# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1253872218 -3600
# Node ID e1bcf240e330fbd431a5dc38a871e143c26295e4
# Parent fa41a706d0181e190512c9665f3e7654ca4ba2f6
x86: Make assigned devices' interrupts delivery to right vcpu.
This patch targets for reducing IPIs when delivery VT-d's devices'
intrs to target vcpus. According to the experiments leveraging 10G
Oplin NIC card, CPU utilization can reduce 5%-6% and NIC's bandwidth
keeps unchanged through testings. And this patch can always benefit
UP guests with MSI-capable devices assigned and SMP guests whose
lapic's destination mode is physical mode. And also it can benefit
SMP guests whose lapic's dest_mode is logical mode but only one
destination is specified. So it should cover major cases in real
environment. Currenlty, this patch intercepts the programming for MSI
intr status, and caculate the destination id for the pirq when do the
programming in advance. When vcpu migratio n occurs or guest
re-programe MSI status, it checks that whether needs to set the
corresponding pirq's affinity of assigned devices and make vcpu's
affinity and pirq's consistent to reduce the IPIs eventually.
Signed-off-by : Xiantao Zhang <xiantao.zhang@xxxxxxxxx>
Signed-off-by: Xiaohui Xin <xiaohui.xin@xxxxxxxxx>
---
xen/arch/x86/hvm/hvm.c | 29 +++++++++++++++++++++++++++++
xen/arch/x86/hvm/vmsi.c | 23 +++++++++++++++++++++++
xen/arch/x86/hvm/vmx/vmcs.c | 1 +
xen/arch/x86/irq.c | 4 ++--
xen/drivers/passthrough/io.c | 18 +++++++++++++++---
xen/include/asm-x86/hvm/hvm.h | 3 +++
xen/include/asm-x86/irq.h | 2 ++
xen/include/xen/hvm/irq.h | 1 +
8 files changed, 76 insertions(+), 5 deletions(-)
diff -r fa41a706d018 -r e1bcf240e330 xen/arch/x86/hvm/hvm.c
--- a/xen/arch/x86/hvm/hvm.c Fri Sep 25 10:47:36 2009 +0100
+++ b/xen/arch/x86/hvm/hvm.c Fri Sep 25 10:50:18 2009 +0100
@@ -211,6 +211,35 @@ void hvm_migrate_timers(struct vcpu *v)
pt_migrate(v);
}
+void hvm_migrate_pirqs(struct vcpu *v)
+{
+ int pirq, irq;
+ struct irq_desc *desc;
+ struct domain *d = v->domain;
+ struct hvm_irq_dpci *hvm_irq_dpci = d->arch.hvm_domain.irq.dpci;
+
+ if ( !iommu_enabled || (hvm_irq_dpci == NULL) )
+ return;
+
+ spin_lock(&d->event_lock);
+ for ( pirq = find_first_bit(hvm_irq_dpci->mapping, d->nr_pirqs);
+ pirq < d->nr_pirqs;
+ pirq = find_next_bit(hvm_irq_dpci->mapping, d->nr_pirqs, pirq + 1) )
+ {
+ if ( !(hvm_irq_dpci->mirq[pirq].flags & HVM_IRQ_DPCI_MACH_MSI) ||
+ (hvm_irq_dpci->mirq[pirq].gmsi.dest_vcpu_id != v->vcpu_id) )
+ continue;
+ desc = domain_spin_lock_irq_desc(v->domain, pirq, NULL);
+ if (!desc)
+ continue;
+ irq = desc - irq_desc;
+ ASSERT(MSI_IRQ(irq));
+ desc->handler->set_affinity(irq, *cpumask_of(v->processor));
+ spin_unlock_irq(&desc->lock);
+ }
+ spin_unlock(&d->event_lock);
