This is done is done as a preparation to VMCS shadowing emulation.
Signed-off-by: Liran Alon <liran.alon@xxxxxxxxxx>
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 74 insertions(+)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 4906bb645ec9..dbbd7e5b49a7 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -645,6 +645,12 @@ struct nested_vmx {
*/
struct vmcs12 *cached_vmcs12;
/*
+ * Cache of the guest's shadow VMCS, existing outside of guest
+ * memory. Loaded from guest memory during VM entry. Flushed
+ * to guest memory during VM exit.
+ */
+ struct vmcs12 *cached_shadow_vmcs12;
+ /*
* Indicates if the shadow vmcs must be updated with the
* data hold by vmcs12
*/
@@ -1077,6 +1083,11 @@ static inline struct vmcs12 *get_vmcs12(struct kvm_vcpu *vcpu)
return to_vmx(vcpu)->nested.cached_vmcs12;
}
+static inline struct vmcs12 *get_shadow_vmcs12(struct kvm_vcpu *vcpu)
+{
+ return to_vmx(vcpu)->nested.cached_shadow_vmcs12;
+}
+
static bool nested_ept_ad_enabled(struct kvm_vcpu *vcpu);
static unsigned long nested_ept_get_cr3(struct kvm_vcpu *vcpu);
static u64 construct_eptp(struct kvm_vcpu *vcpu, unsigned long root_hpa);
@@ -7859,6 +7870,10 @@ static int enter_vmx_operation(struct kvm_vcpu *vcpu)
if (!vmx->nested.cached_vmcs12)
goto out_cached_vmcs12;
+ vmx->nested.cached_shadow_vmcs12 = kmalloc(VMCS12_SIZE, GFP_KERNEL);
+ if (!vmx->nested.cached_shadow_vmcs12)
+ goto out_cached_shadow_vmcs12;
+
if (enable_shadow_vmcs) {
shadow_vmcs = alloc_vmcs();
if (!shadow_vmcs)
@@ -7878,6 +7893,9 @@ static int enter_vmx_operation(struct kvm_vcpu *vcpu)
return 0;
out_shadow_vmcs:
+ kfree(vmx->nested.cached_shadow_vmcs12);
+
+out_cached_shadow_vmcs12:
kfree(vmx->nested.cached_vmcs12);
out_cached_vmcs12:
@@ -8044,6 +8062,7 @@ static void free_nested(struct vcpu_vmx *vmx)
vmx->vmcs01.shadow_vmcs = NULL;
}
kfree(vmx->nested.cached_vmcs12);
+ kfree(vmx->nested.cached_shadow_vmcs12);
/* Unpin physical memory we referred to in the vmcs02 */
if (vmx->nested.apic_access_page) {
kvm_release_page_dirty(vmx->nested.apic_access_page);
@@ -10885,6 +10904,38 @@ static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu,
return true;
}
+static void nested_cache_shadow_vmcs12(struct kvm_vcpu *vcpu,
+ struct vmcs12 *vmcs12)
+{
+ struct vmcs12 *shadow;
+ struct page *page;
+
+ if (!nested_cpu_has_shadow_vmcs(vmcs12) ||
+ vmcs12->vmcs_link_pointer == -1ull)
+ return;
+
+ shadow = get_shadow_vmcs12(vcpu);
+ page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->vmcs_link_pointer);
+
+ memcpy(shadow, kmap(page), VMCS12_SIZE);
+
+ kunmap(page);
+ kvm_release_page_clean(page);
+}
+
+static void nested_flush_cached_shadow_vmcs12(struct kvm_vcpu *vcpu,
+ struct vmcs12 *vmcs12)
+{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+ if (!nested_cpu_has_shadow_vmcs(vmcs12) ||
+ vmcs12->vmcs_link_pointer == -1ull)
+ return;
+
+ kvm_write_guest(vmx->vcpu.kvm, vmcs12->vmcs_link_pointer,
+ get_shadow_vmcs12(vcpu), VMCS12_SIZE);
+}
+
static int nested_vmx_check_apic_access_controls(struct kvm_vcpu *vcpu,
struct vmcs12 *vmcs12)
{
@@ -11884,6 +11935,18 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
}
/*
+ * Must happen outside of enter_vmx_non_root_mode() as it will
+ * also be used as part of restoring nVMX state for
+ * snapshot restore (migration).
+ *
+ * In this flow, it is assumed that vmcs12 cache was
+ * trasferred as part of captured nVMX state and should
+ * therefore not be read from guest memory (which may not
+ * exist on destination host yet).
+ */
+ nested_cache_shadow_vmcs12(vcpu, vmcs12);
+
+ /*
* If we're entering a halted L2 vcpu and the L2 vcpu won't be woken
* by event injection, halt vcpu.
*/
@@ -12392,6 +12455,17 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
prepare_vmcs12(vcpu, vmcs12, exit_reason, exit_intr_info,
exit_qualification);
+ /*
+ * Must happen outside of sync_vmcs12() as it will
+ * also be used to capture vmcs12 cache as part of
+ * capturing nVMX state for snapshot (migration).
+ *
+ * Otherwise, this flush will dirty guest memory at a
+ * point it is already assumed by user-space to be
+ * immutable.
+ */
+ nested_flush_cached_shadow_vmcs12(vcpu, vmcs12);
+
if (nested_vmx_store_msr(vcpu, vmcs12->vm_exit_msr_store_addr,
vmcs12->vm_exit_msr_store_count))
nested_vmx_abort(vcpu, VMX_ABORT_SAVE_GUEST_MSR_FAIL);
--
1.9.1
