[PATCH kernel v6 09/10] KVM: PPC: iommu: Unify TCE checking
Alexey Kardashevskiy
aik at ozlabs.ru
Thu Mar 2 19:56:43 AEDT 2017
This reworks helpers for checking TCE update parameters in way they
can be used in KVM.
This should cause no behavioral change.
Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
---
Changes:
v6:
* s/tce/gpa/ as TCE without permission bits is a GPA and this is what is
passed everywhere
---
arch/powerpc/include/asm/iommu.h | 20 +++++++++++++++-----
arch/powerpc/include/asm/kvm_ppc.h | 6 ++++--
arch/powerpc/kernel/iommu.c | 37 +++++++++++++------------------------
arch/powerpc/kvm/book3s_64_vio_hv.c | 31 +++++++------------------------
4 files changed, 39 insertions(+), 55 deletions(-)
diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index 82e77ebf85f4..1e6b03339a68 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -296,11 +296,21 @@ static inline void iommu_restore(void)
#endif
/* The API to support IOMMU operations for VFIO */
-extern int iommu_tce_clear_param_check(struct iommu_table *tbl,
- unsigned long ioba, unsigned long tce_value,
- unsigned long npages);
-extern int iommu_tce_put_param_check(struct iommu_table *tbl,
- unsigned long ioba, unsigned long tce);
+extern int iommu_tce_check_ioba(unsigned long page_shift,
+ unsigned long offset, unsigned long size,
+ unsigned long ioba, unsigned long npages);
+extern int iommu_tce_check_gpa(unsigned long page_shift,
+ unsigned long gpa);
+
+#define iommu_tce_clear_param_check(tbl, ioba, tce_value, npages) \
+ (iommu_tce_check_ioba((tbl)->it_page_shift, \
+ (tbl)->it_offset, (tbl)->it_size, \
+ (ioba), (npages)) || (tce_value))
+#define iommu_tce_put_param_check(tbl, ioba, gpa) \
+ (iommu_tce_check_ioba((tbl)->it_page_shift, \
+ (tbl)->it_offset, (tbl)->it_size, \
+ (ioba), 1) || \
+ iommu_tce_check_gpa((tbl)->it_page_shift, (gpa)))
extern void iommu_flush_tce(struct iommu_table *tbl);
extern int iommu_take_ownership(struct iommu_table *tbl);
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index eba8988d8443..72c2a155641f 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -169,8 +169,10 @@ extern long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
struct kvm_create_spapr_tce_64 *args);
extern struct kvmppc_spapr_tce_table *kvmppc_find_table(
struct kvm *kvm, unsigned long liobn);
-extern long kvmppc_ioba_validate(struct kvmppc_spapr_tce_table *stt,
- unsigned long ioba, unsigned long npages);
+#define kvmppc_ioba_validate(stt, ioba, npages) \
+ (iommu_tce_check_ioba((stt)->page_shift, (stt)->offset, \
+ (stt)->size, (ioba), (npages)) ? \
+ H_PARAMETER : H_SUCCESS)
extern long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *tt,
unsigned long tce);
extern long kvmppc_gpa_to_ua(struct kvm *kvm, unsigned long gpa,
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index d02b8d22fb50..4269f9f1623b 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -960,47 +960,36 @@ void iommu_flush_tce(struct iommu_table *tbl)
}
EXPORT_SYMBOL_GPL(iommu_flush_tce);
-int iommu_tce_clear_param_check(struct iommu_table *tbl,
- unsigned long ioba, unsigned long tce_value,
- unsigned long npages)
+int iommu_tce_check_ioba(unsigned long page_shift,
+ unsigned long offset, unsigned long size,
+ unsigned long ioba, unsigned long npages)
{
- /* tbl->it_ops->clear() does not support any value but 0 */
- if (tce_value)
- return -EINVAL;
+ unsigned long mask = (1UL << page_shift) - 1;
- if (ioba & ~IOMMU_PAGE_MASK(tbl))
+ if (ioba & mask)
return -EINVAL;
- ioba >>= tbl->it_page_shift;
- if (ioba < tbl->it_offset)
+ ioba >>= page_shift;
+ if (ioba < offset)
return -EINVAL;
- if ((ioba + npages) > (tbl->it_offset + tbl->it_size))
+ if ((ioba + 1) > (offset + size))
return -EINVAL;
return 0;
}
-EXPORT_SYMBOL_GPL(iommu_tce_clear_param_check);
+EXPORT_SYMBOL_GPL(iommu_tce_check_ioba);
-int iommu_tce_put_param_check(struct iommu_table *tbl,
- unsigned long ioba, unsigned long tce)
+int iommu_tce_check_gpa(unsigned long page_shift, unsigned long gpa)
{
- if (tce & ~IOMMU_PAGE_MASK(tbl))
- return -EINVAL;
-
- if (ioba & ~IOMMU_PAGE_MASK(tbl))
- return -EINVAL;
-
- ioba >>= tbl->it_page_shift;
- if (ioba < tbl->it_offset)
- return -EINVAL;
+ unsigned long mask = (1UL << page_shift) - 1;
- if ((ioba + 1) > (tbl->it_offset + tbl->it_size))
+ if (gpa & mask)
return -EINVAL;
return 0;
}
-EXPORT_SYMBOL_GPL(iommu_tce_put_param_check);
+EXPORT_SYMBOL_GPL(iommu_tce_check_gpa);
long iommu_tce_xchg(struct iommu_table *tbl, unsigned long entry,
unsigned long *hpa, enum dma_data_direction *direction)
diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c
index 0f145fc7a3a5..440d3ab5dc32 100644
--- a/arch/powerpc/kvm/book3s_64_vio_hv.c
+++ b/arch/powerpc/kvm/book3s_64_vio_hv.c
@@ -62,27 +62,6 @@ struct kvmppc_spapr_tce_table *kvmppc_find_table(struct kvm *kvm,
EXPORT_SYMBOL_GPL(kvmppc_find_table);
/*
- * Validates IO address.
- *
- * WARNING: This will be called in real-mode on HV KVM and virtual
- * mode on PR KVM
- */
-long kvmppc_ioba_validate(struct kvmppc_spapr_tce_table *stt,
- unsigned long ioba, unsigned long npages)
-{
- unsigned long mask = (1ULL << stt->page_shift) - 1;
- unsigned long idx = ioba >> stt->page_shift;
-
- if ((ioba & mask) || (idx < stt->offset) ||
- (idx - stt->offset + npages > stt->size) ||
- (idx + npages < idx))
- return H_PARAMETER;
-
- return H_SUCCESS;
-}
-EXPORT_SYMBOL_GPL(kvmppc_ioba_validate);
-
-/*
* Validates TCE address.
* At the moment flags and page mask are validated.
* As the host kernel does not access those addresses (just puts them
@@ -95,10 +74,14 @@ EXPORT_SYMBOL_GPL(kvmppc_ioba_validate);
*/
long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt, unsigned long tce)
{
- unsigned long page_mask = ~((1ULL << stt->page_shift) - 1);
- unsigned long mask = ~(page_mask | TCE_PCI_WRITE | TCE_PCI_READ);
+ unsigned long gpa = tce & ~(TCE_PCI_READ | TCE_PCI_WRITE);
+ enum dma_data_direction dir = iommu_tce_direction(tce);
- if (tce & mask)
+ /* Allow userspace to poison TCE table */
+ if (dir == DMA_NONE)
+ return H_SUCCESS;
+
+ if (iommu_tce_check_gpa(stt->page_shift, gpa))
return H_PARAMETER;
return H_SUCCESS;
--
2.11.0
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