall.S > @@ -3,6 +3,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -25,6 +26,8 @@ > TDG_R12 | TDG_R13 | \ > TDG_R14 | TDG_R15 ) > > +#define TDVMCALL_VENDOR_KVM 0x4d564b2e584454 /* "TDX.KVM" */ > + > /* > * TDX guests use the TDCALL instruction to make requests to the > * TDX module and hypercalls to the VMM. It is supported in > @@ -212,3 +215,26 @@ SYM_FUNC_START(__tdx_hypercall) > FRAME_END > retq > SYM_FUNC_END(__tdx_hypercall) > + > +#ifdef CONFIG_INTEL_TDX_GUEST_KVM > + > +/* > + * Helper function for KVM vendor TDVMCALLs. This assembly wrapper > + * lets us reuse do_tdvmcall() for KVM-specific hypercalls ( > + * TDVMCALL_VENDOR_KVM). > + */ > +SYM_FUNC_START(__tdx_hypercall_vendor_kvm) > + FRAME_BEGIN > + /* > + * R10 is not part of the function call ABI, but it is a part > + * of the TDVMCALL ABI. So set it before making call to the > + * do_tdx_hypercall(). > + */ > + movq $TDVMCALL_VENDOR_KVM, %r10 > + call do_tdx_hypercall > + FRAME_END > + retq > +SYM_FUNC_END(__tdx_hypercall_vendor_kvm) > + > +EXPORT_SYMBOL(__tdx_hypercall_vendor_kvm); > +#endif /* CONFIG_INTEL_TDX_GUEST_KVM */ > -- > 2.25.1 > --=20 Sathyanarayanan Kuppuswamy Linux Kernel Developer