From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre Morel Subject: Re: [PATCH v1 4/7] vfio: ap: AP Queue Interrupt Control VFIO ioctl calls Date: Wed, 7 Nov 2018 23:31:59 +0100 Message-ID: References: <1541009577-29656-1-git-send-email-pmorel@linux.ibm.com> <1541009577-29656-5-git-send-email-pmorel@linux.ibm.com> <7e4cbc97-8c77-b393-efdd-6fd8550c15f1@linux.ibm.com> Reply-To: pmorel@linux.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <7e4cbc97-8c77-b393-efdd-6fd8550c15f1@linux.ibm.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Tony Krowiak , borntraeger@de.ibm.com Cc: alex.williamson@redhat.com, cohuck@redhat.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, frankja@linux.ibm.com, pasic@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, freude@linux.ibm.com, mimu@linux.ibm.com List-ID: On 06/11/2018 21:21, Tony Krowiak wrote: > On 10/31/18 2:12 PM, Pierre Morel wrote: >> This is the implementation of the VFIO ioctl calls to handle >> the AQIC interception and use GISA to handle interrupts. >> >> Signed-off-by: Pierre Morel >> --- >>   drivers/s390/crypto/vfio_ap_ops.c | 95 +++++++++++++++++++++++++++++++ >>   1 file changed, 95 insertions(+) >> >> diff --git a/drivers/s390/crypto/vfio_ap_ops.c >> b/drivers/s390/crypto/vfio_ap_ops.c >> index 272ef427dcc0..f68102163bf4 100644 >> --- a/drivers/s390/crypto/vfio_ap_ops.c >> +++ b/drivers/s390/crypto/vfio_ap_ops.c >> @@ -895,12 +895,107 @@ static int >> vfio_ap_mdev_get_device_info(unsigned long arg) >>       return copy_to_user((void __user *)arg, &info, minsz); >>   } >> +static int ap_ioctl_setirq(struct ap_matrix_mdev *matrix_mdev, > > In keeping with the other function names in this file, how about > naming this function vfio_ap_mdev_setirq??? OK, agreed. > >> +               struct vfio_ap_aqic *parm) >> +{ >> +    struct aqic_gisa aqic_gisa = reg2aqic(0); >> +    struct kvm_s390_gisa *gisa = matrix_mdev->kvm->arch.gisa; >> +    struct ap_status ap_status = reg2status(0); >> +    unsigned long p; >> +    int ret = -1; >> +    int apqn; >> +    uint32_t gd; >> + >> +    apqn = (int)(parm->cmd & 0xffff); >> + >> +    gd = matrix_mdev->kvm->vcpus[0]->arch.sie_block->gd; >> +    if (gd & 0x01) >> +        aqic_gisa.f = 1; >> +    aqic_gisa.gisc = matrix_mdev->gisc; > > Can't you get this value from parm? I don't see any relationship > between the mdev device and gisc, why store it there? The idea is that we may want to report this value to the admin or as debug information, so I wanted to keep track of it. > >> +    aqic_gisa.isc = GAL_ISC; >> +    aqic_gisa.ir = 1; >> +    aqic_gisa.gisao = gisa->next_alert >> 4; >> + >> +    p = (unsigned long) page_address(matrix_mdev->map->page); >> +    p += (matrix_mdev->map->guest_addr & 0x0fff); >> + >> +    ret = ap_host_aqic((uint64_t)apqn, aqic2reg(aqic_gisa), p); >> +    parm->status = ret; >> + >> +    ap_status = reg2status(ret); >> +    return (ap_status.rc) ? -EIO : 0; >> +} >> + >> +static int ap_ioctl_clrirq(struct ap_matrix_mdev *matrix_mdev, >> +               struct vfio_ap_aqic *parm) > > In keeping with the other function names in this file, how about > naming this function vfio_ap_mdev_clrirq, or better yet, > vfio_ap_mdev_clear_irq??? agreed too. > >> +{ >> +    struct aqic_gisa aqic_gisa = reg2aqic(0); >> +    struct ap_status ap_status = reg2status(0) > +    int apqn; >> +    int retval; >> +    uint32_t gd; >> + >> +    apqn = (int)(parm->cmd & 0xffff); >> + >> +    gd = matrix_mdev->kvm->vcpus[0]->arch.sie_block->gd; >> +    if (gd & 0x01) >> +        aqic_gisa.f = 1; >> +    aqic_gisa.ir = 0; >> + >> +    retval = ap_host_aqic((uint64_t)apqn, aqic2reg(aqic_gisa), 0); >> +    parm->status = retval; >> + >> +    ap_status = reg2status(retval); >> +    return (ap_status.rc) ? -EIO : 0; >> +} >> + >>   static ssize_t vfio_ap_mdev_ioctl(struct mdev_device *mdev, >>                       unsigned int cmd, unsigned long arg) >>   { >>       int ret; >> +    struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); >> +    struct s390_io_adapter *adapter; >> +    struct vfio_ap_aqic parm; >> +    struct s390_map_info *map; >> +    int apqn, found = 0; >>       switch (cmd) { >> +    case VFIO_AP_SET_IRQ: >> +        if (copy_from_user(&parm, (void __user *)arg, sizeof(parm))) >> +            return -EFAULT; >> +        apqn = (int)(parm.cmd & 0xffff); >> +        parm.status &= 0x00000000ffffffffUL; >> +        matrix_mdev->gisc = parm.status & 0x07; > > It seems that the only reason for the 'gisc' field in matrix_mdev > is to pass the value to the ap_ioctl_setirq() function. Since the > gisc has nothing to do with the mdev device and the 'parm' is being > passed to ap_ioctl_setirq(), why not just eliminate the > matrix_mdev->gisc field and get it from the 'parm' parameter in > ap_ioctl_setirq()? OK, seems better. > >> +        /* find the adapter */ap_ioctl_setirq() >> +        adapter = matrix_mdev->kvm->arch.adapters[parm.adapter_id]; >> +        if (!adapter) >> +            return -ENOENT; >> +        down_write(&adapter->maps_lock); >> +        list_for_each_entry(map, &adapter->maps, list) { >> +            if (map->guest_addr == parm.nib) { >> +                found = 1; >> +                break; >> +            } >> +        } >> +        up_write(&adapter->maps_lock); >> + >> +        if (!found) >> +            return -EINVAL; >> + >> +        matrix_mdev->map = map; > > See my comment above about matrix_mdev->gisc. Can't we just get rid > of the matrix_mdev->map field and pass the map into the > ap_ioctl_setirq() function? or calculate it from parm... as we give parm as argument to this function > >> +        ret = ap_ioctl_setirq(matrix_mdev, &parm); >> +        parm.status &= 0x00000000ffffffffUL; >> +        if (copy_to_user((void __user *)arg, &parm, sizeof(parm))) >> +            return -EFAULT; >> + >> +        break; > > IMHO, the case statements should only determine which ioctl is being > invoked and call the appropriate function to handle it. All of the above > code could be in an intermediate function called from this case > statement, thus reducing the case to calling the intermediate function. OK, I can do so, however I would like to let the __user access here. > >> +    case VFIO_AP_CLEAR_IRQ: >> +        if (copy_from_user(&parm, (void __user *)arg, sizeof(parm))) >> +            return -EFAULT; >> +        ret = ap_ioctl_clrirq(matrix_mdev, &parm); >> +        if (copy_to_user((void __user *)arg, &parm, sizeof(parm))) >> +            return -EFAULT; >> +        break; >>       case VFIO_DEVICE_GET_INFO: >>           ret = vfio_ap_mdev_get_device_info(arg); >>           break; >> > Thanks Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany