From: Christoffer Dall <christoffer.dall@linaro.org> To: "Paolo Bonzini" <pbonzini@redhat.com>, "Radim Krčmář" <rkrcmar@redhat.com> Cc: kvm@vger.kernel.org, Marc Zyngier <marc.zyngier@arm.com>, Andre Przywara <andre.przywara@arm.com>, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu Subject: [PULL 48/59] KVM: arm/arm64: vgic-new: Add userland access to VGIC dist registers Date: Tue, 24 May 2016 11:09:42 +0200 [thread overview] Message-ID: <1464080993-10884-49-git-send-email-christoffer.dall@linaro.org> (raw) In-Reply-To: <1464080993-10884-1-git-send-email-christoffer.dall@linaro.org> From: Andre Przywara <andre.przywara@arm.com> Userland may want to save and restore the state of the in-kernel VGIC, so we provide the code which takes a userland request and translate that into calls to our MMIO framework. >From Christoffer: When accessing the VGIC state from userspace we really don't want a VCPU to be messing with the state at the same time, and the API specifies that we should return -EBUSY if any VCPUs are running. Check and prevent VCPUs from running by grabbing their mutexes, one by one, and error out if we fail. (Note: This could potentially be simplified to just do a simple check and see if any VCPUs are running, and return -EBUSY then, without enforcing the locking throughout the duration of the uaccess, if we think that taking/releasing all these mutexes for every single GIC register access is too heavyweight.) Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> --- virt/kvm/arm/vgic/vgic-kvm-device.c | 55 ++++++++++++++++++++++++++++++++++++- 1 file changed, 54 insertions(+), 1 deletion(-) diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c index 78621283..9ee27cb 100644 --- a/virt/kvm/arm/vgic/vgic-kvm-device.c +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c @@ -238,7 +238,60 @@ static int vgic_attr_regs_access(struct kvm_device *dev, struct kvm_device_attr *attr, u32 *reg, bool is_write) { - return -ENXIO; + gpa_t addr; + int cpuid, ret, c; + struct kvm_vcpu *vcpu, *tmp_vcpu; + int vcpu_lock_idx = -1; + + cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >> + KVM_DEV_ARM_VGIC_CPUID_SHIFT; + vcpu = kvm_get_vcpu(dev->kvm, cpuid); + addr = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK; + + mutex_lock(&dev->kvm->lock); + + ret = vgic_init(dev->kvm); + if (ret) + goto out; + + if (cpuid >= atomic_read(&dev->kvm->online_vcpus)) { + ret = -EINVAL; + goto out; + } + + /* + * Any time a vcpu is run, vcpu_load is called which tries to grab the + * vcpu->mutex. By grabbing the vcpu->mutex of all VCPUs we ensure + * that no other VCPUs are run and fiddle with the vgic state while we + * access it. + */ + ret = -EBUSY; + kvm_for_each_vcpu(c, tmp_vcpu, dev->kvm) { + if (!mutex_trylock(&tmp_vcpu->mutex)) + goto out; + vcpu_lock_idx = c; + } + + switch (attr->group) { + case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: + ret = -EINVAL; + break; + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS: + ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, reg); + break; + default: + ret = -EINVAL; + break; + } + +out: + for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) { + tmp_vcpu = kvm_get_vcpu(dev->kvm, vcpu_lock_idx); + mutex_unlock(&tmp_vcpu->mutex); + } + + mutex_unlock(&dev->kvm->lock); + return ret; } /* V2 ops */ -- 2.1.2.330.g565301e.dirty
WARNING: multiple messages have this Message-ID (diff)
From: christoffer.dall@linaro.org (Christoffer Dall) To: linux-arm-kernel@lists.infradead.org Subject: [PULL 48/59] KVM: arm/arm64: vgic-new: Add userland access to VGIC dist registers Date: Tue, 24 May 2016 11:09:42 +0200 [thread overview] Message-ID: <1464080993-10884-49-git-send-email-christoffer.dall@linaro.org> (raw) In-Reply-To: <1464080993-10884-1-git-send-email-christoffer.dall@linaro.org> From: Andre Przywara <andre.przywara@arm.com> Userland may want to save and restore the state of the in-kernel VGIC, so we provide the code which takes a userland request and translate that into calls to our MMIO framework. >From Christoffer: When accessing the VGIC state from userspace we really don't want a VCPU to be messing with the state at the same time, and the API specifies that we should return -EBUSY if any VCPUs are running. Check and prevent VCPUs from running by grabbing their mutexes, one by one, and error out if we fail. (Note: This could potentially be simplified to just do a simple check and see if any VCPUs are running, and return -EBUSY then, without enforcing the locking throughout the duration of the uaccess, if we think that taking/releasing all these mutexes for every single GIC register access is too heavyweight.) Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> --- virt/kvm/arm/vgic/vgic-kvm-device.c | 55 ++++++++++++++++++++++++++++++++++++- 1 file changed, 54 insertions(+), 1 deletion(-) diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c index 78621283..9ee27cb 100644 --- a/virt/kvm/arm/vgic/vgic-kvm-device.c +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c @@ -238,7 +238,60 @@ static int vgic_attr_regs_access(struct kvm_device *dev, struct kvm_device_attr *attr, u32 *reg, bool is_write) { - return -ENXIO; + gpa_t addr; + int cpuid, ret, c; + struct kvm_vcpu *vcpu, *tmp_vcpu; + int vcpu_lock_idx = -1; + + cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >> + KVM_DEV_ARM_VGIC_CPUID_SHIFT; + vcpu = kvm_get_vcpu(dev->kvm, cpuid); + addr = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK; + + mutex_lock(&dev->kvm->lock); + + ret = vgic_init(dev->kvm); + if (ret) + goto out; + + if (cpuid >= atomic_read(&dev->kvm->online_vcpus)) { + ret = -EINVAL; + goto out; + } + + /* + * Any time a vcpu is run, vcpu_load is called which tries to grab the + * vcpu->mutex. By grabbing the vcpu->mutex of all VCPUs we ensure + * that no other VCPUs are run and fiddle with the vgic state while we + * access it. + */ + ret = -EBUSY; + kvm_for_each_vcpu(c, tmp_vcpu, dev->kvm) { + if (!mutex_trylock(&tmp_vcpu->mutex)) + goto out; + vcpu_lock_idx = c; + } + + switch (attr->group) { + case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: + ret = -EINVAL; + break; + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS: + ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, reg); + break; + default: + ret = -EINVAL; + break; + } + +out: + for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) { + tmp_vcpu = kvm_get_vcpu(dev->kvm, vcpu_lock_idx); + mutex_unlock(&tmp_vcpu->mutex); + } + + mutex_unlock(&dev->kvm->lock); + return ret; } /* V2 ops */ -- 2.1.2.330.g565301e.dirty
next prev parent reply other threads:[~2016-05-24 9:09 UTC|newest] Thread overview: 121+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-05-24 9:08 [PULL 00/59] KVM/ARM Changes for v4.7 take 2 Christoffer Dall 2016-05-24 9:08 ` Christoffer Dall 2016-05-24 9:08 ` [PULL 01/59] kvm: arm64: Fix EC field in inject_abt64 Christoffer Dall 2016-05-24 9:08 ` Christoffer Dall 2016-05-24 9:08 ` Christoffer Dall 2016-05-24 9:08 ` [PULL 02/59] KVM: arm/arm64: vgic: streamline vgic_update_irq_pending() interface Christoffer Dall 2016-05-24 9:08 ` Christoffer Dall 2016-05-24 9:08 ` [PULL 03/59] KVM: arm/arm64: vgic: avoid map in kvm_vgic_inject_mapped_irq() Christoffer Dall 2016-05-24 9:08 ` Christoffer Dall 2016-05-24 9:08 ` [PULL 04/59] KVM: arm/arm64: vgic: avoid map in kvm_vgic_map_is_active() Christoffer Dall 2016-05-24 9:08 ` Christoffer Dall 2016-05-24 9:08 ` [PULL 05/59] KVM: arm/arm64: vgic: avoid map in kvm_vgic_unmap_phys_irq() Christoffer Dall 2016-05-24 9:08 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 06/59] KVM: arm/arm64: Remove the IRQ field from struct irq_phys_map Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 07/59] KVM: arm/arm64: arch_timer: Remove irq_phys_map Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 08/59] KVM: arm/arm64: vgic: Remove irq_phys_map from interface Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 09/59] KVM: arm/arm64: Move timer IRQ map to latest possible time Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 10/59] KVM: arm/arm64: Get rid of vgic_cpu->nr_lr Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 11/59] KVM: arm/arm64: Fix MMIO emulation data handling Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 12/59] KVM: arm/arm64: Export mmio_read/write_bus Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 13/59] KVM: arm/arm64: pmu: abstract access to number of SPIs Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 14/59] KVM: arm/arm64: Provide functionality to pause and resume a guest Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 15/59] KVM: arm/arm64: move GICv2 emulation defines into arm-gic-v3.h Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 16/59] KVM: arm/arm64: vgic-new: Add data structure definitions Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 17/59] KVM: arm/arm64: vgic-new: Add acccessor to new struct vgic_irq instance Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 18/59] KVM: arm/arm64: vgic-new: Implement virtual IRQ injection Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 19/59] KVM: arm/arm64: vgic-new: Add IRQ sorting Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 20/59] KVM: arm/arm64: vgic-new: Add IRQ sync/flush framework Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 