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authorSheng Yang <sheng@linux.intel.com>2008-11-24 14:32:57 +0800
committerAvi Kivity <avi@redhat.com>2008-12-31 16:55:02 +0200
commit5319c662522db8995ff9276ba9d80549c64b294a (patch)
tree9091de707ff40ec148fde7e06dae461a4b5c29de /virt
parent6b9cc7fd469869bed38831c5adac3f59dc25eaf5 (diff)
downloadlinux-linaro-stable-5319c662522db8995ff9276ba9d80549c64b294a.tar.gz
KVM: MSI to INTx translate
Now we use MSI as default one, and translate MSI to INTx when guest need INTx rather than MSI. For legacy device, we provide support for non-sharing host IRQ. Provide a parameter msi2intx for this method. The value is true by default in x86 architecture. We can't guarantee this mode can work on every device, but for most of us tested, it works. If your device encounter some trouble with this mode, you can try set msi2intx modules parameter to 0. If the device is OK with msi2intx=0, then please report it to KVM mailing list or me. We may prepare a blacklist for the device that can't work in this mode. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/kvm_main.c70
1 files changed, 54 insertions, 16 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index bf36ae9ae7df..54d25e6f6d2d 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -64,6 +64,9 @@
MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");
+static int msi2intx = 1;
+module_param(msi2intx, bool, 0);
+
DEFINE_SPINLOCK(kvm_lock);
LIST_HEAD(vm_list);
@@ -250,7 +253,8 @@ static int assigned_device_update_intx(struct kvm *kvm,
return 0;
if (irqchip_in_kernel(kvm)) {
- if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI) {
+ if (!msi2intx &&
+ adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI) {
free_irq(adev->host_irq, (void *)kvm);
pci_disable_msi(adev->dev);
}
@@ -285,21 +289,33 @@ static int assigned_device_update_msi(struct kvm *kvm,
{
int r;
- /* x86 don't care upper address of guest msi message addr */
- adev->guest_msi.address_lo = airq->guest_msi.addr_lo;
- adev->guest_msi.data = airq->guest_msi.data;
- adev->ack_notifier.gsi = -1;
+ if (airq->flags & KVM_DEV_IRQ_ASSIGN_ENABLE_MSI) {
+ /* x86 don't care upper address of guest msi message addr */
+ adev->irq_requested_type |= KVM_ASSIGNED_DEV_GUEST_MSI;
+ adev->irq_requested_type &= ~KVM_ASSIGNED_DEV_GUEST_INTX;
+ adev->guest_msi.address_lo = airq->guest_msi.addr_lo;
+ adev->guest_msi.data = airq->guest_msi.data;
+ adev->ack_notifier.gsi = -1;
+ } else if (msi2intx) {
+ adev->irq_requested_type |= KVM_ASSIGNED_DEV_GUEST_INTX;
+ adev->irq_requested_type &= ~KVM_ASSIGNED_DEV_GUEST_MSI;
+ adev->guest_irq = airq->guest_irq;
+ adev->ack_notifier.gsi = airq->guest_irq;
+ }
if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI)
return 0;
if (irqchip_in_kernel(kvm)) {
- if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_INTX)
- free_irq(adev->host_irq, (void *)adev);
-
- r = pci_enable_msi(adev->dev);
- if (r)
- return r;
+ if (!msi2intx) {
+ if (adev->irq_requested_type &
+ KVM_ASSIGNED_DEV_HOST_INTX)
+ free_irq(adev->host_irq, (void *)adev);
+
+ r = pci_enable_msi(adev->dev);
+ if (r)
+ return r;
+ }
adev->host_irq = adev->dev->irq;
if (request_irq(adev->host_irq, kvm_assigned_dev_intr, 0,
@@ -307,8 +323,10 @@ static int assigned_device_update_msi(struct kvm *kvm,
return -EIO;
}
- adev->irq_requested_type = KVM_ASSIGNED_DEV_GUEST_MSI |
- KVM_ASSIGNED_DEV_HOST_MSI;
+ if (!msi2intx)
+ adev->irq_requested_type = KVM_ASSIGNED_DEV_GUEST_MSI;
+
+ adev->irq_requested_type |= KVM_ASSIGNED_DEV_HOST_MSI;
return 0;
}
#endif
@@ -346,10 +364,19 @@ static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
goto out_release;
else
match->irq_source_id = r;
+
+#ifdef CONFIG_X86
+ /* Determine host device irq type, we can know the
+ * result from dev->msi_enabled */
+ if (msi2intx)
+ pci_enable_msi(match->dev);
+#endif
}
}
- if (assigned_irq->flags & KVM_DEV_IRQ_ASSIGN_ENABLE_MSI) {
+ if ((!msi2intx &&
+ (assigned_irq->flags & KVM_DEV_IRQ_ASSIGN_ENABLE_MSI)) ||
+ (msi2intx && match->dev->msi_enabled)) {
#ifdef CONFIG_X86
r = assigned_device_update_msi(kvm, match, assigned_irq);
if (r) {
@@ -362,8 +389,16 @@ static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
#endif
} else if (assigned_irq->host_irq == 0 && match->dev->irq == 0) {
/* Host device IRQ 0 means don't support INTx */
- printk(KERN_WARNING "kvm: wait device to enable MSI!\n");
- r = 0;
+ if (!msi2intx) {
+ printk(KERN_WARNING
+ "kvm: wait device to enable MSI!\n");
+ r = 0;
+ } else {
+ printk(KERN_WARNING
+ "kvm: failed to enable MSI device!\n");
+ r = -ENOTTY;
+ goto out_release;
+ }
} else {
/* Non-sharing INTx mode */
r = assigned_device_update_intx(kvm, match, assigned_irq);
@@ -2209,6 +2244,9 @@ int kvm_init(void *opaque, unsigned int vcpu_size,
kvm_preempt_ops.sched_in = kvm_sched_in;
kvm_preempt_ops.sched_out = kvm_sched_out;
+#ifndef CONFIG_X86
+ msi2intx = 0;
+#endif
return 0;