[PATCH 4/6] KVM: PPC: Book3S HV Nested: Change nested guest lookup to use idr
Nicholas Piggin
npiggin at gmail.com
Sun Jan 23 23:00:41 AEDT 2022
This removes the fixed sized kvm->arch.nested_guests array.
Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
arch/powerpc/include/asm/kvm_host.h | 3 +-
arch/powerpc/kvm/book3s_hv_nested.c | 110 +++++++++++++++-------------
2 files changed, 59 insertions(+), 54 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index d9bf60bf0816..5fd0564e5c94 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -326,8 +326,7 @@ struct kvm_arch {
struct list_head uvmem_pfns;
struct mutex mmu_setup_lock; /* nests inside vcpu mutexes */
u64 l1_ptcr;
- int max_nested_lpid;
- struct kvm_nested_guest *nested_guests[KVM_MAX_NESTED_GUESTS];
+ struct idr kvm_nested_guest_idr;
/* This array can grow quite large, keep it at the end */
struct kvmppc_vcore *vcores[KVM_MAX_VCORES];
#endif
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 9d373f8963ee..1eff969b095c 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -521,11 +521,6 @@ static void kvmhv_set_nested_ptbl(struct kvm_nested_guest *gp)
kvmhv_set_ptbl_entry(gp->shadow_lpid, dw0, gp->process_table);
}
-void kvmhv_vm_nested_init(struct kvm *kvm)
-{
- kvm->arch.max_nested_lpid = -1;
-}
-
/*
* Handle the H_SET_PARTITION_TABLE hcall.
* r4 = guest real address of partition table + log_2(size) - 12
@@ -660,6 +655,35 @@ static void kvmhv_update_ptbl_cache(struct kvm_nested_guest *gp)
kvmhv_set_nested_ptbl(gp);
}
+void kvmhv_vm_nested_init(struct kvm *kvm)
+{
+ idr_init(&kvm->arch.kvm_nested_guest_idr);
+}
+
+static struct kvm_nested_guest *__find_nested(struct kvm *kvm, int lpid)
+{
+ return idr_find(&kvm->arch.kvm_nested_guest_idr, lpid);
+}
+
+static bool __prealloc_nested(struct kvm *kvm, int lpid)
+{
+ if (idr_alloc(&kvm->arch.kvm_nested_guest_idr,
+ NULL, lpid, lpid + 1, GFP_KERNEL) != lpid)
+ return false;
+ return true;
+}
+
+static void __add_nested(struct kvm *kvm, int lpid, struct kvm_nested_guest *gp)
+{
+ if (idr_replace(&kvm->arch.kvm_nested_guest_idr, gp, lpid))
+ WARN_ON(1);
+}
+
+static void __remove_nested(struct kvm *kvm, int lpid)
+{
+ idr_remove(&kvm->arch.kvm_nested_guest_idr, lpid);
+}
+
static struct kvm_nested_guest *kvmhv_alloc_nested(struct kvm *kvm, unsigned int lpid)
{
struct kvm_nested_guest *gp;
@@ -720,13 +744,8 @@ static void kvmhv_remove_nested(struct kvm_nested_guest *gp)
long ref;
spin_lock(&kvm->mmu_lock);
- if (gp == kvm->arch.nested_guests[lpid]) {
- kvm->arch.nested_guests[lpid] = NULL;
- if (lpid == kvm->arch.max_nested_lpid) {
- while (--lpid >= 0 && !kvm->arch.nested_guests[lpid])
- ;
- kvm->arch.max_nested_lpid = lpid;
- }
+ if (gp == __find_nested(kvm, lpid)) {
+ __remove_nested(kvm, lpid);
--gp->refcnt;
}
ref = gp->refcnt;
@@ -743,24 +762,22 @@ static void kvmhv_remove_nested(struct kvm_nested_guest *gp)
*/
void kvmhv_release_all_nested(struct kvm *kvm)
{
- int i;
+ int lpid;
struct kvm_nested_guest *gp;
struct kvm_nested_guest *freelist = NULL;
struct kvm_memory_slot *memslot;
int srcu_idx, bkt;
spin_lock(&kvm->mmu_lock);
- for (i = 0; i <= kvm->arch.max_nested_lpid; i++) {
- gp = kvm->arch.nested_guests[i];
- if (!gp)
- continue;
- kvm->arch.nested_guests[i] = NULL;
+ idr_for_each_entry(&kvm->arch.kvm_nested_guest_idr, gp, lpid) {
+ __remove_nested(kvm, lpid);
if (--gp->refcnt == 0) {
gp->next = freelist;
freelist = gp;
}
}
- kvm->arch.max_nested_lpid = -1;
