From: Liu Ping Fan <pingf...@linux.vnet.ibm.com> Using irqfd, so we can avoid switch between kernel and user when VMs interrupts each other.
Signed-off-by: Liu Ping Fan <pingf...@linux.vnet.ibm.com> --- hw/ivshmem.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 53 insertions(+), 1 deletions(-) diff --git a/hw/ivshmem.c b/hw/ivshmem.c index 7c8630c..5709e89 100644 --- a/hw/ivshmem.c +++ b/hw/ivshmem.c @@ -19,6 +19,7 @@ #include "hw.h" #include "pc.h" #include "pci.h" +#include "msi.h" #include "msix.h" #include "kvm.h" #include "migration.h" @@ -83,6 +84,7 @@ typedef struct IVShmemState { uint32_t vectors; uint32_t features; EventfdEntry *eventfd_table; + int *vector_virqs; Error *migration_blocker; @@ -625,16 +627,62 @@ static int ivshmem_load(QEMUFile* f, void *opaque, int version_id) return 0; } +static int ivshmem_vector_use(PCIDevice *dev, unsigned vector, + MSIMessage msg) +{ + IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev); + int virq; + EventNotifier *n = &s->peers[s->vm_id].eventfds[vector]; + + virq = kvm_irqchip_add_msi_route(kvm_state, msg); + if (virq >= 0 && kvm_irqchip_add_irqfd_notifier(kvm_state, n, virq) >= 0) { + s->vector_virqs[vector] = virq; + qemu_chr_add_handlers(s->eventfd_chr[vector], NULL, NULL, NULL, NULL); + } else if (virq >= 0) { + kvm_irqchip_release_virq(kvm_state, virq); + error_report("ivshmem, can not setup irqfd\n"); + return -1; + } else { + error_report("ivshmem, no enough msi route to setup irqfd\n"); + return -1; + } + + return 0; +} + +static void ivshmem_vector_release(PCIDevice *dev, unsigned vector) +{ + IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev); + EventNotifier *n = &s->peers[s->vm_id].eventfds[vector]; + int virq = s->vector_virqs[vector]; + + if (s->vector_virqs[vector] >= 0) { + kvm_irqchip_remove_irqfd_notifier(kvm_state, n, virq); + kvm_irqchip_release_virq(kvm_state, virq); + s->vector_virqs[vector] = -1; + } +} + static void ivshmem_write_config(PCIDevice *pci_dev, uint32_t address, uint32_t val, int len) { + bool is_enabled, was_enabled = msi_enabled(pci_dev); + pci_default_write_config(pci_dev, address, val, len); + is_enabled = msi_enabled(pci_dev); + if (!was_enabled && is_enabled) { + msix_set_vector_notifiers(pci_dev, ivshmem_vector_use, + ivshmem_vector_release); + } else if (was_enabled && !is_enabled) { + msix_unset_vector_notifiers(pci_dev); + } } static int pci_ivshmem_init(PCIDevice *dev) { IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev); uint8_t *pci_conf; + int i; if (s->sizearg == NULL) s->ivshmem_size = 4 << 20; /* 4 MB default */ @@ -758,7 +806,10 @@ static int pci_ivshmem_init(PCIDevice *dev) } s->dev.config_write = ivshmem_write_config; - + s->vector_virqs = g_new0(int, s->vectors); + for (i = 0; i < s->vectors; i++) { + s->vector_virqs[i] = -1; + } return 0; } @@ -770,6 +821,7 @@ static void pci_ivshmem_uninit(PCIDevice *dev) migrate_del_blocker(s->migration_blocker); error_free(s->migration_blocker); } + g_free(s->vector_virqs); memory_region_destroy(&s->ivshmem_mmio); memory_region_del_subregion(&s->bar, &s->ivshmem); -- 1.7.4.4