On Sat, Feb 26, 2022 at 12:16 PM Akihiko Odaki <akihiko.od...@gmail.com> wrote:
> On 2022/02/26 17:37, Vladislav Yaroshchuk wrote: > > > > Hi Akihiko, > > > > On Fri, Feb 25, 2022 at 8:46 PM Akihiko Odaki <akihiko.od...@gmail.com > > <mailto:akihiko.od...@gmail.com>> wrote: > > > > On 2022/02/26 2:13, Vladislav Yaroshchuk wrote: > > > Interaction with vmnet.framework in different modes > > > differs only on configuration stage, so we can create > > > common `send`, `receive`, etc. procedures and reuse them. > > > > > > vmnet.framework supports iov, but writing more than > > > one iov into vmnet interface fails with > > > 'VMNET_INVALID_ARGUMENT'. Collecting provided iovs into > > > one and passing it to vmnet works fine. That's the > > > reason why receive_iov() left unimplemented. But it still > > > works with good enough performance having .receive() > > > net/vmnet: implement shared mode (vmnet-shared) > > > > > > Interaction with vmnet.framework in different modes > > > differs only on configuration stage, so we can create > > > common `send`, `receive`, etc. procedures and reuse them. > > > > > > vmnet.framework supports iov, but writing more than > > > one iov into vmnet interface fails with > > > 'VMNET_INVALID_ARGUMENT'. Collecting provided iovs into > > > one and passing it to vmnet works fine. That's the > > > reason why receive_iov() left unimplemented. But it still > > > works with good enough performance having .receive() > > > implemented only. > > > > > > Also, there is no way to unsubscribe from vmnet packages > > > receiving except registering and unregistering event > > > callback or simply drop packages just ignoring and > > > not processing them when related flag is set. Here we do > > > using the second way. > > > > > > Signed-off-by: Phillip Tennen <phil...@axleos.com > > <mailto:phil...@axleos.com>> > > > Signed-off-by: Vladislav Yaroshchuk > > <vladislav.yaroshc...@jetbrains.com > > <mailto:vladislav.yaroshc...@jetbrains.com>> > > > > Thank you for persistently working on this. > > > > > --- > > > net/vmnet-common.m | 302 > > +++++++++++++++++++++++++++++++++++++++++++++ > > > net/vmnet-shared.c | 94 +++++++++++++- > > > net/vmnet_int.h | 39 +++++- > > > 3 files changed, 430 insertions(+), 5 deletions(-) > > > > > > diff --git a/net/vmnet-common.m b/net/vmnet-common.m > > > index 56612c72ce..2f70921cae 100644 > > > --- a/net/vmnet-common.m > > > +++ b/net/vmnet-common.m > > > @@ -10,6 +10,8 @@ > > > */ > > > > > > #include "qemu/osdep.h" > > > +#include "qemu/main-loop.h" > > > +#include "qemu/log.h" > > > #include "qapi/qapi-types-net.h" > > > #include "vmnet_int.h" > > > #include "clients.h" > > > @@ -17,4 +19,304 @@ > > > #include "qapi/error.h" > > > > > > #include <vmnet/vmnet.h> > > > +#include <dispatch/dispatch.h> > > > > > > + > > > +static inline void vmnet_set_send_bh_scheduled(VmnetCommonState > *s, > > > + bool enable) > > > +{ > > > + qatomic_set(&s->send_scheduled, enable); > > > +} > > > + > > > + > > > +static inline bool vmnet_is_send_bh_scheduled(VmnetCommonState > *s) > > > +{ > > > + return qatomic_load_acquire(&s->send_scheduled); > > > +} > > > + > > > + > > > +static inline void vmnet_set_send_enabled(VmnetCommonState *s, > > > + bool enable) > > > +{ > > > + if (enable) { > > > + vmnet_interface_set_event_callback( > > > + s->vmnet_if, > > > + VMNET_INTERFACE_PACKETS_AVAILABLE, > > > + s->if_queue, > > > + ^(interface_event_t event_id, xpc_object_t event) { > > > + assert(event_id == > > VMNET_INTERFACE_PACKETS_AVAILABLE); > > > + /* > > > + * This function is being called from a non qemu > > thread, so > > > + * we only schedule a BH, and do the rest of the > > io completion > > > + * handling from vmnet_send_bh() which runs in a > > qemu context. > > > + * > > > + * Avoid scheduling multiple bottom halves > > > + */ > > > + if (!vmnet_is_send_bh_scheduled(s)) { > > > + vmnet_set_send_bh_scheduled(s, true); > > > > It can be interrupted between vmnet_is_send_bh_scheduled and > > vmnet_set_send_bh_scheduled, which leads to data race. > > > > > > Sorry, I did not clearly understand what you meant. Since this > > callback (block) is submitted on DISPATCH_QUEUE_SERIAL, > > only one instance of the callback will be executed at any > > moment of time. > > https://developer.apple.com/documentation/dispatch/dispatch_queue_serial > > < > https://developer.apple.com/documentation/dispatch/dispatch_queue_serial> > > > > Also this is the only place where we schedule a bottom half. > > > > After we set the 'send_scheduled' flag, all the other > > callback blocks will do nothing (skip the if block) until > > the bottom half is executed and reset 'send_scheduled'. > > I don't see any races here :( > > > > Correct me if I'm wrong please. > > My explanation that the interruption between vmnet_is_send_bh_scheduled > and vmnet_set_send_bh_scheduled is problematic was actually misleading. > > The problem is that vmnet_send_bh resets 'send_scheduled' after calling > vmnet_read. If we got another packet after vmnet_read, it would be > silently ignored. > > By the way, I forgot to mention another problem: vmnet_send_completed > calls vmnet_set_send_enabled, but the other packets in the buffer may > not be sent yet. Also, unregistering callbacks in vmnet_set_send_enabled > is probably not enough to stop the callback being fired since some > dispatch blocks are already in the dispatch queue. > > Now I understand what you mean, thanks. What do you think about the workaround? For me it is quite difficult question how to synchronize qemu with vmnet thread, especially with completion callback. > Regards, > Akihiko Odaki > > > > > > + qemu_bh_schedule(s->send_bh); > > > + } > > > + }); > > > + } else { > > > + vmnet_interface_set_event_callback( > > > + s->vmnet_if, > > > + VMNET_INTERFACE_PACKETS_AVAILABLE, > > > + NULL, > > > + NULL); > > > + } > > > +} > > > + > > > + > > > +static void vmnet_send_completed(NetClientState *nc, ssize_t len) > > > +{ > > > + VmnetCommonState *s = DO_UPCAST(VmnetCommonState, nc, nc); > > > + vmnet_set_send_enabled(s, true); > > > +} > > > + > > > + > > > +static void vmnet_send_bh(void *opaque) > > > +{ > > > + NetClientState *nc = (NetClientState *) opaque; > > > + VmnetCommonState *s = DO_UPCAST(VmnetCommonState, nc, nc); > > > + > > > + struct iovec *iov = s->iov_buf; > > > + struct vmpktdesc *packets = s->packets_buf; > > > + int pkt_cnt; > > > + int i; > > > + > > > + vmnet_return_t status; > > > + ssize_t size; > > > + > > > + /* read as many packets as present */ > > > + pkt_cnt = VMNET_PACKETS_LIMIT; > > > > There could be more than VMNET_PACKETS_LIMIT. You may call > > vmnet_read in > > a loop. > > > > > + for (i = 0; i < pkt_cnt; ++i) { > > > + packets[i].vm_pkt_size = s->max_packet_size; > > > + packets[i].vm_pkt_iovcnt = 1; > > > + packets[i].vm_flags = 0; > > > + } > > > + > > > + status = vmnet_read(s->vmnet_if, packets, &pkt_cnt); > > > + if (status != VMNET_SUCCESS) { > > > + error_printf("vmnet: read failed: %s\n", > > > + vmnet_status_map_str(status)); > > > + goto done; > > > + } > > > + > > > + for (i = 0; i < pkt_cnt; ++i) { > > > + size = qemu_send_packet_async(nc, > > > + iov[i].iov_base, > > > + packets[i].vm_pkt_size, > > > + vmnet_send_completed); > > > + if (size == 0) { > > > + vmnet_set_send_enabled(s, false); > > > + goto done; > > > + } else if (size < 0) { > > > + break; > > > + } > > > > goto is not needed here. "break" when size <= 0. > > > > > + } > > > + > > > +done: > > > + vmnet_set_send_bh_scheduled(s, false); > > > +} > > > + > > > + > > > +static void vmnet_bufs_init(VmnetCommonState *s) > > > +{ > > > + struct vmpktdesc *packets = s->packets_buf; > > > + struct iovec *iov = s->iov_buf; > > > + int i; > > > + > > > + for (i = 0; i < VMNET_PACKETS_LIMIT; ++i) { > > > + iov[i].iov_len = s->max_packet_size; > > > + iov[i].iov_base = g_malloc0(iov[i].iov_len); > > > + packets[i].vm_pkt_iov = iov + i; > > > + } > > > +} > > > + > > > + > > > +const char *vmnet_status_map_str(vmnet_return_t status) > > > +{ > > > + switch (status) { > > > + case VMNET_SUCCESS: > > > + return "success"; > > > + case VMNET_FAILURE: > > > + return "general failure (possibly not enough > privileges)"; > > > + case VMNET_MEM_FAILURE: > > > + return "memory allocation failure"; > > > + case VMNET_INVALID_ARGUMENT: > > > + return "invalid argument specified"; > > > + case VMNET_SETUP_INCOMPLETE: > > > + return "interface setup is not complete"; > > > + case VMNET_INVALID_ACCESS: > > > + return "invalid access, permission denied"; > > > + case VMNET_PACKET_TOO_BIG: > > > + return "packet size is larger than MTU"; > > > + case VMNET_BUFFER_EXHAUSTED: > > > + return "buffers exhausted in kernel"; > > > + case VMNET_TOO_MANY_PACKETS: > > > + return "packet count exceeds limit"; > > > +#if defined(MAC_OS_VERSION_11_0) && \ > > > + MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_VERSION_11_0 > > > + case VMNET_SHARING_SERVICE_BUSY: > > > + return "conflict, sharing service is in use"; > > > +#endif > > > + default: > > > + return "unknown vmnet error"; > > > + } > > > +} > > > + > > > + > > > +int vmnet_if_create(NetClientState *nc, > > > + xpc_object_t if_desc, > > > + Error **errp) > > > +{ > > > + VmnetCommonState *s = DO_UPCAST(VmnetCommonState, nc, nc);; > > > > Duplicate semicolons. > > > > > + dispatch_semaphore_t if_created_sem = > > dispatch_semaphore_create(0); > > > > if_created_sem leaks. > > > > > + __block vmnet_return_t if_status; > > > + > > > + s->if_queue = dispatch_queue_create( > > > + "org.qemu.vmnet.if_queue", > > > + DISPATCH_QUEUE_SERIAL > > > + ); > > > + > > > + xpc_dictionary_set_bool( > > > + if_desc, > > > + vmnet_allocate_mac_address_key, > > > + false > > > + ); > > > +#ifdef DEBUG > > > + qemu_log("vmnet.start.interface_desc:\n"); > > > + xpc_dictionary_apply(if_desc, > > > + ^bool(const char *k, xpc_object_t v) { > > > + char *desc = > xpc_copy_description(v); > > > + qemu_log(" %s=%s\n", k, desc); > > > + free(desc); > > > + return true; > > > + }); > > > +#endif /* DEBUG */ > > > + > > > + s->vmnet_if = vmnet_start_interface( > > > + if_desc, > > > + s->if_queue, > > > + ^(vmnet_return_t status, xpc_object_t interface_param) { > > > + if_status = status; > > > + if (status != VMNET_SUCCESS || !interface_param) { > > > + dispatch_semaphore_signal(if_created_sem); > > > + return; > > > + } > > > + > > > +#ifdef DEBUG > > > + qemu_log("vmnet.start.interface_param:\n"); > > > + xpc_dictionary_apply(interface_param, > > > + ^bool(const char *k, > > xpc_object_t v) { > > > + char *desc = > > xpc_copy_description(v); > > > + qemu_log(" %s=%s\n", k, > desc); > > > + free(desc); > > > + return true; > > > + }); > > > +#endif /* DEBUG */ > > > + > > > + s->mtu = xpc_dictionary_get_uint64( > > > + interface_param, > > > + vmnet_mtu_key); > > > + s->max_packet_size = xpc_dictionary_get_uint64( > > > + interface_param, > > > + vmnet_max_packet_size_key); > > > + > > > + dispatch_semaphore_signal(if_created_sem); > > > + }); > > > + > > > + if (s->vmnet_if == NULL) { > > > + error_setg(errp, > > > + "unable to create interface " > > > + "with requested params"); > > > > You don't need line breaks here. Breaking a string into a few would > > also > > makes it a bit hard to grep. > > > > > + return -1; > > > > s->if_queue leaks. > > > > > + } > > > + > > > + dispatch_semaphore_wait(if_created_sem, > DISPATCH_TIME_FOREVER); > > > + > > > + if (if_status != VMNET_SUCCESS) { > > > + error_setg(errp, > > > + "cannot create vmnet interface: %s", > > > + vmnet_status_map_str(if_status)); > > > + return -1; > > > + } > > > + > > > + s->send_bh = aio_bh_new(qemu_get_aio_context(), > > vmnet_send_bh, nc); > > > + vmnet_bufs_init(s); > > > + vmnet_set_send_bh_scheduled(s, false); > > > + vmnet_set_send_enabled(s, true); > > > + return 0; > > > +} > > > + > > > + > > > +ssize_t vmnet_receive_common(NetClientState *nc, > > > + const uint8_t *buf, > > > + size_t size) > > > +{ > > > + VmnetCommonState *s = DO_UPCAST(VmnetCommonState, nc, nc); > > > + struct vmpktdesc packet; > > > + struct iovec iov; > > > + int pkt_cnt; > > > + vmnet_return_t if_status; > > > + > > > + if (size > s->max_packet_size) { > > > + warn_report("vmnet: packet is too big, %zu > %llu\n", > > > > Use PRIu64. > > > > > + packet.vm_pkt_size, > > > + s->max_packet_size); > > > + return -1; > > > + } > > > + > > > + iov.iov_base = (char *) buf; > > > + iov.iov_len = size; > > > + > > > + packet.vm_pkt_iovcnt = 1; > > > + packet.vm_flags = 0; > > > + packet.vm_pkt_size = size; > > > + packet.vm_pkt_iov = &iov; > > > + pkt_cnt = 1; > > > + > > > + if_status = vmnet_write(s->vmnet_if, &packet, &pkt_cnt); > > > + if (if_status != VMNET_SUCCESS) { > > > + error_report("vmnet: write error: %s\n", > > > + vmnet_status_map_str(if_status)); > > > > Why don't return -1? > > > > > + } > > > + > > > + if (if_status == VMNET_SUCCESS && pkt_cnt) { > > > + return size; > > > + } > > > + return 0; > > > +} > > > + > > > + > > > +void vmnet_cleanup_common(NetClientState *nc) > > > +{ > > > + VmnetCommonState *s = DO_UPCAST(VmnetCommonState, nc, nc);; > > > > Duplicate semicolons. > > > > > + dispatch_semaphore_t if_created_sem; > > > + > > > + qemu_purge_queued_packets(nc); > + > > vmnet_set_send_bh_scheduled(s, true); > > > + vmnet_set_send_enabled(s, false); > > > + > > > + if (s->vmnet_if == NULL) { > > > + return; > > > + } > > > + > > > + if_created_sem = dispatch_semaphore_create(0); > > > + vmnet_stop_interface( > > > + s->vmnet_if, > > > + s->if_queue, > > > + ^(vmnet_return_t status) { > > > + assert(status == VMNET_SUCCESS); > > > + dispatch_semaphore_signal(if_created_sem); > > > + }); > > > + dispatch_semaphore_wait(if_created_sem, > DISPATCH_TIME_FOREVER); > > > + > > > + qemu_bh_delete(s->send_bh); > > > + dispatch_release(if_created_sem); > > > + dispatch_release(s->if_queue); > > > + > > > + for (int i = 0; i < VMNET_PACKETS_LIMIT; ++i) { > > > + g_free(s->iov_buf[i].iov_base); > > > + } > > > +} > > > diff --git a/net/vmnet-shared.c b/net/vmnet-shared.c > > > index f07afaaf21..66f66c034b 100644 > > > --- a/net/vmnet-shared.c > > > +++ b/net/vmnet-shared.c > > > @@ -10,16 +10,102 @@ > > > > > > #include "qemu/osdep.h" > > > #include "qapi/qapi-types-net.h" > > > +#include "qapi/error.h" > > > #include "vmnet_int.h" > > > #include "clients.h" > > > -#include "qemu/error-report.h" > > > -#include "qapi/error.h" > > > > > > #include <vmnet/vmnet.h> > > > > > > +typedef struct VmnetSharedState { > > > + VmnetCommonState cs; > > > +} VmnetSharedState; > > > + > > > + > > > +static bool validate_options(const Netdev *netdev, Error **errp) > > > +{ > > > + const NetdevVmnetSharedOptions *options = > > &(netdev->u.vmnet_shared); > > > + > > > +#if !defined(MAC_OS_VERSION_11_0) || \ > > > + MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_VERSION_11_0 > > > + if (options->has_isolated) { > > > + error_setg(errp, > > > + "vmnet-shared.isolated feature is " > > > + "unavailable: outdated vmnet.framework API"); > > > + return false; > > > + } > > > +#endif > > > + > > > + if ((options->has_start_address || > > > + options->has_end_address || > > > + options->has_subnet_mask) && > > > + !