From 258287c994de8f2f52430b8d79b4fdf2c95f8c91 Mon Sep 17 00:00:00 2001 From: Tony Krowiak Date: Tue, 25 Sep 2018 19:16:26 -0400 Subject: [PATCH] s390: vfio-ap: implement mediated device open callback 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 Acked-by: Halil Pasic Tested-by: Michael Mueller Tested-by: Farhan Ali Tested-by: Pierre Morel Acked-by: Pierre Morel Reviewed-by: Cornelia Huck Message-Id: <20180925231641.4954-12-akrowiak@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger --- arch/s390/include/asm/kvm_host.h | 1 + drivers/s390/crypto/vfio_ap_ops.c | 161 ++++++++++++++++++++++++++++++++++ drivers/s390/crypto/vfio_ap_private.h | 5 ++ 3 files changed, 167 insertions(+) diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 0a78036a802b..36d35313e840 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 3834624dcc2e..1fd0beefeda6 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -13,6 +13,10 @@ #include #include #include +#include +#include +#include +#include #include #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); @@ -305,6 +312,10 @@ 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; @@ -367,6 +378,10 @@ 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; @@ -444,6 +459,10 @@ 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; @@ -501,6 +520,10 @@ 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; @@ -541,6 +564,10 @@ 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; @@ -587,6 +614,10 @@ 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; @@ -696,12 +727,142 @@ static const struct attribute_group *vfio_ap_mdev_attr_groups[] = { NULL }; +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: + apm = (unsigned long *)crycb->apcb0.apm; + aqm = (unsigned long *)crycb->apcb0.aqm; + adm = (unsigned long *)crycb->apcb0.adm; + break; + default: + /* cannot happen */ + return; + } + + 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_set_kvm + * + * @matrix_mdev: a mediated matrix device + * @kvm: reference to KVM instance + * + * Verifies no other mediated matrix device has @kvm and sets a reference to + * it in @matrix_mdev->kvm. + * + * Return 0 if no other mediated matrix device has a reference to @kvm; + * otherwise, returns an -EPERM. + */ +static int vfio_ap_mdev_set_kvm(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; + } + } + + matrix_mdev->kvm = kvm; + 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_set_kvm(matrix_mdev, data); + if (ret) + return NOTIFY_DONE; + + /* If there is no CRYCB pointer, then we can't copy the masks */ + if (!matrix_mdev->kvm->arch.crypto.crycbd) + return NOTIFY_DONE; + + 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 9f197ffab7ad..5675492233c7 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); -- 2.11.0