From patchwork Sat Nov 10 15:43:28 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoffer Dall X-Patchwork-Id: 1723961 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id BE0C7DFE7E for ; Sat, 10 Nov 2012 15:43:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752059Ab2KJPnb (ORCPT ); Sat, 10 Nov 2012 10:43:31 -0500 Received: from mail-we0-f174.google.com ([74.125.82.174]:56477 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751968Ab2KJPna (ORCPT ); Sat, 10 Nov 2012 10:43:30 -0500 Received: by mail-we0-f174.google.com with SMTP id t9so2183999wey.19 for ; Sat, 10 Nov 2012 07:43:30 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=subject:to:from:cc:date:message-id:in-reply-to:references :user-agent:mime-version:content-type:content-transfer-encoding :x-gm-message-state; bh=xK4GEiNnlFI5sardWO/Bvf2T1pWAHPVJDsO0L/6ueyk=; b=XDd7O82mMNnfnSnZkYtKoCGYa+lG+RiaQJWZHQCCEThungH1A6w/X743zSXlfANcKS pS51aPWHwZXYKRyPlfoWLVJtX71Okt4S6e+A50OsvKOQerTu3cSZmuI6Wv31JD1ErWfI zErh/ilLdgwrx1GaIi0lGeafIj4Wj0L5NG0mLhmGgRYlTN11yBVErp0PUhisNdP+EYz2 f0xCRNU8SAPlGnZGeA5vVEPMLFFORvs2ovto7tjc83E+bWGrHNICATpqcfN+1cWJzVQj 5pa6pNkb3/NSl6nfG+QUmYQcBv6Kh6XjkA3lbKB7KGFytOG3vK0qmJMjInq/dYfQI0gQ eX3Q== Received: by 10.216.139.209 with SMTP id c59mr6209842wej.50.1352562209939; Sat, 10 Nov 2012 07:43:29 -0800 (PST) Received: from [127.0.1.1] (ip1.c116.obr91.cust.comxnet.dk. [87.72.8.103]) by mx.google.com with ESMTPS id fa9sm2793616wib.5.2012.11.10.07.43.28 (version=TLSv1/SSLv3 cipher=OTHER); Sat, 10 Nov 2012 07:43:29 -0800 (PST) Subject: [PATCH v4 11/14] KVM: ARM: Demux CCSIDR in the userspace API To: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu From: Christoffer Dall Cc: Marcelo Tosatti , Rusty Russell Date: Sat, 10 Nov 2012 16:43:28 +0100 Message-ID: <20121110154328.2836.78376.stgit@chazy-air> In-Reply-To: <20121110154203.2836.46686.stgit@chazy-air> References: <20121110154203.2836.46686.stgit@chazy-air> User-Agent: StGit/0.15 MIME-Version: 1.0 X-Gm-Message-State: ALoCoQnVv4hWR7R14Bmiogsec0pS6gOm0FOso+S56weCvWEtwsVVqqoe4u11r+06ZWqT7Wq6S+OA Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org The Cache Size Selection Register (CSSELR) selects the current Cache Size ID Register (CCSIDR). You write which cache you are interested in to CSSELR, and read the information out of CCSIDR. Which cache numbers are valid is known by reading the Cache Level ID Register (CLIDR). To export this state to userspace, we add a KVM_REG_ARM_DEMUX numberspace (17), which uses 8 bits to represent which register is being demultiplexed (0 for CCSIDR), and the lower 8 bits to represent this demultiplexing (in our case, the CSSELR value, which is 4 bits). Reviewed-by: Marcelo Tosatti Signed-off-by: Rusty Russell --- Documentation/virtual/kvm/api.txt | 2 arch/arm/include/uapi/asm/kvm.h | 9 ++ arch/arm/kvm/coproc.c | 163 ++++++++++++++++++++++++++++++++++++- 3 files changed, 171 insertions(+), 3 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 9671cd2..bf8f99c 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1804,6 +1804,8 @@ ARM 32-bit CP15 registers have the following id bit patterns: ARM 64-bit CP15 registers have the following id bit patterns: 0x4003 0000 000F +ARM CCSIDR registers are demultiplexed by CSSELR value: + 0x4002 0000 0011 00 4.69 KVM_GET_ONE_REG diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index a807d9a..78a629c 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -80,6 +80,15 @@ struct kvm_arch_memory_slot { #define KVM_REG_ARM_CORE (0x0010 << KVM_REG_ARM_COPROC_SHIFT) #define KVM_REG_ARM_CORE_REG(name) (offsetof(struct kvm_regs, name) / 4) +/* Some registers need more space to represent values. */ +#define KVM_REG_ARM_DEMUX (0x0011 << KVM_REG_ARM_COPROC_SHIFT) +#define KVM_REG_ARM_DEMUX_ID_MASK 0x000000000000FF00 +#define KVM_REG_ARM_DEMUX_ID_SHIFT 8 +#define KVM_REG_ARM_DEMUX_ID_CCSIDR (0x00 << KVM_REG_ARM_DEMUX_ID_SHIFT) +#define KVM_REG_ARM_DEMUX_VAL_MASK 0x00000000000000FF +#define KVM_REG_ARM_DEMUX_VAL_SHIFT 0 + + /* KVM_IRQ_LINE irq field index values */ #define KVM_ARM_IRQ_TYPE_SHIFT 24 #define KVM_ARM_IRQ_TYPE_MASK 0xff diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c index 95a0f5e..9ce5861 100644 --- a/arch/arm/kvm/coproc.c +++ b/arch/arm/kvm/coproc.c @@ -35,6 +35,12 @@ * Co-processor emulation *****************************************************************************/ +/* 3 bits per cache level, as per CLIDR, but non-existent caches always 0 */ +static u32 cache_levels; + +/* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */ +#define CSSELR_MAX 12 + int kvm_handle_cp10_id(struct kvm_vcpu *vcpu, struct kvm_run *run) { kvm_inject_undefined(vcpu); @@ -548,11 +554,112 @@ static int set_invariant_cp15(u64 id, void __user *uaddr) return 0; } +static bool is_valid_cache(u32 val) +{ + u32 level, ctype; + + if (val >= CSSELR_MAX) + return -ENOENT; + + /* Bottom bit is Instruction or Data bit. Next 3 bits are level. */ + level = (val >> 1); + ctype = (cache_levels >> (level * 3)) & 7; + + switch (ctype) { + case 0: /* No cache */ + return false; + case 1: /* Instruction cache only */ + return (val & 1); + case 2: /* Data cache only */ + case 4: /* Unified cache */ + return !(val & 1); + case 3: /* Separate instruction and data caches */ + return true; + default: /* Reserved: we can't know instruction or data. */ + return false; + } +} + +/* Which cache CCSIDR represents depends on CSSELR value. */ +static u32 get_ccsidr(u32 csselr) +{ + u32 ccsidr; + + /* Make sure noone else changes CSSELR during this! */ + local_irq_disable(); + /* Put value into CSSELR */ + asm volatile("mcr p15, 2, %0, c0, c0, 0" : : "r" (csselr)); + /* Read result out of CCSIDR */ + asm volatile("mrc p15, 1, %0, c0, c0, 0" : "=r" (ccsidr)); + local_irq_enable(); + + return ccsidr; +} + +static int demux_c15_get(u64 id, void __user *uaddr) +{ + u32 val; + u32 __user *uval = uaddr; + + /* Fail if we have unknown bits set. */ + if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK + | ((1 << KVM_REG_ARM_COPROC_SHIFT)-1))) + return -ENOENT; + + switch (id & KVM_REG_ARM_DEMUX_ID_MASK) { + case KVM_REG_ARM_DEMUX_ID_CCSIDR: + if (KVM_REG_SIZE(id) != 4) + return -ENOENT; + val = (id & KVM_REG_ARM_DEMUX_VAL_MASK) + >> KVM_REG_ARM_DEMUX_VAL_SHIFT; + if (!is_valid_cache(val)) + return -ENOENT; + + return put_user(get_ccsidr(val), uval); + default: + return -ENOENT; + } +} + +static int demux_c15_set(u64 id, void __user *uaddr) +{ + u32 val, newval; + u32 __user *uval = uaddr; + + /* Fail if we have unknown bits set. */ + if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK + | ((1 << KVM_REG_ARM_COPROC_SHIFT)-1))) + return -ENOENT; + + switch (id & KVM_REG_ARM_DEMUX_ID_MASK) { + case KVM_REG_ARM_DEMUX_ID_CCSIDR: + if (KVM_REG_SIZE(id) != 4) + return -ENOENT; + val = (id & KVM_REG_ARM_DEMUX_VAL_MASK) + >> KVM_REG_ARM_DEMUX_VAL_SHIFT; + if (!is_valid_cache(val)) + return -ENOENT; + + if (get_user(newval, uval)) + return -EFAULT; + + /* This is also invariant: you can't change it. */ + if (newval != get_ccsidr(val)) + return -EINVAL; + return 0; + default: + return -ENOENT; + } +} + int kvm_arm_coproc_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) { const struct coproc_reg *r; void __user *uaddr = (void __user *)(long)reg->addr; + if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX) + return demux_c15_get(reg->id, uaddr); + r = index_to_coproc_reg(vcpu, reg->id); if (!r) return get_invariant_cp15(reg->id, uaddr); @@ -566,6 +673,9 @@ int kvm_arm_coproc_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) const struct coproc_reg *r; void __user *uaddr = (void __user *)(long)reg->addr; + if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX) + return demux_c15_set(reg->id, uaddr); + r = index_to_coproc_reg(vcpu, reg->id); if (!r) return set_invariant_cp15(reg->id, uaddr); @@ -574,6 +684,33 @@ int kvm_arm_coproc_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) return reg_from_user(&vcpu->arch.cp15[r->reg], uaddr, reg->id); } +static unsigned int num_demux_regs(void) +{ + unsigned int i, count = 0; + + for (i = 0; i < CSSELR_MAX; i++) + if (is_valid_cache(i)) + count++; + + return count; +} + +static int write_demux_regids(u64 __user *uindices) +{ + u64 val = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_DEMUX; + unsigned int i; + + val |= KVM_REG_ARM_DEMUX_ID_CCSIDR; + for (i = 0; i < CSSELR_MAX; i++) { + if (!is_valid_cache(i)) + continue; + if (put_user(val | i, uindices)) + return -EFAULT; + uindices++; + } + return 0; +} + static u64 cp15_to_index(const struct coproc_reg *reg) { u64 val = KVM_REG_ARM | (15 << KVM_REG_ARM_COPROC_SHIFT); @@ -649,6 +786,7 @@ static int walk_cp15(struct kvm_vcpu *vcpu, u64 __user *uind) unsigned long kvm_arm_num_coproc_regs(struct kvm_vcpu *vcpu) { return ARRAY_SIZE(invariant_cp15) + + num_demux_regs() + walk_cp15(vcpu, (u64 __user *)NULL); } @@ -665,9 +803,11 @@ int kvm_arm_copy_coproc_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) } err = walk_cp15(vcpu, uindices); - if (err > 0) - err = 0; - return err; + if (err < 0) + return err; + uindices += err; + + return write_demux_regids(uindices); } void kvm_coproc_table_init(void) @@ -681,6 +821,23 @@ void kvm_coproc_table_init(void) /* We abuse the reset function to overwrite the table itself. */ for (i = 0; i < ARRAY_SIZE(invariant_cp15); i++) invariant_cp15[i].reset(NULL, &invariant_cp15[i]); + + /* + * CLIDR format is awkward, so clean it up. See ARM B4.1.20: + * + * If software reads the Cache Type fields from Ctype1 + * upwards, once it has seen a value of 0b000, no caches + * exist at further-out levels of the hierarchy. So, for + * example, if Ctype3 is the first Cache Type field with a + * value of 0b000, the values of Ctype4 to Ctype7 must be + * ignored. + */ + asm volatile("mrc p15, 1, %0, c0, c0, 1" : "=r" (cache_levels)); + for (i = 0; i < 7; i++) + if (((cache_levels >> (i*3)) & 7) == 0) + break; + /* Clear all higher bits. */ + cache_levels &= (1 << (i*3))-1; } /**