Hi all,
We found some issues about interrupt for PV-on-HVM on IPF.
1) IRQ number issue
- In IPF-Linux, IRQ is abstruct value, not hardware IRQ.
(IRQ in IPF-Linux is external interrupt vector indeed.)
* We had implemented PV-on-HVM feature as this semantic.
- In other OS (like Windows), we can't get external interrupt
vector with the driver interface.
2) Ignoring interrupt mask of interrupt controller issue
- We had implemented that the interrupt for event channel handling
was injected without checking interrupt mask of virtual interrupt
controller.
- IPF-Linux make to mask the interrupt with psr.i. But other OSs
make to mask it with IMR(interrupt mask register) of interrupt
controller, thus the interrupt come during to mask interrupt.
3) Interrupt delivery issue
- We had implemented that the interrupt was delivered to only VCPU
0.
- Linux can handle the interrupt on any CPU, but other OS might be
able to handle it on only CPU specified with interrupt controller.
We discussed methods to modify for issue, thus ...
1) We have to change the spec of callback IRQ.
- Currently, it is external interrupt vector, but it has to be
hardware IRQ id.
- In PV-driver code for IPF-Linux, we can get hardware IRQ from
isa_irq_vector_map.
2) We have to modify the interrupt injector of hypervisor.
- Currently, it ignores interrupt mask register of virtual
interrupt controller, but it has to refer the mask.
3) We have to modify that the interrupt is delivered a CPU specified
with virtual interrupt controller
- Currently, it is delivered only VCPU 0, but it has to be
delivered a CPU specified with virtual interrupt controller
I'll send patches to modify the issues.
* pvdrv.patch
- Modify to change the spec of callback IRQ in PV-driver side.
- This patch brakes compatibility with previous version.
* follow-ic.patch
- Follow to change a method of interrupt handling in latest
changeset.
- Modify to change the spec of callback IRQ in hypervisor side.
- Modify to follow status of interrupt mask register of virtual
interupt controller.
- Modify to deliver interupts to a CPU specified with virtual
interrupt controller.
I tested with our simple test of PV-on-HVM on RHEL4 U2.
Thanks,
- Tsunehisa Doi
# HG changeset patch
# User Doi.Tsunehisa@xxxxxxxxxxxxxx
# Node ID 1fa4ce7c60125319243add108604a066e4fe6b0c
# Parent ac5330d4945a6eb388424ba8cf76f494ad9df47a
Change callback_irq spec of PV-on-HVM for IPF
Signed-off-by: Tsunehisa Doi <Doi.Tsunehisa@xxxxxxxxxxxxxx>
Signed-off-by: Kouya SHIMURA <kouya@xxxxxxxxxxxxxx>
diff -r ac5330d4945a -r 1fa4ce7c6012
unmodified_drivers/linux-2.6/platform-pci/platform-pci.c
--- a/unmodified_drivers/linux-2.6/platform-pci/platform-pci.c Wed Nov 15
12:15:34 2006 -0700
+++ b/unmodified_drivers/linux-2.6/platform-pci/platform-pci.c Thu Nov 16
15:29:28 2006 +0900
@@ -179,10 +179,24 @@ static int get_hypercall_stubs(void)
#define get_hypercall_stubs() (0)
#endif
+static int get_callback_irq(struct pci_dev *pdev)
+{
+#ifdef __ia64__
+ int irq;
+ for (irq = 0; irq < 16; irq++) {
+ if (isa_irq_to_vector_map[irq] == pdev->irq)
