KVM: nVMX: remove side effects from nested_vmx_exit_reflected

The name of nested_vmx_exit_reflected suggests that it's purely
a test, but it actually marks VMCS12 pages as dirty.  Move this to
vmx_handle_exit, observing that the initial nested_run_pending check in
nested_vmx_exit_reflected is pointless---nested_run_pending has just
been cleared in vmx_vcpu_run and won't be set until handle_vmlaunch
or handle_vmresume.

Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 8578513..4ff859c 100644 (file)
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -3527,7 +3527,7 @@ static void vmcs12_save_pending_event(struct kvm_vcpu *vcpu,
 }
 
 
-static void nested_mark_vmcs12_pages_dirty(struct kvm_vcpu *vcpu)
+void nested_mark_vmcs12_pages_dirty(struct kvm_vcpu *vcpu)
 {
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
        gfn_t gfn;
@@ -5543,8 +5543,7 @@ bool nested_vmx_exit_reflected(struct kvm_vcpu *vcpu, u32 exit_reason)
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
 
-       if (vmx->nested.nested_run_pending)
-               return false;
+       WARN_ON_ONCE(vmx->nested.nested_run_pending);
 
        if (unlikely(vmx->fail)) {
                trace_kvm_nested_vmenter_failed(
@@ -5553,19 +5552,6 @@ bool nested_vmx_exit_reflected(struct kvm_vcpu *vcpu, u32 exit_reason)
                return true;
        }
 
-       /*
-        * The host physical addresses of some pages of guest memory
-        * are loaded into the vmcs02 (e.g. vmcs12's Virtual APIC
-        * Page). The CPU may write to these pages via their host
-        * physical address while L2 is running, bypassing any
-        * address-translation-based dirty tracking (e.g. EPT write
-        * protection).
-        *
-        * Mark them dirty on every exit from L2 to prevent them from
-        * getting out of sync with dirty tracking.
-        */
-       nested_mark_vmcs12_pages_dirty(vcpu);
-
        trace_kvm_nested_vmexit(kvm_rip_read(vcpu), exit_reason,
                                vmcs_readl(EXIT_QUALIFICATION),
                                vmx->idt_vectoring_info,

diff --git a/arch/x86/kvm/vmx/nested.h b/arch/x86/kvm/vmx/nested.h
index 21d3665..f70968b 100644 (file)
--- a/arch/x86/kvm/vmx/nested.h
+++ b/arch/x86/kvm/vmx/nested.h
@@ -33,6 +33,7 @@ int vmx_get_vmx_msr(struct nested_vmx_msrs *msrs, u32 msr_index, u64 *pdata);
 int get_vmx_mem_address(struct kvm_vcpu *vcpu, unsigned long exit_qualification,
                        u32 vmx_instruction_info, bool wr, int len, gva_t *ret);
 void nested_vmx_pmu_entry_exit_ctls_update(struct kvm_vcpu *vcpu);
+void nested_mark_vmcs12_pages_dirty(struct kvm_vcpu *vcpu);
 bool nested_vmx_check_io_bitmaps(struct kvm_vcpu *vcpu, unsigned int port,
                                 int size);
 

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index b447d66..07299a9 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5851,8 +5851,23 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu,
        if (vmx->emulation_required)
                return handle_invalid_guest_state(vcpu);
 
-       if (is_guest_mode(vcpu) && nested_vmx_exit_reflected(vcpu, exit_reason))
-               return nested_vmx_reflect_vmexit(vcpu, exit_reason);
+       if (is_guest_mode(vcpu)) {
+               /*
+                * The host physical addresses of some pages of guest memory
+                * are loaded into the vmcs02 (e.g. vmcs12's Virtual APIC
+                * Page). The CPU may write to these pages via their host
+                * physical address while L2 is running, bypassing any
+                * address-translation-based dirty tracking (e.g. EPT write
+                * protection).
+                *
+                * Mark them dirty on every exit from L2 to prevent them from
+                * getting out of sync with dirty tracking.
+                */
+               nested_mark_vmcs12_pages_dirty(vcpu);
+
+               if (nested_vmx_exit_reflected(vcpu, exit_reason))
+                       return nested_vmx_reflect_vmexit(vcpu, exit_reason);
+       }
 
        if (exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY) {
                dump_vmcs();