[PATCH 3/5] qemu-kvm: device assignment: Some clean up about MSI-X code

Sheng Yang
2010-11-11T07:51:34Z

Then the code can be easily reviewed.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
---
hw/device-assignment.c | 77 ++++++++++++++++++++++++++++++++---------------
1 files changed, 52 insertions(+), 25 deletions(-)

diff --git a/hw/device-assignment.c b/hw/device-assignment.c
index dfca764..5fe4a55 100644
--- a/hw/device-assignment.c
+++ b/hw/device-assignment.c
@@ -1108,15 +1108,10 @@ static void assigned_dev_update_msi(PCIDevice *pci_dev, unsigned int ctrl_pos)
#ifdef KVM_CAP_DEVICE_MSIX

#define PCI_MSIX_CTRL_MASKBIT 1ul
-static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
+static int get_msix_entries_max_nr(AssignedDevice *adev)
{
- AssignedDevice *adev = container_of(pci_dev, AssignedDevice, dev);
- uint16_t entries_nr = 0, entries_max_nr;
- int pos = 0, i, r = 0;
- uint32_t msg_addr, msg_upper_addr, msg_data, msg_ctrl;
- struct kvm_assigned_msix_nr msix_nr;
- struct kvm_assigned_msix_entry msix_entry;
- void *va = adev->msix_table_page;
+ int pos, entries_max_nr;
+ PCIDevice *pci_dev = &adev->dev;

if (adev->cap.available & ASSIGNED_DEVICE_CAP_MSI)
pos = pci_dev->cap.start + PCI_CAPABILITY_CONFIG_MSI_LENGTH;
@@ -1127,6 +1122,17 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
entries_max_nr &= PCI_MSIX_TABSIZE;
entries_max_nr += 1;

+ return entries_max_nr;
+}
+
+static int get_msix_valid_entries_nr(AssignedDevice *adev,
+ uint16_t entries_max_nr)
+{
+ void *va = adev->msix_table_page;
+ uint32_t msg_ctrl;
+ uint16_t entries_nr = 0;
+ int i;
+
/* Get the usable entry number for allocating */
for (i = 0; i < entries_max_nr; i++) {
memcpy(&msg_ctrl, va + i * 16 + 12, 4);
@@ -1135,11 +1141,20 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
continue;
entries_nr ++;
}
+ return entries_nr;
+}
+
+static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev,
+ uint16_t entries_nr,
+ uint16_t entries_max_nr)
+{
+ AssignedDevice *adev = container_of(pci_dev, AssignedDevice, dev);
+ int i, r = 0;
+ uint32_t msg_addr, msg_upper_addr, msg_data, msg_ctrl;
+ struct kvm_assigned_msix_nr msix_nr;
+ struct kvm_assigned_msix_entry msix_entry;
+ void *va = adev->msix_table_page;

- if (entries_nr == 0) {
- fprintf(stderr, "MSI-X entry number is zero!\n");
- return -EINVAL;
- }
msix_nr.assigned_dev_id = calc_assigned_dev_id(adev->h_segnr, adev->h_busnr,
(uint8_t)adev->h_devfn);
msix_nr.entry_nr = entries_nr;
@@ -1181,8 +1196,8 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
adev->entry[entries_nr].u.msi.address_lo = msg_addr;
adev->entry[entries_nr].u.msi.address_hi = msg_upper_addr;
adev->entry[entries_nr].u.msi.data = msg_data;
- DEBUG("MSI-X data 0x%x, MSI-X addr_lo 0x%x\n!", msg_data, msg_addr);
- kvm_add_routing_entry(&adev->entry[entries_nr]);
+ DEBUG("MSI-X data 0x%x, MSI-X addr_lo 0x%x!\n", msg_data, msg_addr);
+ kvm_add_routing_entry(&adev->entry[entries_nr]);

msix_entry.gsi = adev->entry[entries_nr].gsi;
msix_entry.entry = i;
@@ -1191,7 +1206,7 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
fprintf(stderr, "fail to set MSI-X entry! %s\n", strerror(-r));
break;
}
- DEBUG("MSI-X entry gsi 0x%x, entry %d\n!",
+ DEBUG("MSI-X entry gsi 0x%x, entry %d!\n",
msix_entry.gsi, msix_entry.entry);
entries_nr ++;
}
@@ -1204,12 +1219,12 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
return r;
}