+ idr_destroy(&kvm->arch.kvm_nested_guest_idr);
+ /* idr is empty and may be reused at this point */
spin_unlock(&kvm->mmu_lock);
while ((gp = freelist) != NULL) {
freelist = gp->next;
@@ -797,7 +814,7 @@ struct kvm_nested_guest *kvmhv_get_nested(struct kvm *kvm, int l1_lpid,
return NULL;
spin_lock(&kvm->mmu_lock);
- gp = kvm->arch.nested_guests[l1_lpid];
+ gp = __find_nested(kvm, l1_lpid);
if (gp)
++gp->refcnt;
spin_unlock(&kvm->mmu_lock);
@@ -808,17 +825,19 @@ struct kvm_nested_guest *kvmhv_get_nested(struct kvm *kvm, int l1_lpid,
newgp = kvmhv_alloc_nested(kvm, l1_lpid);
if (!newgp)
return NULL;
+
+ if (!__prealloc_nested(kvm, l1_lpid)) {
+ kvmhv_release_nested(newgp);
+ return NULL;
+ }
+
spin_lock(&kvm->mmu_lock);
- if (kvm->arch.nested_guests[l1_lpid]) {
- /* someone else beat us to it */
- gp = kvm->arch.nested_guests[l1_lpid];
- } else {
- kvm->arch.nested_guests[l1_lpid] = newgp;
+ gp = __find_nested(kvm, l1_lpid);
+ if (!gp) {
+ __add_nested(kvm, l1_lpid, newgp);
++newgp->refcnt;
gp = newgp;
newgp = NULL;
- if (l1_lpid > kvm->arch.max_nested_lpid)
- kvm->arch.max_nested_lpid = l1_lpid;
}
++gp->refcnt;
spin_unlock(&kvm->mmu_lock);
@@ -841,20 +860,13 @@ void kvmhv_put_nested(struct kvm_nested_guest *gp)
kvmhv_release_nested(gp);
}
-static struct kvm_nested_guest *kvmhv_find_nested(struct kvm *kvm, int lpid)
-{
- if (lpid > kvm->arch.max_nested_lpid)
- return NULL;
- return kvm->arch.nested_guests[lpid];
-}
-
pte_t *find_kvm_nested_guest_pte(struct kvm *kvm, unsigned long lpid,
unsigned long ea, unsigned *hshift)
{
struct kvm_nested_guest *gp;
pte_t *pte;
- gp = kvmhv_find_nested(kvm, lpid);
+ gp = __find_nested(kvm, lpid);
if (!gp)
return NULL;
@@ -960,7 +972,7 @@ static void kvmhv_remove_nest_rmap(struct kvm *kvm, u64 n_rmap,
gpa = n_rmap & RMAP_NESTED_GPA_MASK;
lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT;
- gp = kvmhv_find_nested(kvm, lpid);
+ gp = __find_nested(kvm, lpid);
if (!gp)
return;
@@ -1152,16 +1164,13 @@ static void kvmhv_emulate_tlbie_all_lpid(struct kvm_vcpu *vcpu, int ric)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_nested_guest *gp;
- int i;
+ int lpid;
spin_lock(&kvm->mmu_lock);
- for (i = 0; i <= kvm->arch.max_nested_lpid; i++) {
- gp = kvm->arch.nested_guests[i];
- if (gp) {
- spin_unlock(&kvm->mmu_lock);
- kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
- spin_lock(&kvm->mmu_lock);
- }
+ idr_for_each_entry(&kvm->arch.kvm_nested_guest_idr, gp, lpid) {
+ spin_unlock(&kvm->mmu_lock);
+ kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
+ spin_lock(&kvm->mmu_lock);
}
spin_unlock(&kvm->mmu_lock);
}
@@ -1313,7 +1322,7 @@ long do_h_rpt_invalidate_pat(struct kvm_vcpu *vcpu, unsigned long lpid,
* H_ENTER_NESTED call. Since we can't differentiate this case from
* the invalid case, we ignore such flush requests and return success.
*/
- if (!kvmhv_find_nested(vcpu->kvm, lpid))
+ if (!__find_nested(vcpu->kvm, lpid))
return H_SUCCESS;
/*
@@ -1657,15 +1666,12 @@ long int kvmhv_nested_page_fault(struct kvm_vcpu *vcpu)
int kvmhv_nested_next_lpid(struct kvm *kvm, int lpid)
{
- int ret = -1;
+ int ret = lpid + 1;
spin_lock(&kvm->mmu_lock);
- while (++lpid <= kvm->arch.max_nested_lpid) {
- if (kvm->arch.nested_guests[lpid]) {
- ret = lpid;
- break;
- }
- }
+ if (!idr_get_next(&kvm->arch.kvm_nested_guest_idr, &ret))
+ ret = -1;
spin_unlock(&kvm->mmu_lock);
+
return ret;
}
--
2.23.0
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