ivshmem: use kvm irqfd for msi notifications
Use irqfd for improving context switch when notifying the guest. If the host doesn't support kvm irqfd, regular msi notifications are still supported. Note: the ivshmem implementation doesn't allow switching between MSI and IO interrupts, this patch doesn't either. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Marc-André Lureau
parent
0f57350e5c
commit
660c97eef6
@ -19,6 +19,7 @@
|
||||
#include "hw/hw.h"
|
||||
#include "hw/i386/pc.h"
|
||||
#include "hw/pci/pci.h"
|
||||
#include "hw/pci/msi.h"
|
||||
#include "hw/pci/msix.h"
|
||||
#include "sysemu/kvm.h"
|
||||
#include "migration/migration.h"
|
||||
@ -68,6 +69,7 @@ typedef struct Peer {
|
||||
|
||||
typedef struct MSIVector {
|
||||
PCIDevice *pdev;
|
||||
int virq;
|
||||
} MSIVector;
|
||||
|
||||
typedef struct IVShmemState {
|
||||
@ -293,13 +295,73 @@ static void fake_irqfd(void *opaque, const uint8_t *buf, int size) {
|
||||
msix_notify(pdev, vector);
|
||||
}
|
||||
|
||||
static int ivshmem_vector_unmask(PCIDevice *dev, unsigned vector,
|
||||
MSIMessage msg)
|
||||
{
|
||||
IVShmemState *s = IVSHMEM(dev);
|
||||
EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
|
||||
MSIVector *v = &s->msi_vectors[vector];
|
||||
int ret;
|
||||
|
||||
IVSHMEM_DPRINTF("vector unmask %p %d\n", dev, vector);
|
||||
|
||||
ret = kvm_irqchip_update_msi_route(kvm_state, v->virq, msg, dev);
|
||||
if (ret < 0) {
|
||||
return ret;
|
||||
}
|
||||
|
||||
return kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL, v->virq);
|
||||
}
|
||||
|
||||
static void ivshmem_vector_mask(PCIDevice *dev, unsigned vector)
|
||||
{
|
||||
IVShmemState *s = IVSHMEM(dev);
|
||||
EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
|
||||
int ret;
|
||||
|
||||
IVSHMEM_DPRINTF("vector mask %p %d\n", dev, vector);
|
||||
|
||||
ret = kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n,
|
||||
s->msi_vectors[vector].virq);
|
||||
if (ret != 0) {
|
||||
error_report("remove_irqfd_notifier_gsi failed");
|
||||
}
|
||||
}
|
||||
|
||||
static void ivshmem_vector_poll(PCIDevice *dev,
|
||||
unsigned int vector_start,
|
||||
unsigned int vector_end)
|
||||
{
|
||||
IVShmemState *s = IVSHMEM(dev);
|
||||
unsigned int vector;
|
||||
|
||||
IVSHMEM_DPRINTF("vector poll %p %d-%d\n", dev, vector_start, vector_end);
|
||||
|
||||
vector_end = MIN(vector_end, s->vectors);
|
||||
|
||||
for (vector = vector_start; vector < vector_end; vector++) {
|
||||
EventNotifier *notifier = &s->peers[s->vm_id].eventfds[vector];
|
||||
|
||||
if (!msix_is_masked(dev, vector)) {
|
||||
continue;
|
||||
}
|
||||
|
||||
if (event_notifier_test_and_clear(notifier)) {
|
||||
msix_set_pending(dev, vector);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
static CharDriverState* create_eventfd_chr_device(void * opaque, EventNotifier *n,
|
||||
int vector)
|
||||
{
|
||||
/* create a event character device based on the passed eventfd */
|
||||
IVShmemState *s = opaque;
|
||||
CharDriverState * chr;
|
||||
PCIDevice *pdev = PCI_DEVICE(s);
|
||||
int eventfd = event_notifier_get_fd(n);
|
||||
CharDriverState *chr;
|
||||
|
||||
s->msi_vectors[vector].pdev = pdev;
|
||||
|
||||
chr = qemu_chr_open_eventfd(eventfd);
|
||||
|
||||
@ -484,6 +546,58 @@ static bool fifo_update_and_get(IVShmemState *s, const uint8_t *buf, int size,
|
||||
return true;
|
||||
}
|
||||
|
||||
static int ivshmem_add_kvm_msi_virq(IVShmemState *s, int vector)
|
||||
{
|
||||
PCIDevice *pdev = PCI_DEVICE(s);
|
||||
MSIMessage msg = msix_get_message(pdev, vector);
|
||||
int ret;
|
||||
|
||||
IVSHMEM_DPRINTF("ivshmem_add_kvm_msi_virq vector:%d\n", vector);
|
||||
|
||||
if (s->msi_vectors[vector].pdev != NULL) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
ret = kvm_irqchip_add_msi_route(kvm_state, msg, pdev);
|
||||
if (ret < 0) {
|
||||
error_report("ivshmem: kvm_irqchip_add_msi_route failed");
|
||||
return -1;
|
||||
}
|
||||
|
||||
s->msi_vectors[vector].virq = ret;
|
||||