+ return irq;
+ }
+ return 0;
+#else /* !__ia64__ */
+ return pdev->irq;
+#endif
+}
+
static int __devinit platform_pci_init(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
- int i, ret;
+ int i, ret, callback_irq;
long ioaddr, iolen;
long mmio_addr, mmio_len;
@@ -196,7 +210,9 @@ static int __devinit platform_pci_init(s
mmio_addr = pci_resource_start(pdev, 1);
mmio_len = pci_resource_len(pdev, 1);
- if (mmio_addr == 0 || ioaddr == 0) {
+ callback_irq = get_callback_irq(pdev);
+
+ if (mmio_addr == 0 || ioaddr == 0 || callback_irq == 0) {
printk(KERN_WARNING DRV_NAME ":no resources found\n");
return -ENOENT;
}
@@ -231,7 +247,7 @@ static int __devinit platform_pci_init(s
goto out;
}
- if ((ret = set_callback_irq(pdev->irq)))
+ if ((ret = set_callback_irq(callback_irq)))
goto out;
out:
# HG changeset patch
# User Doi.Tsunehisa@xxxxxxxxxxxxxx
# Node ID d14cfa228cc4d7b0622695d8136b16db85ff3e8a
# Parent 1fa4ce7c60125319243add108604a066e4fe6b0c
Modify to follow status of interrupt controller
Signed-off-by: Tsunehisa Doi <Doi.Tsunehisa@xxxxxxxxxxxxxx>
Signed-off-by: Kouya SHIMURA <kouya@xxxxxxxxxxxxxx>
diff -r 1fa4ce7c6012 -r d14cfa228cc4 xen/arch/ia64/vmx/vlsapic.c
--- a/xen/arch/ia64/vmx/vlsapic.c Thu Nov 16 15:29:28 2006 +0900
+++ b/xen/arch/ia64/vmx/vlsapic.c Thu Nov 16 16:26:13 2006 +0900
@@ -103,8 +103,10 @@ static int vmx_vcpu_unpend_interrupt(VCP
ret = test_and_clear_bit(vector, &VCPU(vcpu, irr[0]));
local_irq_restore(spsr);
- if (ret)
+ if (ret) {
vcpu->arch.irq_new_pending = 1;
+ wmb();
+ }
return ret;
}
@@ -514,8 +516,10 @@ int vmx_vcpu_pend_interrupt(VCPU *vcpu,
ret = test_and_set_bit(vector, &VCPU(vcpu, irr[0]));
local_irq_restore(spsr);
- if (!ret)
+ if (!ret) {
vcpu->arch.irq_new_pending = 1;
+ wmb();
+ }
return ret;
}
@@ -537,6 +541,7 @@ void vmx_vcpu_pend_batch_interrupt(VCPU
}
local_irq_restore(spsr);
vcpu->arch.irq_new_pending = 1;
+ wmb();
}
/*
@@ -598,6 +603,7 @@ void guest_write_eoi(VCPU *vcpu)
VLSAPIC_INSVC(vcpu,vec>>6) &= ~(1UL <<(vec&63));
VCPU(vcpu, eoi)=0; // overwrite the data
vcpu->arch.irq_new_pending=1;
+ wmb();
}
int is_unmasked_irq(VCPU *vcpu)
diff -r 1fa4ce7c6012 -r d14cfa228cc4 xen/arch/ia64/vmx/vmx_process.c
--- a/xen/arch/ia64/vmx/vmx_process.c Thu Nov 16 15:29:28 2006 +0900
+++ b/xen/arch/ia64/vmx/vmx_process.c Thu Nov 16 16:26:13 2006 +0900
@@ -225,15 +225,15 @@ void leave_hypervisor_tail(struct pt_reg
if (v->vcpu_id == 0) {
int callback_irq =
d->arch.hvm_domain.params[HVM_PARAM_CALLBACK_IRQ];
- if (callback_irq != 0 && local_events_need_delivery()) {
- /*inject para-device call back irq*/
- v->vcpu_info->evtchn_upcall_mask = 1;
- vmx_vcpu_pend_interrupt(v, callback_irq);
- }
- }
-
- if ( v->arch.irq_new_pending ) {
- v->arch.irq_new_pending = 0;
+ if (callback_irq != 0) {
+ /* change level for para-device callback irq */
+ vmx_vioapic_set_irq(d, callback_irq,
+ local_events_need_delivery());
+ }
+ }
+
+ rmb();
+ if (xchg(&v->arch.irq_new_pending, 0)) {
v->arch.irq_new_condition = 0;
vmx_check_pending_irq(v);
return;
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