From: Isaku Yamahata Enhance tdp_mmu_alloc_sp_split() to allocate a page for sp->external_spt, i.e., the external page table page, for splitting the mirror page table. Signed-off-by: Isaku Yamahata Co-developed-by: Yan Zhao Signed-off-by: Yan Zhao --- RFC v2: - NO change. RFC v1: - Rebased and simplified the code. --- arch/x86/kvm/mmu/tdp_mmu.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index f9a054754544..46b9f276bb6d 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -324,6 +324,8 @@ static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, u64 old_spte, u64 new_spte, int level, bool shared); +static struct kvm_mmu_page *tdp_mmu_alloc_sp_for_split(bool mirror); + static void tdp_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) { kvm_account_pgtable_pages((void *)sp->spt, +1); @@ -1475,7 +1477,7 @@ bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm, return spte_set; } -static struct kvm_mmu_page *tdp_mmu_alloc_sp_for_split(void) +static struct kvm_mmu_page *tdp_mmu_alloc_sp_for_split(bool mirror) { struct kvm_mmu_page *sp; @@ -1489,6 +1491,15 @@ static struct kvm_mmu_page *tdp_mmu_alloc_sp_for_split(void) return NULL; } + if (mirror) { + sp->external_spt = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); + if (!sp->external_spt) { + free_page((unsigned long)sp->spt); + kmem_cache_free(mmu_page_header_cache, sp); + return NULL; + } + } + return sp; } @@ -1568,7 +1579,7 @@ static int tdp_mmu_split_huge_pages_root(struct kvm *kvm, else write_unlock(&kvm->mmu_lock); - sp = tdp_mmu_alloc_sp_for_split(); + sp = tdp_mmu_alloc_sp_for_split(is_mirror_sp(root)); if (shared) read_lock(&kvm->mmu_lock); -- 2.43.2