[PATCH v6 10/16] KVM: x86/tdp_mmu: Allocate private page table for large page split

isaku.yamahata
2023-11-07T15:11:51Z

From: Isaku Yamahata <isaku.yamahata@intel.com>

Make tdp_mmu_alloc_sp_split() aware of private page table.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
arch/x86/kvm/mmu/mmu_internal.h | 14 ++++++++++++++
arch/x86/kvm/mmu/tdp_mmu.c | 8 ++++++--
2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index d8d46a4d00ff..1da98be74ad2 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -202,6 +202,15 @@ static inline void kvm_mmu_alloc_private_spt(struct kvm_vcpu *vcpu, struct kvm_m
}
}

+static inline int kvm_alloc_private_spt_for_split(struct kvm_mmu_page *sp, gfp_t gfp)
+{
+ gfp &= ~__GFP_ZERO;
+ sp->private_spt = (void *)__get_free_page(gfp);
+ if (!sp->private_spt)
+ return -ENOMEM;
+ return 0;
+}
+
static inline void kvm_mmu_free_private_spt(struct kvm_mmu_page *sp)
{
if (sp->private_spt)
@@ -230,6 +239,11 @@ static inline void kvm_mmu_alloc_private_spt(struct kvm_vcpu *vcpu, struct kvm_m
{
}

+static inline int kvm_alloc_private_spt_for_split(struct kvm_mmu_page *sp, gfp_t gfp)
+{
+ return -ENOMEM;
+}
+
static inline void kvm_mmu_free_private_spt(struct kvm_mmu_page *sp)
{
}
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index d806574f7f2d..7873e9ee82ad 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1583,8 +1583,12 @@ static struct kvm_mmu_page *__tdp_mmu_alloc_sp_for_split(gfp_t gfp, union kvm_mm

sp->role = role;
sp->spt = (void *)__get_free_page(gfp);
- /* TODO: large page support for private GPA. */
- WARN_ON_ONCE(kvm_mmu_page_role_is_private(role));
+ if (kvm_mmu_page_role_is_private(role)) {
+ if (kvm_alloc_private_spt_for_split(sp, gfp)) {
+ free_page((unsigned long)sp->spt);
+ sp->spt = NULL;
+ }
+ }
if (!sp->spt) {
kmem_cache_free(mmu_page_header_cache, sp);
return NULL;
--
2.25.1