From 2001825efcea75e4209e4956f6cd619fbc246d16 Mon Sep 17 00:00:00 2001
From: Alexey Kardashevskiy <aik@ozlabs.ru>
Date: Fri, 29 Mar 2019 16:42:20 +1100
Subject: [PATCH] KVM: PPC: Book3S HV: Avoid lockdep debugging in TCE realmode
handlers
References: bsc#1061840
References: bsc#1061840
Patch-mainline: v5.2-rc1
Git-commit: 2001825efcea75e4209e4956f6cd619fbc246d16
The kvmppc_tce_to_ua() helper is called from real and virtual modes
and it works fine as long as CONFIG_DEBUG_LOCKDEP is not enabled.
However if the lockdep debugging is on, the lockdep will most likely break
in kvm_memslots() because of srcu_dereference_check() so we need to use
PPC-own kvm_memslots_raw() which uses realmode safe
rcu_dereference_raw_notrace().
This creates a realmode copy of kvmppc_tce_to_ua() which replaces
kvm_memslots() with kvm_memslots_raw().
Since kvmppc_rm_tce_to_ua() becomes static and can only be used inside
HV KVM, this moves it earlier under CONFIG_KVM_BOOK3S_HV_POSSIBLE.
This moves truly virtual-mode kvmppc_tce_to_ua() to where it belongs and
drops the prmap parameter which was never used in the virtual mode.
Fixes: d3695aa4f452 ("KVM: PPC: Add support for multiple-TCE hcalls", 2016-02-15)
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/include/asm/kvm_ppc.h | 2 --
arch/powerpc/kvm/book3s_64_vio.c | 24 +++++++++++---
arch/powerpc/kvm/book3s_64_vio_hv.c | 51 ++++++++++++++---------------
3 files changed, 44 insertions(+), 33 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index df0b173da3e0..02732eb156ae 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -197,8 +197,6 @@ extern struct kvmppc_spapr_tce_table *kvmppc_find_table(
(iommu_tce_check_ioba((stt)->page_shift, (stt)->offset, \
(stt)->size, (ioba), (npages)) ? \
H_PARAMETER : H_SUCCESS)
-extern long kvmppc_tce_to_ua(struct kvm *kvm, unsigned long tce,
- unsigned long *ua, unsigned long **prmap);
extern void kvmppc_tce_put(struct kvmppc_spapr_tce_table *tt,
unsigned long idx, unsigned long tce);
extern long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c
index f100e331e69b..5e3b62c491f8 100644
--- a/arch/powerpc/kvm/book3s_64_vio.c
+++ b/arch/powerpc/kvm/book3s_64_vio.c
@@ -363,6 +363,22 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
return ret;
}
+static long kvmppc_tce_to_ua(struct kvm *kvm, unsigned long tce,
+ unsigned long *ua)
+{
+ unsigned long gfn = tce >> PAGE_SHIFT;
+ struct kvm_memory_slot *memslot;
+
+ memslot = search_memslots(kvm_memslots(kvm), gfn);
+ if (!memslot)
+ return -EINVAL;
+
+ *ua = __gfn_to_hva_memslot(memslot, gfn) |
+ (tce & ~(PAGE_MASK | TCE_PCI_READ | TCE_PCI_WRITE));
+
+ return 0;
+}
+
static long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt,
unsigned long tce)
{
@@ -378,7 +394,7 @@ static long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt,
if (iommu_tce_check_gpa(stt->page_shift, gpa))
return H_TOO_HARD;
- if (kvmppc_tce_to_ua(stt->kvm, tce, &ua, NULL))
+ if (kvmppc_tce_to_ua(stt->kvm, tce, &ua))
return H_TOO_HARD;
list_for_each_entry_rcu(stit, &stt->iommu_tables, next) {
@@ -551,7 +567,7 @@ long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
dir = iommu_tce_direction(tce);
- if ((dir != DMA_NONE) && kvmppc_tce_to_ua(vcpu->kvm, tce, &ua, NULL)) {
+ if ((dir != DMA_NONE) && kvmppc_tce_to_ua(vcpu->kvm, tce, &ua)) {
ret = H_PARAMETER;
goto unlock_exit;
}
@@ -612,7 +628,7 @@ long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu,
return ret;
idx = srcu_read_lock(&vcpu->kvm->srcu);
- if (kvmppc_tce_to_ua(vcpu->kvm, tce_list, &ua, NULL)) {
+ if (kvmppc_tce_to_ua(vcpu->kvm, tce_list, &ua)) {
ret = H_TOO_HARD;
goto unlock_exit;
}
@@ -647,7 +663,7 @@ long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu,
}
tce = be64_to_cpu(tce);
- if (kvmppc_tce_to_ua(vcpu->kvm, tce, &ua, NULL))
+ if (kvmppc_tce_to_ua(vcpu->kvm, tce, &ua))
return H_PARAMETER;
list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c
index 2206bc729b9a..31e59748832a 100644
--- a/arch/powerpc/kvm/book3s_64_vio_hv.c
+++ b/arch/powerpc/kvm/book3s_64_vio_hv.c
@@ -88,6 +88,25 @@ struct kvmppc_spapr_tce_table *kvmppc_find_table(struct kvm *kvm,
EXPORT_SYMBOL_GPL(kvmppc_find_table);
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+static long kvmppc_rm_tce_to_ua(struct kvm *kvm, unsigned long tce,
+ unsigned long *ua, unsigned long **prmap)
+{
+ unsigned long gfn = tce >> PAGE_SHIFT;
+ struct kvm_memory_slot *memslot;
+
+ memslot = search_memslots(kvm_memslots_raw(kvm), gfn);
+ if (!memslot)
+ return -EINVAL;
+
+ *ua = __gfn_to_hva_memslot(memslot, gfn) |
+ (tce & ~(PAGE_MASK | TCE_PCI_READ | TCE_PCI_WRITE));
+
+ if (prmap)
+ *prmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
+
+ return 0;
+}
+
/*
* Validates TCE address.
