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Message-ID: <1406144530-23002-7-git-send-email-tangchen@cn.fujitsu.com>
Date: Wed, 23 Jul 2014 15:42:10 -0400
From: Tang Chen <tangchen@...fujitsu.com>
To: <gleb@...nel.org>, <mtosatti@...hat.com>, <nadav.amit@...il.com>,
<jan.kiszka@....de>
CC: <kvm@...r.kernel.org>, <laijs@...fujitsu.com>,
<isimatu.yasuaki@...fujitsu.com>, <guz.fnst@...fujitsu.com>,
<linux-kernel@...r.kernel.org>, <tangchen@...fujitsu.com>
Subject: [PATCH v3 6/6] kvm, mem-hotplug: Reload L1's apic access page if it is migrated when L2 is running.
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 <tangchen@...fujitsu.com>
---
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 accordingly.
@@ -8847,6 +8883,7 @@ static struct kvm_x86_ops vmx_x86_ops = {
.update_cr8_intercept = update_cr8_intercept,
.set_virtual_x2apic_mode = vmx_set_virtual_x2apic_mode,
.set_apic_access_page_addr = vmx_set_apic_access_page_addr,
+ .set_nested_apic_page_migrated = vmx_set_nested_apic_page_migrated,
.vm_has_apicv = vmx_vm_has_apicv,
.load_eoi_exitmap = vmx_load_eoi_exitmap,
.hwapic_irr_update = vmx_hwapic_irr_update,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7541a66..0c11e12 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5940,6 +5940,9 @@ static void vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT);
kvm_x86_ops->set_apic_access_page_addr(vcpu->kvm,
page_to_phys(vcpu->kvm->arch.apic_access_page));
+
+ if (is_guest_mode(vcpu))
+ kvm_x86_ops->set_nested_apic_page_migrated(vcpu, true);
}
/*
--
1.8.3.1
--
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