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: 1828831 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 1A64C3FC23 for ; Sat, 1 Dec 2012 02:52:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751299Ab2LACwP (ORCPT ); Fri, 30 Nov 2012 21:52:15 -0500 Received: from mail-ia0-f174.google.com ([209.85.210.174]:50436 "EHLO mail-ia0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751226Ab2LACwO (ORCPT ); Fri, 30 Nov 2012 21:52:14 -0500 Received: by mail-ia0-f174.google.com with SMTP id y25so883810iay.19 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=SFi7f98CVfenVYj9oIot5mfxCit+Of4kOILguXizuRCg5juq5qozC0h6u4M/Tds+Jx zFXErUKg4WHLbACPNAvigdRWC/VqJ/oJgs+PBYbqhaBQ6Se8bX6gt94MOpWXm/dy7mHC yMzBK/gRvWwJa1gGAX2vhQHcdifqHWmGHSf1iWWUU5zUGV2vrMdpJxVqoIt4B/8sMnRW yKTnMz1sAfZf67VqkGZMPSjt06RSNbMuvqSBnlTlMHzceLqOWaLUiFwwXuMBWN7lLIgm NWZRJ9R5ojG2ziMGR4xcrJ8I7ynuIjb6WeXYsF4THZmeXcbTpx6HQzisC5XfJofJHwDM hpRg== 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 Cc: "kvm@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "kvmarm@lists.cs.columbia.edu" X-Gm-Message-State: ALoCoQlhv32PrJ8HNAIAMuW6+x4vMx3EQHH5sPwZ6NABFhRj+H0XJ8GwyJTvBtCzomvlJOLuxUys Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.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 -- 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 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;