From patchwork Thu Mar 21 06:25:01 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bharat Bhushan X-Patchwork-Id: 229565 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 0CFFC2C00C7 for ; Thu, 21 Mar 2013 17:26:48 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756079Ab3CUG0r (ORCPT ); Thu, 21 Mar 2013 02:26:47 -0400 Received: from mail-db8lp0189.outbound.messaging.microsoft.com ([213.199.154.189]:32332 "EHLO db8outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755863Ab3CUG0q (ORCPT ); Thu, 21 Mar 2013 02:26:46 -0400 Received: from mail63-db8-R.bigfish.com (10.174.8.239) by DB8EHSOBE039.bigfish.com (10.174.4.102) with Microsoft SMTP Server id 14.1.225.23; Thu, 21 Mar 2013 06:26:44 +0000 Received: from mail63-db8 (localhost [127.0.0.1]) by mail63-db8-R.bigfish.com (Postfix) with ESMTP id 910556C0113; Thu, 21 Mar 2013 06:26:44 +0000 (UTC) X-Forefront-Antispam-Report: CIP:70.37.183.190; KIP:(null); UIP:(null); IPV:NLI; H:mail.freescale.net; RD:none; EFVD:NLI X-SpamScore: 3 X-BigFish: VS3(zzzz1f42h1ee6h1de0h1202h1e76h1d1ah1d2ah1082kzz8275bhz2dh2a8h668h839he5bhf0ah107ah1288h12a5h12a9h12bdh12e5h137ah139eh13b6h1441h1504h1537h162dh1631h1758h1898h18e1h1946h19b5h1ad9h1b0ah1155h) Received: from mail63-db8 (localhost.localdomain [127.0.0.1]) by mail63-db8 (MessageSwitch) id 136384720367712_15873; Thu, 21 Mar 2013 06:26:43 +0000 (UTC) Received: from DB8EHSMHS016.bigfish.com (unknown [10.174.8.240]) by mail63-db8.bigfish.com (Postfix) with ESMTP id 0D516A8004F; Thu, 21 Mar 2013 06:26:43 +0000 (UTC) Received: from mail.freescale.net (70.37.183.190) by DB8EHSMHS016.bigfish.com (10.174.4.26) with Microsoft SMTP Server (TLS) id 14.1.225.23; Thu, 21 Mar 2013 06:26:42 +0000 Received: from tx30smr01.am.freescale.net (10.81.153.31) by 039-SN1MMR1-001.039d.mgd.msft.net (10.84.1.13) with Microsoft SMTP Server (TLS) id 14.2.328.11; Thu, 21 Mar 2013 06:26:41 +0000 Received: from freescale.com ([10.232.15.72]) by tx30smr01.am.freescale.net (8.14.3/8.14.0) with SMTP id r2L6QZ7W024270; Wed, 20 Mar 2013 23:26:37 -0700 Received: by freescale.com (sSMTP sendmail emulation); Thu, 21 Mar 2013 11:55:29 +0530 From: Bharat Bhushan To: , , , CC: Bharat Bhushan Subject: [PATCH 4/4 v2] KVM: PPC: Add userspace debug stub support Date: Thu, 21 Mar 2013 11:55:01 +0530 Message-ID: <1363847101-26503-5-git-send-email-Bharat.Bhushan@freescale.com> X-Mailer: git-send-email 1.7.0.4 In-Reply-To: <1363847101-26503-1-git-send-email-Bharat.Bhushan@freescale.com> References: <1363847101-26503-1-git-send-email-Bharat.Bhushan@freescale.com> MIME-Version: 1.0 X-OriginatorOrg: freescale.com Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org From: Bharat Bhushan This patch adds the debug stub support on booke/bookehv. Now QEMU debug stub can use hw breakpoint, watchpoint and software breakpoint to debug guest. Debug registers are saved/restored on vcpu_put()/vcpu_get(). Also the debug registers are saved restored only if guest is using debug resources. Signed-off-by: Bharat Bhushan --- v2: - save/restore in vcpu_get()/vcpu_put() - some more minor cleanup based on review