[PATCH v4 2/7] KVM: x86/mmu: Factor out allocating memslot rmap

From: Ben Gardon
Date: Tue May 11 2021 - 13:16:39 EST


Small refactor to facilitate allocating rmaps for all memslots at once.

No functional change expected.

Signed-off-by: Ben Gardon <bgardon@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 39 ++++++++++++++++++++++++++++++---------
1 file changed, 30 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1e1f4f31e586..cc0440b5b35d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10911,10 +10911,35 @@ void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
kvm_page_track_free_memslot(slot);
}

+static int memslot_rmap_alloc(struct kvm_memory_slot *slot,
+ unsigned long npages)
+{
+ int i;
+
+ for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) {
+ int lpages;
+ int level = i + 1;
+
+ lpages = gfn_to_index(slot->base_gfn + npages - 1,
+ slot->base_gfn, level) + 1;
+
+ slot->arch.rmap[i] =
+ kvcalloc(lpages, sizeof(*slot->arch.rmap[i]),
+ GFP_KERNEL_ACCOUNT);
+ if (!slot->arch.rmap[i]) {
+ memslot_rmap_free(slot);
+ return -ENOMEM;
+ }
+ }
+
+ return 0;
+}
+
static int kvm_alloc_memslot_metadata(struct kvm_memory_slot *slot,
unsigned long npages)
{
int i;
+ int r;

/*
* Clear out the previous array pointers for the KVM_MR_MOVE case. The
@@ -10923,7 +10948,11 @@ static int kvm_alloc_memslot_metadata(struct kvm_memory_slot *slot,
*/
memset(&slot->arch, 0, sizeof(slot->arch));

- for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) {
+ r = memslot_rmap_alloc(slot, npages);
+ if (r)
+ return r;
+
+ for (i = 1; i < KVM_NR_PAGE_SIZES; ++i) {
struct kvm_lpage_info *linfo;
unsigned long ugfn;
int lpages;
@@ -10932,14 +10961,6 @@ static int kvm_alloc_memslot_metadata(struct kvm_memory_slot *slot,
lpages = gfn_to_index(slot->base_gfn + npages - 1,
slot->base_gfn, level) + 1;

- slot->arch.rmap[i] =
- kvcalloc(lpages, sizeof(*slot->arch.rmap[i]),
- GFP_KERNEL_ACCOUNT);
- if (!slot->arch.rmap[i])
- goto out_free;
- if (i == 0)
- continue;
-
linfo = kvcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT);
if (!linfo)
goto out_free;
--
2.31.1.607.g51e8a6a459-goog