[RFC PATCH v6 37/92] KVM: VMX: Introduce SPP access bitmap and operation functions
From: Adalbert Lazăr <hidden>
Date: 2019-08-09 16:02:40
Also in:
kvm, linux-mm
Subsystem:
kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Yang Weijiang <redacted> Create access bitmap for SPP subpages, 4KB/128B = 32bits, for each 4KB physical page, 32bits are required. The bitmap can be easily accessed with a gfn. The initial access bitmap for each physical page is 0xFFFFFFFF, meaning SPP is not enabled for the subpages. Co-developed-by: He Chen <redacted> Signed-off-by: He Chen <redacted> Co-developed-by: Zhang Yi <redacted> Signed-off-by: Zhang Yi <redacted> Co-developed-by: Yang Weijiang <redacted> Signed-off-by: Yang Weijiang <redacted> Message-Id: [off-list ref] Signed-off-by: Adalbert Lazăr <redacted> --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/mmu.c | 50 +++++++++++++++++++++++++++++++++ arch/x86/kvm/x86.c | 11 ++++++++ 3 files changed, 62 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c05984f39923..f0878631b12a 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h@@ -790,6 +790,7 @@ struct kvm_lpage_info { struct kvm_arch_memory_slot { struct kvm_rmap_head *rmap[KVM_NR_PAGE_SIZES]; + u32 *subpage_wp_info; struct kvm_lpage_info *lpage_info[KVM_NR_PAGE_SIZES - 1]; unsigned short *gfn_track[KVM_PAGE_TRACK_MAX]; };
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 8a6287cd2be4..f2774bbcfeed 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c@@ -1482,6 +1482,56 @@ static u64 *rmap_get_next(struct rmap_iterator *iter) return sptep; } +#define FULL_SPP_ACCESS ((u32)((1ULL << 32) - 1)) + +static int kvm_subpage_create_bitmaps(struct kvm *kvm) +{ + struct kvm_memslots *slots; + struct kvm_memory_slot *memslot; + int i, j, ret; + u32 *buff; + + for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { + slots = __kvm_memslots(kvm, i); + kvm_for_each_memslot(memslot, slots) { + buff = kvzalloc(memslot->npages* + sizeof(*memslot->arch.subpage_wp_info), + GFP_KERNEL); + + if (!buff) { + ret = -ENOMEM; + goto out_free; + } + memslot->arch.subpage_wp_info = buff; + + for(j = 0; j< memslot->npages; j++) + buff[j] = FULL_SPP_ACCESS; + } + } + + return 0; +out_free: + for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { + slots = __kvm_memslots(kvm, i); + kvm_for_each_memslot(memslot, slots) { + if (memslot->arch.subpage_wp_info) { + kvfree(memslot->arch.subpage_wp_info); + memslot->arch.subpage_wp_info = NULL; + } + } + } + + return ret; +} + +static u32 *gfn_to_subpage_wp_info(struct kvm_memory_slot *slot, gfn_t gfn) +{ + unsigned long idx; + + idx = gfn_to_index(gfn, slot->base_gfn, PT_PAGE_TABLE_LEVEL); + return &slot->arch.subpage_wp_info[idx]; +} + #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ _spte_; _spte_ = rmap_get_next(_iter_))
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ef6d9dd80086..2ac1e0aba1fc 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c@@ -9320,6 +9320,17 @@ void kvm_arch_destroy_vm(struct kvm *kvm) kvm_hv_destroy_vm(kvm); } +void kvm_subpage_free_memslot(struct kvm_memory_slot *free, + struct kvm_memory_slot *dont) +{ + + if (!dont || free->arch.subpage_wp_info != + dont->arch.subpage_wp_info) { + kvfree(free->arch.subpage_wp_info); + free->arch.subpage_wp_info = NULL; + } +} + void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free, struct kvm_memory_slot *dont) {
_______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization