[S390] Use gmap translation for accessing guest memory
This patch removes kvm-s390 internal assumption of a linear mapping
of guest address space to user space. Previously, guest memory was
translated to user addresses using a fixed offset (gmsor). The new
code uses gmap_fault to resolve guest addresses.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kvm/gaccess.h b/arch/s390/kvm/gaccess.h
index 03c716a..c86f6ae 100644
--- a/arch/s390/kvm/gaccess.h
+++ b/arch/s390/kvm/gaccess.h
@@ -1,5 +1,5 @@
/*
- * gaccess.h - access guest memory
+ * access.h - access guest memory
*
* Copyright IBM Corp. 2008,2009
*
@@ -22,20 +22,13 @@
unsigned long guestaddr)
{
unsigned long prefix = vcpu->arch.sie_block->prefix;
- unsigned long origin = vcpu->arch.sie_block->gmsor;
- unsigned long memsize = kvm_s390_vcpu_get_memsize(vcpu);
if (guestaddr < 2 * PAGE_SIZE)
guestaddr += prefix;
else if ((guestaddr >= prefix) && (guestaddr < prefix + 2 * PAGE_SIZE))
guestaddr -= prefix;
- if (guestaddr > memsize)
- return (void __user __force *) ERR_PTR(-EFAULT);
-
- guestaddr += origin;
-
- return (void __user *) guestaddr;
+ return (void __user *) gmap_fault(guestaddr, vcpu->arch.gmap);
}
static inline int get_guest_u64(struct kvm_vcpu *vcpu, unsigned long guestaddr,
@@ -141,11 +134,11 @@
static inline int __copy_to_guest_slow(struct kvm_vcpu *vcpu,
unsigned long guestdest,
- const void *from, unsigned long n)
+ void *from, unsigned long n)
{
int rc;
unsigned long i;
- const u8 *data = from;
+ u8 *data = from;
for (i = 0; i < n; i++) {
rc = put_guest_u8(vcpu, guestdest++, *(data++));
@@ -155,12 +148,95 @@
return 0;
}
+static inline int __copy_to_guest_fast(struct kvm_vcpu *vcpu,
+ unsigned long guestdest,
+ void *from, unsigned long n)
+{
+ int r;
+ void __user *uptr;
+ unsigned long size;
+
+ if (guestdest + n < guestdest)
+ return -EFAULT;
+
+ /* simple case: all within one segment table entry? */
+ if ((guestdest & PMD_MASK) == ((guestdest+n) & PMD_MASK)) {
+ uptr = (void __user *) gmap_fault(guestdest, vcpu->arch.gmap);
+
+ if (IS_ERR((void __force *) uptr))
+ return PTR_ERR((void __force *) uptr);
+
+ r = copy_to_user(uptr, from, n);
+
+ if (r)
+ r = -EFAULT;
+
+ goto out;
+ }
+
+ /* copy first segment */
+ uptr = (void __user *)gmap_fault(guestdest, vcpu->arch.gmap);
+
+ if (IS_ERR((void __force *) uptr))
+ return PTR_ERR((void __force *) uptr);
+
+ size = PMD_SIZE - (guestdest & ~PMD_MASK);
+
+ r = copy_to_user(uptr, from, size);
+
+ if (r) {
+ r = -EFAULT;
+ goto out;
+ }
+ from += size;
+ n -= size;
+ guestdest += size;
+
+ /* copy full segments */
+ while (n >= PMD_SIZE) {
+ uptr = (void __user *)gmap_fault(guestdest, vcpu->arch.gmap);
+
+ if (IS_ERR((void __force *) uptr))
+ return PTR_ERR((void __force *) uptr);
+
+ r = copy_to_user(uptr, from, PMD_SIZE);
+
+ if (r) {
+ r = -EFAULT;
+ goto out;
+ }
+ from += PMD_SIZE;
+ n -= PMD_SIZE;
+ guestdest += PMD_SIZE;
+ }
+
+ /* copy the tail segment */
+ if (n) {
+ uptr = (void __user *)gmap_fault(guestdest, vcpu->arch.gmap);
+
+ if (IS_ERR((void __force *) uptr))
+ return PTR_ERR((void __force *) uptr);
+
+ r = copy_to_user(uptr, from, n);
+
+ if (r)
+ r = -EFAULT;
+ }
+out:
+ return r;
+}
+
+static inline int copy_to_guest_absolute(struct kvm_vcpu *vcpu,
+ unsigned long guestdest,
+ void *from, unsigned long n)
+{
+ return __copy_to_guest_fast(vcpu, guestdest, from, n);
+}
+
static inline int copy_to_guest(struct kvm_vcpu *vcpu, unsigned long guestdest,
- const void *from, unsigned long n)
+ void *from, unsigned long n)
{
unsigned long prefix = vcpu->arch.sie_block->prefix;
- unsigned long origin = vcpu->arch.sie_block->gmsor;
- unsigned long memsize = kvm_s390_vcpu_get_memsize(vcpu);
if ((guestdest < 2 * PAGE_SIZE) && (guestdest + n > 2 * PAGE_SIZE))
goto slowpath;
@@ -177,15 +253,7 @@