comments. arch/powerpc/include/asm/kvm_host.h | 10 ++ arch/powerpc/include/uapi/asm/kvm.h | 22 +++- arch/powerpc/kvm/booke.c | 252 ++++++++++++++++++++++++++++++++--- arch/powerpc/kvm/e500_emulate.c | 10 ++ 4 files changed, 272 insertions(+), 22 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index f4ba881..8571952 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -504,7 +504,17 @@ struct kvm_vcpu_arch { u32 mmucfg; u32 epr; u32 crit_save; + /* guest debug registers*/ struct kvmppc_booke_debug_reg dbg_reg; + /* shadow debug registers */ + struct kvmppc_booke_debug_reg shadow_dbg_reg; + /* host debug registers*/ + struct kvmppc_booke_debug_reg host_dbg_reg; + /* + * Flag indicating that debug registers are used by guest + * and requires save restore. + */ + bool debug_save_restore; #endif gpa_t paddr_accessed; gva_t vaddr_accessed; diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h index 15f9a00..d7ce449 100644 --- a/arch/powerpc/include/uapi/asm/kvm.h +++ b/arch/powerpc/include/uapi/asm/kvm.h @@ -25,6 +25,7 @@ /* Select powerpc specific features in */ #define __KVM_HAVE_SPAPR_TCE #define __KVM_HAVE_PPC_SMT +#define __KVM_HAVE_GUEST_DEBUG struct kvm_regs { __u64 pc; @@ -267,7 +268,24 @@ struct kvm_fpu { __u64 fpr[32]; }; +/* + * Defines for h/w breakpoint, watchpoint (read, write or both) and + * software breakpoint. + * These are used as "type" in KVM_SET_GUEST_DEBUG ioctl and "status" + * for KVM_DEBUG_EXIT. + */ +#define KVMPPC_DEBUG_NONE 0x0 +#define KVMPPC_DEBUG_BREAKPOINT (1UL << 1) +#define KVMPPC_DEBUG_WATCH_WRITE (1UL << 2) +#define KVMPPC_DEBUG_WATCH_READ (1UL << 3) struct kvm_debug_exit_arch { + __u64 address; + /* + * exiting to userspace because of h/w breakpoint, watchpoint + * (read, write or both) and software breakpoint. + */ + __u32 status; + __u32 reserved; }; /* for KVM_SET_GUEST_DEBUG */ @@ -279,10 +297,6 @@ struct kvm_guest_debug_arch { * Type denotes h/w breakpoint, read watchpoint, write * watchpoint or watchpoint (both read and write). */ -#define KVMPPC_DEBUG_NOTYPE 0x0 -#define KVMPPC_DEBUG_BREAKPOINT (1UL << 1) -#define KVMPPC_DEBUG_WATCH_WRITE (1UL << 2) -#define KVMPPC_DEBUG_WATCH_READ (1UL << 3) __u32 type; __u32 reserved; } bp[16]; diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index 1de93a8..bf20056 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -133,6 +133,30 @@ static void kvmppc_vcpu_sync_fpu(struct kvm_vcpu *vcpu) #endif } +static void kvmppc_vcpu_sync_debug(struct kvm_vcpu *vcpu) +{ + /* Synchronize guest's desire to get debug interrupts into shadow MSR */ +#ifndef CONFIG_KVM_BOOKE_HV + vcpu->arch.shadow_msr &= ~MSR_DE; + vcpu->arch.shadow_msr |= vcpu->arch.shared->msr & MSR_DE; +#endif + + /* Force enable debug interrupts when user space wants to debug */ + if (vcpu->guest_debug) { +#ifdef CONFIG_KVM_BOOKE_HV + /* + * Since there is no shadow MSR, sync MSR_DE into the guest + * visible MSR. Do not allow guest to change MSR[DE]. + */ + vcpu->arch.shared->msr |= MSR_DE; + mtspr(SPRN_MSRP, mfspr(SPRN_MSRP) | MSRP_DEP); +#else + vcpu->arch.shadow_msr |= MSR_DE; + vcpu->arch.shared->msr &= ~MSR_DE; +#endif + } +} + /* * Helper function for "full" MSR writes. No need to call this if only * EE/CE/ME/DE/RI are changing. @@ -150,6 +174,7 @@ void kvmppc_set_msr(struct kvm_vcpu *vcpu, u32 new_msr) kvmppc_mmu_msr_notify(vcpu, old_msr); kvmppc_vcpu_sync_spe(vcpu); kvmppc_vcpu_sync_fpu(vcpu); + kvmppc_vcpu_sync_debug(vcpu); } static void kvmppc_booke_queue_irqprio(struct kvm_vcpu *vcpu, @@ -736,6 +761,9 @@ static int emulation_exit(struct kvm_run *run, struct kvm_vcpu *vcpu) run->exit_reason = KVM_EXIT_DCR; return RESUME_HOST; + case EMULATE_EXIT_USER: + return RESUME_HOST; + case EMULATE_FAIL: printk(KERN_CRIT "%s: emulation at %lx failed (%08x)\n", __func__, vcpu->arch.pc, vcpu->arch.last_inst); @@ -751,6 +779,30 @@ static int emulation_exit(struct kvm_run *run, struct kvm_vcpu *vcpu) } } +static int kvmppc_handle_debug(struct kvm_run *run, struct kvm_vcpu *vcpu) +{ + u32 dbsr = mfspr(SPRN_DBSR); + mtspr(SPRN_DBSR, dbsr); + + run->debug.arch.status = 0; + run->debug.arch.address = vcpu->arch.pc; + + if (dbsr & (DBSR_IAC1 | DBSR_IAC2 | DBSR_IAC3 | DBSR_IAC4)) { + run->debug.arch.status |= KVMPPC_DEBUG_BREAKPOINT; + } else { + if (dbsr & (DBSR_DAC1W | DBSR_DAC2W)) + run->debug.arch.status |= KVMPPC_DEBUG_WATCH_WRITE; + else if (dbsr & (DBSR_DAC1R | DBSR_DAC2R)) + run->debug.arch.status |= KVMPPC_DEBUG_WATCH_READ; + if (dbsr & (DBSR_DAC1R | DBSR_DAC1W)) + run->debug.arch.address = vcpu->arch.shadow_dbg_reg.dac[0]; + else if (dbsr & (DBSR_DAC2R | DBSR_DAC2W)) + run->debug.arch.address = vcpu->arch.shadow_dbg_reg.dac[1]; + } + + return RESUME_HOST; +} + static void kvmppc_fill_pt_regs(struct pt_regs *regs) { ulong r1, ip, msr, lr; @@ -1110,18 +1162,10 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu, } case BOOKE_INTERRUPT_DEBUG: { - u32 dbsr; - - vcpu->arch.pc = mfspr(SPRN_CSRR0); - - /* clear IAC events in DBSR register */ - dbsr = mfspr(SPRN_DBSR); - dbsr &= DBSR_IAC1 | DBSR_IAC2 | DBSR_IAC3 | DBSR_IAC4; - mtspr(SPRN_DBSR, dbsr); - - run->exit_reason = KVM_EXIT_DEBUG; + r = kvmppc_handle_debug(run, vcpu); + if (r == RESUME_HOST) + run->exit_reason = KVM_EXIT_DEBUG; kvmppc_account_exit(vcpu, DEBUG_EXITS); - r = RESUME_HOST; break; } @@ -1172,7 +1216,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) kvmppc_set_msr(vcpu, 0); #ifndef CONFIG_KVM_BOOKE_HV - vcpu->arch.shadow_msr = MSR_USER | MSR_DE | MSR_IS | MSR_DS; + vcpu->arch.shadow_msr = MSR_USER | MSR_IS | MSR_DS; vcpu->arch.shadow_pid = 1; vcpu->arch.shared->msr = 0; #endif @@ -1527,12 +1571,6 @@ int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg) return r; } -int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, - struct kvm_guest_debug *dbg) -{ - return -EINVAL; -} - int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) { return -ENOTSUPP; @@ -1638,16 +1676,194 @@ void kvmppc_decrementer_func(unsigned long data) kvmppc_set_tsr_bits(vcpu, TSR_DIS); } +static void kvmppc_booke_vcpu_put_debug_regs(struct kvm_vcpu *vcpu) +{ + if (!vcpu->arch.debug_save_restore) + return; + + /* Restore Host Context. Disable all debug events First */ + mtspr(SPRN_DBCR0, 0x0); + /* Disable pending debug event by Clearing DBSR */ + mtspr(SPRN_DBSR, mfspr(SPRN_DBSR)); + + mtspr(SPRN_DBCR1, vcpu->arch.host_dbg_reg.dbcr1); + mtspr(SPRN_DBCR2, vcpu->arch.host_dbg_reg.dbcr2); +#ifdef CONFIG_KVM_E500MC + mtspr(SPRN_DBCR4, vcpu->arch.host_dbg_reg.dbcr4); +#endif + mtspr(SPRN_IAC1, vcpu->arch.host_dbg_reg.iac[0]); + mtspr(SPRN_IAC2, vcpu->arch.host_dbg_reg.iac[1]); +#if CONFIG_PPC_ADV_DEBUG_IACS > 2 + mtspr(SPRN_IAC3, vcpu->arch.host_dbg_reg.iac[2]); + mtspr(SPRN_IAC4, vcpu->arch.host_dbg_reg.iac[3]); +#endif + mtspr(SPRN_DAC1, vcpu->arch.host_dbg_reg.dac[0]); + mtspr(SPRN_DAC2, vcpu->arch.host_dbg_reg.dac[1]); + + /* Enable debug events after all other debug registers restored */ + mtspr(SPRN_DBCR0, vcpu->arch.host_dbg_reg.dbcr0); + + /* Host debug register are restored */ + vcpu->arch.debug_save_restore = false; +} + +static void kvmppc_booke_vcpu_load_debug_regs(struct kvm_vcpu *vcpu) +{ + /* + * Check whether guest still need debug resource, if not then there + * is no need to resotre guest context. + */ + if (!vcpu->arch.shadow_dbg_reg.dbcr0) + return; + + /* + * Save Host debug register only after restore. If host debug + * registers are saved and not restored then do not save again. + */ + if (!vcpu->arch.debug_save_restore) { + /* Save Host context */ + vcpu->arch.host_dbg_reg.dbcr0 = mfspr(SPRN_DBCR0); + vcpu->arch.host_dbg_reg.dbcr1 = mfspr(SPRN_DBCR1); + vcpu->arch.host_dbg_reg.dbcr2 = mfspr(SPRN_DBCR2); +#ifdef CONFIG_KVM_E500MC + vcpu->arch.host_dbg_reg.dbcr4 = mfspr(SPRN_DBCR4); +#endif + vcpu->arch.host_dbg_reg.iac[0] = mfspr(SPRN_IAC1); + vcpu->arch.host_dbg_reg.iac[1] = mfspr(SPRN_IAC2); +#if CONFIG_PPC_ADV_DEBUG_IACS > 2 + vcpu->arch.host_dbg_reg.iac[2] = mfspr(SPRN_IAC3); + vcpu->arch.host_dbg_reg.iac[3] = mfspr(SPRN_IAC4); +#endif + vcpu->arch.host_dbg_reg.dac[0] = mfspr(SPRN_DAC1); + vcpu->arch.host_dbg_reg.dac[1] = mfspr(SPRN_DAC2); + vcpu->arch.debug_save_restore = true; + } + + /* Restore Guest Context. Disable all debug events First */ + mtspr(SPRN_DBCR0, 0x0); + /* Clear h/w DBSR */ + mtspr(SPRN_DBSR, mfspr(SPRN_DBSR)); + + mtspr(SPRN_DBCR1, vcpu->arch.shadow_dbg_reg.dbcr1); + mtspr(SPRN_DBCR2, vcpu->arch.shadow_dbg_reg.dbcr2); +#ifdef CONFIG_KVM_E500MC + mtspr(SPRN_DBCR4, vcpu->arch.shadow_dbg_reg.dbcr4); +#endif + mtspr(SPRN_IAC1, vcpu->arch.shadow_dbg_reg.iac[0]); + mtspr(SPRN_IAC2, vcpu->arch.shadow_dbg_reg.iac[1]); +#if CONFIG_PPC_ADV_DEBUG_IACS > 2 + mtspr(SPRN_IAC3, vcpu->arch.shadow_dbg_reg.iac[2]); + mtspr(SPRN_IAC4, vcpu->arch.shadow_dbg_reg.iac[3]); +#endif + mtspr(SPRN_DAC1, vcpu->arch.shadow_dbg_reg.dac[0]); + mtspr(SPRN_DAC2, vcpu->arch.shadow_dbg_reg.dac[1]); + + /* Enable debug events after other debug registers restored */ + mtspr(SPRN_DBCR0, vcpu->arch.shadow_dbg_reg.dbcr0); +} + +int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, + struct kvm_guest_debug *dbg) +{ + struct kvmppc_booke_debug_reg *dbg_reg; + int n, b = 0, w = 0; + const u32 bp_code[] = { + DBCR0_IAC1 | DBCR0_IDM, + DBCR0_IAC2 | DBCR0_IDM, + DBCR0_IAC3 | DBCR0_IDM, + DBCR0_IAC4 | DBCR0_IDM + }; + const u32 wp_code[] = { + DBCR0_DAC1W | DBCR0_IDM, + DBCR0_DAC2W | DBCR0_IDM, + DBCR0_DAC1R | DBCR0_IDM, + DBCR0_DAC2R | DBCR0_IDM + }; + + if (!