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KVM: x86: Update IRTE for posted-interrupts
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This patch adds the routine to update IRTE for posted-interrupts
when guest changes the interrupt configuration.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
[Squashed in automatically generated patch from the build robot
 "KVM: x86: vcpu_to_pi_desc() can be static" - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Feng Wu authored and bonzini committed Oct 1, 2015
1 parent 6d7425f commit efc6440
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Showing 4 changed files with 121 additions and 0 deletions.
3 changes: 3 additions & 0 deletions arch/x86/include/asm/kvm_host.h
Original file line number Diff line number Diff line change
Expand Up @@ -897,6 +897,9 @@ struct kvm_x86_ops {
gfn_t offset, unsigned long mask);
/* pmu operations of sub-arch */
const struct kvm_pmu_ops *pmu_ops;

int (*update_pi_irte)(struct kvm *kvm, unsigned int host_irq,
uint32_t guest_irq, bool set);
};

struct kvm_arch_async_pf {
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33 changes: 33 additions & 0 deletions arch/x86/kvm/trace.h
Original file line number Diff line number Diff line change
Expand Up @@ -992,6 +992,39 @@ TRACE_EVENT(kvm_enter_smm,
__entry->smbase)
);

/*
* Tracepoint for VT-d posted-interrupts.
*/
TRACE_EVENT(kvm_pi_irte_update,
TP_PROTO(unsigned int vcpu_id, unsigned int gsi,
unsigned int gvec, u64 pi_desc_addr, bool set),
TP_ARGS(vcpu_id, gsi, gvec, pi_desc_addr, set),

TP_STRUCT__entry(
__field( unsigned int, vcpu_id )
__field( unsigned int, gsi )
__field( unsigned int, gvec )
__field( u64, pi_desc_addr )
__field( bool, set )
),

TP_fast_assign(
__entry->vcpu_id = vcpu_id;
__entry->gsi = gsi;
__entry->gvec = gvec;
__entry->pi_desc_addr = pi_desc_addr;
__entry->set = set;
),

TP_printk("VT-d PI is %s for this irq, vcpu %u, gsi: 0x%x, "
"gvec: 0x%x, pi_desc_addr: 0x%llx",
__entry->set ? "enabled and being updated" : "disabled",
__entry->vcpu_id,
__entry->gsi,
__entry->gvec,
__entry->pi_desc_addr)
);

#endif /* _TRACE_KVM_H */

#undef TRACE_INCLUDE_PATH
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83 changes: 83 additions & 0 deletions arch/x86/kvm/vmx.c
Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,7 @@
#include <asm/debugreg.h>
#include <asm/kexec.h>
#include <asm/apic.h>
#include <asm/irq_remapping.h>

#include "trace.h"
#include "pmu.h"
Expand Down Expand Up @@ -603,6 +604,11 @@ static inline struct vcpu_vmx *to_vmx(struct kvm_vcpu *vcpu)
return container_of(vcpu, struct vcpu_vmx, vcpu);
}

static struct pi_desc *vcpu_to_pi_desc(struct kvm_vcpu *vcpu)
{
return &(to_vmx(vcpu)->pi_desc);
}

#define VMCS12_OFFSET(x) offsetof(struct vmcs12, x)
#define FIELD(number, name) [number] = VMCS12_OFFSET(name)
#define FIELD64(number, name) [number] = VMCS12_OFFSET(name), \
Expand Down Expand Up @@ -10345,6 +10351,81 @@ static void vmx_enable_log_dirty_pt_masked(struct kvm *kvm,
kvm_mmu_clear_dirty_pt_masked(kvm, memslot, offset, mask);
}

/*
* vmx_update_pi_irte - set IRTE for Posted-Interrupts
*
* @kvm: kvm
* @host_irq: host irq of the interrupt
* @guest_irq: gsi of the interrupt
* @set: set or unset PI
* returns 0 on success, < 0 on failure
*/
static int vmx_update_pi_irte(struct kvm *kvm, unsigned int host_irq,
uint32_t guest_irq, bool set)
{
struct kvm_kernel_irq_routing_entry *e;
struct kvm_irq_routing_table *irq_rt;
struct kvm_lapic_irq irq;
struct kvm_vcpu *vcpu;
struct vcpu_data vcpu_info;
int idx, ret = -EINVAL;

if (!kvm_arch_has_assigned_device(kvm) ||
!irq_remapping_cap(IRQ_POSTING_CAP))
return 0;

idx = srcu_read_lock(&kvm->irq_srcu);
irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
BUG_ON(guest_irq >= irq_rt->nr_rt_entries);

hlist_for_each_entry(e, &irq_rt->map[guest_irq], link) {
if (e->type != KVM_IRQ_ROUTING_MSI)
continue;
/*
* VT-d PI cannot support posting multicast/broadcast
* interrupts to a vCPU, we still use interrupt remapping
* for these kind of interrupts.
*
* For lowest-priority interrupts, we only support
* those with single CPU as the destination, e.g. user
* configures the interrupts via /proc/irq or uses
* irqbalance to make the interrupts single-CPU.
*
* We will support full lowest-priority interrupt later.
*/

kvm_set_msi_irq(e, &irq);
if (!kvm_intr_is_single_vcpu(kvm, &irq, &vcpu))
continue;

vcpu_info.pi_desc_addr = __pa(vcpu_to_pi_desc(vcpu));
vcpu_info.vector = irq.vector;

trace_kvm_pi_irte_update(vcpu->vcpu_id, e->gsi,
vcpu_info.vector, vcpu_info.pi_desc_addr, set);

if (set)
ret = irq_set_vcpu_affinity(host_irq, &vcpu_info);
else {
/* suppress notification event before unposting */
pi_set_sn(vcpu_to_pi_desc(vcpu));
ret = irq_set_vcpu_affinity(host_irq, NULL);
pi_clear_sn(vcpu_to_pi_desc(vcpu));
}

if (ret < 0) {
printk(KERN_INFO "%s: failed to update PI IRTE\n",
__func__);
goto out;
}
}

ret = 0;
out:
srcu_read_unlock(&kvm->irq_srcu, idx);
return ret;
}

static struct kvm_x86_ops vmx_x86_ops = {
.cpu_has_kvm_support = cpu_has_kvm_support,
.disabled_by_bios = vmx_disabled_by_bios,
Expand Down Expand Up @@ -10462,6 +10543,8 @@ static struct kvm_x86_ops vmx_x86_ops = {
.enable_log_dirty_pt_masked = vmx_enable_log_dirty_pt_masked,

.pmu_ops = &intel_pmu_ops,

.update_pi_irte = vmx_update_pi_irte,
};

static int __init vmx_init(void)
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2 changes: 2 additions & 0 deletions arch/x86/kvm/x86.c
Original file line number Diff line number Diff line change
Expand Up @@ -64,6 +64,7 @@
#include <asm/fpu/internal.h> /* Ugh! */
#include <asm/pvclock.h>
#include <asm/div64.h>
#include <asm/irq_remapping.h>

#define MAX_IO_MSRS 256
#define KVM_MAX_MCE_BANKS 32
Expand Down Expand Up @@ -8094,3 +8095,4 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_intercepts);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_write_tsc_offset);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_ple_window);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_pml_full);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_pi_irte_update);

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