From patchwork Tue Dec 17 05:29:58 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoffer Dall X-Patchwork-Id: 3359371 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 4CB08C0D4A for ; Tue, 17 Dec 2013 05:53:16 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 27A0D201F9 for ; Tue, 17 Dec 2013 05:53:15 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id BB518201BE for ; Tue, 17 Dec 2013 05:53:13 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VsnH1-0002Va-Qh; Tue, 17 Dec 2013 05:32:54 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VsnGM-0001Bx-3G; Tue, 17 Dec 2013 05:32:10 +0000 Received: from mail-pb0-f46.google.com ([209.85.160.46]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VsnF7-00010b-Ra for linux-arm-kernel@lists.infradead.org; Tue, 17 Dec 2013 05:31:09 +0000 Received: by mail-pb0-f46.google.com with SMTP id md12so6470213pbc.19 for ; Mon, 16 Dec 2013 21:30:32 -0800 (PST) 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=LgLnBZHdNn8mPRo4H+OyVeCFarZ8HT2+S7aVAk3H5Fk=; b=mwWWNYUACIdu6J4GhjIHIUirApQpRSVyGNfu5XpLm9ybP9ZS9TEy77DAvRSnCl4Qs6 BOhYuDt6Db2LP5JBEEwptL6EORpbAP4CXn2D9c/I5Y3IQO8IF/jkA7cf0rF77TTrV6Cr CD/3NJfCWE7Q1obFHz92hK/NSbWW0ZTFcWeeNsFTUTtQE83t5SThh8ml9OqpBeZbKthF gQU7MR2Zio2wv75jzpZIDKyr/r/lM1xHOSO2zs9SevzP1N0/eEQC8pt+qhnBUIp43TBJ dDd2wMYnJBeYK1l5iXlSCmK7n5aMIbH6jvcYwDWvGdfFtMnd4j/WOdqVZbe6wtMiJQ1n UiBQ== X-Gm-Message-State: ALoCoQmeffiQw7cll6eH9kWU4HawnJjX8JdXfKKnOrT4m/85jTGtirXfeIFcyrpSZvIFH0eGGLV5 X-Received: by 10.66.121.131 with SMTP id lk3mr24626495pab.61.1387258232437; Mon, 16 Dec 2013 21:30:32 -0800 (PST) Received: from localhost.localdomain (c-67-169-181-221.hsd1.ca.comcast.net. [67.169.181.221]) by mx.google.com with ESMTPSA id vn10sm30771688pbc.21.2013.12.16.21.30.30 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 16 Dec 2013 21:30:31 -0800 (PST) From: Christoffer Dall To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v5 07/10] KVM: arm-vgic: Add vgic reg access from dev attr Date: Mon, 16 Dec 2013 21:29:58 -0800 Message-Id: <1387258201-8738-8-git-send-email-christoffer.dall@linaro.org> X-Mailer: git-send-email 1.8.5 In-Reply-To: <1387258201-8738-1-git-send-email-christoffer.dall@linaro.org> References: <1387258201-8738-1-git-send-email-christoffer.dall@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131217_003054_169663_02CBBEDE X-CRM114-Status: GOOD ( 24.36 ) X-Spam-Score: -0.1 (/) Cc: linaro-kernel@lists.linaro.org, Christoffer Dall , patches@linaro.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, SUSPICIOUS_RECIPS, UNPARSEABLE_RELAY autolearn=unavailable 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 Add infrastructure to handle distributor and cpu interface register accesses through the KVM_{GET/SET}_DEVICE_ATTR interface by adding the KVM_DEV_ARM_VGIC_GRP_DIST_REGS and KVM_DEV_ARM_VGIC_GRP_CPU_REGS groups and defining the semantics of the attr field to be the MMIO offset as specified in the GICv2 specs. Missing register accesses or other changes in individual register access functions to support save/restore of the VGIC state is added in subsequent patches. Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall --- Documentation/virtual/kvm/devices/arm-vgic.txt | 52 ++++++++ arch/arm/include/uapi/asm/kvm.h | 6 + virt/kvm/arm/vgic.c | 178 +++++++++++++++++++++++++ 3 files changed, 236 insertions(+) Changelog[v4]: - Factored out setting vcpu->cpu = -1 on vcpu_put to separate patch. - Added comment to vgic_attr_regs_access and changed exit handling path. Changelog[v3]: - Spelling and formatting nits - Fill in the phys_addr in kvm_exit_mmio - Put kvm_exit_mmio matching struct on stack - Change if-else-if to switch statement in vgic_attr_regs_access - Properly synchronize access to the VGIC with all VCPUs and the VM structure, ensuring no VCPUs are running while user space is accessing VGIC registers. Changelog[v2]: - Added implementation specific format for the GICC_APRn registers. diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt index c9febb2..7f4e91b 100644 --- a/Documentation/virtual/kvm/devices/arm-vgic.txt +++ b/Documentation/virtual/kvm/devices/arm-vgic.txt @@ -19,3 +19,55 @@ Groups: KVM_VGIC_V2_ADDR_TYPE_CPU (rw, 64-bit) Base address in the guest physical address space of the GIC virtual cpu interface register mappings. + + KVM_DEV_ARM_VGIC_GRP_DIST_REGS + Attributes: + The attr field of kvm_device_attr encodes two values: + bits: | 63 .... 40 | 39 .. 32 | 31 .... 0 | + values: | reserved | cpu id | offset | + + All distributor regs are (rw, 32-bit) + + The offset is relative to the "Distributor base address" as defined in the + GICv2 specs. Getting or setting such a register has the same effect as + reading or writing the register on the actual hardware from the cpu + specified with cpu id field. Note that most distributor fields are not + banked, but return the same value regardless of the cpu id used to access + the register. + Limitations: + - Priorities are not implemented, and registers are RAZ/WI + Errors: + -ENODEV: Getting or setting this register is not yet supported + -EBUSY: One or more VCPUs are running + + KVM_DEV_ARM_VGIC_GRP_CPU_REGS + Attributes: + The attr field of kvm_device_attr encodes two values: + bits: | 63 .... 40 | 39 .. 32 | 31 .... 0 | + values: | reserved | cpu id | offset | + + All CPU interface regs are (rw, 32-bit) + + The offset specifies the offset from the "CPU interface base address" as + defined in the GICv2 specs. Getting or setting such a register has the + same effect as reading or writing the register on the actual hardware. + + The Active Priorities Registers APRn are implementation defined, so we set a + fixed format for our implementation that fits with the model of a "GICv2 + implementation without the security extensions" which we present to the + guest. This interface always exposes four register APR[0-3] describing the + maximum possible 128 preemption levels. The semantics of the register + indicate if any interrupts in a given preemption level are in the active + state by setting the corresponding bit. + + Thus, preemption level X has one or more active interrupts if and only if: + + APRn[X mod 32] == 0b1, where n = X / 32 + + Bits for undefined preemption levels are RAZ/WI. + + Limitations: + - Priorities are not implemented, and registers are RAZ/WI + Errors: + -ENODEV: Getting or setting this register is not yet supported + -EBUSY: One or more VCPUs are running diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index 76a7427..ef0c878 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -165,6 +165,12 @@ struct kvm_arch_memory_slot { /* Device Control API: ARM VGIC */ #define KVM_DEV_ARM_VGIC_GRP_ADDR 0 +#define KVM_DEV_ARM_VGIC_GRP_DIST_REGS 1 +#define KVM_DEV_ARM_VGIC_GRP_CPU_REGS 2 +#define KVM_DEV_ARM_VGIC_CPUID_SHIFT 32 +#define KVM_DEV_ARM_VGIC_CPUID_MASK (0xffULL << KVM_DEV_ARM_VGIC_CPUID_SHIFT) +#define KVM_DEV_ARM_VGIC_OFFSET_SHIFT 0 +#define KVM_DEV_ARM_VGIC_OFFSET_MASK (0xffffffffULL << KVM_DEV_ARM_VGIC_OFFSET_SHIFT) /* KVM_IRQ_LINE irq field index values */ #define KVM_ARM_IRQ_TYPE_SHIFT 24 diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index e2596f6..88599b5 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -589,6 +589,20 @@ static bool handle_mmio_sgi_reg(struct kvm_vcpu *vcpu, return false; } +static bool handle_mmio_sgi_clear(struct kvm_vcpu *vcpu, + struct kvm_exit_mmio *mmio, + phys_addr_t offset) +{ + return false; +} + +static bool handle_mmio_sgi_set(struct kvm_vcpu *vcpu, + struct kvm_exit_mmio *mmio, + phys_addr_t offset) +{ + return false; +} + /* * I would have liked to use the kvm_bus_io_*() API instead, but it * cannot cope with banked registers (only the VM pointer is passed @@ -663,6 +677,16 @@ static const struct mmio_range vgic_dist_ranges[] = { .len = 4, .handle_mmio = handle_mmio_sgi_reg, }, + { + .base = GIC_DIST_SGI_PENDING_CLEAR, + .len = VGIC_NR_SGIS, + .handle_mmio = handle_mmio_sgi_clear, + }, + { + .base = GIC_DIST_SGI_PENDING_SET, + .len = VGIC_NR_SGIS, + .handle_mmio = handle_mmio_sgi_set, + }, {} }; @@ -1557,6 +1581,114 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write) return r; } +static bool handle_cpu_mmio_misc(struct kvm_vcpu *vcpu, + struct kvm_exit_mmio *mmio, phys_addr_t offset) +{ + return true; +} + +static const struct mmio_range vgic_cpu_ranges[] = { + { + .base = GIC_CPU_CTRL, + .len = 12, + .handle_mmio = handle_cpu_mmio_misc, + }, + { + .base = GIC_CPU_ALIAS_BINPOINT, + .len = 4, + .handle_mmio = handle_cpu_mmio_misc, + }, + { + .base = GIC_CPU_ACTIVEPRIO, + .len = 16, + .handle_mmio = handle_cpu_mmio_misc, + }, + { + .base = GIC_CPU_IDENT, + .len = 4, + .handle_mmio = handle_cpu_mmio_misc, + }, +}; + +static int vgic_attr_regs_access(struct kvm_device *dev, + struct kvm_device_attr *attr, + u32 *reg, bool is_write) +{ + const struct mmio_range *r = NULL, *ranges; + phys_addr_t offset; + int ret, cpuid, c; + struct kvm_vcpu *vcpu, *tmp_vcpu; + struct vgic_dist *vgic; + struct kvm_exit_mmio mmio; + + offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK; + cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >> + KVM_DEV_ARM_VGIC_CPUID_SHIFT; + + mutex_lock(&dev->kvm->lock); + + if (cpuid >= atomic_read(&dev->kvm->online_vcpus)) { + ret = -EINVAL; + goto out; + } + + vcpu = kvm_get_vcpu(dev->kvm, cpuid); + vgic = &dev->kvm->arch.vgic; + + mmio.len = 4; + mmio.is_write = is_write; + if (is_write) + mmio_data_write(&mmio, ~0, *reg); + switch (attr->group) { + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS: + mmio.phys_addr = vgic->vgic_dist_base + offset; + ranges = vgic_dist_ranges; + break; + case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: + mmio.phys_addr = vgic->vgic_cpu_base + offset; + ranges = vgic_cpu_ranges; + break; + default: + BUG(); + } + r = find_matching_range(ranges, &mmio, offset); + + if (unlikely(!r || !r->handle_mmio)) { + ret = -ENXIO; + goto out; + } + + + spin_lock(&vgic->lock); + + /* + * Ensure that no other VCPU is running by checking the vcpu->cpu + * field. If no other VPCUs are running we can safely access the VGIC + * state, because even if another VPU is run after this point, that + * VCPU will not touch the vgic state, because it will block on + * getting the vgic->lock in kvm_vgic_sync_hwstate(). + */ + kvm_for_each_vcpu(c, tmp_vcpu, dev->kvm) { + if (unlikely(tmp_vcpu->cpu != -1)) { + ret = -EBUSY; + goto out_vgic_unlock; + } + } + + offset -= r->base; + r->handle_mmio(vcpu, &mmio, offset); + + if (!is_write) + *reg = mmio_data_read(&mmio, ~0); + + ret = 0; +out_vgic_unlock: + spin_unlock(&vgic->lock); +out: + mutex_unlock(&dev->kvm->lock); + return ret; +} + static int vgic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr) { int r; @@ -1573,6 +1705,18 @@ static int vgic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr) r = kvm_vgic_addr(dev->kvm, type, &addr, true); return (r == -ENODEV) ? -ENXIO : r; } + + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS: + case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: { + u32 __user *uaddr = (u32 __user *)(long)attr->addr; + u32 reg; + + if (get_user(reg, uaddr)) + return -EFAULT; + + return vgic_attr_regs_access(dev, attr, ®, true); + } + } return -ENXIO; @@ -1594,14 +1738,42 @@ static int vgic_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr) if (copy_to_user(uaddr, &addr, sizeof(addr))) return -EFAULT; + break; + } + + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS: + case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: { + u32 __user *uaddr = (u32 __user *)(long)attr->addr; + u32 reg = 0; + + r = vgic_attr_regs_access(dev, attr, ®, false); + if (r) + return r; + r = put_user(reg, uaddr); + break; } + } return r; } +static int vgic_has_attr_regs(const struct mmio_range *ranges, + phys_addr_t offset) +{ + struct kvm_exit_mmio dev_attr_mmio; + + dev_attr_mmio.len = 4; + if (find_matching_range(ranges, &dev_attr_mmio, offset)) + return 0; + else + return -ENXIO; +} + static int vgic_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr) { + phys_addr_t offset; + switch (attr->group) { case KVM_DEV_ARM_VGIC_GRP_ADDR: switch (attr->attr) { @@ -1610,6 +1782,12 @@ static int vgic_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr) return 0; } break; + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS: + offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK; + return vgic_has_attr_regs(vgic_dist_ranges, offset); + case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: + offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK; + return vgic_has_attr_regs(vgic_cpu_ranges, offset); } return -ENXIO; }