diff options
| -rw-r--r-- | include/linux/kvm_host.h | 4 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 108 |
2 files changed, 96 insertions, 16 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index a63d83ebd151..ec590aece366 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -160,8 +160,12 @@ enum kvm_bus { int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, const void *val); +int kvm_io_bus_write_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, + int len, const void *val, long cookie); int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, void *val); +int kvm_io_bus_read_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, + int len, void *val, long cookie); int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, struct kvm_io_device *dev); int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 1580dd4ace4e..71960fb03c2a 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2863,13 +2863,33 @@ static int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus, return off; } +static int __kvm_io_bus_write(struct kvm_io_bus *bus, + struct kvm_io_range *range, const void *val) +{ + int idx; + + idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len); + if (idx < 0) + return -EOPNOTSUPP; + + while (idx < bus->dev_count && + kvm_io_bus_sort_cmp(range, &bus->range[idx]) == 0) { + if (!kvm_iodevice_write(bus->range[idx].dev, range->addr, + range->len, val)) + return idx; + idx++; + } + + return -EOPNOTSUPP; +} + /* kvm_io_bus_write - called under kvm->slots_lock */ int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, const void *val) { - int idx; struct kvm_io_bus *bus; struct kvm_io_range range; + int r; range = (struct kvm_io_range) { .addr = addr, @@ -2877,14 +2897,52 @@ int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, }; bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); - idx = kvm_io_bus_get_first_dev(bus, addr, len); + r = __kvm_io_bus_write(bus, &range, val); + return r < 0 ? r : 0; +} + +/* kvm_io_bus_write_cookie - called under kvm->slots_lock */ +int kvm_io_bus_write_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, + int len, const void *val, long cookie) +{ + struct kvm_io_bus *bus; + struct kvm_io_range range; + + range = (struct kvm_io_range) { + .addr = addr, + .len = len, + }; + + bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); + + /* First try the device referenced by cookie. */ + if ((cookie >= 0) && (cookie < bus->dev_count) && + (kvm_io_bus_sort_cmp(&range, &bus->range[cookie]) == 0)) + if (!kvm_iodevice_write(bus->range[cookie].dev, addr, len, + val)) + return cookie; + + /* + * cookie contained garbage; fall back to search and return the + * correct cookie value. + */ + return __kvm_io_bus_write(bus, &range, val); +} + +static int __kvm_io_bus_read(struct kvm_io_bus *bus, struct kvm_io_range *range, + void *val) +{ + int idx; + + idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len); if (idx < 0) return -EOPNOTSUPP; while (idx < bus->dev_count && - kvm_io_bus_sort_cmp(&range, &bus->range[idx]) == 0) { - if (!kvm_iodevice_write(bus->range[idx].dev, addr, len, val)) - return 0; + kvm_io_bus_sort_cmp(range, &bus->range[idx]) == 0) { + if (!kvm_iodevice_read(bus->range[idx].dev, range->addr, + range->len, val)) + return idx; idx++; } @@ -2895,9 +2953,9 @@ int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, void *val) { - int idx; struct kvm_io_bus *bus; struct kvm_io_range range; + int r; range = (struct kvm_io_range) { .addr = addr, @@ -2905,18 +2963,36 @@ int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, }; bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); - idx = kvm_io_bus_get_first_dev(bus, addr, len); - if (idx < 0) - return -EOPNOTSUPP; + r = __kvm_io_bus_read(bus, &range, val); + return r < 0 ? r : 0; +} - while (idx < bus->dev_count && - kvm_io_bus_sort_cmp(&range, &bus->range[idx]) == 0) { - if (!kvm_iodevice_read(bus->range[idx].dev, addr, len, val)) - return 0; - idx++; - } +/* kvm_io_bus_read_cookie - called under kvm->slots_lock */ +int kvm_io_bus_read_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, + int len, void *val, long cookie) +{ + struct kvm_io_bus *bus; + struct kvm_io_range range; - return -EOPNOTSUPP; + range = (struct kvm_io_range) { + .addr = addr, + .len = len, + }; + + bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); + + /* First try the device referenced by cookie. */ + if ((cookie >= 0) && (cookie < bus->dev_count) && + (kvm_io_bus_sort_cmp(&range, &bus->range[cookie]) == 0)) + if (!kvm_iodevice_read(bus->range[cookie].dev, addr, len, + val)) + return cookie; + + /* + * cookie contained garbage; fall back to search and return the + * correct cookie value. + */ + return __kvm_io_bus_read(bus, &range, val); } /* Caller must hold slots_lock. */ |