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[Qemu-devel] [PATCH v2 2/2] ivshmem: use irqfd to interrupt among VMs
From: |
Liu Ping Fan |
Subject: |
[Qemu-devel] [PATCH v2 2/2] ivshmem: use irqfd to interrupt among VMs |
Date: |
Sun, 25 Nov 2012 11:51:57 +0800 |
From: Liu Ping Fan <address@hidden>
Using irqfd, so we can avoid switch between kernel and user when
VMs interrupts each other.
Signed-off-by: Liu Ping Fan <address@hidden>
---
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
Re: [Qemu-devel] [PATCH v2 1/2] ivshmem: remove msix_write_config, liu ping fan, 2012/11/28