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authorDavid Gibson <david@gibson.dropbear.id.au>2016-12-20 08:49:03 +0300
committerPaul Mackerras <paulus@ozlabs.org>2017-01-31 13:59:45 +0300
commitf98a8bf9ee201b7e22fc05e27150b1e481d4949f (patch)
tree31932af265df115788214cc9bc0501fb4b7f509a /arch/powerpc/kvm
parentaae0777f1e8224b4fbb78b2c692060852ee750c8 (diff)
downloadlinux-f98a8bf9ee201b7e22fc05e27150b1e481d4949f.tar.xz
KVM: PPC: Book3S HV: Allow KVM_PPC_ALLOCATE_HTAB ioctl() to change HPT size
The KVM_PPC_ALLOCATE_HTAB ioctl() is used to set the size of hashed page table (HPT) that userspace expects a guest VM to have, and is also used to clear that HPT when necessary (e.g. guest reboot). At present, once the ioctl() is called for the first time, the HPT size can never be changed thereafter - it will be cleared but always sized as from the first call. With upcoming HPT resize implementation, we're going to need to allow userspace to resize the HPT at reset (to change it back to the default size if the guest changed it). So, we need to allow this ioctl() to change the HPT size. This patch also updates Documentation/virtual/kvm/api.txt to reflect the new behaviour. In fact the documentation was already slightly incorrect since 572abd5 "KVM: PPC: Book3S HV: Don't fall back to smaller HPT size in allocation ioctl" Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Diffstat (limited to 'arch/powerpc/kvm')
-rw-r--r--arch/powerpc/kvm/book3s_64_mmu_hv.c29
-rw-r--r--arch/powerpc/kvm/book3s_hv.c5
2 files changed, 17 insertions, 17 deletions
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 62d132a3cec5..3a607faf0f9f 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -102,10 +102,10 @@ void kvmppc_set_hpt(struct kvm *kvm, struct kvm_hpt_info *info)
info->virt, (long)info->order, kvm->arch.lpid);
}
-long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp)
+long kvmppc_alloc_reset_hpt(struct kvm *kvm, int order)
{
long err = -EBUSY;
- long order;
+ struct kvm_hpt_info info;
if (kvm_is_radix(kvm))
return -EINVAL;
@@ -120,8 +120,9 @@ long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp)
goto out;
}
}
- if (kvm->arch.hpt.virt) {
- order = kvm->arch.hpt.order;
+ if (kvm->arch.hpt.order == order) {
+ /* We already have a suitable HPT */
+
/* Set the entire HPT to 0, i.e. invalid HPTEs */
memset((void *)kvm->arch.hpt.virt, 0, 1ul << order);
/*
@@ -130,17 +131,19 @@ long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp)
kvmppc_rmap_reset(kvm);
/* Ensure that each vcpu will flush its TLB on next entry. */
cpumask_setall(&kvm->arch.need_tlb_flush);
- *htab_orderp = order;
err = 0;
- } else {
- struct kvm_hpt_info info;
-
- err = kvmppc_allocate_hpt(&info, *htab_orderp);
- if (err < 0)
- goto out;
- kvmppc_set_hpt(kvm, &info);
+ goto out;
}
- out:
+
+ if (kvm->arch.hpt.virt)
+ kvmppc_free_hpt(&kvm->arch.hpt);
+
+ err = kvmppc_allocate_hpt(&info, order);
+ if (err < 0)
+ goto out;
+ kvmppc_set_hpt(kvm, &info);
+
+out:
mutex_unlock(&kvm->lock);
return err;
}
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 19987e4343c3..fbc901746304 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3704,12 +3704,9 @@ static long kvm_arch_vm_ioctl_hv(struct file *filp,
r = -EFAULT;
if (get_user(htab_order, (u32 __user *)argp))
break;
- r = kvmppc_alloc_reset_hpt(kvm, &htab_order);
+ r = kvmppc_alloc_reset_hpt(kvm, htab_order);
if (r)
break;
- r = -EFAULT;
- if (put_user(htab_order, (u32 __user *)argp))
- break;
r = 0;
break;
}