It is possible that prepare_vmcs02 fails to load the guest state. This
patch adds the proper error handling for such a case. L1 will receive
an INVALID_STATE vmexit with the appropriate exit qualification if it
happens.
A failure to set guest CR3 is the only error propagated from prepare_vmcs02
at the moment.
Signed-off-by: Ladi Prosek <lprosek@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 034dc7a..70598a1 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -9803,8 +9803,11 @@ static int nested_vmx_store_msr(struct kvm_vcpu *vcpu, u64 gpa, u32 count)
* needs. In addition to modifying the active vmcs (which is vmcs02), this
* function also has additional necessary side-effects, like setting various
* vcpu->arch fields.
+ * Returns 0 on success, 1 on failure. Invalid state exit qualification code
+ * is assigned to entry_failure_code on failure.
*/
-static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
+static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
+ unsigned long *entry_failure_code)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
u32 exec_control;
@@ -10124,8 +10127,12 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
nested_ept_enabled) {
vcpu->arch.cr3 = vmcs12->guest_cr3;
__set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);
- } else
- kvm_set_cr3(vcpu, vmcs12->guest_cr3);
+ } else {
+ if (kvm_set_cr3(vcpu, vmcs12->guest_cr3)) {
+ *entry_failure_code = ENTRY_FAIL_DEFAULT;
+ return 1;
+ }
+ }
kvm_mmu_reset_context(vcpu);
@@ -10144,6 +10151,7 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
kvm_register_write(vcpu, VCPU_REGS_RSP, vmcs12->guest_rsp);
kvm_register_write(vcpu, VCPU_REGS_RIP, vmcs12->guest_rip);
+ return 0;
}
/*
@@ -10158,6 +10166,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
struct loaded_vmcs *vmcs02;
bool ia32e;
u32 msr_entry_idx;
+ unsigned long exit_qualification;
if (!nested_vmx_check_permission(vcpu) ||
!nested_vmx_check_vmcs12(vcpu))
@@ -10313,7 +10322,13 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
vmx_segment_cache_clear(vmx);
- prepare_vmcs02(vcpu, vmcs12);
+ if (prepare_vmcs02(vcpu, vmcs12, &exit_qualification)) {
+ leave_guest_mode(vcpu);
+ vmx_load_vmcs01(vcpu);
+ nested_vmx_entry_failure(vcpu, vmcs12,
+ EXIT_REASON_INVALID_STATE, exit_qualification);
+ return 1;
+ }
msr_entry_idx = nested_vmx_load_msr(vcpu,
vmcs12->vm_entry_msr_load_addr,
--
2.7.4
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