[PATCH 8/8] KVM: Emulation MSI-X mask bits for assigned devices

Sheng Yang
2010-10-20T08:25:33Z

This patch enable per-vector mask for assigned devices using MSI-X.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
---
Documentation/kvm/api.txt | 22 ++++++++++++++++
arch/x86/kvm/x86.c | 6 ++++
include/linux/kvm.h | 8 +++++-
virt/kvm/assigned-dev.c | 60 +++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 95 insertions(+), 1 deletions(-)

diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt
index d82d637..f324a50 100644
--- a/Documentation/kvm/api.txt
+++ b/Documentation/kvm/api.txt
@@ -1087,6 +1087,28 @@ of 4 instructions that make up a hypercall.
If any additional field gets added to this structure later on, a bit for that
additional piece of information will be set in the flags bitmap.

+4.47 KVM_ASSIGN_REG_MSIX_MMIO
+
+Capability: KVM_CAP_DEVICE_MSIX_MASK
+Architectures: x86
+Type: vm ioctl
+Parameters: struct kvm_assigned_msix_mmio (in)
+Returns: 0 on success, !0 on error
+
+struct kvm_assigned_msix_mmio {
+ /* Assigned device's ID */
+ __u32 assigned_dev_id;
+ /* MSI-X table MMIO address */
+ __u64 base_addr;
+ /* Must be 0 */
+ __u32 flags;
+ /* Must be 0, reserved for future use */
+ __u64 reserved;
+};
+
+This ioctl would enable in-kernel MSI-X emulation, which would handle MSI-X
+mask bit in the kernel.
+
5. The kvm_run structure

Application code obtains a pointer to the kvm_run structure by
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fc62546..ba07a2f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1927,6 +1927,8 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_X86_ROBUST_SINGLESTEP:
case KVM_CAP_XSAVE:
case KVM_CAP_ENABLE_CAP:
+ case KVM_CAP_DEVICE_MSIX_EXT:
+ case KVM_CAP_DEVICE_MSIX_MASK:
r = 1;
break;
case KVM_CAP_COALESCED_MMIO:
@@ -2717,6 +2719,10 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
return -EINVAL;

switch (cap->cap) {
+ case KVM_CAP_DEVICE_MSIX_EXT:
+ vcpu->kvm->arch.msix_flags_enabled = true;
+ r = 0;
+ break;
default:
r = -EINVAL;
break;
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 0a7bd34..1494ed0 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -540,6 +540,10 @@ struct kvm_ppc_pvinfo {
#endif
#define KVM_CAP_PPC_GET_PVINFO 57
#define KVM_CAP_PPC_IRQ_LEVEL 58
+#ifdef __KVM_HAVE_MSIX
+#define KVM_CAP_DEVICE_MSIX_EXT 59
+#define KVM_CAP_DEVICE_MSIX_MASK 60
+#endif

#ifdef KVM_CAP_IRQ_ROUTING

@@ -671,6 +675,8 @@ struct kvm_clock_data {
#define KVM_XEN_HVM_CONFIG _IOW(KVMIO, 0x7a, struct kvm_xen_hvm_config)
#define KVM_SET_CLOCK _IOW(KVMIO, 0x7b, struct kvm_clock_data)
#define KVM_GET_CLOCK _IOR(KVMIO, 0x7c, struct kvm_clock_data)
+#define KVM_ASSIGN_REG_MSIX_MMIO _IOW(KVMIO, 0x7d, \
+ struct kvm_assigned_msix_mmio)
/* Available with KVM_CAP_PIT_STATE2 */
#define KVM_GET_PIT2 _IOR(KVMIO, 0x9f, struct kvm_pit_state2)
#define KVM_SET_PIT2 _IOW(KVMIO, 0xa0, struct kvm_pit_state2)
@@ -802,7 +808,7 @@ struct kvm_assigned_msix_mmio {
__u32 assigned_dev_id;
__u64 base_addr;
__u32 flags;
- __u32 reserved[2];
+ __u64 reserved;
};

#endif /* __LINUX_KVM_H */
diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index 5d2adc4..9573194 100644
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -17,6 +17,8 @@
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
+#include <linux/irqnr.h>
+
#include "irq.h"

static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct list_head *head,
@@ -169,6 +171,14 @@ static void deassign_host_irq(struct kvm *kvm,
*/
if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) {
int i;
+#ifdef __KVM_HAVE_MSIX
+ if (assigned_dev->msix_mmio_base) {
+ mutex_lock(&kvm->slots_lock);
+ kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS,
+ &assigned_dev->msix_mmio_dev);
+ mutex_unlock(&kvm->slots_lock);
+ }
+#endif
for (i = 0; i < assigned_dev->entries_nr; i++)
disable_irq_nosync(assigned_dev->
host_msix_entries[i].vector);
@@ -318,6 +328,15 @@ static int assigned_device_enable_host_msix(struct kvm *kvm,
goto err;
}

+ if (dev->msix_mmio_base) {
+ mutex_lock(&kvm->slots_lock);
+ r = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS,
+ &dev->msix_mmio_dev);
+ mutex_unlock(&kvm->slots_lock);
+ if (r)
+ goto err;
+ }
+
return 0;
err:
for (i -= 1; i >= 0; i--)
@@ -870,6 +889,31 @@ static const struct kvm_io_device_ops msix_mmio_ops = {
.write = msix_mmio_write,
};

+static int kvm_vm_ioctl_register_msix_mmio(struct kvm *kvm,
+ struct kvm_assigned_msix_mmio *msix_mmio)
+{
+ int r = 0;
+ struct kvm_assigned_dev_kernel *adev;
+
+ mutex_lock(&kvm->lock);
+ adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
+ msix_mmio->assigned_dev_id);
+ if (!adev) {
+ r = -EINVAL;
+ goto out;
+ }
+ if (msix_mmio->base_addr == 0) {
+ r = -EINVAL;
+ goto out;
+ }
+ adev->msix_mmio_base = msix_mmio->base_addr;
+
+ kvm_iodevice_init(&adev->msix_mmio_dev, &msix_mmio_ops);
+out:
+ mutex_unlock(&kvm->lock);
+
+ return r;
+}
#endif

long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl,
@@ -982,6 +1026,22 @@ long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl,
goto out;
break;
}
+ case KVM_ASSIGN_REG_MSIX_MMIO: {
+ struct kvm_assigned_msix_mmio msix_mmio;
+
+ r = -EFAULT;
+ if (copy_from_user(&msix_mmio, argp, sizeof(msix_mmio)))
+ goto out;
+
+ r = -EINVAL;
+ if (msix_mmio.flags != 0 || msix_mmio.reserved != 0)
+ goto out;
+
+ r = kvm_vm_ioctl_register_msix_mmio(kvm, &msix_mmio);
+ if (r)
+ goto out;
+ break;
+ }
#endif
}
out:
--
1.7.0.1