[PATCH 4/5] qemu-kvm: device assignment: emulate MSI-X mask bits

Sheng Yang
2010-10-20T08:28:51Z

This patch emulated MSI-X per vector mask bit on assigned device.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
---
hw/device-assignment.c | 151 ++++++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 145 insertions(+), 6 deletions(-)

diff --git a/hw/device-assignment.c b/hw/device-assignment.c
index 8a98876..d1a6282 100644
--- a/hw/device-assignment.c
+++ b/hw/device-assignment.c
@@ -62,6 +62,11 @@ static void assigned_dev_load_option_rom(AssignedDevice *dev);

static void assigned_dev_unregister_msix_mmio(AssignedDevice *dev);

+static uint32_t calc_assigned_dev_id(uint16_t seg, uint8_t bus, uint8_t devfn)
+{
+ return (uint32_t)seg << 16 | (uint32_t)bus << 8 | (uint32_t)devfn;
+}
+
static uint32_t assigned_dev_ioport_rw(AssignedDevRegion *dev_region,
uint32_t addr, int len, uint32_t *val)
{
@@ -824,11 +829,6 @@ static void free_assigned_device(AssignedDevice *dev)
}
}

-static uint32_t calc_assigned_dev_id(uint16_t seg, uint8_t bus, uint8_t devfn)
-{
- return (uint32_t)seg << 16 | (uint32_t)bus << 8 | (uint32_t)devfn;
-}
-
static void assign_failed_examine(AssignedDevice *dev)
{
char name[PATH_MAX], dir[PATH_MAX], driver[PATH_MAX] = {}, *ns;
@@ -1123,6 +1123,7 @@ static int get_msix_entries_max_nr(AssignedDevice *adev)
return entries_max_nr;
}

+#define MSIX_VECTOR_MASK 0x1
static int get_msix_valid_entries_nr(AssignedDevice *adev,
uint16_t entries_max_nr)
{
@@ -1136,7 +1137,11 @@ static int get_msix_valid_entries_nr(AssignedDevice *adev,
memcpy(&msg_ctrl, va + i * 16 + 12, 4);
memcpy(&msg_data, va + i * 16 + 8, 4);
/* Ignore unused entry even it's unmasked */
+#ifdef KVM_CAP_DEVICE_MSIX_MASK
+ if (msg_data == 0 || (msg_ctrl & MSIX_VECTOR_MASK))
+#else
if (msg_data == 0)
+#endif
continue;
entries_nr ++;
}
@@ -1165,6 +1170,8 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev,
}

free_dev_irq_entries(adev);
+ memset(pci_dev->msix_entry_used, 0, KVM_MAX_MSIX_PER_DEV *
+ sizeof(*pci_dev->msix_entry_used));
adev->irq_entries_nr = entries_nr;
adev->entry = calloc(entries_nr, sizeof(struct kvm_irq_routing_entry));
if (!adev->entry) {
@@ -1179,7 +1186,11 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev,
break;
memcpy(&msg_ctrl, va + i * 16 + 12, 4);
memcpy(&msg_data, va + i * 16 + 8, 4);
+#ifdef KVM_CAP_DEVICE_MSIX_MASK
+ if (msg_data == 0 || (msg_ctrl & MSIX_VECTOR_MASK))
+#else
if (msg_data == 0)
+#endif
continue;

memcpy(&msg_addr, va + i * 16, 4);
@@ -1200,6 +1211,7 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev,

msix_entry.gsi = adev->entry[entries_nr].gsi;
msix_entry.entry = i;
+ pci_dev->msix_entry_used[i] = 1;
r = kvm_assign_set_msix_entry(kvm_context, &msix_entry);
if (r) {
fprintf(stderr, "fail to set MSI-X entry! %s\n", strerror(-r));
@@ -1243,6 +1255,8 @@ static void assigned_dev_update_msix(PCIDevice *pci_dev, int enable_msix)
perror("assigned_dev_update_msix: deassign irq");

assigned_dev->irq_requested_type = 0;
+ memset(pci_dev->msix_entry_used, 0, KVM_MAX_MSIX_PER_DEV *
+ sizeof(*pci_dev->msix_entry_used));
}

