[PATCH v2 14/28] KVM: Introduce kvm_fetch_guest_page() and use it for x86

[Paolo Bonzini <pbonzini@redhat.com>]

Introduce a separate function so that the emulator will be able to take
into account execution memory attributes rather than read.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/x86.c       | 4 ++--
 include/linux/kvm_host.h | 2 ++
 virt/kvm/kvm_main.c      | 9 +++++++++
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 416b2ebf1c70..6c0c95b92b5a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4872,8 +4872,8 @@ static int kvm_fetch_guest_virt(struct x86_emulate_ctxt *ctxt,
 	offset = addr & (PAGE_SIZE-1);
 	if (WARN_ON(offset + bytes > PAGE_SIZE))
 		bytes = (unsigned)PAGE_SIZE - offset;
-	ret = kvm_vcpu_read_guest_page(vcpu, gpa >> PAGE_SHIFT, val,
-				       offset, bytes);
+	ret = kvm_vcpu_fetch_guest_page(vcpu, gpa >> PAGE_SHIFT, val,
+					offset, bytes);
 	if (unlikely(ret < 0))
 		return X86EMUL_IO_NEEDED;
 
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 01223301f0e5..cddf0b943757 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1444,6 +1444,8 @@ DEFINE_VCPU_MAP_CLASS(_readonly);
 
 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_fetch_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data,
+			      int offset, int len);
 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,
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index b1cc570be8df..7cb7ff202fc0 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3291,6 +3291,15 @@ int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data,
 }
 EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_vcpu_read_guest_page);
 
+int kvm_vcpu_fetch_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data,
+			      int offset, int len)
+{
+	struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
+
+	return __kvm_read_guest_page(vcpu->kvm, slot, gfn, data, offset, len);
+}
+EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_vcpu_fetch_guest_page);
+
 int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
 {
 	gfn_t gfn = gpa >> PAGE_SHIFT;
-- 
2.52.0