Resending in plain text mode On Tue, Sep 6, 2016 at 7:17 PM, Vijay Kilari <vijay.kilari@xxxxxxxxx> wrote: > > > On Tue, Aug 30, 2016 at 6:01 PM, Christoffer Dall > <christoffer.dall@xxxxxxxxxx> wrote: >> >> On Wed, Aug 24, 2016 at 04:50:06PM +0530, vijay.kilari@xxxxxxxxx wrote: >> > From: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxx> >> > >> > VGICv3 Distributor and Redistributor registers are accessed using >> > KVM_DEV_ARM_VGIC_GRP_DIST_REGS and KVM_DEV_ARM_VGIC_GRP_DIST_REGS >> > with KVM_SET_DEVICE_ATTR and KVM_GET_DEVICE_ATTR ioctls. >> > These registers are accessed as 32-bit and cpu mpidr >> > value passed along with register offset is used to identify the >> > cpu for redistributor registers access. >> > >> > The version of VGIC v3 specification is define here >> > >> > http://lists.infradead.org/pipermail/linux-arm-kernel/2016-July/445611.html >> > >> > Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxx> >> > --- >> > arch/arm64/include/uapi/asm/kvm.h | 3 + >> > virt/kvm/arm/vgic/vgic-kvm-device.c | 127 >> > +++++++++++++++++++++++++++++++++++- >> > virt/kvm/arm/vgic/vgic-mmio-v3.c | 113 >> > ++++++++++++++++++++++++++++++++ >> > virt/kvm/arm/vgic/vgic-mmio.c | 2 +- >> > virt/kvm/arm/vgic/vgic.h | 8 +++ >> > 5 files changed, 250 insertions(+), 3 deletions(-) >> > >> > diff --git a/arch/arm64/include/uapi/asm/kvm.h >> > b/arch/arm64/include/uapi/asm/kvm.h >> > index 3051f86..94ea676 100644 >> > --- a/arch/arm64/include/uapi/asm/kvm.h >> > +++ b/arch/arm64/include/uapi/asm/kvm.h >> > @@ -201,10 +201,13 @@ struct kvm_arch_memory_slot { >> > #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_V3_CPUID_MASK \ >> > + (0xffffffffULL << >> > KVM_DEV_ARM_VGIC_CPUID_SHIFT) >> >> I think this should be KVM_DEV_ARM_VGIC_V3_MPIDR_MASK, and I would >> probably define a V3 of the shift as well, since we're really talking >> about two distinct APIs here. >> >> > #define KVM_DEV_ARM_VGIC_OFFSET_SHIFT 0 >> > #define KVM_DEV_ARM_VGIC_OFFSET_MASK (0xffffffffULL << >> > KVM_DEV_ARM_VGIC_OFFSET_SHIFT) >> > #define KVM_DEV_ARM_VGIC_GRP_NR_IRQS 3 >> > #define KVM_DEV_ARM_VGIC_GRP_CTRL 4 >> > +#define KVM_DEV_ARM_VGIC_GRP_REDIST_REGS 5 >> > #define KVM_DEV_ARM_VGIC_CTRL_INIT 0 >> > >> > /* Device Control API on vcpu fd */ >> > diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c >> > b/virt/kvm/arm/vgic/vgic-kvm-device.c >> > index 163b057..06f0158 100644 >> > --- a/virt/kvm/arm/vgic/vgic-kvm-device.c >> > +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c >> > @@ -433,16 +433,136 @@ struct kvm_device_ops kvm_arm_vgic_v2_ops = { >> > >> > #ifdef CONFIG_KVM_ARM_VGIC_V3 >> > >> > +static int parse_vgic_v3_attr(struct kvm_device *dev, >> > + struct kvm_device_attr *attr, >> > + struct vgic_reg_attr *reg_attr) >> > +{ >> > + int cpuid; >> > + >> > + cpuid = (attr->attr & KVM_DEV_ARM_VGIC_V3_CPUID_MASK) >> >> > + KVM_DEV_ARM_VGIC_CPUID_SHIFT; >> > + >> > + if (cpuid >= atomic_read(&dev->kvm->online_vcpus)) >> > + return -EINVAL; >> >> huh? it's an MPIDR, not a cpu id. >> >> just resolve it with kvm_mpidr_to_vcpu and check its return value. >> >> >> > + >> > + reg_attr->vcpu = kvm_mpidr_to_vcpu(dev->kvm, cpuid); >> >> please check the return value of this function in any case... >> >> > + reg_attr->addr = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK; >> > + >> > + return 0; >> > +} >> > + >> > +/** >> > + * vgic_attr_regs_access_v3 - allows user space to access VGIC v3 state >> > + * >> > + * @dev: kvm device handle >> > + * @attr: kvm device attribute >> > + * @reg: address the value is read or written >> > + * @is_write: true if userspace is writing a register >> > + */ >> > +static int vgic_attr_regs_access_v3(struct kvm_device *dev, >> > + struct kvm_device_attr *attr, >> > + u64 *reg, bool is_write) >> > +{ >> > + struct vgic_reg_attr reg_attr; >> > + gpa_t addr; >> > + struct kvm_vcpu *vcpu; >> > + int ret; >> > + u32 tmp32; >> > + >> > + ret = parse_vgic_v3_attr(dev, attr, ®_attr); >> > + if (ret) >> > + return ret; >> > + >> > + vcpu = reg_attr.vcpu; >> > + addr = reg_attr.addr; >> > + >> > + mutex_lock(&dev->kvm->lock); >> > + >> > + ret = vgic_init(dev->kvm); >> > + if (ret) >> > + goto out; >> >> no, no, please no more auto-init at userspace access time. This code >> should instead check vgic_initialized() and return an error to userspace >> if not initialized. >> >> Ok. I wil fix it. It is coming from v2 code. > > >> >> > + >> > + if (!lock_all_vcpus(dev->kvm)) { >> > + ret = -EBUSY; >> > + goto out; >> > + } >> > + >> > + switch (attr->group) { >> > + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS: >> > + tmp32 = *reg; >> >> why is this assignment not predicated on if (is_write) ? >> >> also, all this type conversion nonsense is probably unnecessary, see my >> comment below. >> >> > + ret = vgic_v3_dist_uaccess(vcpu, is_write, addr, &tmp32); >> > + if (!is_write) >> > + *reg = tmp32; >> > + break; >> > + case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS: >> > + tmp32 = *reg; >> > + ret = vgic_v3_redist_uaccess(vcpu, is_write, addr, >> > &tmp32); >> > + if (!is_write) >> > + *reg = tmp32; >> > + break; >> > + default: >> > + ret = -EINVAL; >> > + break; >> > + } >> > + >> > + unlock_all_vcpus(dev->kvm); >> > +out: >> > + mutex_unlock(&dev->kvm->lock); >> > + return ret; >> > +} >> > + >> > static int vgic_v3_set_attr(struct kvm_device *dev, >> > struct kvm_device_attr *attr) >> > { >> > - return vgic_set_common_attr(dev, attr); >> > + int ret; >> > + >> > + ret = vgic_set_common_attr(dev, attr); >> > + if (ret != -ENXIO) >> > + return ret; >> > + >> > + switch (attr->group) { >> > + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS: >> > + case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS: { >> > + u32 __user *uaddr = (u32 __user *)(long)attr->addr; >> > + u32 tmp32; >> > + u64 reg; >> > + >> > + if (get_user(tmp32, uaddr)) >> > + return -EFAULT; >> > + >> > + reg = tmp32; >> > + return vgic_attr_regs_access_v3(dev, attr, ®, true); >> >> oh, but wait, you already had a 32-bit value, which you convert into a >> 64-bit value, just to convert it back again, to do some extra data >> copies? >> >> I'm really confused as to why this has to be so complicated. >> >> Why not simply use u32 all the way? > > > vgic_attr_regs_access_v3() is used for handling both GICD/GICR and > SYSREGS. For this reason we convert u32 to 64 and vice versa. > To avoid these conversions, I can create separate vgic_attr_regs_access_v3() > functions for GICD and SYSREGS. > > _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
