[PATCH v1 06/13] KVM: PPC: Add @offset to kvmppc_spapr_tce_table

[Alexey Kardashevskiy <aik@ozlabs.ru>]

This enables guest visible TCE tables to start from non-zero offset
on a bus. This will be used for VFIO support.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/include/asm/kvm_host.h | 1 +
 arch/powerpc/kvm/book3s_64_vio_hv.c | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index d3a154c..ed96b09 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -181,6 +181,7 @@ struct kvmppc_spapr_tce_table {
 	struct kvm *kvm;
 	u64 liobn;
 	u32 page_shift;
+	u64 offset;		/* in pages */
 	u64 size;		/* in pages */
 	struct page *pages[0];
 };
diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c
index fadfacb..a3a6597 100644
--- a/arch/powerpc/kvm/book3s_64_vio_hv.c
+++ b/arch/powerpc/kvm/book3s_64_vio_hv.c
@@ -74,7 +74,8 @@ long kvmppc_ioba_validate(struct kvmppc_spapr_tce_table *stt,
 	unsigned long mask = (1 << IOMMU_PAGE_SHIFT_4K) - 1;
 	unsigned long idx = ioba >> IOMMU_PAGE_SHIFT_4K;
 
-	if ((ioba & mask) || (stt->size + npages <= idx))
+	if ((ioba & mask) || (idx < stt->offset) ||
+			(stt->offset + stt->size + npages <= idx))
 		return H_PARAMETER;
 
 	return H_SUCCESS;
@@ -146,6 +147,7 @@ void kvmppc_tce_put(struct kvmppc_spapr_tce_table *stt,
 	struct page *page;
 	u64 *tbl;
 
+	idx -= stt->offset;
 	page = stt->pages[idx / TCES_PER_PAGE];
 	tbl = kvmppc_page_address(page);
 
@@ -351,6 +353,7 @@ long kvmppc_h_get_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
 		return ret;
 
 	idx = ioba >> IOMMU_PAGE_SHIFT_4K;
+	idx -= stt->offset;
 	page = stt->pages[idx / TCES_PER_PAGE];
 	tbl = (u64 *)page_address(page);
 
-- 
2.0.0