[PATCH v6 1/2] KVM: nVMX: introduce nested_get_vmcs12_pages

From: Wanpeng Li
Date: Thu Aug 21 2014 - 07:44:40 EST


Introduce function nested_get_vmcs12_pages() to check the valid
of nested apic access page and virtual apic page earlier.

Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxxxxxx>
---
v5 -> v6:
* replace the name apic_access_and_virtual_page_valid by nested_get_vmcs12_pages

arch/x86/kvm/vmx.c | 37 +++++++++++++++++++++++++------------
1 file changed, 25 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 286c283..24380a9 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7826,6 +7826,30 @@ static void vmx_inject_page_fault_nested(struct kvm_vcpu *vcpu,
kvm_inject_page_fault(vcpu, fault);
}

+static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu,
+ struct vmcs12 *vmcs12)
+{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+ if (nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) {
+ if (!PAGE_ALIGNED(vmcs12->apic_access_addr))
+ /*TODO: Also verify bits beyond physical address width are 0*/
+ return false;
+
+ /*
+ * Translate L1 physical address to host physical
+ * address for vmcs02. Keep the page pinned, so this
+ * physical address remains valid. We keep a reference
+ * to it so we can release it later.
+ */
+ if (vmx->nested.apic_access_page) /* shouldn't happen */
+ nested_release_page(vmx->nested.apic_access_page);
+ vmx->nested.apic_access_page =
+ nested_get_page(vcpu, vmcs12->apic_access_addr);
+ }
+ return true;
+}
+
static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu)
{
u64 preemption_timeout = get_vmcs12(vcpu)->vmx_preemption_timer_value;
@@ -7972,16 +7996,6 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)

if (exec_control & SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES) {
/*
- * Translate L1 physical address to host physical
- * address for vmcs02. Keep the page pinned, so this
- * physical address remains valid. We keep a reference
- * to it so we can release it later.
- */
- if (vmx->nested.apic_access_page) /* shouldn't happen */
- nested_release_page(vmx->nested.apic_access_page);
- vmx->nested.apic_access_page =
- nested_get_page(vcpu, vmcs12->apic_access_addr);
- /*
* If translation failed, no matter: This feature asks
* to exit when accessing the given address, and if it
* can never be accessed, this feature won't do
@@ -8187,8 +8201,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
return 1;
}

- if (nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES) &&
- !PAGE_ALIGNED(vmcs12->apic_access_addr)) {
+ if (!nested_get_vmcs12_pages(vcpu, vmcs12)) {
/*TODO: Also verify bits beyond physical address width are 0*/
nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
return 1;
--
1.9.1

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