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>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 6c8e124..3a121ce 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1100,6 +1100,11 @@
}
EXPORT_SYMBOL_GPL(gfn_to_memslot);
+struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn)
+{
+ return __gfn_to_memslot(kvm_vcpu_memslots(vcpu), gfn);
+}
+
int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
{
struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn);
@@ -1175,6 +1180,12 @@
}
EXPORT_SYMBOL_GPL(gfn_to_hva);
+unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn)
+{
+ return gfn_to_hva_many(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn, NULL);
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_hva);
+
/*
* If writable is set to false, the hva returned by this function is only
* allowed to be read.
@@ -1197,6 +1208,13 @@
return gfn_to_hva_memslot_prot(slot, gfn, writable);
}
+unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable)
+{
+ struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
+
+ return gfn_to_hva_memslot_prot(slot, gfn, writable);
+}
+
static int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm,
unsigned long start, int write, struct page **page)
{
@@ -1412,12 +1430,24 @@
}
EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic);
+pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn)
+{
+ return gfn_to_pfn_memslot_atomic(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_atomic);
+
pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
{
return gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn);
}
EXPORT_SYMBOL_GPL(gfn_to_pfn);
+pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn)
+{
+ return gfn_to_pfn_memslot(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn);
+
int gfn_to_page_many_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
struct page **pages, int nr_pages)
{
@@ -1458,6 +1488,16 @@
}
EXPORT_SYMBOL_GPL(gfn_to_page);
+struct page *kvm_vcpu_gfn_to_page(struct kvm_vcpu *vcpu, gfn_t gfn)
+{
+ pfn_t pfn;
+
+ pfn = kvm_vcpu_gfn_to_pfn(vcpu, gfn);
+
+ return kvm_pfn_to_page(pfn);
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_page);
+
void kvm_release_page_clean(struct page *page)
{
WARN_ON(is_error_page(page));
@@ -1520,13 +1560,13 @@
return len;
}
-int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
- int len)
+static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn,
+ void *data, int offset, int len)
{
int r;
unsigned long addr;
- addr = gfn_to_hva_prot(kvm, gfn, NULL);
+ addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
if (kvm_is_error_hva(addr))
return -EFAULT;
r = __copy_from_user(data, (void __user *)addr + offset, len);
@@ -1534,8 +1574,25 @@
return -EFAULT;
return 0;
}
+
+int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
+ int len)
+{
+ struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
+
+ return __kvm_read_guest_page(slot, gfn, data, offset, len);
+}
EXPORT_SYMBOL_GPL(kvm_read_guest_page);
+int kvm_vcpu_read_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(slot, gfn, data, offset, len);
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_page);
+
int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
{
gfn_t gfn = gpa >> PAGE_SHIFT;
@@ -1556,15 +1613,33 @@
}
EXPORT_SYMBOL_GPL(kvm_read_guest);
-int kvm_read_guest_atomic(struct kvm *kvm, 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)
+{
+ gfn_t gfn = gpa >> PAGE_SHIFT;
+ int seg;
+ int offset = offset_in_page(gpa);
+ int ret;
+
+ while ((seg = next_segment(len, offset)) != 0) {
+ ret = kvm_vcpu_read_guest_page(vcpu, gfn, data, offset, seg);
+ if (ret < 0)
+ return ret;
+ offset = 0;
+ len -= seg;
+ data += seg;
+ ++gfn;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest);
+
+static int __kvm_read_guest_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
+ void *data, int offset, unsigned long len)
{
int r;
unsigned long addr;
- gfn_t gfn = gpa >> PAGE_SHIFT;
- int offset = offset_in_page(gpa);
- addr = gfn_to_hva_prot(kvm, gfn, NULL);
+ addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
if (kvm_is_error_hva(addr))
return -EFAULT;
pagefault_disable();
@@ -1574,16 +1649,35 @@
return -EFAULT;
return 0;
}
-EXPORT_SYMBOL(kvm_read_guest_atomic);
-int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
- int offset, int len)
+int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
+ unsigned long len)
+{
+ gfn_t gfn = gpa >> PAGE_SHIFT;
+ struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
+ int offset = offset_in_page(gpa);
+
+ return __kvm_read_guest_atomic(slot, gfn, data, offset, len);
+}
+EXPORT_SYMBOL_GPL(kvm_read_guest_atomic);
+
+int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa,
+ void *data, unsigned long len)
+{
+ gfn_t gfn = gpa >> PAGE_SHIFT;
+ struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
+ int offset = offset_in_page(gpa);
+
+ return __kvm_read_guest_atomic(slot, gfn, data, offset, len);
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_atomic);
+
+static int __kvm_write_guest_page(struct kvm_memory_slot *memslot, gfn_t gfn,
+ const void *data, int offset, int len)
{
int r;
- struct kvm_memory_slot *memslot;
unsigned long addr;
- memslot = gfn_to_memslot(kvm, gfn);
addr = gfn_to_hva_memslot(memslot, gfn);
if (kvm_is_error_hva(addr))
return -EFAULT;
@@ -1593,8 +1687,25 @@
mark_page_dirty_in_slot(memslot, gfn);
return 0;
}
+
+int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn,
+ const void *data, int offset, int len)
+{
+ struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
+
+ return __kvm_write_guest_page(slot, gfn, data, offset, len);
+}
EXPORT_SYMBOL_GPL(kvm_write_guest_page);
+int kvm_vcpu_write_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn,
+ const void *data, int offset, int len)
+{
+ struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
+
+ return __kvm_write_guest_page(slot, gfn, data, offset, len);
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest_page);
+
int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
unsigned long len)
{
@@ -1616,6 +1727,27 @@
}
EXPORT_SYMBOL_GPL(kvm_write_guest);
+int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, gpa_t gpa, const void *data,
+ unsigned long len)
+{
+ gfn_t gfn = gpa >> PAGE_SHIFT;
+ int seg;
+ int offset = offset_in_page(gpa);
+ int ret;
+
+ while ((seg = next_segment(len, offset)) != 0) {
+ ret = kvm_vcpu_write_guest_page(vcpu, gfn, data, offset, seg);
+ if (ret < 0)
+ return ret;
+ offset = 0;
+ len -= seg;
+ data += seg;
+ ++gfn;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest);
+
int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
gpa_t gpa, unsigned long len)
{
@@ -1750,6 +1882,15 @@
}
EXPORT_SYMBOL_GPL(mark_page_dirty);
+void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn)
+{
+ struct kvm_memory_slot *memslot;
+
+ memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
+ mark_page_dirty_in_slot(memslot, gfn);
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_mark_page_dirty);
+
static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu)
{
if (kvm_arch_vcpu_runnable(vcpu)) {