* At the moment flags and page mask are validated.
@@ -111,7 +130,7 @@ static long kvmppc_rm_tce_validate(struct kvmppc_spapr_tce_table *stt,
if (iommu_tce_check_gpa(stt->page_shift, gpa))
return H_PARAMETER;
- if (kvmppc_tce_to_ua(stt->kvm, tce, &ua, NULL))
+ if (kvmppc_rm_tce_to_ua(stt->kvm, tce, &ua, NULL))
return H_TOO_HARD;
list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
@@ -181,28 +200,6 @@ void kvmppc_tce_put(struct kvmppc_spapr_tce_table *stt,
}
EXPORT_SYMBOL_GPL(kvmppc_tce_put);
-long kvmppc_tce_to_ua(struct kvm *kvm, unsigned long tce,
- unsigned long *ua, unsigned long **prmap)
-{
- unsigned long gfn = tce >> PAGE_SHIFT;
- struct kvm_memory_slot *memslot;
-
- memslot = search_memslots(kvm_memslots(kvm), gfn);
- if (!memslot)
- return -EINVAL;
-
- *ua = __gfn_to_hva_memslot(memslot, gfn) |
- (tce & ~(PAGE_MASK | TCE_PCI_READ | TCE_PCI_WRITE));
-
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
- if (prmap)
- *prmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
-#endif
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(kvmppc_tce_to_ua);
-
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
static long iommu_tce_xchg_rm(struct mm_struct *mm, struct iommu_table *tbl,
unsigned long entry, unsigned long *hpa,
@@ -390,7 +387,7 @@ long kvmppc_rm_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
return ret;
dir = iommu_tce_direction(tce);
- if ((dir != DMA_NONE) && kvmppc_tce_to_ua(vcpu->kvm, tce, &ua, NULL))
+ if ((dir != DMA_NONE) && kvmppc_rm_tce_to_ua(vcpu->kvm, tce, &ua, NULL))
return H_PARAMETER;
entry = ioba >> stt->page_shift;
@@ -492,7 +489,7 @@ long kvmppc_rm_h_put_tce_indirect(struct kvm_vcpu *vcpu,
*/
struct mm_iommu_table_group_mem_t *mem;
- if (kvmppc_tce_to_ua(vcpu->kvm, tce_list, &ua, NULL))
+ if (kvmppc_rm_tce_to_ua(vcpu->kvm, tce_list, &ua, NULL))
return H_TOO_HARD;
mem = mm_iommu_lookup_rm(vcpu->kvm->mm, ua, IOMMU_PAGE_SIZE_4K);
@@ -508,7 +505,7 @@ long kvmppc_rm_h_put_tce_indirect(struct kvm_vcpu *vcpu,
* We do not require memory to be preregistered in this case
* so lock rmap and do __find_linux_pte_or_hugepte().
*/
- if (kvmppc_tce_to_ua(vcpu->kvm, tce_list, &ua, &rmap))
+ if (kvmppc_rm_tce_to_ua(vcpu->kvm, tce_list, &ua, &rmap))
return H_TOO_HARD;
rmap = (void *) vmalloc_to_phys(rmap);
@@ -542,7 +539,7 @@ long kvmppc_rm_h_put_tce_indirect(struct kvm_vcpu *vcpu,
unsigned long tce = be64_to_cpu(((u64 *)tces)[i]);
ua = 0;
- if (kvmppc_tce_to_ua(vcpu->kvm, tce, &ua, NULL))
+ if (kvmppc_rm_tce_to_ua(vcpu->kvm, tce, &ua, NULL))
return H_PARAMETER;
list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
--
2.20.1