[PATCHv3 10/13] qemu: MSI-X support in virtio PCI

Michael S. Tsirkin
2009-06-05T10:27:16Z

This enables actual support for MSI-X in virtio PCI.
First user will be virtio-net.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
hw/virtio-pci.c | 152 ++++++++++++++++++++++++++++++++++++++++--------------
1 files changed, 112 insertions(+), 40 deletions(-)

diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index 7dfdd80..294f4c7 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -18,6 +18,7 @@
#include "virtio.h"
#include "pci.h"
//#include "sysemu.h"
+#include "msix.h"

/* from Linux's linux/virtio_pci.h */

@@ -47,7 +48,24 @@
* a read-and-acknowledge. */
#define VIRTIO_PCI_ISR 19

-#define VIRTIO_PCI_CONFIG 20
+/* MSI-X registers: only enabled if MSI-X is enabled. */
+/* A 16-bit vector for configuration changes. */
+#define VIRTIO_MSI_CONFIG_VECTOR 20
+/* A 16-bit vector for selected queue notifications. */
+#define VIRTIO_MSI_QUEUE_VECTOR 22
+
+/* Config space size */
+#define VIRTIO_PCI_CONFIG_NOMSI 20
+#define VIRTIO_PCI_CONFIG_MSI 24
+#define VIRTIO_PCI_REGION_SIZE(dev) (msix_present(dev) ? \
+ VIRTIO_PCI_CONFIG_MSI : \
+ VIRTIO_PCI_CONFIG_NOMSI)
+
+/* The remaining space is defined by each driver as the per-driver
+ * configuration space */
+#define VIRTIO_PCI_CONFIG(dev) (msix_enabled(dev) ? \
+ VIRTIO_PCI_CONFIG_MSI : \
+ VIRTIO_PCI_CONFIG_NOMSI)

/* Virtio ABI version, if we increment this, we break the guest driver. */
#define VIRTIO_PCI_ABI_VERSION 0
@@ -81,14 +99,17 @@ typedef struct {
static void virtio_pci_notify(void *opaque, uint16_t vector)
{
VirtIOPCIProxy *proxy = opaque;
-
- qemu_set_irq(proxy->pci_dev.irq[0], proxy->vdev->isr & 1);
+ if (msix_enabled(&proxy->pci_dev))
+ msix_notify(&proxy->pci_dev, vector);
+ else
+ qemu_set_irq(proxy->pci_dev.irq[0], proxy->vdev->isr & 1);
}

static void virtio_pci_reset(void *opaque)
{
VirtIOPCIProxy *proxy = opaque;
virtio_reset(proxy->vdev);
+ msix_reset(&proxy->pci_dev);
}

static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val)
@@ -97,8 +118,6 @@ static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val)
VirtIODevice *vdev = proxy->vdev;
target_phys_addr_t pa;

- addr -= proxy->addr;
-
switch (addr) {
case VIRTIO_PCI_GUEST_FEATURES:
/* Guest does not negotiate properly? We have to assume nothing. */
@@ -131,17 +150,33 @@ static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val)
if (vdev->status == 0)
virtio_pci_reset(proxy);
break;
+ case VIRTIO_MSI_CONFIG_VECTOR:
+ msix_vector_unuse(&proxy->pci_dev, vdev->config_vector);
+ /* Make it possible for guest to discover an error took place. */
+ if (msix_vector_use(&proxy->pci_dev, val) < 0)
+ val = VIRTIO_NO_VECTOR;
+ vdev->config_vector = val;
+ break;
+ case VIRTIO_MSI_QUEUE_VECTOR:
+ msix_vector_unuse(&proxy->pci_dev,
+ virtio_queue_vector(vdev, vdev->queue_sel));
+ /* Make it possible for guest to discover an error took place. */
+ if (msix_vector_use(&proxy->pci_dev, val) < 0)
+ val = VIRTIO_NO_VECTOR;
+ virtio_queue_set_vector(vdev, vdev->queue_sel, val);
+ break;
+ default:
+ fprintf(stderr, "%s: unexpected address 0x%x value 0x%x\n",
+ __func__, addr, val);
+ break;
}
}

