Hi, Avi
This is the key fix for 2.6.28 merge. Without this patch, guest
may hang once configured with more than 2 vcpus, it is because x86 side
changed the halt handling's common logic, but it misses to change ia64
side.
Thanks
Xiantao
>From 82b5626f9e3e422e1cd4352ecdff08c1c0dd394e Mon Sep 17 00:00:00 2001
From: Xiantao Zhang <xiantao.zhang@xxxxxxxxx>
Date: Wed, 15 Oct 2008 19:49:38 +0800
Subject: [PATCH] kvm/ia64: Fix halt emulation logic.
Common halt halding logic is changed by x86 side, this patch
fix it for ia64 side. Otherwise, guest may hang once configured
more than 2 vcpus.
Signed-off-by: Xiantao Zhang <xiantao.zhang@xxxxxxxxx>
---
arch/ia64/include/asm/kvm_host.h | 3 +-
arch/ia64/kvm/kvm-ia64.c | 79
++++++++++++++++++++------------------
arch/ia64/kvm/kvm_fw.c | 9 +++-
arch/ia64/kvm/process.c | 2 +-
4 files changed, 52 insertions(+), 41 deletions(-)
diff --git a/arch/ia64/include/asm/kvm_host.h
b/arch/ia64/include/asm/kvm_host.h
index 85db124..b9e3c7f 100644
--- a/arch/ia64/include/asm/kvm_host.h
+++ b/arch/ia64/include/asm/kvm_host.h
@@ -365,7 +365,8 @@ struct kvm_vcpu_arch {
long itc_offset;
unsigned long itc_check;
unsigned long timer_check;
- unsigned long timer_pending;
+ unsigned int timer_pending;
+ unsigned int timer_fired;
unsigned long vrr[8];
unsigned long ibr[8];
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index c0699f0..ae0c8dd 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -325,6 +325,7 @@ static struct kvm_vcpu *lid_to_vcpu(struct kvm *kvm,
unsigned long id,
return NULL;
}
+
static int handle_ipi(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
struct exit_ctl_data *p = kvm_get_exit_data(vcpu);
@@ -385,6 +386,7 @@ static int handle_global_purge(struct kvm_vcpu
*vcpu, struct kvm_run *kvm_run)
struct kvm *kvm = vcpu->kvm;
struct call_data call_data;
int i;
+
call_data.ptc_g_data = p->u.ptc_g_data;
for (i = 0; i < KVM_MAX_VCPUS; i++) {
@@ -398,8 +400,11 @@ static int handle_global_purge(struct kvm_vcpu
*vcpu, struct kvm_run *kvm_run)
if (kvm->vcpus[i]->cpu != -1) {
call_data.vcpu = kvm->vcpus[i];
- smp_call_function_single(kvm->vcpus[i]->cpu,
+ if (kvm->vcpus[i]->cpu != smp_processor_id())
+
smp_call_function_single(kvm->vcpus[i]->cpu,
vcpu_global_purge, &call_data,
1);
+ else
+ vcpu_global_purge(&call_data);
} else
printk(KERN_WARNING"kvm: Uninit vcpu received
ipi!\n");
@@ -418,33 +423,41 @@ int kvm_emulate_halt(struct kvm_vcpu *vcpu)
ktime_t kt;
long itc_diff;
unsigned long vcpu_now_itc;
-
unsigned long expires;
struct hrtimer *p_ht = &vcpu->arch.hlt_timer;
unsigned long cyc_per_usec = local_cpu_data->cyc_per_usec;
struct vpd *vpd = to_host(vcpu->kvm, vcpu->arch.vpd);
- vcpu_now_itc = ia64_getreg(_IA64_REG_AR_ITC) +
vcpu->arch.itc_offset;
+ if (irqchip_in_kernel(vcpu->kvm)) {
- if (time_after(vcpu_now_itc, vpd->itm)) {
- vcpu->arch.timer_check = 1;
- return 1;
- }
- itc_diff = vpd->itm - vcpu_now_itc;
- if (itc_diff < 0)
- itc_diff = -itc_diff;
+ vcpu_now_itc = ia64_getreg(_IA64_REG_AR_ITC) +
vcpu->arch.itc_offset;
+
+ if (time_after(vcpu_now_itc, vpd->itm)) {
+ vcpu->arch.timer_check = 1;
+ return 1;
+ }
+ itc_diff = vpd->itm - vcpu_now_itc;
+ if (itc_diff < 0)
+ itc_diff = -itc_diff;
- expires = div64_u64(itc_diff, cyc_per_usec);
- kt = ktime_set(0, 1000 * expires);
- vcpu->arch.ht_active = 1;
- hrtimer_start(p_ht, kt, HRTIMER_MODE_ABS);
+ expires = div64_u64(itc_diff, cyc_per_usec);
+ kt = ktime_set(0, 1000 * expires);
+
+ down_read(&vcpu->kvm->slots_lock);
+ vcpu->arch.ht_active = 1;
+ hrtimer_start(p_ht, kt, HRTIMER_MODE_ABS);
- if (irqchip_in_kernel(vcpu->kvm)) {
vcpu->arch.mp_state = KVM_MP_STATE_HALTED;
kvm_vcpu_block(vcpu);
hrtimer_cancel(p_ht);
vcpu->arch.ht_active = 0;
+ if (test_and_clear_bit(KVM_REQ_UNHALT, &vcpu->requests))
+ if (vcpu->arch.mp_state == KVM_MP_STATE_HALTED)
+ vcpu->arch.mp_state =
+ KVM_MP_STATE_RUNNABLE;
+ up_read(&vcpu->kvm->slots_lock);
+
if (vcpu->arch.mp_state != KVM_MP_STATE_RUNNABLE)
return -EINTR;
return 1;
@@ -484,10 +497,6 @@ static int (*kvm_vti_exit_handlers[])(struct
kvm_vcpu *vcpu,
