We are handling "L1 and L2 share one apic access page" situation when migrating
apic access page. We should do some handling when migration happens in the
following situations:
1) when L0 is running: Update L1's vmcs in the next L0->L1 entry and L2's
vmcs in the next L1->L2 entry.
2) when L1 is running: Force a L1->L0 exit, update L1's vmcs in the next
L0->L1 entry and L2's vmcs in the next L1->L2 entry.
3) when L2 is running: Force a L2->L0 exit, update L2's vmcs in the next
L0->L2 entry and L1's vmcs in the next L2->L1 exit.
This patch handles 3).
In L0->L2 entry, L2's vmcs will be updated in prepare_vmcs02() called by
nested_vm_run(). So we need to do nothing.
In L2->L1 exit, this patch requests apic access page reload in L2->L1 vmexit.
Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/vmx.c | 6 ++++++
arch/x86/kvm/x86.c | 3 ++-
3 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 56156eb..1a8317e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1047,6 +1047,7 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
int kvm_cpu_get_interrupt(struct kvm_vcpu *v);
void kvm_vcpu_reset(struct kvm_vcpu *vcpu);
+void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu);
void kvm_define_shared_msr(unsigned index, u32 msr);
void kvm_set_shared_msr(unsigned index, u64 val, u64 mask);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c8e90ec..baac78a 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8803,6 +8803,12 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
}
/*
+ * We are now running in L2, mmu_notifier will force to reload the
+ * page's hpa for L2 vmcs. Need to reload it for L1 before entering L1.
+ */
+ kvm_vcpu_reload_apic_access_page(vcpu);
+
+ /*
* Exiting from L2 to L1, we're now back to L1 which thinks it just
* finished a VMLAUNCH or VMRESUME instruction, so we need to set the
* success or failure flag accordingly.
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fc54fa6..2ae2dc7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5989,7 +5989,7 @@ static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
kvm_apic_update_tmr(vcpu, tmr);
}
-static void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
+void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
{
/*
* Only APIC access page shared by L1 and L2 vm is handled. The APIC
@@ -6009,6 +6009,7 @@ static void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
page_to_phys(vcpu->kvm->arch.apic_access_page));
}
}
+EXPORT_SYMBOL_GPL(kvm_vcpu_reload_apic_access_page);
/*
* Returns 1 to let __vcpu_run() continue the guest execution loop without
--
1.8.3.1
--
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