From patchwork Thu Apr 1 15:02:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicholas Piggin X-Patchwork-Id: 1461237 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=PYWuIBPi; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4FB9b00L4rz9sRK for ; Fri, 2 Apr 2021 04:46:04 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236321AbhDARoU (ORCPT ); Thu, 1 Apr 2021 13:44:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234839AbhDARko (ORCPT ); Thu, 1 Apr 2021 13:40:44 -0400 Received: from mail-pg1-x536.google.com (mail-pg1-x536.google.com [IPv6:2607:f8b0:4864:20::536]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BEADC0F26E5 for ; Thu, 1 Apr 2021 08:04:26 -0700 (PDT) Received: by mail-pg1-x536.google.com with SMTP id k8so1706329pgf.4 for ; Thu, 01 Apr 2021 08:04:26 -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=XjF5TtCs5PSH9ByuLTWe4h3SOH/P0lkGFD2KO7SyoC8=; b=PYWuIBPip6/1DHylMfS+ijuP3kSBXDzqMEq4OIF2MvpDzUNlfdjyYLR+BaACL90put bEwnZSOdCtgHoFrUpGpZ31QGX5ZJrPD7C5Ix9n2p3c76+mwif/E+/eJ/Eh7P53cQnOni alzEe4C8Aky/1zbX2XUWuJ1SLxEwuDqxDJg3JQrHbM6kLTkQznMqofeIQh/ZlfvPhD/q asRACh4/E2oW99E4cwuQK1EuSGBrWHeukTneLwOE9tJ3xEo6EDIlBPhejOUGNMiTWwdw uUKXRuxEg1L+BTj6atKnLDuaVmua6v5Sljc7wUJyAOtSzJe4Ek+KWO32wpmPUrRKZnjv hPXg== 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=XjF5TtCs5PSH9ByuLTWe4h3SOH/P0lkGFD2KO7SyoC8=; b=T0DgisVy+o8SoUmEEaIGWa0KFC6gU5SZLqvKfnkCECHPFmai+jYRiJ88RSGDc+0Tpz 3gw+ca858pqe/gZCf+F9rZJHrV2rAO4M+Or14p6gYySf1p7GNgvShrg+dIhlsCaf4wLl LCk+TiV1P+Sf9b7ABpDWKeZI1pBk+9IdktxvdUz38elht/UogjgkbwWNHiykGablxTJd qLkCjTHGrY3yNq7K5OTh0nUvArOY5bBukIGT9+eb5AiEnCiR+BdXWMJtf3auKJcEt36z BrABXhCUMoAeUljYqyNc+HXbCbsrA+WdNIbovDdoVrucZF1BKaSDF0FPECsouHzf77Hp OWWw== X-Gm-Message-State: AOAM530eZbWQPhYLPyBlCWXMby/2LryNSPGHo2alqG3LvMjWnTl9wiz4 g6g6dQRcud7sli0gcbelAXqFitfli5E= X-Google-Smtp-Source: ABdhPJzbU2fh9FQ9Tk6iU0lkodbRxQlT3MqYtXU77BZauY9ResHDzyqkZsQNeuoaPoz5SayLHH86ww== X-Received: by 2002:a63:650:: with SMTP id 77mr7735886pgg.190.1617289465378; Thu, 01 Apr 2021 08:04:25 -0700 (PDT) Received: from bobo.ibm.com ([1.128.218.207]) by smtp.gmail.com with ESMTPSA id l3sm5599632pju.44.2021.04.01.08.04.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 01 Apr 2021 08:04:25 -0700 (PDT) From: Nicholas Piggin To: kvm-ppc@vger.kernel.org Cc: Nicholas Piggin , linuxppc-dev@lists.ozlabs.org Subject: [PATCH v5 15/48] KVM: PPC: Book3S 64: Move hcall early register setup to KVM Date: Fri, 2 Apr 2021 01:02:52 +1000 Message-Id: <20210401150325.442125-16-npiggin@gmail.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com> References: <20210401150325.442125-1-npiggin@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org System calls / hcalls have a different calling convention than other interrupts, so there is code in the KVMTEST to massage these into the same form as other interrupt handlers. Move this work into the KVM hcall handler. This means teaching KVM a little more about the low level interrupt handler setup, PACA save areas, etc., although that's not obviously worse than the current approach of coming up with an entirely