From: David Gibson <david@gibson.dropbear.id.au>
To: paulus@samba.org
Cc: michael@ellerman.id.au, benh@kernel.crashing.org,
sjitindarsingh@gmail.com, thuth@redhat.com, lvivier@redhat.com,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH 06/11] powerpc/kvm: Allow KVM_PPC_ALLOCATE_HTAB ioctl() to change HPT size
Date: Thu, 15 Dec 2016 16:53:59 +1100 [thread overview]
Message-ID: <20161215055404.29351-7-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20161215055404.29351-1-david@gibson.dropbear.id.au>
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.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
arch/powerpc/include/asm/kvm_ppc.h | 2 +-
arch/powerpc/kvm/book3s_64_mmu_hv.c | 53 ++++++++++++++++++++-----------------
arch/powerpc/kvm/book3s_hv.c | 5 +---
3 files changed, 30 insertions(+), 30 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 41575b8..3b837bc 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -157,7 +157,7 @@ extern void kvmppc_map_magic(struct kvm_vcpu *vcpu);
extern int kvmppc_allocate_hpt(struct kvm_hpt_info *info, u32 order);
extern void kvmppc_set_hpt(struct kvm *kvm, struct kvm_hpt_info *info);
-extern long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp);
+extern long kvmppc_alloc_reset_hpt(struct kvm *kvm, int order);
extern void kvmppc_free_hpt(struct kvm_hpt_info *info);
extern long kvmppc_prepare_vrma(struct kvm *kvm,
struct kvm_userspace_memory_region *mem);
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 68bb228..8e5ac2f 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -104,10 +104,22 @@ 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)
+void kvmppc_free_hpt(struct kvm_hpt_info *info)
+{
+ vfree(info->rev);
+ if (info->cma)
+ kvm_free_hpt_cma(virt_to_page(info->virt),
+ 1 << (info->order - PAGE_SHIFT));
+ else
+ free_pages(info->virt, info->order - PAGE_SHIFT);
+ info->virt = 0;
+ info->order = 0;
+}
+
+long kvmppc_alloc_reset_hpt(struct kvm *kvm, int order)
{
long err = -EBUSY;
- long order;
+ struct kvm_hpt_info info;
mutex_lock(&kvm->lock);
if (kvm->arch.hpte_setup_done) {
@@ -119,8 +131,9 @@ 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);
/*
@@ -129,33 +142,23 @@ 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;
}
-void kvmppc_free_hpt(struct kvm_hpt_info *info)
-{
- vfree(info->rev);
- if (info->cma)
- kvm_free_hpt_cma(virt_to_page(info->virt),
- 1 << (info->order - PAGE_SHIFT));
- else
- free_pages(info->virt, info->order - PAGE_SHIFT);
- info->virt = 0;
- info->order = 0;
-}
-
/* Bits in first HPTE dword for pagesize 4k, 64k or 16M */
static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize)
{
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 71c5adb..957e473 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3600,12 +3600,9 @@ 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;
}
--
2.9.3
next prev parent reply other threads:[~2016-12-15 6:00 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-15 5:53 [PATCH 00/11] KVM implementation of PAPR HPT resizing extension David Gibson
2016-12-15 5:53 ` [PATCH 01/11] powerpc/kvm: Reserve capabilities and ioctls for HPT resizing David Gibson
2016-12-16 9:25 ` Thomas Huth
2016-12-19 6:36 ` David Gibson
2016-12-16 13:15 ` Thomas Huth
2016-12-19 6:37 ` David Gibson
2016-12-15 5:53 ` [PATCH 02/11] powerpc/kvm: Rename kvm_alloc_hpt() for clarity David Gibson
2016-12-16 9:03 ` Thomas Huth
2016-12-15 5:53 ` [PATCH 03/11] powerpc/kvm: Gather HPT related variables into sub-structure David Gibson
2016-12-16 9:24 ` Thomas Huth
2016-12-19 0:03 ` David Gibson
2016-12-15 5:53 ` [PATCH 04/11] powerpc/kvm: Don't store values derivable from HPT order David Gibson
2016-12-16 10:39 ` Thomas Huth
2016-12-19 0:04 ` David Gibson
2016-12-15 5:53 ` [PATCH 05/11] powerpc/kvm: Split HPT allocation from activation David Gibson
2016-12-16 11:57 ` Thomas Huth
2016-12-19 0:24 ` David Gibson
2016-12-15 5:53 ` David Gibson [this message]
2016-12-16 12:44 ` [PATCH 06/11] powerpc/kvm: Allow KVM_PPC_ALLOCATE_HTAB ioctl() to change HPT size Thomas Huth
2016-12-19 0:48 ` David Gibson
2016-12-19 7:49 ` Thomas Huth
2016-12-19 23:16 ` David Gibson
2016-12-15 5:54 ` [PATCH 07/11] powerpc/kvm: Create kvmppc_unmap_hpte_helper() David Gibson
2016-12-16 12:48 ` Thomas Huth
2016-12-15 5:54 ` [PATCH 08/11] powerpc/kvm: KVM-HV HPT resizing stub implementation David Gibson
2016-12-16 15:35 ` Thomas Huth
2016-12-15 5:54 ` [PATCH 09/11] powerpc/kvm: Outline of KVM-HV HPT resizing implementation David Gibson
2016-12-15 5:54 ` [PATCH 10/11] powerpc/kvm: " David Gibson
2016-12-15 5:54 ` [PATCH 11/11] powerpc/kvm: Advertise availablity of HPT resizing on KVM HV David Gibson
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