Commit 96b100cd authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

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: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent bb03911f

arch/x86/kvm/vmx/nested.c

+2 −16
Original line number Diff line number Diff line
@@ -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,

arch/x86/kvm/vmx/nested.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

arch/x86/kvm/vmx/vmx.c

+17 −2
Original line number Diff line number Diff line
@@ -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))

	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();

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