entries_max_nr = get_msix_entries_max_nr(assigned_dev);
@@ -1250,10 +1264,16 @@ static void assigned_dev_update_msix(PCIDevice *pci_dev, int enable_msix)
fprintf(stderr, "assigned_dev_update_msix: MSI-X entries_max_nr == 0");
return;
}
+ /*
+ * Guest may try to enable MSI-X before setting MSI-X entry done, so
+ * let's wait until guest unmask the entries.
+ */
entries_nr = get_msix_valid_entries_nr(assigned_dev, entries_max_nr);
if (entries_nr == 0) {
+#ifndef KVM_CAP_DEVICE_MSIX_MASK
if (enable_msix)
fprintf(stderr, "MSI-X entry number is zero!\n");
+#endif
return;
}
if (enable_msix) {
@@ -1297,7 +1317,8 @@ static void assigned_device_pci_cap_write_config(PCIDevice *pci_dev, uint32_t ad
if (address <= ctrl_pos && address + len > ctrl_pos) {
ctrl_pos--; /* control is word long */
ctrl_word = (uint16_t *)(pci_dev->config + ctrl_pos);
- assigned_dev_update_msix(pci_dev, (*ctrl_word & PCI_MSIX_ENABLE));
+ assigned_dev_update_msix(pci_dev,
+ (*ctrl_word & PCI_MSIX_ENABLE) && !(*ctrl_word & PCI_MSIX_MASK));
}
pos += PCI_CAPABILITY_CONFIG_MSIX_LENGTH;
}
@@ -1389,6 +1410,104 @@ static uint32_t msix_mmio_readw(void *opaque, target_phys_addr_t addr)
(8 * (addr & 3))) & 0xffff;
}

+#ifdef KVM_CAP_DEVICE_MSIX_MASK
+static void msix_mmio_access_mask_bit(AssignedDevice *adev, int index)
+{
+ void *page = adev->msix_table_page;
+ uint32_t msg_ctrl, msg_data, msg_upper_addr, msg_addr;
+ struct kvm_assigned_msix_entry msix_entry;
+ int r = 0, pos, ctrl_word, entry_idx, entries_max_nr;
+ struct kvm_irq_routing_entry new_entry = {};
+
+ memcpy(&msg_addr, (char *)page + index * 16, 4);
+ memcpy(&msg_upper_addr, (char *)page + index * 16 + 4, 4);
+ memcpy(&msg_data, (char *)page + index * 16 + 8, 4);
+ memcpy(&msg_ctrl, (char *)page + index * 16 + 12, 4);
+ DEBUG("Access mask bit: MSI-X entries index %d: "
+ "msg_addr 0x%x, msg_upper_addr 0x%x, msg_data 0x%x, vec_ctl 0x%x\n",
+ index, msg_addr, msg_upper_addr, msg_data, msg_ctrl);
+
+ if (adev->cap.available & ASSIGNED_DEVICE_CAP_MSI)
+ pos = adev->dev.cap.start + PCI_CAPABILITY_CONFIG_MSI_LENGTH;
+ else
+ pos = adev->dev.cap.start;
+
+ ctrl_word = *(uint16_t *)(adev->dev.config + pos + 2);
+
+ if (!((ctrl_word & PCI_MSIX_ENABLE) && !(ctrl_word & PCI_MSIX_MASK)))
+ return;
+
+ if (!adev->dev.msix_entry_used[index]) {
+ if ((msg_ctrl & MSIX_VECTOR_MASK) == 0) {
+ DEBUG("Try to modify unenabled MSI-X entry %d's mask. "
+ "Reenable MSI-X.\n",
+ index);
+ assigned_dev_update_msix(&adev->dev, 1);
+ }
+ return;
+ }
+
+ /* find the correlated index of adev->entry */
+ entries_max_nr = get_msix_entries_max_nr(adev);
+ entry_idx = 0;
+ while (entry_idx < entries_max_nr) {
+ if (adev->dev.msix_entry_used[entry_idx] && entry_idx == index)
+ break;
+ entry_idx ++;
+ }
+ if (entry_idx >= entries_max_nr) {
+ fprintf(stderr, "msix_mmio_access_mask_bit: Entry idx exceed limit!\n");
+ return;
+ }
+
+ msix_entry.assigned_dev_id = calc_assigned_dev_id(adev->h_segnr,
+ adev->h_busnr,
+ (uint8_t)adev->h_devfn);
+ msix_entry.gsi = adev->entry[entry_idx].gsi;
+ msix_entry.entry = index;
+ if (msg_ctrl & MSIX_VECTOR_MASK)
+ msix_entry.flags = KVM_MSIX_FLAG_MASK;
+ else
+ msix_entry.flags = 0;
+ DEBUG("set MSI-X index %d, esi 0x%x, mask %d\n",
+ index, msix_entry.gsi, msix_entry.flags);
+ r = kvm_assign_set_msix_entry(kvm_context, &msix_entry);
+ if (r) {
+ perror("msix_mmio_access_mask_bit: "
+ "fail to set MSI-X entry!");
+ return;
+ }
+
+ if (msix_entry.flags == 0) {
+ new_entry.gsi = adev->entry[entry_idx].gsi;
+ new_entry.type = KVM_IRQ_ROUTING_MSI;
+ new_entry.flags = 0;
+ new_entry.u.msi.address_lo = msg_addr;
+ new_entry.u.msi.address_hi = msg_upper_addr;
+ new_entry.u.msi.data = msg_data;
+ if (memcmp(&adev->entry[entry_idx].u.msi, &new_entry.u.msi,
+ sizeof new_entry.u.msi)) {
+ int r;
+ r = kvm_update_routing_entry(&adev->entry[entry_idx], &new_entry);
+ if (r) {
+ perror("msix_mmio_access_mask_bit: "
+ "kvm_update_routing_entry failed\n");
+ return;
+ }
+ r = kvm_commit_irq_routes();
+ if (r) {
+ perror("msix_mmio_access_mask_bit: "
+ "kvm_commit_irq_routes failed\n");
+ return;
+ }
+ }
+ adev->entry[entry_idx].u.msi.address_lo = msg_addr;
+ adev->entry[entry_idx].u.msi.address_hi = msg_upper_addr;
+ adev->entry[entry_idx].u.msi.data = msg_data;
+ }
+}
+#endif
+
static void msix_mmio_writel(void *opaque,
target_phys_addr_t addr, uint32_t val)
{
@@ -1399,6 +1518,12 @@ static void msix_mmio_writel(void *opaque,
DEBUG("write to MSI-X entry table mmio offset 0x%lx, val 0x%x\n",
addr, val);
memcpy((void *)((char *)page + offset), &val, 4);
+
+#ifdef KVM_CAP_DEVICE_MSIX_MASK
+ /* Check if mask bit is being accessed */
+ if (offset % 16 == 12)
+ msix_mmio_access_mask_bit(adev, offset / 16);
+#endif
}