21/59] KVM: arm/arm64: vgic-new: Add GICv2 world switch backend Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 22/59] KVM: arm/arm64: vgic-new: Add GICv3 " Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 23/59] KVM: arm/arm64: vgic-new: Implement kvm_vgic_vcpu_pending_irq Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 24/59] KVM: arm/arm64: vgic-new: Add MMIO handling framework Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 25/59] KVM: arm/arm64: vgic-new: Add GICv2 " Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 26/59] KVM: arm/arm64: vgic-new: Add CTLR, TYPER and IIDR handlers Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 27/59] KVM: arm/arm64: vgic-new: Add ENABLE registers handlers Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 28/59] KVM: arm/arm64: vgic-new: Add PENDING " Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 29/59] KVM: arm/arm64: vgic-new: Add ACTIVE " Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 30/59] KVM: arm/arm64: vgic-new: Add PRIORITY " Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 31/59] KVM: arm/arm64: vgic-new: Add CONFIG " Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 32/59] KVM: arm/arm64: vgic-new: Add TARGET " Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 33/59] KVM: arm/arm64: vgic-new: Add SGIR register handler Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 34/59] KVM: arm/arm64: vgic-new: Add SGIPENDR register handlers Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 35/59] KVM: arm/arm64: vgic-new: Add GICv3 MMIO handling framework Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 36/59] KVM: arm/arm64: vgic-new: Add GICv3 CTLR, IIDR, TYPER handlers Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 37/59] KVM: arm/arm64: vgic-new: Add GICv3 redistributor IIDR and TYPER handler Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 38/59] KVM: arm/arm64: vgic-new: Add GICv3 IDREGS register handler Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 39/59] KVM: arm/arm64: vgic-new: Add GICv3 IROUTER register handlers Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 40/59] KVM: arm/arm64: vgic-new: Add GICv3 SGI system register trap handler Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 41/59] KVM: arm/arm64: vgic-new: vgic_kvm_device: KVM device ops registration Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 42/59] KVM: arm/arm64: vgic-new: vgic_kvm_device: KVM_DEV_ARM_VGIC_GRP_NR_IRQS Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 43/59] KVM: arm/arm64: vgic-new: vgic_kvm_device: KVM_DEV_ARM_VGIC_GRP_CTRL Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 44/59] KVM: arm/arm64: vgic-new: vgic_kvm_device: implement kvm_vgic_addr Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 45/59] KVM: arm/arm64: vgic-new: vgic_kvm_device: KVM_DEV_ARM_VGIC_GRP_ADDR Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 46/59] KVM: arm/arm64: vgic-new: vgic_kvm_device: access to VGIC registers Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 47/59] KVM: arm/arm64: vgic-new: Export register access interface Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall [this message] 2016-05-24 9:09 ` [PULL 48/59] KVM: arm/arm64: vgic-new: Add userland access to VGIC dist registers Christoffer Dall 2016-05-24 9:09 ` [PULL 49/59] KVM: arm/arm64: vgic-new: Add GICH_VMCR accessors Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 50/59] KVM: arm/arm64: vgic-new: Add userland GIC CPU interface access Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 51/59] KVM: arm/arm64: vgic-new: vgic_init: implement kvm_vgic_hyp_init Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 52/59] KVM: arm/arm64: vgic-new: vgic_init: implement vgic_create Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 53/59] KVM: arm/arm64: vgic-new: vgic_init: implement vgic_init Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 54/59] KVM: arm/arm64: vgic-new: vgic_init: implement map_resources Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 55/59] KVM: arm/arm64: vgic-new: Add vgic_v2/v3_enable Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 56/59] KVM: arm/arm64: vgic-new: Wire up irqfd injection Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 57/59] KVM: arm/arm64: vgic-new: implement mapped IRQ handling Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 58/59] KVM: arm/arm64: vgic-new: enable build Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall 2016-05-24 9:09 ` [PULL 59/59] KVM: arm/arm64: vgic-new: Synchronize changes to active state Christoffer Dall 2016-05-24 9:09 ` Christoffer Dall
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