From nobody Sat Apr 11 21:18:00 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7FF65C19F2A for ; Sun, 7 Aug 2022 22:08:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241989AbiHGWIR (ORCPT ); Sun, 7 Aug 2022 18:08:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48268 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235912AbiHGWDd (ORCPT ); Sun, 7 Aug 2022 18:03:33 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 217AAB1FF; Sun, 7 Aug 2022 15:02:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1659909771; x=1691445771; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=xQLKwfKVkuEDkBOvP3PJaQTb1vORW38GK7+OxIugMXU=; b=Gzjcqob6885J43n/3WmoIQDxD3zj0iK2L6lWD0NlsxCJEdP7rswTJyFt VfUqPgDSkt++6IQwsIQCQ1iL8js61O+5mGjvPHZ8cbUWxoYh12a+NCYLZ WAXhD1tVemh4vxGzophnZCywgoRapaMnQoEtVd04jCNB5H1CX31Dn+PgI RrazZJGhnVREIK462DIBeMHAXxoQlIy48O36tMofgwClM1aPMuScYJeg/ rp9r0t+/Ggy3sZpp4ou7p30XhcsQQ9b59bZMLKzc7lbosMR3O+ZrHr869 k+2MrkisrkenzFsaXhSPAZqYekdwsl2DGsalXyExE96ZzLR995tROsH4i A==; X-IronPort-AV: E=McAfee;i="6400,9594,10432"; a="291695705" X-IronPort-AV: E=Sophos;i="5.93,220,1654585200"; d="scan'208";a="291695705" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Aug 2022 15:02:39 -0700 X-IronPort-AV: E=Sophos;i="5.93,220,1654585200"; d="scan'208";a="663682652" Received: from ls.sc.intel.com (HELO localhost) ([143.183.96.54]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Aug 2022 15:02:38 -0700 From: isaku.yamahata@intel.com To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: isaku.yamahata@intel.com, isaku.yamahata@gmail.com, Paolo Bonzini , erdemaktas@google.com, Sean Christopherson , Sagi Shahar Subject: [PATCH v8 063/103] KVM: TDX: Add helper assembly function to TDX vcpu Date: Sun, 7 Aug 2022 15:01:48 -0700 Message-Id: <1773b2242db2acc7e79fa54f7888e387011a5d60.1659854790.git.isaku.yamahata@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Isaku Yamahata TDX defines an API to run TDX vcpu with its own ABI. Define an assembly helper function to run TDX vcpu to hide the special ABI so that C code can call it with function call ABI. Signed-off-by: Isaku Yamahata --- arch/x86/kvm/vmx/vmenter.S | 146 +++++++++++++++++++++++++++++++++++++ 1 file changed, 146 insertions(+) diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S index 4182c7ffc909..5cc9c50e70a3 100644 --- a/arch/x86/kvm/vmx/vmenter.S +++ b/arch/x86/kvm/vmx/vmenter.S @@ -3,6 +3,7 @@ #include #include #include +#include #include #include #include @@ -31,6 +32,13 @@ #define VCPU_R15 __VCPU_REGS_R15 * WORD_SIZE #endif =20 +#ifdef CONFIG_INTEL_TDX_HOST +#define TDENTER 0 +#define EXIT_REASON_TDCALL 77 +#define TDENTER_ERROR_BIT 63 +#define seamcall .byte 0x66,0x0f,0x01,0xcf +#endif + .section .noinstr.text, "ax" =20 /** @@ -358,3 +366,141 @@ SYM_FUNC_START(vmx_do_interrupt_nmi_irqoff) pop %_ASM_BP RET