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[Qemu-devel] [PATCH v2 1/7] kvm: Decouple 'async interrupt delivery' fro
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PATCH v2 1/7] kvm: Decouple 'async interrupt delivery' from 'kernel irqchip' |
Date: |
Thu, 26 Jul 2012 15:35:11 +0100 |
On x86 userspace delivers interrupts to the kernel asynchronously
(and therefore VCPU idle management is done in the kernel) if and
only if there is an in-kernel irqchip. On other architectures this
isn't necessarily true (they may always send interrupts
asynchronously), so define a new kvm_async_interrupts_enabled()
function instead of misusing kvm_irqchip_in_kernel().
Signed-off-by: Peter Maydell <address@hidden>
---
cpus.c | 3 ++-
kvm-all.c | 7 ++++++-
kvm-stub.c | 1 +
kvm.h | 13 +++++++++++++
4 files changed, 22 insertions(+), 2 deletions(-)
diff --git a/cpus.c b/cpus.c
index 756e624..8c54dd0 100644
--- a/cpus.c
+++ b/cpus.c
@@ -69,7 +69,8 @@ static bool cpu_thread_is_idle(CPUArchState *env)
if (env->stopped || !runstate_is_running()) {
return true;
}
- if (!env->halted || qemu_cpu_has_work(env) || kvm_irqchip_in_kernel()) {
+ if (!env->halted || qemu_cpu_has_work(env) ||
+ kvm_async_interrupts_enabled()) {
return false;
}
return true;
diff --git a/kvm-all.c b/kvm-all.c
index 2148b20..0a38ba1 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -100,6 +100,7 @@ struct KVMState
KVMState *kvm_state;
bool kvm_kernel_irqchip;
+bool kvm_async_interrupts_allowed;
static const KVMCapabilityInfo kvm_required_capabilites[] = {
KVM_CAP_INFO(USER_MEMORY),
@@ -857,7 +858,7 @@ int kvm_irqchip_set_irq(KVMState *s, int irq, int level)
struct kvm_irq_level event;
int ret;
- assert(kvm_irqchip_in_kernel());
+ assert(kvm_async_interrupts_enabled());
event.level = level;
event.irq = irq;
@@ -1201,6 +1202,10 @@ static int kvm_irqchip_create(KVMState *s)
s->irqchip_inject_ioctl = KVM_IRQ_LINE_STATUS;
}
kvm_kernel_irqchip = true;
+ /* If we have an in-kernel IRQ chip then we must have asynchronous
+ * interrupt delivery (though the reverse is not necessarily true)
+ */
+ kvm_async_interrupts_allowed = true;
kvm_init_irq_routing(s);
diff --git a/kvm-stub.c b/kvm-stub.c
index d23b11c..a7a03e1 100644
--- a/kvm-stub.c
+++ b/kvm-stub.c
@@ -19,6 +19,7 @@
KVMState *kvm_state;
bool kvm_kernel_irqchip;
+bool kvm_async_interrupts_allowed;
int kvm_init_vcpu(CPUArchState *env)
{
diff --git a/kvm.h b/kvm.h
index 2617dd5..09818f3 100644
--- a/kvm.h
+++ b/kvm.h
@@ -24,13 +24,26 @@
extern int kvm_allowed;
extern bool kvm_kernel_irqchip;
+extern bool kvm_async_interrupts_allowed;
#if defined CONFIG_KVM || !defined NEED_CPU_H
#define kvm_enabled() (kvm_allowed)
#define kvm_irqchip_in_kernel() (kvm_kernel_irqchip)
+
+/**
+ * kvm_async_interrupts_enabled:
+ *
+ * Returns: true if we can deliver interrupts to KVM
+ * asynchronously (ie by ioctl from any thread at any time)
+ * rather than having to do interrupt delivery synchronously
+ * (where the vcpu must be stopped at a suitable point first).
+ */
+#define kvm_async_interrupts_enabled() (kvm_async_interrupts_allowed)
+
#else
#define kvm_enabled() (0)
#define kvm_irqchip_in_kernel() (false)
+#define kvm_async_interrupts_enabled() (false)
#endif
struct kvm_run;
--
1.7.5.4
- [Qemu-devel] [PATCH v2 0/7] split out uses of kvm_irqchip_in_kernel(), Peter Maydell, 2012/07/26
- [Qemu-devel] [PATCH v2 3/7] kvm: Move kvm_allows_irq0_override() to target-i386, fix return type, Peter Maydell, 2012/07/26
- [Qemu-devel] [PATCH v2 7/7] kvm: Add documentation comment for kvm_irqchip_in_kernel(), Peter Maydell, 2012/07/26
- [Qemu-devel] [PATCH v2 2/7] kvm: Rename kvm_irqchip_set_irq() to kvm_set_irq(), Peter Maydell, 2012/07/26
- [Qemu-devel] [PATCH v2 6/7] kvm: Decouple 'GSI routing' from 'kernel irqchip', Peter Maydell, 2012/07/26
- [Qemu-devel] [PATCH v2 4/7] kvm: Decouple 'irqfds usable' from 'kernel irqchip', Peter Maydell, 2012/07/26
- [Qemu-devel] [PATCH v2 5/7] kvm: Decouple 'MSI routing via irqfds' from 'kernel irqchip', Peter Maydell, 2012/07/26
- [Qemu-devel] [PATCH v2 1/7] kvm: Decouple 'async interrupt delivery' from 'kernel irqchip',
Peter Maydell <=