KVM: add vcpu-specific functions to read/write/translate GFNs

We need to hide SMRAM from guests not running in SMM.  Therefore, all
uses of kvm_read_guest* and kvm_write_guest* must be changed to use
different address spaces, depending on whether the VCPU is in system
management mode.  We need to introduce a new family of functions for
this purpose.

For now, the VCPU-based functions have the same behavior as the
existing per-VM ones, they just accept a different type for the
first argument.  Later however they will be changed to use one of many
"struct kvm_memslots" stored in struct kvm, through an architecture hook.
VM-based functions will unconditionally use the first memslots pointer.

Whenever possible, this patch introduces slot-based functions with an
__ prefix, with two wrappers for generic and vcpu-based actions.
The exceptions are kvm_read_guest and kvm_write_guest, which are copied
into the new functions kvm_vcpu_read_guest and kvm_vcpu_write_guest.

Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index b019fee6d941..ba1ea43998e4 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -471,6 +471,11 @@ static inline struct kvm_memslots *kvm_memslots(struct kvm *kvm)
 			|| lockdep_is_held(&kvm->slots_lock));
 }
 
+static inline struct kvm_memslots *kvm_vcpu_memslots(struct kvm_vcpu *vcpu)
+{
+	return kvm_memslots(vcpu->kvm);
+}
+
 static inline struct kvm_memory_slot *
 id_to_memslot(struct kvm_memslots *slots, int id)
 {
@@ -576,6 +581,25 @@ int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn);
 unsigned long kvm_host_page_size(struct kvm *kvm, gfn_t gfn);
 void mark_page_dirty(struct kvm *kvm, gfn_t gfn);
 
+struct kvm_memslots *kvm_vcpu_memslots(struct kvm_vcpu *vcpu);
+struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn);
+pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn);
+pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn);
+struct page *kvm_vcpu_gfn_to_page(struct kvm_vcpu *vcpu, gfn_t gfn);
+unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn);
+unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable);
+int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data, int offset,
+			     int len);
+int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa, void *data,
+			       unsigned long len);
+int kvm_vcpu_read_guest(struct kvm_vcpu *vcpu, gpa_t gpa, void *data,
+			unsigned long len);
+int kvm_vcpu_write_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, const void *data,
+			      int offset, int len);
+int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, gpa_t gpa, const void *data,
+			 unsigned long len);
+void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn);
+
 void kvm_vcpu_block(struct kvm_vcpu *vcpu);
 void kvm_vcpu_kick(struct kvm_vcpu *vcpu);
 int kvm_vcpu_yield_to(struct kvm_vcpu *target);