From patchwork Sat May 16 04:45:50 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhichao Huang X-Patchwork-Id: 6419031 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 320139F1C1 for ; Sat, 16 May 2015 04:47:28 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C2AA5203AA for ; Sat, 16 May 2015 04:47:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 589D020204 for ; Sat, 16 May 2015 04:47:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030285AbbEPErU (ORCPT ); Sat, 16 May 2015 00:47:20 -0400 Received: from mail-pd0-f174.google.com ([209.85.192.174]:33668 "EHLO mail-pd0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030224AbbEPErR (ORCPT ); Sat, 16 May 2015 00:47:17 -0400 Received: by pdbqa5 with SMTP id qa5so46346659pdb.0 for ; Fri, 15 May 2015 21:47:16 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=hw0BcCVYQ+95acNAY84Hqdu+YpbpMF7TRj6WeYCQL28=; b=hHlGt191zVgfU1ZAd75BuhsNsRe6hKw2xLSLhAPxLhVI/lQ5fK1f0T6C4woFihm48W mtykkB/J3O/02FwGkXbsmC6IXja8Y2JQ7LA0jwQf7q91uGw1MtU4lMw2AK+68EifCihR MkwW4v4l5hNHct6sAjl9A+NKZLRGhKx1hqP5bAJVuE9jDTn6jzFELT/3O1giUes44Y88 uoRhWEv9WobDuUDx0hT1peE2UgNi+CTUUGCu1jARwYtWCB8TL3za6KbC99IureMywHj7 qEidHdkq0qdAKPb233nbILWQr4o8tdApFwsP/F1b9Lk2Y9HlzJjUIQWev4BPuEBoZSRx 1ong== X-Gm-Message-State: ALoCoQmtqOAk2DFQaAvLTgxyTj16DZE+h/iigcTzrSe6W+ZUYSi7WNv6JdHOivWurndhyGJykEFv X-Received: by 10.66.216.161 with SMTP id or1mr24544052pac.34.1431751636699; Fri, 15 May 2015 21:47:16 -0700 (PDT) Received: from localhost ([167.160.116.91]) by mx.google.com with ESMTPSA id f1sm3382726pdp.24.2015.05.15.21.47.12 (version=TLSv1 cipher=RC4-SHA bits=128/128); Fri, 15 May 2015 21:47:15 -0700 (PDT) From: Zhichao Huang To: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, christoffer.dall@linaro.org, marc.zyngier@arm.com, alex.bennee@linaro.org Cc: huangzhichao@huawei.com, Zhichao Huang Subject: [PATCH 09/10] KVM: arm: implement lazy world switch for debug registers Date: Sat, 16 May 2015 12:45:50 +0800 Message-Id: <1431751551-4788-10-git-send-email-zhichao.huang@linaro.org> X-Mailer: git-send-email 1.9.5.msysgit.1 In-Reply-To: <1431751551-4788-1-git-send-email-zhichao.huang@linaro.org> References: <1431751551-4788-1-git-send-email-zhichao.huang@linaro.org> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Implement switching of the debug registers. While the number of registers is massive, CPUs usually don't implement them all (A15 has 6 breakpoints and 4 watchpoints, which gives us a total of 22 registers "only"). Also, we only save/restore them when DBGDSCR has debug enabled, or when we've flagged the debug registers as dirty. It means that most of the time, we only save/restore DBGDSCR. Signed-off-by: Zhichao Huang --- arch/arm/kvm/interrupts.S | 16 +++ arch/arm/kvm/interrupts_head.S | 256 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 272 insertions(+) diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S index 79caf79..d626275 100644 --- a/arch/arm/kvm/interrupts.S +++ b/arch/arm/kvm/interrupts.S @@ -116,6 +116,12 @@ ENTRY(__kvm_vcpu_run) read_cp15_state store_to_vcpu = 0 write_cp15_state read_from_vcpu = 1 + @ Store hardware CP14 state and load guest state + compute_debug_state 1f + bl __save_host_debug_regs + bl __restore_guest_debug_regs + +1: @ If the host kernel has not been configured with VFPv3 support, @ then it is safer if we deny guests from using it as well. #ifdef CONFIG_VFPv3 @@ -201,6 +207,16 @@ after_vfp_restore: mrc p15, 0, r2, c0, c0, 5 mcr p15, 4, r2, c0, c0, 5 + @ Store guest CP14 state and restore host state + skip_debug_state 1f + bl __save_guest_debug_regs + bl __restore_host_debug_regs + /* Clear the dirty flag for the next run, as all the state has + * already been saved. Note that we nuke the whole 32bit word. + * If we ever add more flags, we'll have to be more careful... + */ + clear_debug_dirty_bit +1: @ Store guest CP15 state and restore host state read_cp15_state store_to_vcpu = 1 write_cp15_state read_from_vcpu = 0 diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S index 3a0128c..ed406be 100644 --- a/arch/arm/kvm/interrupts_head.S +++ b/arch/arm/kvm/interrupts_head.S @@ -7,6 +7,7 @@ #define VCPU_USR_SP (VCPU_USR_REG(13)) #define VCPU_USR_LR (VCPU_USR_REG(14)) #define CP15_OFFSET(_cp15_reg_idx) (VCPU_CP15 + (_cp15_reg_idx * 4)) +#define CP14_OFFSET(_cp14_reg_idx) (VCPU_CP14 + ((_cp14_reg_idx) * 4)) /* * Many of these macros need to access the VCPU structure, which is always @@ -99,6 +100,10 @@ vcpu .req r0 @ vcpu pointer always in r0 mrs r8, LR_fiq mrs r9, SPSR_fiq push {r2-r9} + + /* DBGDSCR reg */ + mrc p14, 0, r2, c0, c1, 0 + push {r2} .endm .macro pop_host_regs_mode mode @@ -113,6 +118,9 @@ vcpu .req r0 @ vcpu pointer always in r0 * Clobbers all registers, in all modes, except r0 and r1. */ .macro restore_host_regs + pop {r2} + mcr p14, 0, r2, c0, c2, 2 + pop {r2-r9} msr r8_fiq, r2 msr r9_fiq, r3 @@ -161,6 +169,9 @@ vcpu .req r0 @ vcpu pointer always in r0 * Clobbers *all* registers. */ .macro restore_guest_regs + ldr r2, [vcpu, #CP14_OFFSET(cp14_DBGDSCRext)] + mcr p14, 0, r2, c0, c2, 2 + restore_guest_regs_mode svc, #VCPU_SVC_REGS restore_guest_regs_mode abt, #VCPU_ABT_REGS restore_guest_regs_mode und, #VCPU_UND_REGS @@ -239,6 +250,10 @@ vcpu .req r0 @ vcpu pointer always in r0 save_guest_regs_mode abt, #VCPU_ABT_REGS save_guest_regs_mode und, #VCPU_UND_REGS save_guest_regs_mode irq, #VCPU_IRQ_REGS + + /* DBGDSCR reg */ + mrc p14, 0, r2, c0, c1, 0 + str r2, [vcpu, #CP14_OFFSET(cp14_DBGDSCRext)] .endm /* Reads cp15 registers from hardware and stores them in memory @@ -438,6 +453,231 @@ vcpu .req r0 @ vcpu pointer always in r0 str r5, [vcpu, #VCPU_DEBUG_FLAGS] .endm +/* Assume r11/r12 in used, clobbers r2-r10 */ +.macro cp14_read_and_push Op2 skip_num + cmp \skip_num, #8 + // if (skip_num >= 8) then skip c8-c15 directly + bge 1f + adr r2, 9998f + add r2, r2, \skip_num, lsl #2 + bx r2 +1: + adr r2, 9999f + sub r3, \skip_num, #8 + add r2, r2, r3, lsl #2 + bx r2 +9998: + mrc p14, 0, r10, c0, c15, \Op2 + mrc p14, 0, r9, c0, c14, \Op2 + mrc p14, 0, r8, c0, c13, \Op2 + mrc p14, 0, r7, c0, c12, \Op2 + mrc p14, 0, r6, c0, c11, \Op2 + mrc p14, 0, r5, c0, c10, \Op2 + mrc p14, 0, r4, c0, c9, \Op2 + mrc p14, 0, r3, c0, c8, \Op2 + push {r3-r10} +9999: + mrc p14, 0, r10, c0, c7, \Op2 + mrc p14, 0, r9, c0, c6, \Op2 + mrc p14, 0, r8, c0, c5, \Op2 + mrc p14, 0, r7, c0, c4, \Op2 + mrc p14, 0, r6, c0, c3, \Op2 + mrc