(options->has_start_address && > > > + options->has_end_address && > > > + options->has_subnet_mask)) { > > > + error_setg(errp, > > > + "'start-address', 'end-address', > 'subnet-mask' " > > > + "should be provided together" > > > + ); > > > + return false; > > > + } > > > + > > > + return true; > > > +} > > > + > > > +static xpc_object_t build_if_desc(const Netdev *netdev) > > > +{ > > > + const NetdevVmnetSharedOptions *options = > > &(netdev->u.vmnet_shared); > > > + xpc_object_t if_desc = xpc_dictionary_create(NULL, NULL, 0); > > > + > > > + xpc_dictionary_set_uint64( > > > + if_desc, > > > + vmnet_operation_mode_key, > > > + VMNET_SHARED_MODE > > > + ); > > > + > > > + if (options->has_nat66_prefix) { > > > + xpc_dictionary_set_string(if_desc, > > > + vmnet_nat66_prefix_key, > > > + options->nat66_prefix); > > > + } > > > + > > > + if (options->has_start_address) { > > > + xpc_dictionary_set_string(if_desc, > > > + vmnet_start_address_key, > > > + options->start_address); > > > + xpc_dictionary_set_string(if_desc, > > > + vmnet_end_address_key, > > > + options->end_address); > > > + xpc_dictionary_set_string(if_desc, > > > + vmnet_subnet_mask_key, > > > + options->subnet_mask); > > > + } > > > + > > > +#if defined(MAC_OS_VERSION_11_0) && \ > > > + MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_VERSION_11_0 > > > + xpc_dictionary_set_bool( > > > + if_desc, > > > + vmnet_enable_isolation_key, > > > + options->isolated > > > + ); > > > +#endif > > > + > > > + return if_desc; > > > +} > > > + > > > +static NetClientInfo net_vmnet_shared_info = { > > > + .type = NET_CLIENT_DRIVER_VMNET_SHARED, > > > + .size = sizeof(VmnetSharedState), > > > + .receive = vmnet_receive_common, > > > + .cleanup = vmnet_cleanup_common, > > > +}; > > > + > > > int net_init_vmnet_shared(const Netdev *netdev, const char > *name, > > > NetClientState *peer, Error **errp) > > > { > > > - error_setg(errp, "vmnet-shared is not implemented yet"); > > > - return -1; > > > + NetClientState *nc = > qemu_new_net_client(&net_vmnet_shared_info, > > > + peer, > > "vmnet-shared", name); > > > + if (!validate_options(netdev, errp)) { > > > + g_assert_not_reached(); > > > > g_assert_not_reached is for debugging purpose and may be dropped > > depending on the build option. > > > > > + } > > > + return vmnet_if_create(nc, build_if_desc(netdev), errp); > > > } > > > diff --git a/net/vmnet_int.h b/net/vmnet_int.h > > > index aac4d5af64..acfe3a88c0 100644 > > > --- a/net/vmnet_int.h > > > +++ b/net/vmnet_int.h > > > @@ -15,11 +15,48 @@ > > > #include "clients.h" > > > > > > #include <vmnet/vmnet.h> > > > +#include <dispatch/dispatch.h> > > > + > > > +/** > > > + * From vmnet.framework documentation > > > + * > > > + * Each read/write call allows up to 200 packets to be > > > + * read or written for a maximum of 256KB. > > > + * > > > + * Each packet written should be a complete > > > + * ethernet frame. > > > + * > > > + * https://developer.apple.com/documentation/vmnet > > <https://developer.apple.com/documentation/vmnet> > > > + */ > > > +#define VMNET_PACKETS_LIMIT 200 > > > > > > typedef struct VmnetCommonState { > > > - NetClientState nc; > > > + NetClientState nc; > > > + interface_ref vmnet_if; > > > + > > > + bool send_scheduled; > > > > > > + uint64_t mtu; > > > + uint64_t max_packet_size; > > > + > > > + struct vmpktdesc packets_buf[VMNET_PACKETS_LIMIT]; > > > + struct iovec iov_buf[VMNET_PACKETS_LIMIT]; > > > + > > > + dispatch_queue_t if_queue; > > > + > > > + QEMUBH *send_bh; > > > } VmnetCommonState; > > > > > > +const char *vmnet_status_map_str(vmnet_return_t status); > > > + > > > +int vmnet_if_create(NetClientState *nc, > > > + xpc_object_t if_desc, > > > + Error **errp); > > > + > > > +ssize_t vmnet_receive_common(NetClientState *nc, > > > + const uint8_t *buf, > > > + size_t size); > > > + > > > +void vmnet_cleanup_common(NetClientState *nc); > > > > > > #endif /* VMNET_INT_H */ > > > > > > Other issues will be fixed and submitted later, > > thank you! > > > > Regards, > > Vladislav Yaroshchuk > > Regards, Vladislav Yaroshchuk