-static uint32_t virtio_ioport_read(void *opaque, uint32_t addr)
+static uint32_t virtio_ioport_read(VirtIOPCIProxy *proxy, uint32_t addr)
{
- VirtIOPCIProxy *proxy = opaque;
VirtIODevice *vdev = proxy->vdev;
uint32_t ret = 0xFFFFFFFF;

- addr -= proxy->addr;
-
switch (addr) {
case VIRTIO_PCI_HOST_FEATURES:
ret = vdev->get_features(vdev);
@@ -169,6 +204,12 @@ static uint32_t virtio_ioport_read(void *opaque, uint32_t addr)
vdev->isr = 0;
qemu_set_irq(proxy->pci_dev.irq[0], 0);
break;
+ case VIRTIO_MSI_CONFIG_VECTOR:
+ ret = vdev->config_vector;
+ break;
+ case VIRTIO_MSI_QUEUE_VECTOR:
+ ret = virtio_queue_vector(vdev, vdev->queue_sel);
+ break;
default:
break;
}
@@ -179,42 +220,72 @@ static uint32_t virtio_ioport_read(void *opaque, uint32_t addr)
static uint32_t virtio_pci_config_readb(void *opaque, uint32_t addr)
{
VirtIOPCIProxy *proxy = opaque;
- addr -= proxy->addr + VIRTIO_PCI_CONFIG;
+ uint32_t config = VIRTIO_PCI_CONFIG(&proxy->pci_dev);
+ addr -= proxy->addr;
+ if (addr < config)
+ return virtio_ioport_read(proxy, addr);
+ addr -= config;
return virtio_config_readb(proxy->vdev, addr);
}

static uint32_t virtio_pci_config_readw(void *opaque, uint32_t addr)
{
VirtIOPCIProxy *proxy = opaque;
- addr -= proxy->addr + VIRTIO_PCI_CONFIG;
+ uint32_t config = VIRTIO_PCI_CONFIG(&proxy->pci_dev);
+ addr -= proxy->addr;
+ if (addr < config)
+ return virtio_ioport_read(proxy, addr);
+ addr -= config;
return virtio_config_readw(proxy->vdev, addr);
}

static uint32_t virtio_pci_config_readl(void *opaque, uint32_t addr)
{
VirtIOPCIProxy *proxy = opaque;
- addr -= proxy->addr + VIRTIO_PCI_CONFIG;
+ uint32_t config = VIRTIO_PCI_CONFIG(&proxy->pci_dev);
+ addr -= proxy->addr;
+ if (addr < config)
+ return virtio_ioport_read(proxy, addr);
+ addr -= config;
return virtio_config_readl(proxy->vdev, addr);
}

static void virtio_pci_config_writeb(void *opaque, uint32_t addr, uint32_t val)
{
VirtIOPCIProxy *proxy = opaque;
- addr -= proxy->addr + VIRTIO_PCI_CONFIG;
+ uint32_t config = VIRTIO_PCI_CONFIG(&proxy->pci_dev);
+ addr -= proxy->addr;
+ if (addr < config) {
+ virtio_ioport_write(proxy, addr, val);
+ return;
+ }
+ addr -= config;
virtio_config_writeb(proxy->vdev, addr, val);
}

static void virtio_pci_config_writew(void *opaque, uint32_t addr, uint32_t val)
{
VirtIOPCIProxy *proxy = opaque;
- addr -= proxy->addr + VIRTIO_PCI_CONFIG;
+ uint32_t config = VIRTIO_PCI_CONFIG(&proxy->pci_dev);
+ addr -= proxy->addr;
+ if (addr < config) {
+ virtio_ioport_write(proxy, addr, val);
+ return;
+ }
+ addr -= config;
virtio_config_writew(proxy->vdev, addr, val);
}

static void virtio_pci_config_writel(void *opaque, uint32_t addr, uint32_t val)
{
VirtIOPCIProxy *proxy = opaque;
- addr -= proxy->addr + VIRTIO_PCI_CONFIG;
+ uint32_t config = VIRTIO_PCI_CONFIG(&proxy->pci_dev);
+ addr -= proxy->addr;
+ if (addr < config) {
+ virtio_ioport_write(proxy, addr, val);
+ return;
+ }
+ addr -= config;
virtio_config_writel(proxy->vdev, addr, val);
}

