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authorHeiko Carstens <heiko.carstens@de.ibm.com>2013-03-05 13:14:45 +0100
committerMarcelo Tosatti <mtosatti@redhat.com>2013-03-07 16:21:21 -0300
commitf9dc72e82d32cc9fe40d1dea7709d434bba2d4a9 (patch)
tree61a650e12d2942dc2878dfd303756a8852e64a1e /arch/s390/kvm/gaccess.h
parent396083a964aa4e86061d0e3449b1e0548a8197a9 (diff)
s390/kvm,gaccess: shorten copy_to/from_guest code
The code can be significantly shortened. There is no functional change, except that for large (> PAGE_SIZE) copies the guest translation would be done more frequently. However, there is not a single user which does this currently. If one gets added later on this functionality can be added easily again. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/s390/kvm/gaccess.h')
-rw-r--r--arch/s390/kvm/gaccess.h294
1 files changed, 41 insertions, 253 deletions
diff --git a/arch/s390/kvm/gaccess.h b/arch/s390/kvm/gaccess.h
index 82f450ecb585..8608d7e6a334 100644
--- a/arch/s390/kvm/gaccess.h
+++ b/arch/s390/kvm/gaccess.h
@@ -18,16 +18,19 @@
#include <asm/uaccess.h>
#include "kvm-s390.h"
-static inline void *__gptr_to_uptr(struct kvm_vcpu *vcpu, void *gptr)
+static inline void *__gptr_to_uptr(struct kvm_vcpu *vcpu, void *gptr,
+ int prefixing)
{
unsigned long prefix = vcpu->arch.sie_block->prefix;
unsigned long gaddr = (unsigned long) gptr;
unsigned long uaddr;
- if (gaddr < 2 * PAGE_SIZE)
- gaddr += prefix;
- else if ((gaddr >= prefix) && (gaddr < prefix + 2 * PAGE_SIZE))
- gaddr -= prefix;
+ if (prefixing) {
+ if (gaddr < 2 * PAGE_SIZE)
+ gaddr += prefix;
+ else if ((gaddr >= prefix) && (gaddr < prefix + 2 * PAGE_SIZE))
+ gaddr -= prefix;
+ }
uaddr = gmap_fault(gaddr, vcpu->arch.gmap);
if (IS_ERR_VALUE(uaddr))
uaddr = -EFAULT;
@@ -36,7 +39,7 @@ static inline void *__gptr_to_uptr(struct kvm_vcpu *vcpu, void *gptr)
#define get_guest(vcpu, x, gptr) \
({ \
- __typeof__(gptr) __uptr = __gptr_to_uptr(vcpu, gptr); \
+ __typeof__(gptr) __uptr = __gptr_to_uptr(vcpu, gptr, 1);\
int __mask = sizeof(__typeof__(*(gptr))) - 1; \
int __ret = PTR_RET(__uptr); \
\
@@ -49,7 +52,7 @@ static inline void *__gptr_to_uptr(struct kvm_vcpu *vcpu, void *gptr)
#define put_guest(vcpu, x, gptr) \
({ \
- __typeof__(gptr) __uptr = __gptr_to_uptr(vcpu, gptr); \
+ __typeof__(gptr) __uptr = __gptr_to_uptr(vcpu, gptr, 1);\
int __mask = sizeof(__typeof__(*(gptr))) - 1; \
int __ret = PTR_RET(__uptr); \
\
@@ -60,255 +63,40 @@ static inline void *__gptr_to_uptr(struct kvm_vcpu *vcpu, void *gptr)
__ret; \
})
-static inline int __copy_to_guest_slow(struct kvm_vcpu *vcpu,
- unsigned long guestdest,
- void *from, unsigned long n)
-{
- int rc;
- unsigned long i;
- u8 *data = from;
-
- for (i = 0; i < n; i++) {
- rc = put_guest(vcpu, *(data++), (u8 *)guestdest++);
- if (rc < 0)
- return rc;
- }
- 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,
- void *from, unsigned long n)
-{
- unsigned long prefix = vcpu->arch.sie_block->prefix;
-
- if ((guestdest < 2 * PAGE_SIZE) && (guestdest + n > 2 * PAGE_SIZE))
- goto slowpath;
-
- if ((guestdest < prefix) && (guestdest + n > prefix))
- goto slowpath;
-
- if ((guestdest < prefix + 2 * PAGE_SIZE)
- && (guestdest + n > prefix + 2 * PAGE_SIZE))
- goto slowpath;
-
- if (guestdest < 2 * PAGE_SIZE)
- guestdest += prefix;
- else if ((guestdest >= prefix) && (guestdest < prefix + 2 * PAGE_SIZE))
- guestdest -= prefix;
-
- return __copy_to_guest_fast(vcpu, guestdest, from, n);
-slowpath:
- return __copy_to_guest_slow(vcpu, guestdest, from, n);
-}
-
-static inline int __copy_from_guest_slow(struct kvm_vcpu *vcpu, void *to,
- unsigned long guestsrc,
- unsigned long n)
+static inline int __copy_guest(struct kvm_vcpu *vcpu, unsigned long to,
+ unsigned long from, unsigned long len,
+ int to_guest, int prefixing)
{
- int rc;
- unsigned long i;
- u8 *data = to;
-
- for (i = 0; i < n; i++) {
- rc = get_guest(vcpu, *(data++), (u8 *)guestsrc++);
- if (rc < 0)
- return rc;
+ unsigned long _len, rc;
+ void *uptr;
+
+ while (len) {
+ uptr = to_guest ? (void *)to : (void *)from;
+ uptr = __gptr_to_uptr(vcpu, uptr, prefixing);
+ if (IS_ERR(uptr))
+ return -EFAULT;
+ _len = PAGE_SIZE - ((unsigned long)uptr & (PAGE_SIZE - 1));
+ _len = min(_len, len);
+ if (to_guest)
+ rc = copy_to_user(uptr, (void *)from, _len);
+ else
+ rc = copy_from_user((void *)to, uptr, _len);
+ if (rc)
+ return -EFAULT;
+ len -= _len;
+ from += _len;
+ to += _len;
}
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);
+#define copy_to_guest(vcpu, to, from, size) \
+ __copy_guest(vcpu, to, (unsigned long)from, size, 1, 1)
+#define copy_from_guest(vcpu, to, from, size) \
+ __copy_guest(vcpu, (unsigned long)to, from, size, 0, 1)
+#define copy_to_guest_absolute(vcpu, to, from, size) \
+ __copy_guest(vcpu, to, (unsigned long)from, size, 1, 0)
+#define copy_from_guest_absolute(vcpu, to, from, size) \
+ __copy_guest(vcpu, (unsigned long)to, from, size, 0, 0)
- 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;
-
- if ((guestsrc < 2 * PAGE_SIZE) && (guestsrc + n > 2 * PAGE_SIZE))
- goto slowpath;
-
- if ((guestsrc < prefix) && (guestsrc + n > prefix))
- goto slowpath;
-
- if ((guestsrc < prefix + 2 * PAGE_SIZE)
- && (guestsrc + n > prefix + 2 * PAGE_SIZE))
- goto slowpath;
-
- if (guestsrc < 2 * PAGE_SIZE)
- guestsrc += prefix;
- else if ((guestsrc >= prefix) && (guestsrc < prefix + 2 * PAGE_SIZE))
- guestsrc -= prefix;
-
- return __copy_from_guest_fast(vcpu, to, guestsrc, n);
-slowpath:
- return __copy_from_guest_slow(vcpu, to, guestsrc, n);
-}
-#endif
+#endif /* __KVM_S390_GACCESS_H */