From: Matthew Rosato <mjrosato@xxxxxxxxxxxxx> These routines will be wired into a kvm ioctl in order to respond to requests to enable / disable a device for Adapter Event Notifications / Adapter Interuption Forwarding. Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx> Acked-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx> Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220606203325.110625-16-mjrosato@xxxxxxxxxxxxx Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx> --- arch/s390/kvm/pci.c | 247 +++++++++++++++++++++++++++++++++++++ arch/s390/kvm/pci.h | 1 + arch/s390/pci/pci_insn.c | 1 + include/linux/sched/user.h | 3 +- 4 files changed, 251 insertions(+), 1 deletion(-) diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c index d566551d3018..b232c8cbaa81 100644 --- a/arch/s390/kvm/pci.c +++ b/arch/s390/kvm/pci.c @@ -11,6 +11,7 @@ #include <linux/pci.h> #include <asm/pci.h> #include <asm/pci_insn.h> +#include <asm/pci_io.h> #include "pci.h" struct zpci_aift *aift; @@ -152,6 +153,252 @@ int kvm_s390_pci_aen_init(u8 nisc) return rc; } +/* Modify PCI: Register floating adapter interruption forwarding */ +static int kvm_zpci_set_airq(struct zpci_dev *zdev) +{ + u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_REG_INT); + struct zpci_fib fib = {}; + u8 status; + + fib.fmt0.isc = zdev->kzdev->fib.fmt0.isc; + fib.fmt0.sum = 1; /* enable summary notifications */ + fib.fmt0.noi = airq_iv_end(zdev->aibv); + fib.fmt0.aibv = virt_to_phys(zdev->aibv->vector); + fib.fmt0.aibvo = 0; + fib.fmt0.aisb = virt_to_phys(aift->sbv->vector + (zdev->aisb / 64) * 8); + fib.fmt0.aisbo = zdev->aisb & 63; + fib.gd = zdev->gisa; + + return zpci_mod_fc(req, &fib, &status) ? -EIO : 0; +} + +/* Modify PCI: Unregister floating adapter interruption forwarding */ +static int kvm_zpci_clear_airq(struct zpci_dev *zdev) +{ + u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_DEREG_INT); + struct zpci_fib fib = {}; + u8 cc, status; + + fib.gd = zdev->gisa; + + cc = zpci_mod_fc(req, &fib, &status); + if (cc == 3 || (cc == 1 && status == 24)) + /* Function already gone or IRQs already deregistered. */ + cc = 0; + + return cc ? -EIO : 0; +} + +static inline void unaccount_mem(unsigned long nr_pages) +{ + struct user_struct *user = get_uid(current_user()); + + if (user) + atomic_long_sub(nr_pages, &user->locked_vm); + if (current->mm) + atomic64_sub(nr_pages, ¤t->mm->pinned_vm); +} + +static inline int account_mem(unsigned long nr_pages) +{ + struct user_struct *user = get_uid(current_user()); + unsigned long page_limit, cur_pages, new_pages; + + page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; + + do { + cur_pages = atomic_long_read(&user->locked_vm); + new_pages = cur_pages + nr_pages; + if (new_pages > page_limit) + return -ENOMEM; + } while (atomic_long_cmpxchg(&user->locked_vm, cur_pages, + new_pages) != cur_pages); + + atomic64_add(nr_pages, ¤t->mm->pinned_vm); + + return 0; +} + +static int