Make use of the new KVM feature that allows legacy interrupt sharing
for PCI-2.3-compliant devices. As exclusive mode (with IRQ masking at
interrupt controller level) is generally faster, the new mode has to be
enabled explicitly via the property "host_pci_2_3".
Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
---
hw/device-assignment.c | 37 ++++++++++++++++++++++++++++++-------
hw/device-assignment.h | 3 +++
qemu-kvm.c | 8 ++++++++
qemu-kvm.h | 3 +++
4 files changed, 44 insertions(+), 7 deletions(-)
diff --git a/hw/device-assignment.c b/hw/device-assignment.c
index 5f5bde1..30e05f1 100644
--- a/hw/device-assignment.c
+++ b/hw/device-assignment.c
@@ -404,12 +404,18 @@ static uint8_t pci_find_cap_offset(PCIDevice *d, uint8_t cap)
return 0;
}
+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 assigned_dev_pci_write_config(PCIDevice *d, uint32_t address,
uint32_t val, int len)
{
int fd;
ssize_t ret;
AssignedDevice *pci_dev = container_of(d, AssignedDevice, dev);
+ struct kvm_assigned_pci_dev assigned_dev_data;
DEBUG("(%x.%x): address=%04x val=0x%08x len=%d\n",
((d->devfn >> 3) & 0x1F), (d->devfn & 0x7),
@@ -417,6 +423,17 @@ static void assigned_dev_pci_write_config(PCIDevice *d, uint32_t address,
if (address == 0x4) {
pci_default_write_config(d, address, val, len);
+ pci_dev->intx_masked = val & PCI_COMMAND_INTX_DISABLE;
+#ifdef KVM_CAP_PCI_2_3
+ memset(&assigned_dev_data, 0, sizeof(assigned_dev_data));
+ assigned_dev_data.assigned_dev_id =
+ calc_assigned_dev_id(pci_dev->h_segnr, pci_dev->h_busnr,
+ pci_dev->h_devfn);
+ if (pci_dev->intx_masked) {
+ assigned_dev_data.flags = KVM_DEV_ASSIGN_MASK_INTX;
+ }
+ kvm_assign_set_intx_mask(kvm_context, &assigned_dev_data);
+#endif
/* Continue to program the card */
}
@@ -494,6 +511,10 @@ do_log:
else if (address == 6)
val &= ~0x10;
}
+ if (address == PCI_COMMAND) {
+ val &= ~PCI_COMMAND_INTX_DISABLE;
+ val |= pci_dev->intx_masked;
+ }
return val;
}
@@ -824,11 +845,6 @@ 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;
@@ -919,6 +935,11 @@ static int assign_device(AssignedDevice *dev)
"cause host memory corruption if the device issues DMA write "
"requests!\n");
}
+#ifdef KVM_CAP_PCI_2_3
+ if (dev->features & ASSIGNED_DEVICE_USE_PCI_2_3_MASK) {
+ assigned_dev_data.flags |= KVM_DEV_ASSIGN_PCI_2_3;
+ }
+#endif /* KVM_CAP_PCI_2_3 */
r = kvm_assign_pci_device(kvm_context, &assigned_dev_data);
if (r < 0) {
@@ -981,8 +1002,8 @@ static int assign_irq(AssignedDevice *dev)
if (r < 0) {
fprintf(stderr, "Failed to assign irq for \"%s\": %s\n",
dev->dev.qdev.id, strerror(-r));
- fprintf(stderr, "Perhaps you are assigning a device "
- "that shares an IRQ with another device?\n");
+ fprintf(stderr, "If the assigned device shares an IRQ with another "
+ "device, try host_pci_2_3=on.\n");
return r;
}
@@ -1554,6 +1575,8 @@ static PCIDeviceInfo assign_info = {
ASSIGNED_DEVICE_USE_IOMMU_BIT, true),
DEFINE_PROP_BIT("prefer_msi", AssignedDevice, features,
ASSIGNED_DEVICE_PREFER_MSI_BIT, true),
+ DEFINE_PROP_BIT("host_pci_2_3", AssignedDevice, features,
+ ASSIGNED_DEVICE_USE_PCI_2_3_BIT, false),
DEFINE_PROP_STRING("configfd", AssignedDevice, configfd_name),
DEFINE_PROP_END_OF_LIST(),
},
diff --git a/hw/device-assignment.h b/hw/device-assignment.h
index c94a730..71ba94c 100644
--- a/hw/device-assignment.h
+++ b/hw/device-assignment.h
@@ -76,15 +76,18 @@ typedef struct {
#define ASSIGNED_DEVICE_USE_IOMMU_BIT 0
#define ASSIGNED_DEVICE_PREFER_MSI_BIT 1
+#define ASSIGNED_DEVICE_USE_PCI_2_3_BIT 2
#define ASSIGNED_DEVICE_USE_IOMMU_MASK (1 << ASSIGNED_DEVICE_USE_IOMMU_BIT)
#define ASSIGNED_DEVICE_PREFER_MSI_MASK (1 << ASSIGNED_DEVICE_PREFER_MSI_BIT)
+#define ASSIGNED_DEVICE_USE_PCI_2_3_MASK (1 << ASSIGNED_DEVICE_USE_PCI_2_3_BIT)
typedef struct AssignedDevice {
PCIDevice dev;
PCIHostDevice host;
uint32_t features;
int intpin;
+ uint32_t intx_masked;
uint8_t debug_flags;
AssignedDevRegion v_addrs[PCI_NUM_REGIONS - 1];
PCIDevRegions real_device;
diff --git a/qemu-kvm.c b/qemu-kvm.c
index 471306b..8157b4f 100644
--- a/qemu-kvm.c
+++ b/qemu-kvm.c
@@ -740,6 +740,14 @@ int kvm_deassign_pci_device(kvm_context_t kvm,
}
#endif
+#ifdef KVM_CAP_PCI_2_3
+int kvm_assign_set_intx_mask(kvm_context_t kvm,
+ struct kvm_assigned_pci_dev *assigned_dev)
+{
+ return kvm_vm_ioctl(kvm_state, KVM_ASSIGN_SET_INTX_MASK, assigned_dev);
+}
+#endif
+
int kvm_reinject_control(kvm_context_t kvm, int pit_reinject)
{
#ifdef KVM_CAP_REINJECT_CONTROL
diff --git a/qemu-kvm.h b/qemu-kvm.h
index 0f3fb50..7f26f1a 100644
--- a/qemu-kvm.h
+++ b/qemu-kvm.h
@@ -631,6 +631,9 @@ int kvm_assign_set_msix_entry(kvm_context_t kvm,
struct kvm_assigned_msix_entry *entry);
#endif
+int kvm_assign_set_intx_mask(kvm_context_t kvm,
+ struct kvm_assigned_pci_dev *assigned_dev);
+
#else /* !CONFIG_KVM */
typedef struct kvm_context *kvm_context_t;
--
1.7.1
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