Commit 158a48ec authored by Maxim Levitsky's avatar Maxim Levitsky Committed by Paolo Bonzini
Browse files

KVM: x86: avoid loading PDPTRs after migration when possible 



if new KVM_*_SREGS2 ioctls are used, the PDPTRs are
a part of the migration state and are correctly
restored by those ioctls.

Signed-off-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210607090203.133058-9-mlevitsk@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 6dba9403

arch/x86/include/asm/kvm_host.h

+6 −0
Original line number Diff line number Diff line
@@ -862,6 +862,12 @@ struct kvm_vcpu_arch { 
	/* Protected Guests */

	bool guest_state_protected;



	/*

	 * Set when PDPTS were loaded directly by the userspace without

	 * reading the guest memory

	 */

	bool pdptrs_from_userspace;



#if IS_ENABLED(CONFIG_HYPERV)

	hpa_t hv_root_tdp;

#endif

arch/x86/kvm/svm/nested.c

+2 −1
Original line number Diff line number Diff line
@@ -1367,7 +1367,8 @@ static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu) 
	if (WARN_ON(!is_guest_mode(vcpu)))

		return true;



	if (!nested_npt_enabled(svm) && is_pae_paging(vcpu))

	if (!vcpu->arch.pdptrs_from_userspace &&

	    !nested_npt_enabled(svm) && is_pae_paging(vcpu))

		/*

		 * Reload the guest's PDPTRs since after a migration

		 * the guest CR3 might be restored prior to setting the nested

arch/x86/kvm/vmx/nested.c

+2 −1
Original line number Diff line number Diff line
@@ -3122,7 +3122,8 @@ static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) 
	struct page *page;

	u64 hpa;



	if (!nested_cpu_has_ept(vmcs12) && is_pae_paging(vcpu)) {

	if (!vcpu->arch.pdptrs_from_userspace &&

	    !nested_cpu_has_ept(vmcs12) && is_pae_paging(vcpu)) {

		/*

		 * Reload the guest's PDPTRs since after a migration

		 * the guest CR3 might be restored prior to setting the nested

arch/x86/kvm/x86.c

+3 −0
Original line number Diff line number Diff line
@@ -820,6 +820,8 @@ int load_pdptrs(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, unsigned long cr3) 


	memcpy(mmu->pdptrs, pdpte, sizeof(mmu->pdptrs));

	kvm_register_mark_dirty(vcpu, VCPU_EXREG_PDPTR);

	vcpu->arch.pdptrs_from_userspace = false;



out:



	return ret;
@@ -10265,6 +10267,7 @@ static int __set_sregs2(struct kvm_vcpu *vcpu, struct kvm_sregs2 *sregs2) 


		kvm_register_mark_dirty(vcpu, VCPU_EXREG_PDPTR);

		mmu_reset_needed = 1;

		vcpu->arch.pdptrs_from_userspace = true;

	}

	if (mmu_reset_needed)

		kvm_mmu_reset_context(vcpu);