-static void assigned_dev_update_msix(PCIDevice *pci_dev, unsigned int ctrl_pos)
+static void assigned_dev_update_msix(PCIDevice *pci_dev, int enable_msix)
{
struct kvm_assigned_irq assigned_irq_data;
AssignedDevice *assigned_dev = container_of(pci_dev, AssignedDevice, dev);
- uint16_t *ctrl_word = (uint16_t *)(pci_dev->config + ctrl_pos);
int r;
+ uint16_t entries_nr, entries_max_nr;

memset(&assigned_irq_data, 0, sizeof assigned_irq_data);
assigned_irq_data.assigned_dev_id =
@@ -1220,8 +1235,7 @@ static void assigned_dev_update_msix(PCIDevice *pci_dev, unsigned int ctrl_pos)
* try to catch this by only deassigning irqs if the guest is using
* MSIX or intends to start. */
if ((assigned_dev->irq_requested_type & KVM_DEV_IRQ_GUEST_MSIX) ||
- (*ctrl_word & PCI_MSIX_ENABLE)) {
-
+ enable_msix) {
assigned_irq_data.flags = assigned_dev->irq_requested_type;
free_dev_irq_entries(assigned_dev);
r = kvm_deassign_irq(kvm_context, &assigned_irq_data);
@@ -1232,14 +1246,25 @@ static void assigned_dev_update_msix(PCIDevice *pci_dev, unsigned int ctrl_pos)
assigned_dev->irq_requested_type = 0;
}

- if (*ctrl_word & PCI_MSIX_ENABLE) {
- assigned_irq_data.flags = KVM_DEV_IRQ_HOST_MSIX |
- KVM_DEV_IRQ_GUEST_MSIX;
-
- if (assigned_dev_update_msix_mmio(pci_dev) < 0) {
+ entries_max_nr = get_msix_entries_max_nr(assigned_dev);
+ if (entries_max_nr == 0) {
+ fprintf(stderr, "assigned_dev_update_msix: MSI-X entries_max_nr == 0");
+ return;
+ }
+ entries_nr = get_msix_valid_entries_nr(assigned_dev, entries_max_nr);
+ if (entries_nr == 0) {
+ if (enable_msix)
+ fprintf(stderr, "MSI-X entry number is zero!\n");
+ return;
+ }
+ if (enable_msix) {
+ if (assigned_dev_update_msix_mmio(pci_dev,
+ entries_nr, entries_max_nr) < 0) {
perror("assigned_dev_update_msix_mmio");
return;
}
+ assigned_irq_data.flags = KVM_DEV_IRQ_HOST_MSIX |
+ KVM_DEV_IRQ_GUEST_MSIX;
if (kvm_assign_irq(kvm_context, &assigned_irq_data) < 0) {
perror("assigned_dev_enable_msix: assign irq");
return;
@@ -1255,6 +1280,7 @@ static void assigned_device_pci_cap_write_config(PCIDevice *pci_dev, uint32_t ad
{
AssignedDevice *assigned_dev = container_of(pci_dev, AssignedDevice, dev);
unsigned int pos = pci_dev->cap.start, ctrl_pos;
+ uint16_t *ctrl_word;

pci_default_cap_write_config(pci_dev, address, val, len);
#ifdef KVM_CAP_IRQ_ROUTING
@@ -1271,7 +1297,8 @@ static void assigned_device_pci_cap_write_config(PCIDevice *pci_dev, uint32_t ad
ctrl_pos = pos + 3;
if (address <= ctrl_pos && address + len > ctrl_pos) {
ctrl_pos--; /* control is word long */
- assigned_dev_update_msix(pci_dev, ctrl_pos);
+ ctrl_word = (uint16_t *)(pci_dev->config + ctrl_pos);
+ assigned_dev_update_msix(pci_dev, (*ctrl_word & PCI_MSIX_ENABLE));
}
pos += PCI_CAPABILITY_CONFIG_MSIX_LENGTH;
}
--
1.7.0.1