different interrupt register / save convention. Signed-off-by: Nicholas Piggin --- arch/powerpc/include/asm/exception-64s.h | 13 ++++++++ arch/powerpc/kernel/exceptions-64s.S | 42 +----------------------- arch/powerpc/kvm/book3s_64_entry.S | 30 +++++++++++++++++ 3 files changed, 44 insertions(+), 41 deletions(-) diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h index c1a8aac01cf9..bb6f78fcf981 100644 --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -35,6 +35,19 @@ /* PACA save area size in u64 units (exgen, exmc, etc) */ #define EX_SIZE 10 +/* PACA save area offsets */ +#define EX_R9 0 +#define EX_R10 8 +#define EX_R11 16 +#define EX_R12 24 +#define EX_R13 32 +#define EX_DAR 40 +#define EX_DSISR 48 +#define EX_CCR 52 +#define EX_CFAR 56 +#define EX_PPR 64 +#define EX_CTR 72 + /* * maximum recursive depth of MCE exceptions */ diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 98bf73df0f57..a23feaa445b5 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -21,22 +21,6 @@ #include #include -/* PACA save area offsets (exgen, exmc, etc) */ -#define EX_R9 0 -#define EX_R10 8 -#define EX_R11 16 -#define EX_R12 24 -#define EX_R13 32 -#define EX_DAR 40 -#define EX_DSISR 48 -#define EX_CCR 52 -#define EX_CFAR 56 -#define EX_PPR 64 -#define EX_CTR 72 -.if EX_SIZE != 10 - .error "EX_SIZE is wrong" -.endif - /* * Following are fixed section helper macros. * @@ -1964,29 +1948,8 @@ EXC_VIRT_END(system_call, 0x4c00, 0x100) #ifdef CONFIG_KVM_BOOK3S_64_HANDLER TRAMP_REAL_BEGIN(system_call_kvm) - /* - * This is a hcall, so register convention is as above, with these - * differences: - * r13 = PACA - * ctr = orig r13 - * orig r10 saved in PACA - */ - /* - * 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 mfctr r10 - SET_SCRATCH0(r10) - mfcr r10 - std r12,HSTATE_SCRATCH0(r13) - sldi r12,r10,32 - ori r12,r12,0xc00 + SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */ #ifdef CONFIG_RELOCATABLE /* * Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives @@ -1994,15 +1957,12 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) */ __LOAD_FAR_HANDLER(r10, kvmppc_hcall) mtctr r10 - ld r10,PACA_EXGEN+EX_R10(r13) bctr #else - ld r10,PACA_EXGEN+EX_R10(r13) b kvmppc_hcall #endif #endif - /** * Interrupt 0xd00 - Trace Interrupt. * This is a synchronous interrupt in response to instruction step or diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S index 5b177c6d495b..71043b36afc3 100644 --- a/arch/powerpc/kvm/book3s_64_entry.S +++ b/arch/powerpc/kvm/book3s_64_entry.S @@ -14,6 +14,36 @@ .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 + * + * This may also be a syscall from PR-KVM userspace that is to be + * reflected to the PR guest kernel, so registers may be set up for + * a system call rather than hcall. We don't currently clobber + * anything here, but the 0xc00 handler has already clobbered CTR + * and CR0, so PR-KVM can not support a guest kernel that preserves + * those registers across its system calls. + */ + /* + * 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) .global kvmppc_interrupt .balign IFETCH_ALIGN_BYTES