static void msix_mmio_writew(void *opaque,
@@ -1425,6 +1550,16 @@ static CPUReadMemoryFunc *msix_mmio_read[] = {

static int assigned_dev_register_msix_mmio(AssignedDevice *dev)
{
+#ifdef KVM_CAP_DEVICE_MSIX_MASK
+#ifndef KVM_CAP_DEVICE_MSIX_EXT
+#error
+#endif
+ /* Request for MSI-X masking support */
+ if (kvm_enable_cap(first_cpu, KVM_CAP_DEVICE_MSIX_EXT) != 0) {
+ fprintf(stderr, "fail to enable MSI-X extending support!\n");
+ return -EFAULT;
+ }
+#endif
dev->msix_table_page = mmap(NULL, 0x1000,
PROT_READ|PROT_WRITE,
MAP_ANONYMOUS|MAP_PRIVATE, 0, 0);
@@ -1436,6 +1571,8 @@ static int assigned_dev_register_msix_mmio(AssignedDevice *dev)
memset(dev->msix_table_page, 0, 0x1000);
dev->mmio_index = cpu_register_io_memory(
msix_mmio_read, msix_mmio_write, dev);
+ dev->dev.msix_entry_used = qemu_mallocz(KVM_MAX_MSIX_PER_DEV *
+ sizeof *dev->dev.msix_entry_used);
return 0;
}

@@ -1452,6 +1589,8 @@ static void assigned_dev_unregister_msix_mmio(AssignedDevice *dev)
strerror(errno));
}
dev->msix_table_page = NULL;
+ free(dev->dev.msix_entry_used);
+ dev->dev.msix_entry_used = NULL;
}

static int assigned_initfn(struct PCIDevice *pci_dev)
--
1.7.0.1