Commit e3d8ed55 authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Michael Ellerman
Browse files

powerpc/kvm/book3s: Use find_kvm_host_pte in h_enter 



Since kvmppc_do_h_enter can get called in realmode use low level
arch_spin_lock which is safe to be called in realmode.

Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200505071729.54912-15-aneesh.kumar@linux.ibm.com
parent 9781e759

arch/powerpc/kvm/book3s_64_mmu_hv.c

+2 −3
Original line number Diff line number Diff line
@@ -281,11 +281,10 @@ static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, 
{

	long ret;



	/* Protect linux PTE lookup from page table destruction */

	rcu_read_lock_sched();	/* this disables preemption too */

	preempt_disable();

	ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel,

				kvm->mm->pgd, false, pte_idx_ret);

	rcu_read_unlock_sched();

	preempt_enable();

	if (ret == H_TOO_HARD) {

		/* this can't happen */

		pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n");

arch/powerpc/kvm/book3s_hv_rm_mmu.c

+6 −16
Original line number Diff line number Diff line
@@ -210,7 +210,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags, 
	pte_t *ptep;

	unsigned int writing;

	unsigned long mmu_seq;

	unsigned long rcbits, irq_flags = 0;

	unsigned long rcbits;



	if (kvm_is_radix(kvm))

		return H_FUNCTION;
@@ -248,17 +248,9 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags, 


	/* Translate to host virtual address */

	hva = __gfn_to_hva_memslot(memslot, gfn);

	/*

	 * If we had a page table table change after lookup, we would

	 * retry via mmu_notifier_retry.

	 */

	if (!realmode)

		local_irq_save(irq_flags);

	/*

	 * If called in real mode we have MSR_EE = 0. Otherwise

	 * we disable irq above.

	 */

	ptep = __find_linux_pte(pgdir, hva, NULL, &hpage_shift);



	arch_spin_lock(&kvm->mmu_lock.rlock.raw_lock);

	ptep = find_kvm_host_pte(kvm, mmu_seq, hva, &hpage_shift);

	if (ptep) {

		pte_t pte;

		unsigned int host_pte_size;
@@ -272,8 +264,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags, 
		 * to <= host page size, if host is using hugepage

		 */

		if (host_pte_size < psize) {

			if (!realmode)

				local_irq_restore(flags);

			arch_spin_unlock(&kvm->mmu_lock.rlock.raw_lock);

			return H_PARAMETER;

		}

		pte = kvmppc_read_update_linux_pte(ptep, writing);
@@ -287,8 +278,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags, 
			pa |= gpa & ~PAGE_MASK;

		}

	}

	if (!realmode)

		local_irq_restore(irq_flags);

	arch_spin_unlock(&kvm->mmu_lock.rlock.raw_lock);



	ptel &= HPTE_R_KEY | HPTE_R_PP0 | (psize-1);

	ptel |= pa;