This reworks the existing H_PUT_TCE/H_GET_TCE handlers to have one
exit path. This allows next patch to add locks nicely.
This moves the ioba boundaries check to a helper and adds a check for
least bits which have to be zeros.
The patch is pretty mechanical (only check for least ioba bits is added)
so no change in behaviour is expected.
Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
arch/powerpc/kvm/book3s_64_vio_hv.c | 102 +++++++++++++++++++++++-------------
1 file changed, 66 insertions(+), 36 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c
b/arch/powerpc/kvm/book3s_64_vio_hv.c
index 89e96b3..8ae12ac 100644
--- a/arch/powerpc/kvm/book3s_64_vio_hv.c
+++ b/arch/powerpc/kvm/book3s_64_vio_hv.c
@@ -35,71 +35,101 @@
#include <asm/ppc-opcode.h>
#include <asm/kvm_host.h>
#include <asm/udbg.h>
+#include <asm/iommu.h>
#define TCES_PER_PAGE (PAGE_SIZE / sizeof(u64))
+/*
+ * Finds a TCE table descriptor by LIOBN.
+ *
+ * WARNING: This will be called in real or virtual mode on HV KVM and virtual
+ * mode on PR KVM
+ */
+static struct kvmppc_spapr_tce_table *kvmppc_find_table(struct kvm_vcpu *vcpu,
+ unsigned long liobn)
+{
+ struct kvm *kvm = vcpu->kvm;
+ struct kvmppc_spapr_tce_table *stt;
+
+ list_for_each_entry_rcu_notrace(stt, &kvm->arch.spapr_tce_tables, list)
+ if (stt->liobn == liobn)
+ return stt;
+
+ return NULL;
+}
+
+/*
+ * Validates IO address.
+ *
+ * WARNING: This will be called in real-mode on HV KVM and virtual
+ * mode on PR KVM
+ */
+static long kvmppc_ioba_validate(struct kvmppc_spapr_tce_table *stt,
+ unsigned long ioba, unsigned long npages)
+{
+ unsigned long mask = (1ULL << IOMMU_PAGE_SHIFT_4K) - 1;
+ unsigned long idx = ioba >> IOMMU_PAGE_SHIFT_4K;
+ unsigned long size = stt->window_size >> IOMMU_PAGE_SHIFT_4K;
+
+ if ((ioba & mask) || (size + npages <= idx))
+ return H_PARAMETER;
+
+ return H_SUCCESS;
+}
+
/* WARNING: This will be called in real-mode on HV KVM and virtual
* mode on PR KVM
*/
long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
unsigned long ioba, unsigned long tce)
{
- struct kvm *kvm = vcpu->kvm;
- struct kvmppc_spapr_tce_table *stt;
+ struct kvmppc_spapr_tce_table *stt = kvmppc_find_table(vcpu, liobn);
+ long ret = H_TOO_HARD;
+ unsigned long idx;
+ struct page *page;
+ u64 *tbl;
/* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */
/* liobn, ioba, tce); */
- list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) {
- if (stt->liobn == liobn) {
- unsigned long idx = ioba >> SPAPR_TCE_SHIFT;
- struct page *page;
- u64 *tbl;
+ if (!stt)
+ return ret;
- /* udbg_printf("H_PUT_TCE: liobn 0x%lx => stt=%p
window_size=0x%x\n", */
- /* liobn, stt, stt->window_size); */
- if (ioba >= stt->window_size)
- return H_PARAMETER;
+ ret = kvmppc_ioba_validate(stt, ioba, 1);
+ if (ret)
+ return ret;
- page = stt->pages[idx / TCES_PER_PAGE];
- tbl = (u64 *)page_address(page);
+ idx = ioba >> SPAPR_TCE_SHIFT;
+ page = stt->pages[idx / TCES_PER_PAGE];
+ tbl = (u64 *)page_address(page);
- /* FIXME: Need to validate the TCE itself */
- /* udbg_printf("tce @ %p\n", &tbl[idx %
TCES_PER_PAGE]); */
- tbl[idx % TCES_PER_PAGE] = tce;
- return H_SUCCESS;
- }
- }
+ /* FIXME: Need to validate the TCE itself */
+ /* udbg_printf("tce @ %p\n", &tbl[idx % TCES_PER_PAGE]); */
+ tbl[idx % TCES_PER_PAGE] = tce;
- /* Didn't find the liobn, punt it to userspace */
- return H_TOO_HARD;
+ return ret;
}
EXPORT_SYMBOL_GPL(kvmppc_h_put_tce);
long kvmppc_h_get_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
unsigned long ioba)
{
- struct kvm *kvm = vcpu->kvm;
- struct kvmppc_spapr_tce_table *stt;
+ struct kvmppc_spapr_tce_table *stt = kvmppc_find_table(vcpu, liobn);
+ long ret = H_TOO_HARD;
- list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) {
- if (stt->liobn == liobn) {
+
+ if (stt) {
+ ret = kvmppc_ioba_validate(stt, ioba, 1);
+ if (!ret) {
unsigned long idx = ioba >> SPAPR_TCE_SHIFT;
- struct page *page;
- u64 *tbl;
-
- if (ioba >= stt->window_size)
- return H_PARAMETER;
-
- page = stt->pages[idx / TCES_PER_PAGE];
- tbl = (u64 *)page_address(page);
+ struct page *page = stt->pages[idx / TCES_PER_PAGE];
+ u64 *tbl = (u64 *)page_address(page);
vcpu->arch.gpr[4] = tbl[idx % TCES_PER_PAGE];
- return H_SUCCESS;
}
}
- /* Didn't find the liobn, punt it to userspace */
- return H_TOO_HARD;
+
+ return ret;
}
EXPORT_SYMBOL_GPL(kvmppc_h_get_tce);
--
2.4.0.rc3.8.gfb3e7d5
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