This patch only handle "L1 and L2 vm share one apic access page" situation.
When L1 vm is running, if the shared apic access page is migrated, mmu_notifier
will
request all vcpus to exit to L0, and reload apic access page physical address
for
all the vcpus' vmcs (which is done by patch 5/6). And when it enters L2 vm,
L2's vmcs
will be updated in prepare_vmcs02() called by nested_vm_run(). So we need to do
nothing.
When L2 vm is running, if the shared apic access page is migrated, mmu_notifier
will
request all vcpus to exit to L0, and reload apic access page physical address
for
all L2 vmcs. And this patch requests apic access page reload in L2->L1 vmexit.
Signed-off-by: Tang Chen
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/svm.c | 6 ++
arch/x86/kvm/vmx.c | 37 +
arch/x86/kvm/x86.c | 3 +++
4 files changed, 47 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 9ce6bfd..613ee7f 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -738,6 +738,7 @@ struct kvm_x86_ops {
void (*load_eoi_exitmap)(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap);
void (*set_virtual_x2apic_mode)(struct kvm_vcpu *vcpu, bool set);
void (*set_apic_access_page_addr)(struct kvm *kvm, hpa_t hpa);
+ void (*set_nested_apic_page_migrated)(struct kvm_vcpu *vcpu, bool set);
void (*deliver_posted_interrupt)(struct kvm_vcpu *vcpu, int vector);
void (*sync_pir_to_irr)(struct kvm_vcpu *vcpu);
int (*set_tss_addr)(struct kvm *kvm, unsigned int addr);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index dc76f29..87273ef 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3617,6 +3617,11 @@ static void svm_set_apic_access_page_addr(struct kvm
*kvm, hpa_t hpa)
return;
}
+static void svm_set_nested_apic_page_migrated(struct kvm_vcpu *vcpu, bool set)
+{
+ return;
+}
+
static int svm_vm_has_apicv(struct kvm *kvm)
{
return 0;
@@ -4371,6 +4376,7 @@ static struct kvm_x86_ops svm_x86_ops = {
.update_cr8_intercept = update_cr8_intercept,
.set_virtual_x2apic_mode = svm_set_virtual_x2apic_mode,
.set_apic_access_page_addr = svm_set_apic_access_page_addr,
+ .set_nested_apic_page_migrated = svm_set_nested_apic_page_migrated,
.vm_has_apicv = svm_vm_has_apicv,
.load_eoi_exitmap = svm_load_eoi_exitmap,
.hwapic_isr_update = svm_hwapic_isr_update,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c123c1d..9231afe 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -379,6 +379,16 @@ struct nested_vmx {
* we must keep them pinned while L2 runs.
*/
struct page *apic_access_page;
+ /*
+* L1's apic access page can be migrated. When L1 and L2 are sharing
+* the apic access page, after the page is migrated when L2 is running,
+* we have to reload it to L1 vmcs before we enter L1.
+*
+* When the shared apic access page is migrated in L1 mode, we don't
+* need to do anything else because we reload apic access page each
+* time when entering L2 in prepare_vmcs02().
+*/
+ bool apic_access_page_migrated;
u64 msr_ia32_feature_control;
struct hrtimer preemption_timer;
@@ -7077,6 +7087,12 @@ static void vmx_set_apic_access_page_addr(struct kvm
*kvm, hpa_t hpa)
vmcs_write64(APIC_ACCESS_ADDR, hpa);
}
+static void vmx_set_nested_apic_page_migrated(struct kvm_vcpu *vcpu, bool set)
+{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+ vmx->nested.apic_access_page_migrated = set;
+}
+
static void vmx_hwapic_isr_update(struct kvm *kvm, int isr)
{
u16 status;
@@ -8727,6 +8743,26 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32
exit_reason,
}
/*
+* When shared (L1 & L2) apic access page is migrated during L2 is
+* running, mmu_notifier will force to reload the page's hpa for L2
+* vmcs. Need to reload it for L1 before entering L1.
+*/
+ if (vmx->nested.apic_access_page_migrated) {
+ /*
+* Do not call kvm_reload_apic_access_page() because we are now
+* in L2. We should not call make_all_cpus_request() to exit to
+* L0, otherwise we will reload for L2 vmcs again.
+*/
+ int i;
+
+ for (i = 0; i < atomic_read(&vcpu->kvm->online_vcpus); i++)
+ kvm_make_request(KVM_REQ_APIC_PAGE_RELOAD,
+vcpu->kvm->vcpus[i]);
+
+ vmx->nested.apic_access_page_migrated = false;
+ }
+
+ /*
* 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