Implement dirty list full forcing vcpus to exit.
Signed-off-by: Lei Cao <lei.cao@xxxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 7 +++++++
arch/x86/kvm/mmu.c | 7 +++++++
arch/x86/kvm/vmx.c | 7 +++++++
arch/x86/kvm/x86.c | 10 ++++++++++
include/linux/kvm_host.h | 1 +
include/uapi/linux/kvm.h | 1 +
virt/kvm/kvm_main.c | 36 ++++++++++++++++++++++++++++++++++++
7 files changed, 69 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 6dfb14a..20a9fc8 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -75,6 +75,7 @@
#define KVM_REQ_HV_RESET 28
#define KVM_REQ_HV_EXIT 29
#define KVM_REQ_HV_STIMER 30
+#define KVM_REQ_EXIT_DIRTY_LOG_FULL 31
#define CR0_RESERVED_BITS \
(~(unsigned long)(X86_CR0_PE | X86_CR0_MP | X86_CR0_EM | X86_CR0_TS \
@@ -997,6 +998,8 @@ struct kvm_x86_ops {
* - enable_log_dirty_pt_masked:
* called when reenabling log dirty for the GFNs in the mask after
* corresponding bits are cleared in slot->dirty_bitmap.
+ * - cpu_dirty_log_size:
+ * called to inquire about the size of the hardware dirty log
*/
void (*slot_enable_log_dirty)(struct kvm *kvm,
struct kvm_memory_slot *slot);
@@ -1006,6 +1009,8 @@ struct kvm_x86_ops {
void (*enable_log_dirty_pt_masked)(struct kvm *kvm,
struct kvm_memory_slot *slot,
gfn_t offset, unsigned long mask);
+ int (*cpu_dirty_log_size)(void);
+
/* pmu operations of sub-arch */
const struct kvm_pmu_ops *pmu_ops;
@@ -1388,6 +1393,8 @@ bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
void kvm_set_msi_irq(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e,
struct kvm_lapic_irq *irq);
+int kvm_mt_cpu_dirty_log_size(void);
+
static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu)
{
if (kvm_x86_ops->vcpu_blocking)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 7012de4..e0668a0 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4980,6 +4980,13 @@ void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, struct kvm_memslots *slots)
}
}
+int kvm_mt_cpu_dirty_log_size(void)
+{
+ if (kvm_x86_ops->cpu_dirty_log_size)
+ return kvm_x86_ops->cpu_dirty_log_size();
+ return 0;
+}
+
static unsigned long
mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
{
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ba20b00..76f88b0 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6729,6 +6729,7 @@ static __init int hardware_setup(void)
kvm_x86_ops->slot_disable_log_dirty = NULL;
kvm_x86_ops->flush_log_dirty = NULL;
kvm_x86_ops->enable_log_dirty_pt_masked = NULL;
+ kvm_x86_ops->cpu_dirty_log_size = NULL;
}
if (cpu_has_vmx_preemption_timer() && enable_preemption_timer) {
@@ -11503,6 +11504,11 @@ static void vmx_setup_mce(struct kvm_vcpu *vcpu)
~FEATURE_CONTROL_LMCE;
}
+static int vmx_cpu_dirty_log_size(void)
+{
+ return PML_ENTITY_NUM;
+}
+
static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
.cpu_has_kvm_support = cpu_has_kvm_support,
.disabled_by_bios = vmx_disabled_by_bios,
@@ -11617,6 +11623,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
.slot_disable_log_dirty = vmx_slot_disable_log_dirty,
.flush_log_dirty = vmx_flush_log_dirty,
.enable_log_dirty_pt_masked = vmx_enable_log_dirty_pt_masked,
+ .cpu_dirty_log_size = vmx_cpu_dirty_log_size,
.pre_block = vmx_pre_block,
