pseries: Add support for new KVM hash table control call

This adds support for then new "reset htab" ioctl which allows qemu
to properly cleanup the MMU hash table when the guest is reset. With
the corresponding kernel support, reset of a guest now works properly.

This also paves the way for indicating a different size hash table
to the kernel and for the kernel to be able to impose limits on
the requested size.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 29 insertions, 0 deletions

diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index 1a7489bac8..546c11604c 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -1010,6 +1010,7 @@ int kvmppc_smt_threads(void)
     return cap_ppc_smt ? cap_ppc_smt : 1;
 }
 
+#ifdef TARGET_PPC64
 off_t kvmppc_alloc_rma(const char *name, MemoryRegion *sysmem)
 {
     void *rma;
@@ -1053,6 +1054,16 @@ off_t kvmppc_alloc_rma(const char *name, MemoryRegion *sysmem)
     return size;
 }
 
+uint64_t kvmppc_rma_size(uint64_t current_size, unsigned int hash_shift)
+{
+    if (cap_ppc_rma >= 2) {
+        return current_size;
+    }
+    return MIN(current_size,
+               getrampagesize() << (hash_shift - 7));
+}
+#endif
+
 void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t window_size, int *pfd)
 {
     struct kvm_create_spapr_tce args = {
@@ -1112,6 +1123,24 @@ int kvmppc_remove_spapr_tce(void *table, int fd, uint32_t window_size)
     return 0;
 }
 
+int kvmppc_reset_htab(int shift_hint)
+{
+    uint32_t shift = shift_hint;
+
+    if (kvm_enabled() &&
+        kvm_check_extension(kvm_state, KVM_CAP_PPC_ALLOC_HTAB)) {
+        int ret;
+        ret = kvm_vm_ioctl(kvm_state, KVM_PPC_ALLOCATE_HTAB, &shift);
+        if (ret < 0) {
+            return ret;
+        }
+        return shift;
+    }
+
+    /* For now.. */
+    return 0;
+}
+
 static inline uint32_t mfpvr(void)
 {
     uint32_t pvr;