From patchwork Tue Mar 23 01:02:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicholas Piggin X-Patchwork-Id: 1456904 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=kvm-ppc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=SqjRpG/L; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4F4Cny65LZz9sj1 for ; Tue, 23 Mar 2021 12:04:54 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231441AbhCWBET (ORCPT ); Mon, 22 Mar 2021 21:04:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231424AbhCWBEP (ORCPT ); Mon, 22 Mar 2021 21:04:15 -0400 Received: from mail-pf1-x42f.google.com (mail-pf1-x42f.google.com [IPv6:2607:f8b0:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ACA28C061574 for ; Mon, 22 Mar 2021 18:04:14 -0700 (PDT) Received: by mail-pf1-x42f.google.com with SMTP id x26so12513299pfn.0 for ; Mon, 22 Mar 2021 18:04:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=JAFMIe0yYAzJxMahTUIpwR/Z3qkqPJ3NyE7gYKKG1lM=; b=SqjRpG/LV5qxZO0/uQ9B0O/oX8S/biUOnkAYQJo8Hklmi2HiMSJZ9sk1N3JwUly4Iq nS8sPVbJdZIOPtBaHjbinklJ9rx5dBHKGmIM7rJyg8IMUiFizB+mOSOe81T1J7H2eTAw 3+8faNQok0aaacPNtpvpynDEDe0fbQZHU+RfFlRuilmKGPkPQNukZLmfbEWotZTrY9+z dsQ7f6kV0JAUYNquaymDbf7gAc2ZMrdIucAURvdEclsygDlooC0xFU1L7ZepMNixNJNy kf9eg99w3INSdyB3hIuvkvJkCN9hh8ki5H0TK6+f3qOVE3OnXPZ0HRc+EGMkGPrrMLDb vzqg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=JAFMIe0yYAzJxMahTUIpwR/Z3qkqPJ3NyE7gYKKG1lM=; b=lErBMkDHn7K9piPUFiknbUyUldm0L/szKhwvDZuAR5fPIfL/DQkTTwZmOiu9XTuC8Q Pd7OP0P7DTLI4v1q0s7CPhZxg8zj3Wj/gPasPhF6yS43SwWKjJKgSpv1uNye3rOWMv7s hdr0allcpuVP1WpwwIVqXO5KtV/OkF5dMtguTYMDjHbmMwrJ93PWwyZ5njF8NU6T5v71 tiiHXzUTcGuHoN4uhDHvfpWq8fbNppNquQtT605u5dZATk+T6VLEZLDH3JMt6qBWzpNe CO+l6+JbCjiK+00waVFlTK38n5J3cAB16jf8OIQqg7Z7YhWCZnbkoAoRff9q09KWjEm4 7eZA== X-Gm-Message-State: AOAM531Vd+BhriAltJyMTsV2tApxAGcETNBhyqkI6GcFInWW16q1MhJE GCQVgizRMQYRgV9G3UpJsc3SMvUnCHM= X-Google-Smtp-Source: ABdhPJxQtY3Qu8F6RhkcuFbetWI7b6b/giOuOx5PBgVAxD0hA4IXugK6JAgKWZGM1yxMWasEmirY0w== X-Received: by 2002:a17:903:4112:b029:e5:f79d:3eb1 with SMTP id r18-20020a1709034112b02900e5f79d3eb1mr2303702pld.48.1616461454131; Mon, 22 Mar 2021 18:04:14 -0700 (PDT) Received: from bobo.ibm.com ([58.84.78.96]) by smtp.gmail.com with ESMTPSA id e7sm14491894pfc.88.2021.03.22.18.04.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Mar 2021 18:04:13 -0700 (PDT) From: Nicholas Piggin To: kvm-ppc@vger.kernel.org Cc: Nicholas Piggin , linuxppc-dev@lists.ozlabs.org, Alexey Kardashevskiy Subject: [PATCH v4 18/46] KVM: PPC: Book3S 64: Minimise hcall handler calling convention differences Date: Tue, 23 Mar 2021 11:02:37 +1000 Message-Id: <20210323010305.1045293-19-npiggin@gmail.