@@ -223,32 +294,26 @@ static void virtio_map(PCIDevice *pci_dev, int region_num,
{
VirtIOPCIProxy *proxy = container_of(pci_dev, VirtIOPCIProxy, pci_dev);
VirtIODevice *vdev = proxy->vdev;
- int i;
+ unsigned config_len = VIRTIO_PCI_REGION_SIZE(pci_dev) + vdev->config_len;

proxy->addr = addr;
- for (i = 0; i < 3; i++) {
- register_ioport_write(addr, VIRTIO_PCI_CONFIG, 1 << i,
- virtio_ioport_write, proxy);
- register_ioport_read(addr, VIRTIO_PCI_CONFIG, 1 << i,
- virtio_ioport_read, proxy);
- }

- if (vdev->config_len) {
- register_ioport_write(addr + VIRTIO_PCI_CONFIG, vdev->config_len, 1,
- virtio_pci_config_writeb, proxy);
- register_ioport_write(addr + VIRTIO_PCI_CONFIG, vdev->config_len, 2,
- virtio_pci_config_writew, proxy);
- register_ioport_write(addr + VIRTIO_PCI_CONFIG, vdev->config_len, 4,
- virtio_pci_config_writel, proxy);
- register_ioport_read(addr + VIRTIO_PCI_CONFIG, vdev->config_len, 1,
- virtio_pci_config_readb, proxy);
- register_ioport_read(addr + VIRTIO_PCI_CONFIG, vdev->config_len, 2,
- virtio_pci_config_readw, proxy);
- register_ioport_read(addr + VIRTIO_PCI_CONFIG, vdev->config_len, 4,
- virtio_pci_config_readl, proxy);
+ register_ioport_write(addr, config_len, 1, virtio_pci_config_writeb, proxy);
+ register_ioport_write(addr, config_len, 2, virtio_pci_config_writew, proxy);
+ register_ioport_write(addr, config_len, 4, virtio_pci_config_writel, proxy);
+ register_ioport_read(addr, config_len, 1, virtio_pci_config_readb, proxy);
+ register_ioport_read(addr, config_len, 2, virtio_pci_config_readw, proxy);
+ register_ioport_read(addr, config_len, 4, virtio_pci_config_readl, proxy);

+ if (vdev->config_len)
vdev->get_config(vdev, vdev->config);
- }
+}
+
+static void virtio_write_config(PCIDevice *pci_dev, uint32_t address,
+ uint32_t val, int len)
+{
+ pci_default_write_config(pci_dev, address, val, len);
+ msix_write_config(pci_dev, address, val, len);
}

static const VirtIOBindings virtio_pci_bindings = {
@@ -264,9 +329,6 @@ static void virtio_init_pci(VirtIOPCIProxy *proxy, VirtIODevice *vdev,

proxy->vdev = vdev;

- /* No support for multiple vectors yet. */
- proxy->vdev->nvectors = 0;
-
config = proxy->pci_dev.config;
pci_config_set_vendor_id(config, vendor);
pci_config_set_device_id(config, device);
@@ -284,7 +346,17 @@ static void virtio_init_pci(VirtIOPCIProxy *proxy, VirtIODevice *vdev,

config[0x3d] = 1;

- size = 20 + vdev->config_len;
+ if (vdev->nvectors && !msix_init(&proxy->pci_dev, vdev->nvectors, 1, 0)) {
+ pci_register_io_region(&proxy->pci_dev, 1,
+ msix_bar_size(&proxy->pci_dev),
+ PCI_ADDRESS_SPACE_MEM,
+ msix_mmio_map);
+ proxy->pci_dev.config_write = virtio_write_config;
+ proxy->pci_dev.unregister = msix_uninit;
+ } else
+ vdev->nvectors = 0;
+
+ size = VIRTIO_PCI_REGION_SIZE(&proxy->pci_dev) + vdev->config_len;
if (size & (size-1))
size = 1 << qemu_fls(size);

--
1.6.3.1.56.g79e1.dirty