+}
+
void hvm_do_resume(struct vcpu *v)
{
ioreq_t *p;
diff -r fa41a706d018 -r e1bcf240e330 xen/arch/x86/hvm/vmsi.c
--- a/xen/arch/x86/hvm/vmsi.c Fri Sep 25 10:47:36 2009 +0100
+++ b/xen/arch/x86/hvm/vmsi.c Fri Sep 25 10:50:18 2009 +0100
@@ -124,6 +124,29 @@ int vmsi_deliver(struct domain *d, int p
return 1;
}
+/* Return value, -1 : multi-dests, non-negative value: dest_vcpu_id */
+int hvm_girq_dest_2_vcpu_id(struct domain *d, uint8_t dest, uint8_t dest_mode)
+{
+ int dest_vcpu_id = -1, w = 0;
+ struct vcpu *v;
+
+ if ( d->max_vcpus == 1 )
+ return 0;
+
+ for_each_vcpu ( d, v )
+ {
+ if ( vlapic_match_dest(vcpu_vlapic(v), NULL, 0, dest, dest_mode) )
+ {
+ w++;
+ dest_vcpu_id = v->vcpu_id;
+ }
+ }
+ if ( w > 1 )
+ return -1;
+
+ return dest_vcpu_id;
+}
+
/* MSI-X mask bit hypervisor interception */
struct msixtbl_entry
{
diff -r fa41a706d018 -r e1bcf240e330 xen/arch/x86/hvm/vmx/vmcs.c
--- a/xen/arch/x86/hvm/vmx/vmcs.c Fri Sep 25 10:47:36 2009 +0100
+++ b/xen/arch/x86/hvm/vmx/vmcs.c Fri Sep 25 10:50:18 2009 +0100
@@ -940,6 +940,7 @@ void vmx_do_resume(struct vcpu *v)
vmx_clear_vmcs(v);
vmx_load_vmcs(v);
hvm_migrate_timers(v);
+ hvm_migrate_pirqs(v);
vmx_set_host_env(v);
vpid_sync_vcpu_all(v);
}
diff -r fa41a706d018 -r e1bcf240e330 xen/arch/x86/irq.c
--- a/xen/arch/x86/irq.c Fri Sep 25 10:47:36 2009 +0100
+++ b/xen/arch/x86/irq.c Fri Sep 25 10:50:18 2009 +0100
@@ -1517,7 +1517,7 @@ static void dump_irqs(unsigned char key)
/* Only show CPU0 - CPU31's affinity info.*/
printk(" IRQ:%4d, IRQ affinity:0x%08x, Vec:%3d type=%-15s"
" status=%08x mapped, unbound\n",
- irq, *(int*)cfg->domain.bits, cfg->vector,
+ irq, *(int*)desc->affinity.bits, cfg->vector,
desc->handler->typename, desc->status);
else
{
@@ -1525,7 +1525,7 @@ static void dump_irqs(unsigned char key)
printk(" IRQ:%4d, IRQ affinity:0x%08x, Vec:%3d type=%-15s "
"status=%08x in-flight=%d domain-list=",
- irq, *(int*)cfg->domain.bits, cfg->vector,
+ irq, *(int*)desc->affinity.bits, cfg->vector,
desc->handler->typename, desc->status, action->in_flight);
for ( i = 0; i < action->nr_guests; i++ )
diff -r fa41a706d018 -r e1bcf240e330 xen/drivers/passthrough/io.c
--- a/xen/drivers/passthrough/io.c Fri Sep 25 10:47:36 2009 +0100
+++ b/xen/drivers/passthrough/io.c Fri Sep 25 10:50:18 2009 +0100
@@ -139,8 +139,10 @@ int pt_irq_create_bind_vtd(
bitmap_zero(hvm_irq_dpci->mapping, d->nr_pirqs);
memset(hvm_irq_dpci->hvm_timer, 0,
nr_irqs * sizeof(*hvm_irq_dpci->hvm_timer));
- for ( int i = 0; i < d->nr_pirqs; i++ )
+ for ( int i = 0; i < d->nr_pirqs; i++ ) {
INIT_LIST_HEAD(&hvm_irq_dpci->mirq[i].digl_list);
+ hvm_irq_dpci->mirq[i].gmsi.dest_vcpu_id = -1;
+ }
for ( int i = 0; i < NR_HVM_IRQS; i++ )
INIT_LIST_HEAD(&hvm_irq_dpci->girq[i]);