p14, 0, r5, c0, c2, \Op2 + mrc p14, 0, r4, c0, c1, \Op2 + mrc p14, 0, r3, c0, c0, \Op2 + push {r3-r10} +.endm + +/* Assume r11/r12 in used, clobbers r2-r10 */ +.macro cp14_pop_and_write Op2 skip_num + cmp \skip_num, #8 + // if (skip_num >= 8) then skip c8-c15 directly + bge 1f + adr r2, 9998f + add r2, r2, \skip_num, lsl #2 + pop {r3-r10} + bx r2 +1: + adr r2, 9999f + sub r3, \skip_num, #8 + add r2, r2, r3, lsl #2 + pop {r3-r10} + bx r2 + +9998: + mcr p14, 0, r10, c0, c15, \Op2 + mcr p14, 0, r9, c0, c14, \Op2 + mcr p14, 0, r8, c0, c13, \Op2 + mcr p14, 0, r7, c0, c12, \Op2 + mcr p14, 0, r6, c0, c11, \Op2 + mcr p14, 0, r5, c0, c10, \Op2 + mcr p14, 0, r4, c0, c9, \Op2 + mcr p14, 0, r3, c0, c8, \Op2 + + pop {r3-r10} +9999: + mcr p14, 0, r10, c0, c7, \Op2 + mcr p14, 0, r9, c0, c6, \Op2 + mcr p14, 0, r8, c0, c5, \Op2 + mcr p14, 0, r7, c0, c4, \Op2 + mcr p14, 0, r6, c0, c3, \Op2 + mcr p14, 0, r5, c0, c2, \Op2 + mcr p14, 0, r4, c0, c1, \Op2 + mcr p14, 0, r3, c0, c0, \Op2 +.endm + +/* Assume r11/r12 in used, clobbers r2-r3 */ +.macro cp14_read_and_str Op2 cp14_reg0 skip_num + adr r3, 1f + add r3, r3, \skip_num, lsl #3 + bx r3 +1: + mrc p14, 0, r2, c0, c15, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0+15)] + mrc p14, 0, r2, c0, c14, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0+14)] + mrc p14, 0, r2, c0, c13, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0+13)] + mrc p14, 0, r2, c0, c12, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0+12)] + mrc p14, 0, r2, c0, c11, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0+11)] + mrc p14, 0, r2, c0, c10, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0+10)] + mrc p14, 0, r2, c0, c9, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0+9)] + mrc p14, 0, r2, c0, c8, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0+8)] + mrc p14, 0, r2, c0, c7, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0+7)] + mrc p14, 0, r2, c0, c6, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0+6)] + mrc p14, 0, r2, c0, c5, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0+5)] + mrc p14, 0, r2, c0, c4, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0+4)] + mrc p14, 0, r2, c0, c3, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0+3)] + mrc p14, 0, r2, c0, c2, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0+2)] + mrc p14, 0, r2, c0, c1, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0+1)] + mrc p14, 0, r2, c0, c0, \Op2 + str r2, [vcpu, #CP14_OFFSET(\cp14_reg0)] +.endm + +/* Assume r11/r12 in used, clobbers r2-r3 */ +.macro cp14_ldr_and_write Op2 cp14_reg0 skip_num + adr r3, 1f + add r3, r3, \skip_num, lsl #3 + bx r3 +1: + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0+15)] + mcr p14, 0, r2, c0, c15, \Op2 + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0+14)] + mcr p14, 0, r2, c0, c14, \Op2 + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0+13)] + mcr p14, 0, r2, c0, c13, \Op2 + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0+12)] + mcr p14, 0, r2, c0, c12, \Op2 + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0+11)] + mcr p14, 0, r2, c0, c11, \Op2 + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0+10)] + mcr p14, 0, r2, c0, c10, \Op2 + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0+9)] + mcr p14, 0, r2, c0, c9, \Op2 + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0+8)] + mcr p14, 0, r2, c0, c8, \Op2 + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0+7)] + mcr p14, 0, r2, c0, c7, \Op2 + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0+6)] + mcr p14, 0, r2, c0, c6, \Op2 + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0+5)] + mcr p14, 0, r2, c0, c5, \Op2 + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0+4)] + mcr p14, 0, r2, c0, c4, \Op2 + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0+3)] + mcr p14, 0, r2, c0, c3, \Op2 + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0+2)] + mcr p14, 0, r2, c0, c2, \Op2 + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0+1)] + mcr p14, 0, r2, c0, c1, \Op2 + ldr r2, [vcpu, #CP14_OFFSET(\cp14_reg0)] + mcr p14, 0, r2, c0, c0, \Op2 +.endm + +/* Get extract number of BRPs and WRPs. Saved in r11/r12 */ +.macro read_hw_dbg_num + mrc p14, 0, r2, c0, c0, 0 + ubfx r11, r2, #24, #4 + add r11, r11, #1 // Extract BRPs + ubfx r12, r2, #28, #4 + add r12, r12, #1 // Extract WRPs + mov r2, #16 + sub r11, r2, r11 // How many BPs to skip + sub r12, r2, r12 // How many WPs to skip +.endm + +/* Reads cp14 registers from hardware. + * Writes cp14 registers in-order to the stack. + * + * Assumes vcpu pointer in vcpu reg + * + * Clobbers r2-r12 + */ +.macro save_host_debug_regs + read_hw_dbg_num + cp14_read_and_push #4, r11 @ DBGBVR + cp14_read_and_push #5, r11 @ DBGBCR + cp14_read_and_push #6, r12 @ DBGWVR + cp14_read_and_push #7, r12 @ DBGWCR +.endm + +/* Reads cp14 registers from hardware. + * Writes cp14 registers in-order to the VCPU struct pointed to by vcpup. + * + * Assumes vcpu pointer in vcpu reg + * + * Clobbers r2-r12 + */ +.macro save_guest_debug_regs + read_hw_dbg_num + cp14_read_and_str #4, cp14_DBGBVR0, r11 + cp14_read_and_str #5, cp14_DBGBCR0, r11 + cp14_read_and_str #6, cp14_DBGWVR0, r12 + cp14_read_and_str #7, cp14_DBGWCR0, r12 +.endm + +/* Reads cp14 registers in-order from the stack. + * Writes cp14 registers to hardware. + * + * Assumes vcpu pointer in vcpu reg + * + * Clobbers r2-r12 + */ +.macro restore_host_debug_regs + read_hw_dbg_num + cp14_pop_and_write #4, r11 @ DBGBVR + cp14_pop_and_write #5, r11 @ DBGBCR + cp14_pop_and_write #6, r12 @ DBGWVR + cp14_pop_and_write #7, r12 @ DBGWCR +.endm + +/* Reads cp14 registers in-order from the VCPU struct pointed to by vcpup + * Writes cp14 registers to hardware. + * + * Assumes vcpu pointer in vcpu reg + * + * Clobbers r2-r12 + */ +.macro restore_guest_debug_regs + read_hw_dbg_num + cp14_ldr_and_write #4, cp14_DBGBVR0, r11 + cp14_ldr_and_write #5, cp14_DBGBCR0, r11 + cp14_ldr_and_write #6, cp14_DBGWVR0, r12 + cp14_ldr_and_write #7, cp14_DBGWCR0, r12 +.endm + /* * Save the VGIC CPU state into memory * @@ -673,3 +913,19 @@ ARM_BE8(rev r6, r6 ) .macro load_vcpu mrc p15, 4, vcpu, c13, c0, 2 @ HTPIDR .endm + +__save_host_debug_regs: + save_host_debug_regs + bx lr + +__save_guest_debug_regs: + save_guest_debug_regs + bx lr + +__restore_host_debug_regs: + restore_host_debug_regs + bx lr + +__restore_guest_debug_regs: + restore_guest_debug_regs + bx lr