Mailing List Archive

# HG changeset patch
# User Keir Fraser <keir.fraser@citrix.com>
# Date 1271695990 -3600
# Node ID db149766aef1958dab27932950a53eec7c06ca6a
# Parent 5175e5e5eb548973481611404a4ef0756a47a064
x86 hvm: Simplify vlapic init-sipi logic (no async pause logic)

This is possible now that tasklets run in idle-vcpu context

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
---
xen/arch/x86/hvm/vlapic.c | 108 ++++++++++++++++-----------------------
xen/include/asm-x86/hvm/vlapic.h | 4 +
2 files changed, 48 insertions(+), 64 deletions(-)

diff -r 5175e5e5eb54 -r db149766aef1 xen/arch/x86/hvm/vlapic.c
--- a/xen/arch/x86/hvm/vlapic.c Mon Apr 19 17:48:20 2010 +0100
+++ b/xen/arch/x86/hvm/vlapic.c Mon Apr 19 17:53:10 2010 +0100
@@ -226,73 +226,46 @@ bool_t vlapic_match_dest(
return 0;
}

-static int vlapic_vcpu_pause_async(struct vcpu *v)
-{
- vcpu_pause_nosync(v);
-
- if ( v->is_running )
- {
- vcpu_unpause(v);
- return 0;
- }
-
- sync_vcpu_execstate(v);
- return 1;
-}
-
-static void vlapic_init_action(unsigned long _vcpu)
+static void vlapic_init_sipi_action(unsigned long _vcpu)
{
struct vcpu *v = (struct vcpu *)_vcpu;
struct domain *d = v->domain;
- bool_t fpu_initialised;
-
- /* If the VCPU is not on its way down we have nothing to do. */
- if ( !test_bit(_VPF_down, &v->pause_flags) )
- return;
-
- if ( !vlapic_vcpu_pause_async(v) )
- {
- tasklet_schedule(&vcpu_vlapic(v)->init_tasklet);
- return;
- }
-
- /* Reset necessary VCPU state. This does not include FPU state. */
- domain_lock(d);
- fpu_initialised = v->fpu_initialised;
- vcpu_reset(v);
- v->fpu_initialised = fpu_initialised;
- vlapic_reset(vcpu_vlapic(v));
- domain_unlock(d);
+ uint32_t icr = vcpu_vlapic(v)->init_sipi_tasklet_icr;
+
+ vcpu_pause(v);
+
+ switch ( icr & APIC_MODE_MASK )
+ {
+ case APIC_DM_INIT: {
+ bool_t fpu_initialised;
+ domain_lock(d);
+ /* Reset necessary VCPU state. This does not include FPU state. */
+ fpu_initialised = v->fpu_initialised;
+ vcpu_reset(v);
+ v->fpu_initialised = fpu_initialised;
+ vlapic_reset(vcpu_vlapic(v));
+ domain_unlock(d);
+ break;
+ }
+
+ case APIC_DM_STARTUP: {
+ uint16_t reset_cs = (icr & 0xffu) << 8;
+ hvm_vcpu_reset_state(v, reset_cs, 0);
+ break;
+ }
+
+ default:
+ BUG();
+ }

vcpu_unpause(v);
}

-static int vlapic_accept_init(struct vcpu *v)
-{
- /* Nothing to do if the VCPU is already reset. */
- if ( !v->is_initialised )
- return X86EMUL_OKAY;
-
- /* Asynchronously take the VCPU down and schedule reset work. */
- hvm_vcpu_down(v);
- tasklet_schedule(&vcpu_vlapic(v)->init_tasklet);
+static int vlapic_schedule_init_sipi_tasklet(struct vcpu *v, uint32_t icr)
+{
+ vcpu_vlapic(v)->init_sipi_tasklet_icr = icr;
+ tasklet_schedule(&vcpu_vlapic(v)->init_sipi_tasklet);
return X86EMUL_RETRY;
-}
-
-static int vlapic_accept_sipi(struct vcpu *v, int trampoline_vector)
-{
- /* If the VCPU is not on its way down we have nothing to do. */
- if ( !test_bit(_VPF_down, &v->pause_flags) )
- return X86EMUL_OKAY;
-
- if ( !vlapic_vcpu_pause_async(v) )
- return X86EMUL_RETRY;
-
- hvm_vcpu_reset_state(v, trampoline_vector << 8, 0);
-
- vcpu_unpause(v);
-
- return X86EMUL_OKAY;
}

/* Add a pending IRQ into lapic. */
@@ -329,11 +302,18 @@ static int vlapic_accept_irq(struct vcpu
if ( (icr_low & (APIC_INT_LEVELTRIG | APIC_INT_ASSERT)) ==
APIC_INT_LEVELTRIG )
break;
- rc = vlapic_accept_init(v);
+ /* Nothing to do if the VCPU is already reset. */
+ if ( !v->is_initialised )
+ break;
+ hvm_vcpu_down(v);
+ rc = vlapic_schedule_init_sipi_tasklet(v, icr_low);
break;

case APIC_DM_STARTUP:
- rc = vlapic_accept_sipi(v, vector);
+ /* Nothing to do if the VCPU is not on its way down. */
+ if ( !test_bit(_VPF_down, &v->pause_flags) )
+ break;
+ rc = vlapic_schedule_init_sipi_tasklet(v, icr_low);
break;

default:
@@ -1002,7 +982,9 @@ int vlapic_init(struct vcpu *v)
if ( v->vcpu_id == 0 )
vlapic->hw.apic_base_msr |= MSR_IA32_APICBASE_BSP;

- tasklet_init(&vlapic->init_tasklet, vlapic_init_action, (unsigned long)v);
+ tasklet_init(&vlapic->init_sipi_tasklet,
+ vlapic_init_sipi_action,
+ (unsigned long)v);

return 0;
}
@@ -1011,7 +993,7 @@ void vlapic_destroy(struct vcpu *v)
{
struct vlapic *vlapic = vcpu_vlapic(v);

- tasklet_kill(&vlapic->init_tasklet);
+ tasklet_kill(&vlapic->init_sipi_tasklet);
destroy_periodic_time(&vlapic->pt);
unmap_domain_page_global(vlapic->regs);
free_domheap_page(vlapic->regs_page);
diff -r 5175e5e5eb54 -r db149766aef1 xen/include/asm-x86/hvm/vlapic.h
--- a/xen/include/asm-x86/hvm/vlapic.h Mon Apr 19 17:48:20 2010 +0100
+++ b/xen/include/asm-x86/hvm/vlapic.h Mon Apr 19 17:53:10 2010 +0100
@@ -58,7 +58,9 @@ struct vlapic {
struct periodic_time pt;
s_time_t timer_last_update;
struct page_info *regs_page;
- struct tasklet init_tasklet;
+ /* INIT-SIPI-SIPI work gets deferred to a tasklet. */
+ uint32_t init_sipi_tasklet_icr;
+ struct tasklet init_sipi_tasklet;
};

static inline uint32_t vlapic_get_reg(struct vlapic *vlapic, uint32_t reg)

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