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20210323010305.1045293-1-npiggin@gmail.com> References: <20210323010305.1045293-1-npiggin@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org This sets up the same calling convention from interrupt entry to KVM interrupt handler for system calls as exists for other interrupt types. This is a better API, it uses a save area rather than SPR, and it has more registers free to use. Using a single common API helps maintain it, and it becomes easier to use in C in a later patch. Reviewed-by: Alexey Kardashevskiy Signed-off-by: Nicholas Piggin --- arch/powerpc/kernel/exceptions-64s.S | 21 +++++++++++++++- arch/powerpc/kvm/book3s_64_entry.S | 37 +++++++++------------------- 2 files changed, 32 insertions(+), 26 deletions(-) diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 115cf79f3e82..4615057681c3 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -1892,8 +1892,27 @@ EXC_VIRT_END(system_call, 0x4c00, 0x100) #ifdef CONFIG_KVM_BOOK3S_64_HANDLER TRAMP_REAL_BEGIN(kvm_hcall) + std r9,PACA_EXGEN+EX_R9(r13) + std r11,PACA_EXGEN+EX_R11(r13) + std r12,PACA_EXGEN+EX_R12(r13) + mfcr r9 mfctr r10 - SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */ + std r10,PACA_EXGEN+EX_R13(r13) + li r10,0 + std r10,PACA_EXGEN+EX_CFAR(r13) + std r10,PACA_EXGEN+EX_CTR(r13) + /* + * Save the PPR (on systems that support it) before changing to + * HMT_MEDIUM. That allows the KVM code to save that value into the + * guest state (it is the guest's PPR value). + */ +BEGIN_FTR_SECTION + mfspr r10,SPRN_PPR + std r10,PACA_EXGEN+EX_PPR(r13) +END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) + + HMT_MEDIUM + #ifdef CONFIG_RELOCATABLE /* * Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S index b6149df21de3..de81ab69555b 100644 --- a/arch/powerpc/kvm/book3s_64_entry.S +++ b/arch/powerpc/kvm/book3s_64_entry.S @@ -11,33 +11,21 @@ * These are branched to from interrupt handlers in exception-64s.S which set * IKVM_REAL or IKVM_VIRT, if HSTATE_IN_GUEST was found to be non-zero. */ + +/* + * This is a hcall, so guest register call convention is as + * Documentation/powerpc/papr_hcalls.rst. + * + * The state of registers is as below, except CFAR is not saved, R13 is not + * in SCRATCH0, and R10 does not contain the trap. + */ .global kvmppc_hcall .balign IFETCH_ALIGN_BYTES kvmppc_hcall: - /* - * This is a hcall, so register convention is as - * Documentation/powerpc/papr_hcalls.rst, with these additions: - * R13 = PACA - * guest R13 saved in SPRN_SCRATCH0 - * R10 = free - * guest r10 saved in PACA_EXGEN - */ - /* - * Save the PPR (on systems that support it) before changing to - * HMT_MEDIUM. That allows the KVM code to save that value into the - * guest state (it is the guest's PPR value). - */ -BEGIN_FTR_SECTION - mfspr r10,SPRN_PPR - std r10,HSTATE_PPR(r13) -END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) - HMT_MEDIUM - mfcr r10 - std r12,HSTATE_SCRATCH0(r13) - sldi r12,r10,32 - ori r12,r12,0xc00 - ld r10,PACA_EXGEN+EX_R10(r13) - b do_kvm_interrupt + ld r10,PACA_EXGEN+EX_R13(r13) + SET_SCRATCH0(r10) + li r10,0xc00 + /* Now we look like kvmppc_interrupt */ /* * KVM interrupt entry occurs after GEN_INT_ENTRY runs, and follows that @@ -84,7 +72,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) ld r10,EX_R10(r11) ld r11,EX_R11(r11) -do_kvm_interrupt: /* * Hcalls and other interrupts come here after normalising register * contents and save locations: