From patchwork Sat Dec 1 02:52:13 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoffer Dall X-Patchwork-Id: 1828841 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id 3E84BDF24C for ; Sat, 1 Dec 2012 02:55:30 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TedBk-0005Hk-FW; Sat, 01 Dec 2012 02:52:20 +0000 Received: from mail-ie0-f177.google.com ([209.85.223.177]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1TedBg-0005HO-Qx for linux-arm-kernel@lists.infradead.org; Sat, 01 Dec 2012 02:52:17 +0000 Received: by mail-ie0-f177.google.com with SMTP id k13so1608792iea.36 for ; Fri, 30 Nov 2012 18:52:14 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:x-originating-ip:in-reply-to:references:date :message-id:subject:from:to:cc:content-type:x-gm-message-state; bh=IC6pRUz0IzWcys27DxeUYttY8wiET9wvmlEA4Ges3FA=; b=Ajins+wrUbvO9kk015vkEpYnhdcpahtGONPu7OmqGFRZ76mRP6qNFDYK07UCY1IYqx IVq7Q8+m0FQ+XpJRUsw+bTlQGxF5ii2AsCo8HVU18rFQz2W8Ze+5LtNetrYp+QZ6TNwC jQDNg6+DrCRfPHxVKwR/r5/57OynYWPFaHR9aYQ009HrH8TzQp+GKInC3xifKtzdf5jY gr9IDSwD2EH6a8B8DzeSvsxvCZb25RRSe4sekYdpUUrHZjn0u6picnJWpGZeS5Su4DaW Emi+yy+ANY2wTx329m+nJYVWa/aOTObPZWunZuUf9RlmgxHhYA3E+yOIKKNxzo4tdqt/ 8Mnw== MIME-Version: 1.0 Received: by 10.50.140.38 with SMTP id rd6mr519761igb.35.1354330333897; Fri, 30 Nov 2012 18:52:13 -0800 (PST) Received: by 10.64.44.174 with HTTP; Fri, 30 Nov 2012 18:52:13 -0800 (PST) X-Originating-IP: [72.80.83.148] In-Reply-To: <20121128131139.GG21671@mudshark.cambridge.arm.com> References: <20121110154358.3061.16338.stgit@chazy-air> <20121110154451.3061.74235.stgit@chazy-air> <20121128131139.GG21671@mudshark.cambridge.arm.com> Date: Fri, 30 Nov 2012 21:52:13 -0500 Message-ID: Subject: Re: [PATCH v4 05/13] ARM: KVM: VGIC accept vcpu and dist base addresses from user space From: Christoffer Dall To: Will Deacon X-Gm-Message-State: ALoCoQk4FRQ1HWIyVjZ/719rEiuIhPxghQVA3JedgcHlYhJX2q+dwN+yCKNXSccbstzkSHiypiHy X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20121130_215217_001602_1CD92252 X-CRM114-Status: GOOD ( 25.82 ) X-Spam-Score: -2.6 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.223.177 listed in list.dnswl.org] -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: "linux-arm-kernel@lists.infradead.org" , "kvm@vger.kernel.org" , "kvmarm@lists.cs.columbia.edu" X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org On Wed, Nov 28, 2012 at 8:11 AM, Will Deacon wrote: > On Sat, Nov 10, 2012 at 03:44:51PM +0000, Christoffer Dall wrote: >> User space defines the model to emulate to a guest and should therefore >> decide which addresses are used for both the virtual CPU interface >> directly mapped in the guest physical address space and for the emulated >> distributor interface, which is mapped in software by the in-kernel VGIC >> support. >> >> Signed-off-by: Christoffer Dall >> --- >> arch/arm/include/asm/kvm_mmu.h | 2 + >> arch/arm/include/asm/kvm_vgic.h | 9 ++++++ >> arch/arm/kvm/arm.c | 16 ++++++++++ >> arch/arm/kvm/vgic.c | 61 +++++++++++++++++++++++++++++++++++++++ >> 4 files changed, 87 insertions(+), 1 deletion(-) >> >> diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h >> index 9bd0508..0800531 100644 >> --- a/arch/arm/include/asm/kvm_mmu.h >> +++ b/arch/arm/include/asm/kvm_mmu.h >> @@ -26,6 +26,8 @@ >> * To save a bit of memory and to avoid alignment issues we assume 39-bit IPA >> * for now, but remember that the level-1 table must be aligned to its size. >> */ >> +#define KVM_PHYS_SHIFT (38) > > Seems a bit small... > >> +#define KVM_PHYS_MASK ((1ULL << KVM_PHYS_SHIFT) - 1) >> #define PTRS_PER_PGD2 512 >> #define PGD2_ORDER get_order(PTRS_PER_PGD2 * sizeof(pgd_t)) >> >> diff --git a/arch/arm/include/asm/kvm_vgic.h b/arch/arm/include/asm/kvm_vgic.h >> index b444ecf..9ca8d21 100644 >> --- a/arch/arm/include/asm/kvm_vgic.h >> +++ b/arch/arm/include/asm/kvm_vgic.h >> @@ -20,6 +20,9 @@ >> #define __ASM_ARM_KVM_VGIC_H >> >> struct vgic_dist { >> + /* Distributor and vcpu interface mapping in the guest */ >> + phys_addr_t vgic_dist_base; >> + phys_addr_t vgic_cpu_base; >> }; >> >> struct vgic_cpu { >> @@ -31,6 +34,7 @@ struct kvm_run; >> struct kvm_exit_mmio; >> >> #ifdef CONFIG_KVM_ARM_VGIC >> +int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr); >> bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run, >> struct kvm_exit_mmio *mmio); >> >> @@ -40,6 +44,11 @@ static inline int kvm_vgic_hyp_init(void) >> return 0; >> } >> >> +static inline int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr) >> +{ >> + return 0; >> +} >> + >> static inline int kvm_vgic_init(struct kvm *kvm) >> { >> return 0; >> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c >> index 426828a..3ac1aab 100644 >> --- a/arch/arm/kvm/arm.c >> +++ b/arch/arm/kvm/arm.c >> @@ -61,6 +61,8 @@ static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1); >> static u8 kvm_next_vmid; >> static DEFINE_SPINLOCK(kvm_vmid_lock); >> >> +static bool vgic_present; >> + >> static void kvm_arm_set_running_vcpu(struct kvm_vcpu *vcpu) >> { >> BUG_ON(preemptible()); >> @@ -825,7 +827,19 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) >> static int kvm_vm_ioctl_set_device_address(struct kvm *kvm, >> struct kvm_device_address *dev_addr) >> { >> - return -ENODEV; >> + unsigned long dev_id, type; >> + >> + dev_id = (dev_addr->id & KVM_DEVICE_ID_MASK) >> KVM_DEVICE_ID_SHIFT; >> + type = (dev_addr->id & KVM_DEVICE_TYPE_MASK) >> KVM_DEVICE_TYPE_SHIFT; >> + >> + switch (dev_id) { >> + case KVM_ARM_DEVICE_VGIC_V2: >> + if (!vgic_present) >> + return -ENXIO; >> + return kvm_vgic_set_addr(kvm, type, dev_addr->addr); >> + default: >> + return -ENODEV; >> + } >> } >> >> long kvm_arch_vm_ioctl(struct file *filp, >> diff --git a/arch/arm/kvm/vgic.c b/arch/arm/kvm/vgic.c >> index 26ada3b..f85b275 100644 >> --- a/arch/arm/kvm/vgic.c >> +++ b/arch/arm/kvm/vgic.c >> @@ -22,6 +22,13 @@ >> #include >> #include >> >> +#define VGIC_ADDR_UNDEF (-1) >> +#define IS_VGIC_ADDR_UNDEF(_x) ((_x) == (typeof(_x))VGIC_ADDR_UNDEF) >> + >> +#define VGIC_DIST_SIZE 0x1000 >> +#define VGIC_CPU_SIZE 0x2000 > > These defines might be useful to userspace so that they don't request the > distributor and the cpu interface to be place too close together (been there, > done that :). > >> + >> + >> #define ACCESS_READ_VALUE (1 << 0) >> #define ACCESS_READ_RAZ (0 << 0) >> #define ACCESS_READ_MASK(x) ((x) & (1 << 0)) >> @@ -136,3 +143,57 @@ bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run, struct kvm_exi >> { >> return KVM_EXIT_MMIO; >> } >> + >> +static bool vgic_ioaddr_overlap(struct kvm *kvm) >> +{ >> + phys_addr_t dist = kvm->arch.vgic.vgic_dist_base; >> + phys_addr_t cpu = kvm->arch.vgic.vgic_cpu_base; >> + >> + if (IS_VGIC_ADDR_UNDEF(dist) || IS_VGIC_ADDR_UNDEF(cpu)) >> + return false; >> + if ((dist <= cpu && dist + VGIC_DIST_SIZE > cpu) || >> + (cpu <= dist && cpu + VGIC_CPU_SIZE > dist)) >> + return true; >> + return false; > > Just