From: Tony Krowiak <[email protected]> Implements the open callback on the mediated matrix device. The function registers a group notifier to receive notification of the VFIO_GROUP_NOTIFY_SET_KVM event. When notified, the vfio_ap device driver will get access to the guest's kvm structure. The open callback must ensure that only one mediated device shall be opened per guest.
Signed-off-by: Tony Krowiak <[email protected]> Acked-by: Halil Pasic <[email protected]> Tested-by: Michael Mueller <[email protected]> Tested-by: Farhan Ali <[email protected]> Tested-by: Pierre Morel <[email protected]> Acked-by: Pierre Morel <[email protected]> Signed-off-by: Christian Borntraeger <[email protected]> --- arch/s390/include/asm/kvm_host.h | 1 + drivers/s390/crypto/vfio_ap_ops.c | 168 +++++++++++++++++++++++++++++++++ drivers/s390/crypto/vfio_ap_private.h | 5 + 3 files changed, 174 insertions(+), 0 deletions(-) diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 1e758fe..b32bd1b 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -258,6 +258,7 @@ struct kvm_s390_sie_block { __u64 tecmc; /* 0x00e8 */ __u8 reservedf0[12]; /* 0x00f0 */ #define CRYCB_FORMAT_MASK 0x00000003 +#define CRYCB_FORMAT0 0x00000000 #define CRYCB_FORMAT1 0x00000001 #define CRYCB_FORMAT2 0x00000003 __u32 crycbd; /* 0x00fc */ diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c index 2a2dcf7..8bc0cdd 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -13,6 +13,10 @@ #include <linux/device.h> #include <linux/list.h> #include <linux/ctype.h> +#include <linux/bitops.h> +#include <linux/kvm_host.h> +#include <linux/module.h> +#include <asm/kvm.h> #include <asm/zcrypt.h> #include "vfio_ap_private.h" @@ -54,6 +58,9 @@ static int vfio_ap_mdev_remove(struct mdev_device *mdev) { struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); + if (matrix_mdev->kvm) + return -EBUSY; + mutex_lock(&matrix_dev->lock); list_del(&matrix_mdev->node); mutex_unlock(&matrix_dev->lock); @@ -309,6 +316,10 @@ static ssize_t assign_adapter_store(struct device *dev, struct mdev_device *mdev = mdev_from_dev(dev); struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); + /* If the guest is running, disallow assignment of adapter */ + if (matrix_mdev->kvm) + return -EBUSY; + ret = kstrtoul(buf, 0, &apid); if (ret) return ret; @@ -370,6 +381,10 @@ static ssize_t unassign_adapter_store(struct device *dev, struct mdev_device *mdev = mdev_from_dev(dev); struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); + /* If the guest is running, disallow un-assignment of adapter */ + if (matrix_mdev->kvm) + return -EBUSY; + ret = kstrtoul(buf, 0, &apid); if (ret) return ret; @@ -447,6 +462,10 @@ static ssize_t assign_domain_store(struct device *dev, struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); unsigned long max_apqi = matrix_mdev->matrix.aqm_max; + /* If the guest is running, disallow assignment of domain */ + if (matrix_mdev->kvm) + return -EBUSY; + ret = kstrtoul(buf, 0, &apqi); if (ret) return ret; @@ -504,6 +523,10 @@ static ssize_t unassign_domain_store(struct device *dev, struct mdev_device *mdev = mdev_from_dev(dev); struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); + /* If the guest is running, disallow un-assignment of domain */ + if (matrix_mdev->kvm) + return -EBUSY; + ret = kstrtoul(buf, 0, &apqi); if (ret) return ret; @@ -544,6 +567,10 @@ static ssize_t assign_control_domain_store(struct device *dev, struct mdev_device *mdev = mdev_from_dev(dev); struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); + /* If the guest is running, disallow assignment of control domain */ + if (matrix_mdev->kvm) + return -EBUSY; + ret = kstrtoul(buf, 0, &id); if (ret) return ret; @@ -590,6 +617,10 @@ static ssize_t unassign_control_domain_store(struct device *dev, struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); unsigned long max_domid = matrix_mdev->matrix.adm_max; + /* If the guest is running, disallow un-assignment of control domain */ + if (matrix_mdev->kvm) + return -EBUSY; + ret = kstrtoul(buf, 0, &domid); if (ret) return ret; @@ -699,12 +730,149 @@ static ssize_t matrix_show(struct device *dev, struct device_attribute *attr, NULL }; +/** + * Verify that the AP instructions are available on the guest. This is indicated + * via the KVM_S390_VM_CPU_FEAT_AP CPU model feature. + */ +static int kvm_ap_validate_crypto_setup(struct kvm *kvm) +{ + if (test_bit_inv(KVM_S390_VM_CPU_FEAT_AP, kvm->arch.cpu_feat)) + return 0; + + return -EOPNOTSUPP; +} + +static void vfio_ap_mdev_copy_masks(struct ap_matrix_mdev *matrix_mdev) +{ + int nbytes; + unsigned long *apm, *aqm, *adm; + struct kvm_s390_crypto_cb *crycb = matrix_mdev->kvm->arch.crypto.crycb; + + switch (matrix_mdev->kvm->arch.crypto.crycbd & CRYCB_FORMAT_MASK) { + case CRYCB_FORMAT2: + apm = (unsigned long *)crycb->apcb1.apm; + aqm = (unsigned long *)crycb->apcb1.aqm; + adm = (unsigned long *)crycb->apcb1.adm; + break; + case CRYCB_FORMAT1: + case CRYCB_FORMAT0: + default: + apm = (unsigned long *)crycb->apcb0.apm; + aqm = (unsigned long *)crycb->apcb0.aqm; + adm = (unsigned long *)crycb->apcb0.adm; + break; + } + + nbytes = DIV_ROUND_UP(matrix_mdev->matrix.apm_max + 1, BITS_PER_BYTE); + memcpy(apm, matrix_mdev->matrix.apm, nbytes); + nbytes = DIV_ROUND_UP(matrix_mdev->matrix.aqm_max + 1, BITS_PER_BYTE); + memcpy(aqm, matrix_mdev->matrix.aqm, nbytes); + nbytes = DIV_ROUND_UP(matrix_mdev->matrix.adm_max + 1, BITS_PER_BYTE); + memcpy(adm, matrix_mdev->matrix.adm, nbytes); +} + +/** + * vfio_ap_mdev_open_once + * + * @matrix_mdev: a mediated matrix device + * + * Return 0 if no other mediated matrix device has been opened for the + * KVM guest assigned to @matrix_mdev; otherwise, returns an error. + */ +static int vfio_ap_mdev_open_once(struct ap_matrix_mdev *matrix_mdev, + struct kvm *kvm) +{ + struct ap_matrix_mdev *m; + + mutex_lock(&matrix_dev->lock); + + list_for_each_entry(m, &matrix_dev->mdev_list, node) { + if ((m != matrix_mdev) && (m->kvm == kvm)) { + mutex_unlock(&matrix_dev->lock); + return -EPERM; + } + } + + mutex_unlock(&matrix_dev->lock); + + return 0; +} + +static int vfio_ap_mdev_group_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + int ret; + struct ap_matrix_mdev *matrix_mdev; + + if (action != VFIO_GROUP_NOTIFY_SET_KVM) + return NOTIFY_OK; + + matrix_mdev = container_of(nb, struct ap_matrix_mdev, group_notifier); + + if (!data) { + matrix_mdev->kvm = NULL; + return NOTIFY_OK; + } + + ret = vfio_ap_mdev_open_once(matrix_mdev, data); + if (ret) + return NOTIFY_DONE; + + matrix_mdev->kvm = data; + + ret = kvm_ap_validate_crypto_setup(matrix_mdev->kvm); + if (ret) + return ret; + + vfio_ap_mdev_copy_masks(matrix_mdev); + + return NOTIFY_OK; +} + +static int vfio_ap_mdev_open(struct mdev_device *mdev) +{ + struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); + unsigned long events; + int ret; + + + if (!try_module_get(THIS_MODULE)) + return -ENODEV; + + matrix_mdev->group_notifier.notifier_call = vfio_ap_mdev_group_notifier; + events = VFIO_GROUP_NOTIFY_SET_KVM; + + ret = vfio_register_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY, + &events, &matrix_mdev->group_notifier); + if (ret) { + module_put(THIS_MODULE); + return ret; + } + + return 0; +} + +static void vfio_ap_mdev_release(struct mdev_device *mdev) +{ + struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); + + if (matrix_mdev->kvm) + kvm_arch_crypto_clear_masks(matrix_mdev->kvm); + + vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY, + &matrix_mdev->group_notifier); + matrix_mdev->kvm = NULL; + module_put(THIS_MODULE); +} + static const struct mdev_parent_ops vfio_ap_matrix_ops = { .owner = THIS_MODULE, .supported_type_groups = vfio_ap_mdev_type_groups, .mdev_attr_groups = vfio_ap_mdev_attr_groups, .create = vfio_ap_mdev_create, .remove = vfio_ap_mdev_remove, + .open = vfio_ap_mdev_open, + .release = vfio_ap_mdev_release, }; int vfio_ap_mdev_register(void) diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h index a2eab78..ebad5db 100644 --- a/drivers/s390/crypto/vfio_ap_private.h +++ b/drivers/s390/crypto/vfio_ap_private.h @@ -71,10 +71,15 @@ struct ap_matrix { * @list: allows the ap_matrix_mdev struct to be added to a list * @matrix: the adapters, usage domains and control domains assigned to the * mediated matrix device. + * @group_notifier: notifier block used for specifying callback function for + * handling the VFIO_GROUP_NOTIFY_SET_KVM event + * @kvm: the struct holding guest's state */ struct ap_matrix_mdev { struct list_head node; struct ap_matrix matrix; + struct notifier_block group_notifier; + struct kvm *kvm; }; extern int vfio_ap_mdev_register(void); -- 1.7.1
