mirror of https://gitee.com/openkylin/linux.git
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>
This commit is contained in:
Heiko Carstens
Marcelo Tosatti
parent
396083a964
commit
f9dc72e82d
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@ -18,16 +18,19 @@
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#include <asm/uaccess.h>
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#include "kvm-s390.h"
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static inline void *__gptr_to_uptr(struct kvm_vcpu *vcpu, void *gptr)
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static inline void *__gptr_to_uptr(struct kvm_vcpu *vcpu, void *gptr,
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int prefixing)
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{
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unsigned long prefix = vcpu->arch.sie_block->prefix;
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unsigned long gaddr = (unsigned long) gptr;
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unsigned long uaddr;
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if (gaddr < 2 * PAGE_SIZE)
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gaddr += prefix;
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else if ((gaddr >= prefix) && (gaddr < prefix + 2 * PAGE_SIZE))
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gaddr -= prefix;
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if (prefixing) {
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if (gaddr < 2 * PAGE_SIZE)
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gaddr += prefix;
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else if ((gaddr >= prefix) && (gaddr < prefix + 2 * PAGE_SIZE))
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gaddr -= prefix;
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}
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uaddr = gmap_fault(gaddr, vcpu->arch.gmap);
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if (IS_ERR_VALUE(uaddr))
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uaddr = -EFAULT;
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@ -36,7 +39,7 @@ static inline void *__gptr_to_uptr(struct kvm_vcpu *vcpu, void *gptr)
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#define get_guest(vcpu, x, gptr) \
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({ \
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__typeof__(gptr) __uptr = __gptr_to_uptr(vcpu, gptr); \
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__typeof__(gptr) __uptr = __gptr_to_uptr(vcpu, gptr, 1);\
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int __mask = sizeof(__typeof__(*(gptr))) - 1; \
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int __ret = PTR_RET(__uptr); \
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\
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@ -49,7 +52,7 @@ static inline void *__gptr_to_uptr(struct kvm_vcpu *vcpu, void *gptr)
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#define put_guest(vcpu, x, gptr) \
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({ \
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__typeof__(gptr) __uptr = __gptr_to_uptr(vcpu, gptr); \
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__typeof__(gptr) __uptr = __gptr_to_uptr(vcpu, gptr, 1);\
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int __mask = sizeof(__typeof__(*(gptr))) - 1; \
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int __ret = PTR_RET(__uptr); \
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\
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@ -60,255 +63,40 @@ static inline void *__gptr_to_uptr(struct kvm_vcpu *vcpu, void *gptr)
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__ret; \
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})
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static inline int __copy_to_guest_slow(struct kvm_vcpu *vcpu,
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unsigned long guestdest,
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void *from, unsigned long n)
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static inline int __copy_guest(struct kvm_vcpu *vcpu, unsigned long to,
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unsigned long from, unsigned long len,
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int to_guest, int prefixing)
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{
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int rc;
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unsigned long i;
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u8 *data = from;
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unsigned long _len, rc;
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void *uptr;
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for (i = 0; i < n; i++) {
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rc = put_guest(vcpu, *(data++), (u8 *)guestdest++);
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if (rc < 0)
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return rc;
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while (len) {
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uptr = to_guest ? (void *)to : (void *)from;
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uptr = __gptr_to_uptr(vcpu, uptr, prefixing);
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if (IS_ERR(uptr))
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return -EFAULT;
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_len = PAGE_SIZE - ((unsigned long)uptr & (PAGE_SIZE - 1));
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_len = min(_len, len);
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if (to_guest)
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rc = copy_to_user(uptr, (void *)from, _len);
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else
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rc = copy_from_user((void *)to, uptr, _len);
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if (rc)
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return -EFAULT;
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len -= _len;
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from += _len;
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to += _len;
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}
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return 0;
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}
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static inline int __copy_to_guest_fast(struct kvm_vcpu *vcpu,
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unsigned long guestdest,
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void *from, unsigned long n)
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{
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int r;
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void __user *uptr;
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unsigned long size;
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#define copy_to_guest(vcpu, to, from, size) \
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__copy_guest(vcpu, to, (unsigned long)from, size, 1, 1)
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#define copy_from_guest(vcpu, to, from, size) \
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__copy_guest(vcpu, (unsigned long)to, from, size, 0, 1)
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#define copy_to_guest_absolute(vcpu, to, from, size) \
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__copy_guest(vcpu, to, (unsigned long)from, size, 1, 0)
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#define copy_from_guest_absolute(vcpu, to, from, size) \
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__copy_guest(vcpu, (unsigned long)to, from, size, 0, 0)
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if (guestdest + n < guestdest)
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return -EFAULT;
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/* simple case: all within one segment table entry? */
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if ((guestdest & PMD_MASK) == ((guestdest+n) & PMD_MASK)) {
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uptr = (void __user *) gmap_fault(guestdest, vcpu->arch.gmap);
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if (IS_ERR((void __force *) uptr))
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return PTR_ERR((void __force *) uptr);
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r = copy_to_user(uptr, from, n);
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if (r)
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r = -EFAULT;
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goto out;
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}
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/* copy first segment */
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uptr = (void __user *)gmap_fault(guestdest, vcpu->arch.gmap);
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if (IS_ERR((void __force *) uptr))
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return PTR_ERR((void __force *) uptr);
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size = PMD_SIZE - (guestdest & ~PMD_MASK);
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r = copy_to_user(uptr, from, size);
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if (r) {
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r = -EFAULT;
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goto out;
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}
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from += size;
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n -= size;
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guestdest += size;
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/* copy full segments */
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while (n >= PMD_SIZE) {
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uptr = (void __user *)gmap_fault(guestdest, vcpu->arch.gmap);
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if (IS_ERR((void __force *) uptr))
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return PTR_ERR((void __force *) uptr);
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r = copy_to_user(uptr, from, PMD_SIZE);
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if (r) {
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r = -EFAULT;
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goto out;
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}
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from += PMD_SIZE;
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n -= PMD_SIZE;
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guestdest += PMD_SIZE;
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}
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/* copy the tail segment */
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if (n) {
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uptr = (void __user *)gmap_fault(guestdest, vcpu->arch.gmap);
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if (IS_ERR((void __force *) uptr))
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return PTR_ERR((void __force *) uptr);
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r = copy_to_user(uptr, from, n);
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if (r)
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r = -EFAULT;
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}
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out:
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return r;
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}
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static inline int copy_to_guest_absolute(struct kvm_vcpu *vcpu,
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unsigned long guestdest,
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void *from, unsigned long n)
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{
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return __copy_to_guest_fast(vcpu, guestdest, from, n);
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}
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static inline int copy_to_guest(struct kvm_vcpu *vcpu, unsigned long guestdest,
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void *from, unsigned long n)
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{
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unsigned long prefix = vcpu->arch.sie_block->prefix;
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if ((guestdest < 2 * PAGE_SIZE) && (guestdest + n > 2 * PAGE_SIZE))
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goto slowpath;
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if ((guestdest < prefix) && (guestdest + n > prefix))
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goto slowpath;
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if ((guestdest < prefix + 2 * PAGE_SIZE)
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&& (guestdest + n > prefix + 2 * PAGE_SIZE))
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goto slowpath;
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if (guestdest < 2 * PAGE_SIZE)
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guestdest += prefix;
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else if ((guestdest >= prefix) && (guestdest < prefix + 2 * PAGE_SIZE))
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guestdest -= prefix;
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return __copy_to_guest_fast(vcpu, guestdest, from, n);
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slowpath:
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return __copy_to_guest_slow(vcpu, guestdest, from, n);
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}
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static inline int __copy_from_guest_slow(struct kvm_vcpu *vcpu, void *to,
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unsigned long guestsrc,
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unsigned long n)
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{
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int rc;
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unsigned long i;
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u8 *data = to;
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for (i = 0; i < n; i++) {
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rc = get_guest(vcpu, *(data++), (u8 *)guestsrc++);
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if (rc < 0)
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return rc;
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}
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return 0;
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}
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static inline int __copy_from_guest_fast(struct kvm_vcpu *vcpu, void *to,
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unsigned long guestsrc,
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unsigned long n)
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{
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int r;
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void __user *uptr;
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unsigned long size;
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if (guestsrc + n < guestsrc)
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return -EFAULT;
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/* simple case: all within one segment table entry? */
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if ((guestsrc & PMD_MASK) == ((guestsrc+n) & PMD_MASK)) {
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uptr = (void __user *) gmap_fault(guestsrc, vcpu->arch.gmap);
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if (IS_ERR((void __force *) uptr))
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return PTR_ERR((void __force *) uptr);
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r = copy_from_user(to, uptr, n);
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if (r)
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r = -EFAULT;
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goto out;
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}
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/* copy first segment */
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uptr = (void __user *)gmap_fault(guestsrc, vcpu->arch.gmap);
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if (IS_ERR((void __force *) uptr))
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return PTR_ERR((void __force *) uptr);
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size = PMD_SIZE - (guestsrc & ~PMD_MASK);
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r = copy_from_user(to, uptr, size);
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if (r) {
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r = -EFAULT;
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goto out;
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}
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to += size;
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n -= size;
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guestsrc += size;
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/* copy full segments */
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while (n >= PMD_SIZE) {
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uptr = (void __user *)gmap_fault(guestsrc, vcpu->arch.gmap);
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if (IS_ERR((void __force *) uptr))
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return PTR_ERR((void __force *) uptr);
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r = copy_from_user(to, uptr, PMD_SIZE);
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if (r) {
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r = -EFAULT;
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goto out;
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}
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to += PMD_SIZE;
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n -= PMD_SIZE;
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guestsrc += PMD_SIZE;
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}
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/* copy the tail segment */
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if (n) {
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uptr = (void __user *)gmap_fault(guestsrc, vcpu->arch.gmap);
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if (IS_ERR((void __force *) uptr))
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return PTR_ERR((void __force *) uptr);
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r = copy_from_user(to, uptr, n);
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if (r)
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r = -EFAULT;
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}
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out:
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return r;
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}
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static inline int copy_from_guest_absolute(struct kvm_vcpu *vcpu, void *to,
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unsigned long guestsrc,
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unsigned long n)
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{
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return __copy_from_guest_fast(vcpu, to, guestsrc, n);
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}
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static inline int copy_from_guest(struct kvm_vcpu *vcpu, void *to,
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unsigned long guestsrc, unsigned long n)
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{
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unsigned long prefix = vcpu->arch.sie_block->prefix;
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if ((guestsrc < 2 * PAGE_SIZE) && (guestsrc + n > 2 * PAGE_SIZE))
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goto slowpath;
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if ((guestsrc < prefix) && (guestsrc + n > prefix))
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goto slowpath;
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if ((guestsrc < prefix + 2 * PAGE_SIZE)
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&& (guestsrc + n > prefix + 2 * PAGE_SIZE))
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goto slowpath;
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if (guestsrc < 2 * PAGE_SIZE)
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guestsrc += prefix;
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else if ((guestsrc >= prefix) && (guestsrc < prefix + 2 * PAGE_SIZE))
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guestsrc -= prefix;
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return __copy_from_guest_fast(vcpu, to, guestsrc, n);
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slowpath:
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return __copy_from_guest_slow(vcpu, to, guestsrc, n);
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}
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#endif
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#endif /* __KVM_S390_GACCESS_H */
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