From bd36adb8df5d62a2b4d4ded6357fb50b69a508fa Mon Sep 17 00:00:00 2001 From: Jagannathan Raman Date: Fri, 29 Jan 2021 11:46:19 -0500 Subject: multi-process: create IOHUB object to handle irq IOHUB object is added to manage PCI IRQs. It uses KVM_IRQFD ioctl to create irqfd to injecting PCI interrupts to the guest. IOHUB object forwards the irqfd to the remote process. Remote process uses this fd to directly send interrupts to the guest, bypassing QEMU. Signed-off-by: John G Johnson Signed-off-by: Jagannathan Raman Signed-off-by: Elena Ufimtseva Reviewed-by: Stefan Hajnoczi Message-id: 51d5c3d54e28a68b002e3875c59599c9f5a424a1.1611938319.git.jag.raman@oracle.com Signed-off-by: Stefan Hajnoczi --- hw/remote/iohub.c | 119 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) create mode 100644 hw/remote/iohub.c (limited to 'hw/remote/iohub.c') diff --git a/hw/remote/iohub.c b/hw/remote/iohub.c new file mode 100644 index 0000000000..e4ff131a6b --- /dev/null +++ b/hw/remote/iohub.c @@ -0,0 +1,119 @@ +/* + * Remote IO Hub + * + * Copyright © 2018, 2021 Oracle and/or its affiliates. + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ + +#include "qemu/osdep.h" +#include "qemu-common.h" + +#include "hw/pci/pci.h" +#include "hw/pci/pci_ids.h" +#include "hw/pci/pci_bus.h" +#include "qemu/thread.h" +#include "hw/boards.h" +#include "hw/remote/machine.h" +#include "hw/remote/iohub.h" +#include "qemu/main-loop.h" + +void remote_iohub_init(RemoteIOHubState *iohub) +{ + int pirq; + + memset(&iohub->irqfds, 0, sizeof(iohub->irqfds)); + memset(&iohub->resamplefds, 0, sizeof(iohub->resamplefds)); + + for (pirq = 0; pirq < REMOTE_IOHUB_NB_PIRQS; pirq++) { + qemu_mutex_init(&iohub->irq_level_lock[pirq]); + iohub->irq_level[pirq] = 0; + event_notifier_init_fd(&iohub->irqfds[pirq], -1); + event_notifier_init_fd(&iohub->resamplefds[pirq], -1); + } +} + +void remote_iohub_finalize(RemoteIOHubState *iohub) +{ + int pirq; + + for (pirq = 0; pirq < REMOTE_IOHUB_NB_PIRQS; pirq++) { + qemu_set_fd_handler(event_notifier_get_fd(&iohub->resamplefds[pirq]), + NULL, NULL, NULL); + event_notifier_cleanup(&iohub->irqfds[pirq]); + event_notifier_cleanup(&iohub->resamplefds[pirq]); + qemu_mutex_destroy(&iohub->irq_level_lock[pirq]); + } +} + +int remote_iohub_map_irq(PCIDevice *pci_dev, int intx) +{ + return pci_dev->devfn; +} + +void remote_iohub_set_irq(void *opaque, int pirq, int level) +{ + RemoteIOHubState *iohub = opaque; + + assert(pirq >= 0); + assert(pirq < PCI_DEVFN_MAX); + + QEMU_LOCK_GUARD(&iohub->irq_level_lock[pirq]); + + if (level) { + if (++iohub->irq_level[pirq] == 1) { + event_notifier_set(&iohub->irqfds[pirq]); + } + } else if (iohub->irq_level[pirq] > 0) { + iohub->irq_level[pirq]--; + } +} + +static void intr_resample_handler(void *opaque) +{ + ResampleToken *token = opaque; + RemoteIOHubState *iohub = token->iohub; + int pirq, s; + + pirq = token->pirq; + + s = event_notifier_test_and_clear(&iohub->resamplefds[pirq]); + + assert(s >= 0); + + QEMU_LOCK_GUARD(&iohub->irq_level_lock[pirq]); + + if (iohub->irq_level[pirq]) { + event_notifier_set(&iohub->irqfds[pirq]); + } +} + +void process_set_irqfd_msg(PCIDevice *pci_dev, MPQemuMsg *msg) +{ + RemoteMachineState *machine = REMOTE_MACHINE(current_machine); + RemoteIOHubState *iohub = &machine->iohub; + int pirq, intx; + + intx = pci_get_byte(pci_dev->config + PCI_INTERRUPT_PIN) - 1; + + pirq = remote_iohub_map_irq(pci_dev, intx); + + if (event_notifier_get_fd(&iohub->irqfds[pirq]) != -1) { + qemu_set_fd_handler(event_notifier_get_fd(&iohub->resamplefds[pirq]), + NULL, NULL, NULL); + event_notifier_cleanup(&iohub->irqfds[pirq]); + event_notifier_cleanup(&iohub->resamplefds[pirq]); + memset(&iohub->token[pirq], 0, sizeof(ResampleToken)); + } + + event_notifier_init_fd(&iohub->irqfds[pirq], msg->fds[0]); + event_notifier_init_fd(&iohub->resamplefds[pirq], msg->fds[1]); + + iohub->token[pirq].iohub = iohub; + iohub->token[pirq].pirq = pirq; + + qemu_set_fd_handler(msg->fds[1], intr_resample_handler, NULL, + &iohub->token[pirq]); +} -- cgit v1.2.3