SYM_FUNC_END(vmx_do_interrupt_nmi_irqoff) + +#ifdef CONFIG_INTEL_TDX_HOST + +.pushsection .noinstr.text, "ax" + +/** + * __tdx_vcpu_run - Call SEAMCALL(TDENTER) to run a TD vcpu + * @tdvpr: physical address of TDVPR + * @regs: void * (to registers of TDVCPU) + * @gpr_mask: non-zero if guest registers need to be loaded prior to TDENT= ER + * + * Returns: + * TD-Exit Reason + * + * Note: KVM doesn't support using XMM in its hypercalls, it's the HyperV + * code's responsibility to save/restore XMM registers on TDVMCALL. + */ +SYM_FUNC_START(__tdx_vcpu_run) + push %rbp + mov %rsp, %rbp + + push %r15 + push %r14 + push %r13 + push %r12 + push %rbx + + /* Save @regs, which is needed after TDENTER to capture output. */ + push %rsi + + /* Load @tdvpr to RCX */ + mov %rdi, %rcx + + /* No need to load guest GPRs if the last exit wasn't a TDVMCALL. */ + test %dx, %dx + je 1f + + /* Load @regs to RAX, which will be clobbered with $TDENTER anyways. */ + mov %rsi, %rax + + mov VCPU_RBX(%rax), %rbx + mov VCPU_RDX(%rax), %rdx + mov VCPU_RBP(%rax), %rbp + mov VCPU_RSI(%rax), %rsi + mov VCPU_RDI(%rax), %rdi + + mov VCPU_R8 (%rax), %r8 + mov VCPU_R9 (%rax), %r9 + mov VCPU_R10(%rax), %r10 + mov VCPU_R11(%rax), %r11 + mov VCPU_R12(%rax), %r12 + mov VCPU_R13(%rax), %r13 + mov VCPU_R14(%rax), %r14 + mov VCPU_R15(%rax), %r15 + + /* Load TDENTER to RAX. This kills the @regs pointer! */ +1: mov $TDENTER, %rax + +2: seamcall + + /* Skip to the exit path if TDENTER failed. */ + bt $TDENTER_ERROR_BIT, %rax + jc 4f + + /* Temporarily save the TD-Exit reason. */ + push %rax + + /* check if TD-exit due to TDVMCALL */ + cmp $EXIT_REASON_TDCALL, %ax + + /* Reload @regs to RAX. */ + mov 8(%rsp), %rax + + /* Jump on non-TDVMCALL */ + jne 3f + + /* Save all output from SEAMCALL(TDENTER) */ + mov %rbx, VCPU_RBX(%rax) + mov %rbp, VCPU_RBP(%rax) + mov %rsi, VCPU_RSI(%rax) + mov %rdi, VCPU_RDI(%rax) + mov %r10, VCPU_R10(%rax) + mov %r11, VCPU_R11(%rax) + mov %r12, VCPU_R12(%rax) + mov %r13, VCPU_R13(%rax) + mov %r14, VCPU_R14(%rax) + mov %r15, VCPU_R15(%rax) + +3: mov %rcx, VCPU_RCX(%rax) + mov %rdx, VCPU_RDX(%rax) + mov %r8, VCPU_R8 (%rax) + mov %r9, VCPU_R9 (%rax) + + /* + * Clear all general purpose registers except RSP and RAX to prevent + * speculative use of the guest's values. + */ + xor %rbx, %rbx + xor %rcx, %rcx + xor %rdx, %rdx + xor %rsi, %rsi + xor %rdi, %rdi + xor %rbp, %rbp + xor %r8, %r8 + xor %r9, %r9 + xor %r10, %r10 + xor %r11, %r11 + xor %r12, %r12 + xor %r13, %r13 + xor %r14, %r14 + xor %r15, %r15 + + /* Restore the TD-Exit reason to RAX for return. */ + pop %rax + + /* "POP" @regs. */ +4: add $8, %rsp + pop %rbx + pop %r12 + pop %r13 + pop %r14 + pop %r15 + + pop %rbp + RET + +5: cmpb $0, kvm_rebooting + je 6f + mov $-EFAULT, %rax + jmp 4b +6: ud2 + _ASM_EXTABLE(2b, 5b) + +SYM_FUNC_END(__tdx_vcpu_run) + +.popsection + +#endif --=20 2.25.1