static const int kvm_vti_max_exit_handlers =
sizeof(kvm_vti_exit_handlers)/sizeof(*kvm_vti_exit_handlers);
-static void kvm_prepare_guest_switch(struct kvm_vcpu *vcpu)
-{
-}
-
static uint32_t kvm_get_exit_reason(struct kvm_vcpu *vcpu)
{
struct exit_ctl_data *p_exit_data;
@@ -600,10 +609,9 @@ static int __vcpu_run(struct kvm_vcpu *vcpu, struct
kvm_run *kvm_run)
again:
preempt_disable();
-
- kvm_prepare_guest_switch(vcpu);
local_irq_disable();
+
if (signal_pending(current)) {
local_irq_enable();
preempt_enable();
@@ -614,7 +622,7 @@ again:
vcpu->guest_mode = 1;
kvm_guest_enter();
-
+ down_read(&vcpu->kvm->slots_lock);
r = vti_vcpu_run(vcpu, kvm_run);
if (r < 0) {
local_irq_enable();
@@ -634,9 +642,8 @@ again:
* But we need to prevent reordering, hence this barrier():
*/
barrier();
-
kvm_guest_exit();
-
+ up_read(&vcpu->kvm->slots_lock);
preempt_enable();
r = kvm_handle_exit(kvm_run, vcpu);
@@ -673,6 +680,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu,
struct kvm_run *kvm_run)
if (unlikely(vcpu->arch.mp_state == KVM_MP_STATE_UNINITIALIZED))
{
kvm_vcpu_block(vcpu);
+ clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
vcpu_put(vcpu);
return -EAGAIN;
}
@@ -1123,15 +1131,16 @@ static enum hrtimer_restart hlt_timer_fn(struct
hrtimer *data)
wait_queue_head_t *q;
vcpu = container_of(data, struct kvm_vcpu, arch.hlt_timer);
+ q = &vcpu->wq;
+
if (vcpu->arch.mp_state != KVM_MP_STATE_HALTED)
goto out;
- q = &vcpu->wq;
- if (waitqueue_active(q)) {
- vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
+ if (waitqueue_active(q))
wake_up_interruptible(q);
- }
+
out:
+ vcpu->arch.timer_fired = 1;
vcpu->arch.timer_check = 1;
return HRTIMER_NORESTART;
}
@@ -1700,12 +1709,14 @@ static void vcpu_kick_intr(void *info)
void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
{
int ipi_pcpu = vcpu->cpu;
+ int cpu = get_cpu();
if (waitqueue_active(&vcpu->wq))
wake_up_interruptible(&vcpu->wq);
- if (vcpu->guest_mode)
+ if (vcpu->guest_mode && cpu != ipi_pcpu)
smp_call_function_single(ipi_pcpu, vcpu_kick_intr, vcpu,
0);
+ put_cpu();
}
int kvm_apic_set_irq(struct kvm_vcpu *vcpu, u8 vec, u8 trig)
@@ -1715,13 +1726,7 @@ int kvm_apic_set_irq(struct kvm_vcpu *vcpu, u8
vec, u8 trig)
if (!test_and_set_bit(vec, &vpd->irr[0])) {
vcpu->arch.irq_new_pending = 1;
- if (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE)
- kvm_vcpu_kick(vcpu);
- else if (vcpu->arch.mp_state == KVM_MP_STATE_HALTED) {
- vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
- if (waitqueue_active(&vcpu->wq))
- wake_up_interruptible(&vcpu->wq);
- }
+ kvm_vcpu_kick(vcpu);
return 1;
}
return 0;
@@ -1791,7 +1796,7 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu)
int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
{
- return 0;
+ return vcpu->arch.timer_fired;
}
gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn)
diff --git a/arch/ia64/kvm/kvm_fw.c b/arch/ia64/kvm/kvm_fw.c
index 0c69d9e..cb7600b 100644
--- a/arch/ia64/kvm/kvm_fw.c
+++ b/arch/ia64/kvm/kvm_fw.c
@@ -286,6 +286,12 @@ static u64 kvm_get_pal_call_index(struct kvm_vcpu
*vcpu)
return index;
}
+static void prepare_for_halt(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.timer_pending = 1;
+ vcpu->arch.timer_fired = 0;
+}
+
int kvm_pal_emul(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
@@ -304,11 +310,10 @@ int kvm_pal_emul(struct kvm_vcpu *vcpu, struct
kvm_run *run)
break;
case PAL_HALT_LIGHT:
{
- vcpu->arch.timer_pending = 1;
INIT_PAL_STATUS_SUCCESS(result);
+ prepare_for_halt(vcpu);
if (kvm_highest_pending_irq(vcpu) == -1)
ret = kvm_emulate_halt(vcpu);
-
}
break;
diff --git a/arch/ia64/kvm/process.c b/arch/ia64/kvm/process.c
index 3417783..8008173 100644
--- a/arch/ia64/kvm/process.c
+++ b/arch/ia64/kvm/process.c
@@ -713,7 +713,7 @@ void leave_hypervisor_tail(void)
if (!(VCPU(v, itv) & (1 << 16))) {
vcpu_pend_interrupt(v, VCPU(v,
itv)
& 0xff);
- VMX(v, itc_check) = 0;
+ VMX(v, itc_check) = 0;
} else {
v->arch.timer_pending = 1;
}
--
1.5.1
Attachment:
0001-kvm-ia64-Fix-halt-emulation-logic.patch
Description: 0001-kvm-ia64-Fix-halt-emulation-logic.patch
