[PATCH kernel 2/2] KVM: PPC: Allow backing bigger guest IOMMU pages with smaller physical pages
Alexey Kardashevskiy
aik at ozlabs.ru
Wed May 2 14:07:23 AEST 2018
At the moment we only support in the host the IOMMU page sizes which
the guest is aware of, which is 4KB/64KB/16MB. However P9 does not support
16MB IOMMU pages, 2MB and 1GB pages are supported instead. We can still
emulate bigger guest pages (for example 16MB) with smaller host pages
(4KB/64KB/2MB).
This allows the physical IOMMU pages to use a page size smaller or equal
than the guest visible IOMMU page size.
Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
---
arch/powerpc/kvm/book3s_64_vio.c | 66 +++++++++++++++++++++++++++++--------
arch/powerpc/kvm/book3s_64_vio_hv.c | 52 +++++++++++++++++++++++++----
2 files changed, 98 insertions(+), 20 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c
index 041e54d..e10d6a3 100644
--- a/arch/powerpc/kvm/book3s_64_vio.c
+++ b/arch/powerpc/kvm/book3s_64_vio.c
@@ -176,14 +176,12 @@ extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd,
if (!tbltmp)
continue;
- /*
- * Make sure hardware table parameters are exactly the same;
- * this is used in the TCE handlers where boundary checks
- * use only the first attached table.
- */
- if ((tbltmp->it_page_shift == stt->page_shift) &&
- (tbltmp->it_offset == stt->offset) &&
- (tbltmp->it_size == stt->size)) {
+ /* Make sure hardware table parameters are compatible */
+ if ((tbltmp->it_page_shift <= stt->page_shift) &&
+ (tbltmp->it_offset << tbltmp->it_page_shift ==
+ stt->offset << stt->page_shift) &&
+ (tbltmp->it_size << tbltmp->it_page_shift ==
+ stt->size << stt->page_shift)) {
/*
* Reference the table to avoid races with
* add/remove DMA windows.
@@ -396,7 +394,7 @@ static long kvmppc_tce_iommu_mapped_dec(struct kvm *kvm,
return H_SUCCESS;
}
-static long kvmppc_tce_iommu_unmap(struct kvm *kvm,
+static long kvmppc_tce_iommu_do_unmap(struct kvm *kvm,
struct iommu_table *tbl, unsigned long entry)
{
enum dma_data_direction dir = DMA_NONE;
@@ -416,7 +414,25 @@ static long kvmppc_tce_iommu_unmap(struct kvm *kvm,
return ret;
}
-long kvmppc_tce_iommu_map(struct kvm *kvm, struct iommu_table *tbl,
+static long kvmppc_tce_iommu_unmap(struct kvm *kvm,
+ struct kvmppc_spapr_tce_table *stt, struct iommu_table *tbl,
+ unsigned long entry)
+{
+ unsigned long ret = H_SUCCESS;
+ unsigned long subpages = 1ULL << (stt->page_shift - tbl->it_page_shift);
+ unsigned long io_entry = entry * subpages;
+ unsigned long subpg;
+
+ for (subpg = 0; subpg < subpages; ++subpg) {
+ ret = kvmppc_tce_iommu_do_unmap(kvm, tbl, io_entry + subpg);
+ if (ret != H_SUCCESS)
+ break;
+ }
+
+ return ret;
+}
+
+long kvmppc_tce_iommu_do_map(struct kvm *kvm, struct iommu_table *tbl,
unsigned long entry, unsigned long ua,
enum dma_data_direction dir)
{
@@ -453,6 +469,28 @@ long kvmppc_tce_iommu_map(struct kvm *kvm, struct iommu_table *tbl,
return 0;
}
+static long kvmppc_tce_iommu_map(struct kvm *kvm,
+ struct kvmppc_spapr_tce_table *stt, struct iommu_table *tbl,
+ unsigned long entry, unsigned long ua,
+ enum dma_data_direction dir)
+{
+ unsigned long ret = H_SUCCESS;
+ unsigned long subpages = 1ULL << (stt->page_shift - tbl->it_page_shift);
+ unsigned long io_entry = entry * subpages;
+ unsigned long subpg, pgoff;
+
+ for (subpg = 0, pgoff = 0; subpg < subpages;
+ ++subpg, pgoff += IOMMU_PAGE_SIZE(tbl)) {
+
+ ret = kvmppc_tce_iommu_do_map(kvm, tbl,
+ io_entry + subpg, ua + pgoff, dir);
+ if (ret != H_SUCCESS)
+ break;
+ }
+
+ return ret;
+}
+
long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
unsigned long ioba, unsigned long tce)
{
@@ -491,10 +529,10 @@ long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
if (dir == DMA_NONE)
- ret = kvmppc_tce_iommu_unmap(vcpu->kvm,
+ ret = kvmppc_tce_iommu_unmap(vcpu->kvm, stt,
stit->tbl, entry);
else