@@ -154,6 +156,8 @@ int pt_irq_create_bind_vtd(
if ( pt_irq_bind->irq_type == PT_IRQ_TYPE_MSI )
{
+ uint8_t dest, dest_mode;
+ int dest_vcpu_id;
if ( !test_and_set_bit(pirq, hvm_irq_dpci->mapping))
{
@@ -195,6 +199,14 @@ int pt_irq_create_bind_vtd(
hvm_irq_dpci->mirq[pirq].gmsi.gvec = pt_irq_bind->u.msi.gvec;
hvm_irq_dpci->mirq[pirq].gmsi.gflags = pt_irq_bind->u.msi.gflags;
}
+ /* Caculate dest_vcpu_id for MSI-type pirq migration */
+ dest = hvm_irq_dpci->mirq[pirq].gmsi.gflags & VMSI_DEST_ID_MASK;
+ dest_mode = !!(hvm_irq_dpci->mirq[pirq].gmsi.gflags & VMSI_DM_MASK);
+ dest_vcpu_id = hvm_girq_dest_2_vcpu_id(d, dest, dest_mode);
+ hvm_irq_dpci->mirq[pirq].gmsi.dest_vcpu_id = dest_vcpu_id;
+ spin_unlock(&d->event_lock);
+ if ( dest_vcpu_id >= 0 )
+ hvm_migrate_pirqs(d->vcpu[dest_vcpu_id]);
}
else
{
@@ -278,8 +290,8 @@ int pt_irq_create_bind_vtd(
gdprintk(XENLOG_INFO VTDPREFIX,
"VT-d irq bind: m_irq = %x device = %x intx = %x\n",
machine_gsi, device, intx);
- }
- spin_unlock(&d->event_lock);
+ spin_unlock(&d->event_lock);
+ }
return 0;
}
diff -r fa41a706d018 -r e1bcf240e330 xen/include/asm-x86/hvm/hvm.h
--- a/xen/include/asm-x86/hvm/hvm.h Fri Sep 25 10:47:36 2009 +0100
+++ b/xen/include/asm-x86/hvm/hvm.h Fri Sep 25 10:50:18 2009 +0100
@@ -157,6 +157,8 @@ void hvm_set_guest_time(struct vcpu *v,
void hvm_set_guest_time(struct vcpu *v, u64 guest_time);
u64 hvm_get_guest_time(struct vcpu *v);
+int hvm_girq_dest_2_vcpu_id(struct domain *d, uint8_t dest, uint8_t dest_mode);
+
#define hvm_paging_enabled(v) \
(!!((v)->arch.hvm_vcpu.guest_cr[0] & X86_CR0_PG))
#define hvm_wp_enabled(v) \
@@ -230,6 +232,7 @@ void hvm_cpuid(unsigned int input, unsig
unsigned int *ecx, unsigned int *edx);
void hvm_migrate_timers(struct vcpu *v);
void hvm_do_resume(struct vcpu *v);
+void hvm_migrate_pirqs(struct vcpu *v);
static inline void
hvm_inject_exception(unsigned int trapnr, int errcode, unsigned long cr2)
diff -r fa41a706d018 -r e1bcf240e330 xen/include/asm-x86/irq.h
--- a/xen/include/asm-x86/irq.h Fri Sep 25 10:47:36 2009 +0100
+++ b/xen/include/asm-x86/irq.h Fri Sep 25 10:50:18 2009 +0100
@@ -112,6 +112,8 @@ struct irq_desc;
struct irq_desc;
extern void irq_complete_move(struct irq_desc **descp);
+extern struct irq_desc *irq_desc;
+
void lock_vector_lock(void);
void unlock_vector_lock(void);
diff -r fa41a706d018 -r e1bcf240e330 xen/include/xen/hvm/irq.h
--- a/xen/include/xen/hvm/irq.h Fri Sep 25 10:47:36 2009 +0100
+++ b/xen/include/xen/hvm/irq.h Fri Sep 25 10:50:18 2009 +0100
@@ -50,6 +50,7 @@ struct hvm_gmsi_info {
struct hvm_gmsi_info {
uint32_t gvec;
uint32_t gflags;
+ int dest_vcpu_id; /* -1 :multi-dest, non-negative: dest_vcpu_id */
};
struct hvm_mirq_dpci_mapping {
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