else if ((guestdest >= prefix) && (guestdest < prefix + 2 * PAGE_SIZE))
guestdest -= prefix;
- if (guestdest + n > memsize)
- return -EFAULT;
-
- if (guestdest + n < guestdest)
- return -EFAULT;
-
- guestdest += origin;
-
- return copy_to_user((void __user *) guestdest, from, n);
+ return __copy_to_guest_fast(vcpu, guestdest, from, n);
slowpath:
return __copy_to_guest_slow(vcpu, guestdest, from, n);
}
@@ -206,12 +274,95 @@
return 0;
}
+static inline int __copy_from_guest_fast(struct kvm_vcpu *vcpu, void *to,
+ unsigned long guestsrc,
+ unsigned long n)
+{
+ int r;
+ void __user *uptr;
+ unsigned long size;
+
+ if (guestsrc + n < guestsrc)
+ return -EFAULT;
+
+ /* simple case: all within one segment table entry? */
+ if ((guestsrc & PMD_MASK) == ((guestsrc+n) & PMD_MASK)) {
+ uptr = (void __user *) gmap_fault(guestsrc, vcpu->arch.gmap);
+
+ if (IS_ERR((void __force *) uptr))
+ return PTR_ERR((void __force *) uptr);
+
+ r = copy_from_user(to, uptr, n);
+
+ if (r)
+ r = -EFAULT;
+
+ goto out;
+ }
+
+ /* copy first segment */
+ uptr = (void __user *)gmap_fault(guestsrc, vcpu->arch.gmap);
+
+ if (IS_ERR((void __force *) uptr))
+ return PTR_ERR((void __force *) uptr);
+
+ size = PMD_SIZE - (guestsrc & ~PMD_MASK);
+
+ r = copy_from_user(to, uptr, size);
+
+ if (r) {
+ r = -EFAULT;
+ goto out;
+ }
+ to += size;
+ n -= size;
+ guestsrc += size;
+
+ /* copy full segments */
+ while (n >= PMD_SIZE) {
+ uptr = (void __user *)gmap_fault(guestsrc, vcpu->arch.gmap);
+
+ if (IS_ERR((void __force *) uptr))
+ return PTR_ERR((void __force *) uptr);
+
+ r = copy_from_user(to, uptr, PMD_SIZE);
+
+ if (r) {
+ r = -EFAULT;
+ goto out;
+ }
+ to += PMD_SIZE;
+ n -= PMD_SIZE;
+ guestsrc += PMD_SIZE;
+ }
+
+ /* copy the tail segment */
+ if (n) {
+ uptr = (void __user *)gmap_fault(guestsrc, vcpu->arch.gmap);
+
+ if (IS_ERR((void __force *) uptr))
+ return PTR_ERR((void __force *) uptr);
+
+ r = copy_from_user(to, uptr, n);
+
+ if (r)
+ r = -EFAULT;
+ }
+out:
+ return r;
+}
+
+static inline int copy_from_guest_absolute(struct kvm_vcpu *vcpu, void *to,
+ unsigned long guestsrc,
+ unsigned long n)
+{
+ return __copy_from_guest_fast(vcpu, to, guestsrc, n);
+}
+
static inline int copy_from_guest(struct kvm_vcpu *vcpu, void *to,
unsigned long guestsrc, unsigned long n)
{
unsigned long prefix = vcpu->arch.sie_block->prefix;
- unsigned long origin = vcpu->arch.sie_block->gmsor;
- unsigned long memsize = kvm_s390_vcpu_get_memsize(vcpu);
if ((guestsrc < 2 * PAGE_SIZE) && (guestsrc + n > 2 * PAGE_SIZE))
goto slowpath;
@@ -228,52 +379,8 @@
else if ((guestsrc >= prefix) && (guestsrc < prefix + 2 * PAGE_SIZE))
guestsrc -= prefix;
- if (guestsrc + n > memsize)
- return -EFAULT;
-
- if (guestsrc + n < guestsrc)
- return -EFAULT;
-
- guestsrc += origin;
-
- return copy_from_user(to, (void __user *) guestsrc, n);
+ return __copy_from_guest_fast(vcpu, to, guestsrc, n);
slowpath:
return __copy_from_guest_slow(vcpu, to, guestsrc, n);
}
-
-static inline int copy_to_guest_absolute(struct kvm_vcpu *vcpu,
- unsigned long guestdest,
- const void *from, unsigned long n)
-{
- unsigned long origin = vcpu->arch.sie_block->gmsor;
- unsigned long memsize = kvm_s390_vcpu_get_memsize(vcpu);
-
- if (guestdest + n > memsize)
- return -EFAULT;
-
- if (guestdest + n < guestdest)
- return -EFAULT;
-
- guestdest += origin;
-
- return copy_to_user((void __user *) guestdest, from, n);
-}
-
-static inline int copy_from_guest_absolute(struct kvm_vcpu *vcpu, void *to,
- unsigned long guestsrc,
- unsigned long n)
-{
- unsigned long origin = vcpu->arch.sie_block->gmsor;
- unsigned long memsize = kvm_s390_vcpu_get_memsize(vcpu);
-
- if (guestsrc + n > memsize)
- return -EFAULT;
-
- if (guestsrc + n < guestsrc)
- return -EFAULT;
-
- guestsrc += origin;
-
- return copy_from_user(to, (void __user *) guestsrc, n);
-}
#endif