[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>
This commit is contained in:
Carsten Otte
committed by
Martin Schwidefsky
Martin Schwidefsky
parent
598841ca99
commit
092670cd90
@@ -1,5 +1,5 @@
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/*
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* gaccess.h - access guest memory
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* access.h - access guest memory
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*
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* Copyright IBM Corp. 2008,2009
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*
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@@ -22,20 +22,13 @@ static inline void __user *__guestaddr_to_user(struct kvm_vcpu *vcpu,
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unsigned long guestaddr)
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{
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unsigned long prefix = vcpu->arch.sie_block->prefix;
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unsigned long origin = vcpu->arch.sie_block->gmsor;
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unsigned long memsize = kvm_s390_vcpu_get_memsize(vcpu);
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if (guestaddr < 2 * PAGE_SIZE)
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guestaddr += prefix;
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else if ((guestaddr >= prefix) && (guestaddr < prefix + 2 * PAGE_SIZE))
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guestaddr -= prefix;
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if (guestaddr > memsize)
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return (void __user __force *) ERR_PTR(-EFAULT);
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guestaddr += origin;
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return (void __user *) guestaddr;
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return (void __user *) gmap_fault(guestaddr, vcpu->arch.gmap);
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}
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static inline int get_guest_u64(struct kvm_vcpu *vcpu, unsigned long guestaddr,
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@@ -141,11 +134,11 @@ static inline int put_guest_u8(struct kvm_vcpu *vcpu, unsigned long guestaddr,
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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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const void *from, unsigned long n)
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void *from, unsigned long n)
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{
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int rc;
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unsigned long i;
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const u8 *data = from;
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u8 *data = from;
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for (i = 0; i < n; i++) {
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rc = put_guest_u8(vcpu, guestdest++, *(data++));
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@@ -155,12 +148,95 @@ static inline int __copy_to_guest_slow(struct kvm_vcpu *vcpu,
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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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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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const void *from, unsigned long n)
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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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unsigned long origin = vcpu->arch.sie_block->gmsor;
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unsigned long memsize = kvm_s390_vcpu_get_memsize(vcpu);
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if ((guestdest < 2 * PAGE_SIZE) && (guestdest + n > 2 * PAGE_SIZE))
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goto slowpath;
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@@ -177,15 +253,7 @@ static inline int copy_to_guest(struct kvm_vcpu *vcpu, unsigned long guestdest,
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else if ((guestdest >= prefix) && (guestdest < prefix + 2 * PAGE_SIZE))
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guestdest -= prefix;
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if (guestdest + n > memsize)
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return -EFAULT;
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if (guestdest + n < guestdest)
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return -EFAULT;
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guestdest += origin;
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return copy_to_user((void __user *) guestdest, from, n);
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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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@@ -206,12 +274,95 @@ static inline int __copy_from_guest_slow(struct kvm_vcpu *vcpu, void *to,
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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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unsigned long origin = vcpu->arch.sie_block->gmsor;
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unsigned long memsize = kvm_s390_vcpu_get_memsize(vcpu);
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if ((guestsrc < 2 * PAGE_SIZE) && (guestsrc + n > 2 * PAGE_SIZE))
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goto slowpath;
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@@ -228,52 +379,8 @@ static inline int copy_from_guest(struct kvm_vcpu *vcpu, void *to,
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else if ((guestsrc >= prefix) && (guestsrc < prefix + 2 * PAGE_SIZE))
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guestsrc -= prefix;
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if (guestsrc + n > memsize)
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return -EFAULT;
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if (guestsrc + n < guestsrc)
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return -EFAULT;
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guestsrc += origin;
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return copy_from_user(to, (void __user *) guestsrc, n);
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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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static inline int copy_to_guest_absolute(struct kvm_vcpu *vcpu,
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unsigned long guestdest,
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const void *from, unsigned long n)
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{
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unsigned long origin = vcpu->arch.sie_block->gmsor;
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unsigned long memsize = kvm_s390_vcpu_get_memsize(vcpu);
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if (guestdest + n > memsize)
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return -EFAULT;
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if (guestdest + n < guestdest)
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return -EFAULT;
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guestdest += origin;
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return copy_to_user((void __user *) guestdest, from, n);
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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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unsigned long origin = vcpu->arch.sie_block->gmsor;
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unsigned long memsize = kvm_s390_vcpu_get_memsize(vcpu);
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if (guestsrc + n > memsize)
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return -EFAULT;
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if (guestsrc + n < guestsrc)
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return -EFAULT;
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guestsrc += origin;
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return copy_from_user(to, (void __user *) guestsrc, n);
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}
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#endif
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