s->msi_vectors[vector].pdev = pdev;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void setup_interrupt(IVShmemState *s, int vector)
|
||||
{
|
||||
EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
|
||||
bool with_irqfd = kvm_msi_via_irqfd_enabled() &&
|
||||
ivshmem_has_feature(s, IVSHMEM_MSI);
|
||||
PCIDevice *pdev = PCI_DEVICE(s);
|
||||
|
||||
IVSHMEM_DPRINTF("setting up interrupt for vector: %d\n", vector);
|
||||
|
||||
if (!with_irqfd) {
|
||||
IVSHMEM_DPRINTF("with eventfd");
|
||||
s->eventfd_chr[vector] = create_eventfd_chr_device(s, n, vector);
|
||||
} else if (msix_enabled(pdev)) {
|
||||
IVSHMEM_DPRINTF("with irqfd");
|
||||
if (ivshmem_add_kvm_msi_virq(s, vector) < 0) {
|
||||
return;
|
||||
}
|
||||
|
||||
if (!msix_is_masked(pdev, vector)) {
|
||||
kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL,
|
||||
s->msi_vectors[vector].virq);
|
||||
}
|
||||
} else {
|
||||
/* it will be delayed until msix is enabled, in write_config */
|
||||
IVSHMEM_DPRINTF("with irqfd, delayed until msix enabled");
|
||||
}
|
||||
}
|
||||
|
||||
static void ivshmem_read(void *opaque, const uint8_t *buf, int size)
|
||||
{
|
||||
IVShmemState *s = opaque;
|
||||
@ -586,11 +700,10 @@ static void ivshmem_read(void *opaque, const uint8_t *buf, int size)
|
||||
IVSHMEM_DPRINTF("eventfds[%ld][%d] = %d\n", incoming_posn,
|
||||
new_eventfd, incoming_fd);
|
||||
event_notifier_init_fd(&peer->eventfds[new_eventfd], incoming_fd);
|
||||
fcntl_setfl(incoming_fd, O_NONBLOCK); /* msix/irqfd poll non block */
|
||||
|
||||
if (incoming_posn == s->vm_id) {
|
||||
s->eventfd_chr[new_eventfd] = create_eventfd_chr_device(s,
|
||||
&s->peers[s->vm_id].eventfds[new_eventfd],
|
||||
new_eventfd);
|
||||
setup_interrupt(s, new_eventfd);
|
||||
}
|
||||
|
||||
if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
|
||||
@ -665,10 +778,65 @@ static int ivshmem_setup_msi(IVShmemState * s)
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void ivshmem_write_config(PCIDevice *pci_dev, uint32_t address,
|
||||
static void ivshmem_enable_irqfd(IVShmemState *s)
|
||||
{
|
||||
PCIDevice *pdev = PCI_DEVICE(s);
|
||||
int i;
|
||||
|
||||
for (i = 0; i < s->peers[s->vm_id].nb_eventfds; i++) {
|
||||
ivshmem_add_kvm_msi_virq(s, i);
|
||||
}
|
||||
|
||||
if (msix_set_vector_notifiers(pdev,
|
||||
ivshmem_vector_unmask,
|
||||
ivshmem_vector_mask,
|
||||
ivshmem_vector_poll)) {
|
||||
error_report("ivshmem: msix_set_vector_notifiers failed");
|
||||
}
|
||||
}
|
||||
|
||||
static void ivshmem_remove_kvm_msi_virq(IVShmemState *s, int vector)
|
||||
{
|
||||
IVSHMEM_DPRINTF("ivshmem_remove_kvm_msi_virq vector:%d\n", vector);
|
||||
|
||||
if (s->msi_vectors[vector].pdev == NULL) {
|
||||
return;
|
||||
}
|
||||
|
||||
/* it was cleaned when masked in the frontend. */
|
||||
kvm_irqchip_release_virq(kvm_state, s->msi_vectors[vector].virq);
|
||||
|
||||
s->msi_vectors[vector].pdev = NULL;
|
||||
}
|
||||
|
||||
static void ivshmem_disable_irqfd(IVShmemState *s)
|
||||
{
|
||||
PCIDevice *pdev = PCI_DEVICE(s);
|
||||
int i;
|
||||
|
||||
for (i = 0; i < s->peers[s->vm_id].nb_eventfds; i++) {
|
||||
ivshmem_remove_kvm_msi_virq(s, i);
|
||||
}
|
||||
|
||||
msix_unset_vector_notifiers(pdev);
|
||||
}
|
||||
|
||||
static void ivshmem_write_config(PCIDevice *pdev, uint32_t address,
|
||||
uint32_t val, int len)
|
||||
{
|
||||
pci_default_write_config(pci_dev, address, val, len);
|
||||
IVShmemState *s = IVSHMEM(pdev);
|
||||
int is_enabled, was_enabled = msix_enabled(pdev);
|
||||
|
||||
pci_default_write_config(pdev, address, val, len);
|
||||
is_enabled = msix_enabled(pdev);
|
||||
|
||||
if (kvm_msi_via_irqfd_enabled() && s->vm_id != -1) {
|
||||
if (!was_enabled && is_enabled) {
|
||||
ivshmem_enable_irqfd(s);
|
||||
} else if (was_enabled && !is_enabled) {
|
||||
ivshmem_disable_irqfd(s);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
static void pci_ivshmem_realize(PCIDevice *dev, Error **errp)
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user