.post_block = vmx_post_block,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5707129..e2f4cee 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6714,6 +6714,16 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
*/
if (kvm_check_request(KVM_REQ_HV_STIMER, vcpu))
kvm_hv_process_stimers(vcpu);
+ if (kvm_check_request(KVM_REQ_EXIT_DIRTY_LOG_FULL, vcpu)) {
+ vcpu->run->exit_reason = KVM_EXIT_DIRTY_LOG_FULL;
+ r = -EINTR;
+ if (vcpu->need_exit) {
+ vcpu->need_exit = false;
+ kvm_make_all_cpus_request(vcpu->kvm,
+ KVM_REQ_EXIT_DIRTY_LOG_FULL);
+ }
+ goto out;
+ }
}
/*
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 7a85b30..b7fedeb 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -283,6 +283,7 @@ struct kvm_vcpu {
struct dentry *debugfs_dentry;
#ifdef KVM_DIRTY_LOG_PAGE_OFFSET
struct gfn_list_t *dirty_logs;
+ bool need_exit;
#endif
};
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 05332de..bacb8db 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -205,6 +205,7 @@ struct kvm_hyperv_exit {
#define KVM_EXIT_S390_STSI 25
#define KVM_EXIT_IOAPIC_EOI 26
#define KVM_EXIT_HYPERV 27
+#define KVM_EXIT_DIRTY_LOG_FULL 28
/* For KVM_EXIT_INTERNAL_ERROR */
/* Emulate instruction failed. */
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index bff980c..00d7989 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -270,6 +270,7 @@ int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
}
vcpu->dirty_logs = page_address(page);
}
+ vcpu->need_exit = false;
#endif
kvm_vcpu_set_in_spin_loop(vcpu, false);
@@ -3030,6 +3031,29 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
}
#ifdef KVM_DIRTY_LOG_PAGE_OFFSET
+static void kvm_mt_dirty_log_full(struct kvm *kvm, struct kvm_vcpu *vcpu)
+{
+ /*
+ * Request vcpu exits, but if interrupts are disabled, we have
+ * to defer the requests because smp_call_xxx may deadlock when
+ * called that way.
+ */
+ if (vcpu && irqs_disabled()) {
+ kvm_make_request(KVM_REQ_EXIT_DIRTY_LOG_FULL, vcpu);
+ vcpu->need_exit = true;
+ } else {
+ WARN_ON(irqs_disabled());
+ kvm_make_all_cpus_request(kvm,
+ KVM_REQ_EXIT_DIRTY_LOG_FULL);
+ }
+}
+
+/*
+ * estimated number of pages being dirtied during vcpu exit, not counting
+ * hardware dirty log (PML) flush
+ */
+#define KVM_MT_DIRTY_PAGE_NUM_EXTRA 128
+
void kvm_mt_mark_page_dirty(struct kvm *kvm, struct kvm_memory_slot *slot,
struct kvm_vcpu *vcpu, gfn_t gfn)
{
@@ -3037,6 +3061,7 @@ void kvm_mt_mark_page_dirty(struct kvm *kvm, struct kvm_memory_slot *slot,
int slot_id;
u32 as_id = 0;
u64 offset;
+ u32 extra = KVM_MT_DIRTY_PAGE_NUM_EXTRA;
if (!slot || !slot->dirty_bitmap || !kvm->dirty_log_size)
return;
@@ -3068,6 +3093,17 @@ void kvm_mt_mark_page_dirty(struct kvm *kvm, struct kvm_memory_slot *slot,
gfnlist->dirty_gfns[gfnlist->dirty_index].offset = offset;
smp_wmb();
gfnlist->dirty_index++;
+
+ /*
+ * more pages will be dirtied during vcpu exit, e.g. pml log
+ * being flushed. So allow some buffer space.
+ */
+ if (vcpu)
+ extra += kvm_mt_cpu_dirty_log_size();
+
+ if (gfnlist->dirty_index == (kvm->max_dirty_logs - extra))
+ kvm_mt_dirty_log_full(kvm, vcpu);
+
if (!vcpu)
spin_unlock(&kvm->dirty_log_lock);
}
--
2.5.0
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