- ret = kvmppc_tce_iommu_map(vcpu->kvm, stit->tbl,
+ ret = kvmppc_tce_iommu_map(vcpu->kvm, stt, stit->tbl,
entry, ua, dir);
if (ret == H_SUCCESS)
@@ -570,7 +608,7 @@ long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu,
return H_PARAMETER;
list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
- ret = kvmppc_tce_iommu_map(vcpu->kvm,
+ ret = kvmppc_tce_iommu_map(vcpu->kvm, stt,
stit->tbl, entry + i, ua,
iommu_tce_direction(tce));
@@ -618,7 +656,7 @@ long kvmppc_h_stuff_tce(struct kvm_vcpu *vcpu,
unsigned long entry = ioba >> stt->page_shift;
for (i = 0; i < npages; ++i) {
- ret = kvmppc_tce_iommu_unmap(vcpu->kvm,
+ ret = kvmppc_tce_iommu_unmap(vcpu->kvm, stt,
stit->tbl, entry + i);
if (ret == H_SUCCESS)
diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c
index e220fab..258e786 100644
--- a/arch/powerpc/kvm/book3s_64_vio_hv.c
+++ b/arch/powerpc/kvm/book3s_64_vio_hv.c
@@ -221,7 +221,7 @@ static long kvmppc_rm_tce_iommu_mapped_dec(struct kvm *kvm,
return H_SUCCESS;
}
-static long kvmppc_rm_tce_iommu_unmap(struct kvm *kvm,
+static long kvmppc_rm_tce_iommu_do_unmap(struct kvm *kvm,
struct iommu_table *tbl, unsigned long entry)
{
enum dma_data_direction dir = DMA_NONE;
@@ -245,7 +245,25 @@ static long kvmppc_rm_tce_iommu_unmap(struct kvm *kvm,
return ret;
}
-static long kvmppc_rm_tce_iommu_map(struct kvm *kvm, struct iommu_table *tbl,
+static long kvmppc_rm_tce_iommu_unmap(struct kvm *kvm,
+ struct kvmppc_spapr_tce_table *stt, struct iommu_table *tbl,
+ unsigned long entry)
+{
+ unsigned long ret = H_SUCCESS;
+ unsigned long subpages = 1ULL << (stt->page_shift - tbl->it_page_shift);
+ unsigned long io_entry = entry * subpages;
+ unsigned long subpg;
+
+ for (subpg = 0; subpg < subpages; ++subpg) {
+ ret = kvmppc_rm_tce_iommu_do_unmap(kvm, tbl, io_entry + subpg);
+ if (ret != H_SUCCESS)
+ break;
+ }
+
+ return ret;
+}
+
+static long kvmppc_rm_tce_iommu_do_map(struct kvm *kvm, struct iommu_table *tbl,
unsigned long entry, unsigned long ua,
enum dma_data_direction dir)
{
@@ -290,6 +308,28 @@ static long kvmppc_rm_tce_iommu_map(struct kvm *kvm, struct iommu_table *tbl,
return 0;
}
+static long kvmppc_rm_tce_iommu_map(struct kvm *kvm,
+ struct kvmppc_spapr_tce_table *stt, struct iommu_table *tbl,
+ unsigned long entry, unsigned long ua,
+ enum dma_data_direction dir)
+{
+ unsigned long ret = H_SUCCESS;
+ unsigned long subpages = 1ULL << (stt->page_shift - tbl->it_page_shift);
+ unsigned long io_entry = entry * subpages;
+ unsigned long subpg, pgoff;
+
+ for (subpg = 0, pgoff = 0; subpg < subpages;
+ ++subpg, pgoff += IOMMU_PAGE_SIZE(tbl)) {
+
+ ret = kvmppc_rm_tce_iommu_do_map(kvm, tbl,
+ io_entry + subpg, ua + pgoff, dir);
+ if (ret != H_SUCCESS)
+ break;
+ }
+
+ return ret;
+}
+
long kvmppc_rm_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
unsigned long ioba, unsigned long tce)
{
@@ -327,10 +367,10 @@ long kvmppc_rm_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
if (dir == DMA_NONE)
- ret = kvmppc_rm_tce_iommu_unmap(vcpu->kvm,
+ ret = kvmppc_rm_tce_iommu_unmap(vcpu->kvm, stt,
stit->tbl, entry);
else
- ret = kvmppc_rm_tce_iommu_map(vcpu->kvm,
+ ret = kvmppc_rm_tce_iommu_map(vcpu->kvm, stt,
stit->tbl, entry, ua, dir);
if (ret == H_SUCCESS)
@@ -477,7 +517,7 @@ long kvmppc_rm_h_put_tce_indirect(struct kvm_vcpu *vcpu,
return H_PARAMETER;
list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
- ret = kvmppc_rm_tce_iommu_map(vcpu->kvm,
+ ret = kvmppc_rm_tce_iommu_map(vcpu->kvm, stt,
stit->tbl, entry + i, ua,
iommu_tce_direction(tce));
@@ -529,7 +569,7 @@ long kvmppc_rm_h_stuff_tce(struct kvm_vcpu *vcpu,
unsigned long entry = ioba >> stt->page_shift;
for (i = 0; i < npages; ++i) {
- ret = kvmppc_rm_tce_iommu_unmap(vcpu->kvm,
+ ret = kvmppc_rm_tce_iommu_unmap(vcpu->kvm, stt,
stit->tbl, entry + i);
if (ret == H_SUCCESS)
--
2.11.0
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