(dbg->control & KVM_GUESTDBG_ENABLE)) { + /* Clear All debug events */ + vcpu->arch.shadow_dbg_reg.dbcr0 = 0; + vcpu->guest_debug = 0; + return 0; + } + + vcpu->guest_debug = dbg->control; + vcpu->arch.shadow_dbg_reg.dbcr0 = 0; + /* Set DBCR0_EDM in guest visible DBCR0 register. */ + vcpu->arch.dbg_reg.dbcr0 = DBCR0_EDM; + + if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) + vcpu->arch.shadow_dbg_reg.dbcr0 |= DBCR0_IDM | DBCR0_IC; + + if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) { + /* Code below handles only HW breakpoints */ + kvmppc_booke_vcpu_load_debug_regs(vcpu); + return 0; + } + + dbg_reg = &(vcpu->arch.shadow_dbg_reg); + + /* + * On BOOKE (e500v2); Set DBCR1 and DBCR2 to allow debug events + * to occur when MSR.PR is set. + * On BOOKE-HV (e500mc+); MSR.PR = 0 when guest is running. So we + * should clear DBCR1 and DBCR2. + */ +#ifdef CONFIG_KVM_BOOKE_HV + dbg_reg->dbcr1 = 0; + dbg_reg->dbcr2 = 0; +#else + dbg_reg->dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US | DBCR1_IAC3US | + DBCR1_IAC4US; + dbg_reg->dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US; +#endif + + for (n = 0; n < (KVMPPC_BOOKE_IAC_NUM + KVMPPC_BOOKE_DAC_NUM); n++) { + u32 type = dbg->arch.bp[n].type; + + if (!type) + break; + + if (type & (KVMPPC_DEBUG_WATCH_READ | + KVMPPC_DEBUG_WATCH_WRITE)) { + if (w >= KVMPPC_BOOKE_DAC_NUM) + continue; + + if (type & KVMPPC_DEBUG_WATCH_READ) + dbg_reg->dbcr0 |= wp_code[w + 2]; + if (type & KVMPPC_DEBUG_WATCH_WRITE) + dbg_reg->dbcr0 |= wp_code[w]; + + dbg_reg->dac[w] = dbg->arch.bp[n].addr; + w++; + } else if (type & KVMPPC_DEBUG_BREAKPOINT) { + if (b >= KVMPPC_BOOKE_IAC_NUM) + continue; + + dbg_reg->dbcr0 |= bp_code[b]; + dbg_reg->iac[b] = dbg->arch.bp[n].addr; + b++; + } + } + + kvmppc_booke_vcpu_load_debug_regs(vcpu); + return 0; +} + void kvmppc_booke_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { vcpu->cpu = smp_processor_id(); current->thread.kvm_vcpu = vcpu; + + kvmppc_booke_vcpu_load_debug_regs(vcpu); } void kvmppc_booke_vcpu_put(struct kvm_vcpu *vcpu) { current->thread.kvm_vcpu = NULL; vcpu->cpu = -1; + + kvmppc_booke_vcpu_put_debug_regs(vcpu); } int __init kvmppc_booke_init(void) diff --git a/arch/powerpc/kvm/e500_emulate.c b/arch/powerpc/kvm/e500_emulate.c index e78f353..cefdd38 100644 --- a/arch/powerpc/kvm/e500_emulate.c +++ b/arch/powerpc/kvm/e500_emulate.c @@ -26,6 +26,7 @@ #define XOP_TLBRE 946 #define XOP_TLBWE 978 #define XOP_TLBILX 18 +#define XOP_EHPRIV 270 #ifdef CONFIG_KVM_E500MC static int dbell2prio(ulong param) @@ -130,6 +131,15 @@ int kvmppc_core_emulate_op(struct kvm_run *run, struct kvm_vcpu *vcpu, emulated = kvmppc_e500_emul_tlbivax(vcpu, ea); break; + case XOP_EHPRIV: + run->exit_reason = KVM_EXIT_DEBUG; + run->debug.arch.address = vcpu->arch.pc; + run->debug.arch.status = 0; + kvmppc_account_exit(vcpu, DEBUG_EXITS); + emulated = EMULATE_EXIT_USER; + *advance = 0; + break; + default: emulated = EMULATE_FAIL; }