return the predicate that you're testing. > >> +} >> + >> +int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr) >> +{ >> + int r = 0; >> + struct vgic_dist *vgic = &kvm->arch.vgic; >> + >> + if (addr & ~KVM_PHYS_MASK) >> + return -E2BIG; >> + >> + if (addr & ~PAGE_MASK) >> + return -EINVAL; >> + >> + mutex_lock(&kvm->lock); >> + switch (type) { >> + case KVM_VGIC_V2_ADDR_TYPE_DIST: >> + if (!IS_VGIC_ADDR_UNDEF(vgic->vgic_dist_base)) >> + return -EEXIST; >> + if (addr + VGIC_DIST_SIZE < addr) >> + return -EINVAL; > > I think somebody else pointed out the missing mutex_unlocks on the failure > paths. > >> + kvm->arch.vgic.vgic_dist_base = addr; >> + break; >> + case KVM_VGIC_V2_ADDR_TYPE_CPU: >> + if (!IS_VGIC_ADDR_UNDEF(vgic->vgic_cpu_base)) >> + return -EEXIST; >> + if (addr + VGIC_CPU_SIZE < addr) >> + return -EINVAL; >> + kvm->arch.vgic.vgic_cpu_base = addr; >> + break; >> + default: >> + r = -ENODEV; >> + } >> + >> + if (vgic_ioaddr_overlap(kvm)) { >> + kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF; >> + kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF; >> + return -EINVAL; > > Perhaps we could put all the address checking in one place, so that the wrapping > round zero checks and the overlap checks can be in the same function? > Like this (?): } --- Thanks, -Christoffer diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 7f057a2..0b6b95e 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2163,6 +2163,7 @@ Errors: ENXIO: Device not supported on current system EEXIST: Address already set E2BIG: Address outside guest physical address space + EBUSY: Address overlaps with other device range struct kvm_device_address { __u64 id; diff --git a/arch/arm/kvm/vgic.c b/arch/arm/kvm/vgic.c index f697c14..660fe24 100644 --- a/arch/arm/kvm/vgic.c +++ b/arch/arm/kvm/vgic.c @@ -1230,11 +1230,28 @@ static bool vgic_ioaddr_overlap(struct kvm *kvm) phys_addr_t cpu = kvm->arch.vgic.vgic_cpu_base; if (IS_VGIC_ADDR_UNDEF(dist) || IS_VGIC_ADDR_UNDEF(cpu)) - return false; + return 0; if ((dist <= cpu && dist + VGIC_DIST_SIZE > cpu) || (cpu <= dist && cpu + VGIC_CPU_SIZE > dist)) - return true; - return false; + return -EBUSY; + return 0; +} + +static int vgic_ioaddr_assign(struct kvm *kvm, phys_addr_t *ioaddr, + phys_addr_t addr, phys_addr_t size) +{ + int ret; + + if (!IS_VGIC_ADDR_UNDEF(*ioaddr)) + return -EEXIST; + if (addr + size < addr) + return -EINVAL; + + ret = vgic_ioaddr_overlap(kvm); + if (ret) + return ret; + *ioaddr = addr; + return ret; } int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr) @@ -1251,29 +1268,21 @@ int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr) mutex_lock(&kvm->lock); switch (type) { case KVM_VGIC_V2_ADDR_TYPE_DIST: - if (!IS_VGIC_ADDR_UNDEF(vgic->vgic_dist_base)) - return -EEXIST; - if (addr + VGIC_DIST_SIZE < addr) - return -EINVAL; - kvm->arch.vgic.vgic_dist_base = addr; + r = vgic_ioaddr_assign(kvm, &vgic->vgic_dist_base, + addr, VGIC_DIST_SIZE); break; case KVM_VGIC_V2_ADDR_TYPE_CPU: if (!IS_VGIC_ADDR_UNDEF(vgic->vgic_cpu_base)) return -EEXIST; if (addr + VGIC_CPU_SIZE < addr) return -EINVAL; - kvm->arch.vgic.vgic_cpu_base = addr; + r = vgic_ioaddr_assign(kvm, &vgic->vgic_cpu_base, + addr, VGIC_CPU_SIZE); break; default: r = -ENODEV; } - if (vgic_ioaddr_overlap(kvm)) { - kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF; - kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF; - r = -EINVAL; - } - mutex_unlock(&kvm->lock); return r;