kvm_s390_pci_aif_enable(struct zpci_dev *zdev, struct zpci_fib *fib, + bool assist) +{ + struct page *pages[1], *aibv_page, *aisb_page = NULL; + unsigned int msi_vecs, idx; + struct zpci_gaite *gaite; + unsigned long hva, bit; + struct kvm *kvm; + phys_addr_t gaddr; + int rc = 0, gisc, npages, pcount = 0; + + /* + * Interrupt forwarding is only applicable if the device is already + * enabled for interpretation + */ + if (zdev->gisa == 0) + return -EINVAL; + + kvm = zdev->kzdev->kvm; + msi_vecs = min_t(unsigned int, fib->fmt0.noi, zdev->max_msi); + + /* Get the associated forwarding ISC - if invalid, return the error */ + gisc = kvm_s390_gisc_register(kvm, fib->fmt0.isc); + if (gisc < 0) + return gisc; + + /* Replace AIBV address */ + idx = srcu_read_lock(&kvm->srcu); + hva = gfn_to_hva(kvm, gpa_to_gfn((gpa_t)fib->fmt0.aibv)); + npages = pin_user_pages_fast(hva, 1, FOLL_WRITE | FOLL_LONGTERM, pages); + srcu_read_unlock(&kvm->srcu, idx); + if (npages < 1) { + rc = -EIO; + goto out; + } + aibv_page = pages[0]; + pcount++; + gaddr = page_to_phys(aibv_page) + (fib->fmt0.aibv & ~PAGE_MASK); + fib->fmt0.aibv = gaddr; + + /* Pin the guest AISB if one was specified */ + if (fib->fmt0.sum == 1) { + idx = srcu_read_lock(&kvm->srcu); + hva = gfn_to_hva(kvm, gpa_to_gfn((gpa_t)fib->fmt0.aisb)); + npages = pin_user_pages_fast(hva, 1, FOLL_WRITE | FOLL_LONGTERM, + pages); + srcu_read_unlock(&kvm->srcu, idx); + if (npages < 1) { + rc = -EIO; + goto unpin1; + } + aisb_page = pages[0]; + pcount++; + } + + /* Account for pinned pages, roll back on failure */ + if (account_mem(pcount)) + goto unpin2; + + /* AISB must be allocated before we can fill in GAITE */ + mutex_lock(&aift->aift_lock); + bit = airq_iv_alloc_bit(aift->sbv); + if (bit == -1UL) + goto unlock; + zdev->aisb = bit; /* store the summary bit number */ + zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA | + AIRQ_IV_BITLOCK | + AIRQ_IV_GUESTVEC, + phys_to_virt(fib->fmt0.aibv)); + + spin_lock_irq(&aift->gait_lock); + gaite = (struct zpci_gaite *)aift->gait + (zdev->aisb * + sizeof(struct zpci_gaite)); + + /* If assist not requested, host will get all alerts */ + if (assist) + gaite->gisa = (u32)virt_to_phys(&kvm->arch.sie_page2->gisa); + else + gaite->gisa = 0; + + gaite->gisc = fib->fmt0.isc; + gaite->count++; + gaite->aisbo = fib->fmt0.aisbo; + gaite->aisb = virt_to_phys(page_address(aisb_page) + (fib->fmt0.aisb & + ~PAGE_MASK)); + aift->kzdev[zdev->aisb] = zdev->kzdev; + spin_unlock_irq(&aift->gait_lock); + + /* Update guest FIB for re-issue */ + fib->fmt0.aisbo = zdev->aisb & 63; + fib->fmt0.aisb = virt_to_phys(aift->sbv->vector + (zdev->aisb / 64) * 8); + fib->fmt0.isc = gisc; + + /* Save some guest fib values in the host for later use */ + zdev->kzdev->fib.fmt0.isc = fib->fmt0.isc; + zdev->kzdev->fib.fmt0.aibv = fib->fmt0.aibv; + mutex_unlock(&aift->aift_lock); + + /* Issue the clp to setup the irq now */ + rc = kvm_zpci_set_airq(zdev); + return rc; + +unlock: + mutex_unlock(&aift->aift_lock); +unpin2: + if (fib->fmt0.sum == 1) + unpin_user_page(aisb_page); +unpin1: + unpin_user_page(aibv_page); +out: + return rc; +} + +static int kvm_s390_pci_aif_disable(struct zpci_dev *zdev, bool force) +{ + struct kvm_zdev *kzdev = zdev->kzdev; + struct zpci_gaite *gaite; + struct page *vpage = NULL, *spage = NULL; + int rc, pcount = 0; + u8 isc; + + if (zdev->gisa == 0) + return -EINVAL; + + mutex_lock(&aift->aift_lock); + + /* + * If the clear fails due to an error, leave now unless we know this + * device is about to go away (force) -- In that case clear the GAITE + * regardless. + */ + rc = kvm_zpci_clear_airq(zdev); + if (rc && !force) + goto out; + + if (zdev->kzdev->fib.fmt0.aibv == 0) + goto out; + spin_lock_irq(&aift->gait_lock); + gaite = (struct zpci_gaite *)aift->gait + (zdev->aisb * + sizeof(struct zpci_gaite)); + isc = gaite->gisc; + gaite->count--; + if (gaite->count == 0) { + /* Release guest AIBV and AISB */ + vpage = phys_to_page(kzdev->fib.fmt0.aibv); + if (gaite->aisb != 0) + spage = phys_to_page(gaite->aisb); + /* Clear the GAIT entry */ + gaite->aisb = 0; + gaite->gisc = 0; + gaite->aisbo = 0; + gaite->gisa = 0; + aift->kzdev[zdev->aisb] = 0; + /* Clear zdev info */ + airq_iv_free_bit(aift->sbv, zdev->aisb); + airq_iv_release(zdev->aibv); + zdev->aisb = 0; + zdev->aibv = NULL; + } + spin_unlock_irq(&aift->gait_lock); + kvm_s390_gisc_unregister(kzdev->kvm, isc); + kzdev->fib.fmt0.isc = 0; + kzdev->fib.fmt0.aibv = 0; + + if (vpage) { + unpin_user_page(vpage); + pcount++; + } + if (spage) { + unpin_user_page(spage); + pcount++; + } + if (pcount > 0) + unaccount_mem(pcount); +out: + mutex_unlock(&aift->aift_lock); + + return rc; +} + static int kvm_s390_pci_dev_open(struct zpci_dev *zdev) { struct kvm_zdev *kzdev; diff --git a/arch/s390/kvm/pci.h b/arch/s390/kvm/pci.h index 9f7828d97605..9d091033fc02 100644 --- a/arch/s390/kvm/pci.h +++ b/arch/s390/kvm/pci.h @@ -20,6 +20,7 @@ struct kvm_zdev { struct zpci_dev *zdev; struct kvm *kvm; + struct zpci_fib fib; }; struct zpci_gaite { diff --git a/arch/s390/pci/pci_insn.c b/arch/s390/pci/pci_insn.c index 5798178aec9d..56480be48244 100644 --- a/arch/s390/pci/pci_insn.c +++ b/arch/s390/pci/pci_insn.c @@ -92,6 +92,7 @@ u8 zpci_mod_fc(u64 req, struct zpci_fib *fib, u8 *status) return cc; } +EXPORT_SYMBOL_GPL(zpci_mod_fc); /* Refresh PCI Translations */ static inline u8 __rpcit(u64 fn, u64 addr, u64 range, u8 *status) diff --git a/include/linux/sched/user.h b/include/linux/sched/user.h index 00ed419dd464..f054d0360a75 100644 --- a/include/linux/sched/user.h +++ b/include/linux/sched/user.h @@ -24,7 +24,8 @@ struct user_struct { kuid_t uid; #if defined(CONFIG_PERF_EVENTS) || defined(CONFIG_BPF_SYSCALL) || \ - defined(CONFIG_NET) || defined(CONFIG_IO_URING) + defined(CONFIG_NET) || defined(CONFIG_IO_URING) || \ + defined(CONFIG_VFIO_PCI_ZDEV_KVM) atomic_long_t locked_vm; #endif #ifdef CONFIG_WATCH_QUEUE -- 2.36.1
