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[Qemu-devel] [PATCH] ivshmem: use irqfd to interrupt among VMs
From: |
Liu Ping Fan |
Subject: |
[Qemu-devel] [PATCH] ivshmem: use irqfd to interrupt among VMs |
Date: |
Wed, 21 Nov 2012 14:02:31 +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 | 48 +++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 47 insertions(+), 1 deletions(-)
diff --git a/hw/ivshmem.c b/hw/ivshmem.c
index f6dbb21..81c7354 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"
@@ -54,6 +55,11 @@ typedef struct EventfdEntry {
int vector;
} EventfdEntry;
+typedef struct IrqfdEntry {
+ int virq;
+ bool used;
+} IrqfdEntry;
+
typedef struct IVShmemState {
PCIDevice dev;
uint32_t intrmask;
@@ -83,6 +89,8 @@ typedef struct IVShmemState {
uint32_t vectors;
uint32_t features;
EventfdEntry *eventfd_table;
+ IrqfdEntry *vector_irqfd;
+ bool irqfd_enable;
Error *migration_blocker;
@@ -632,6 +640,38 @@ static void ivshmem_write_config(PCIDevice *pci_dev,
uint32_t address,
msix_write_config(pci_dev, address, val, len);
}
+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_irqfd[vector].virq = virq;
+ s->vector_irqfd[vector].used = true;
+ qemu_chr_add_handlers(s->eventfd_chr[vector], NULL, NULL, NULL, NULL);
+ } else if (virq >= 0) {
+ kvm_irqchip_release_virq(kvm_state, virq);
+ }
+ 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_irqfd[vector].virq;
+
+ if (s->vector_irqfd[vector].used) {
+ kvm_irqchip_remove_irqfd_notifier(kvm_state, n, virq);
+ kvm_irqchip_release_virq(kvm_state, virq);
+ s->vector_irqfd[vector].virq = -1;
+ s->vector_irqfd[vector].used = false;
+ }
+}
+
static int pci_ivshmem_init(PCIDevice *dev)
{
IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);
@@ -759,7 +799,13 @@ static int pci_ivshmem_init(PCIDevice *dev)
}
s->dev.config_write = ivshmem_write_config;
-
+ if (kvm_gsi_routing_enabled()) {
+ s->irqfd_enable = msix_set_vector_notifiers(dev, ivshmem_vector_use,
+ ivshmem_vector_release) >= 0 ? true : false;
+ if (s->irqfd_enable) {
+ s->vector_irqfd = g_new0(IrqfdEntry, s->vectors);
+ }
+ }
return 0;
}
--
1.7.4.4
- [Qemu-devel] [PATCH] ivshmem: use irqfd to interrupt among VMs,
Liu Ping Fan <=