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authorMario Preksavec <mario@slackware.hr>2020-06-02 01:23:58 +0200
committerWilly Sudiarto Raharjo <willysr@slackbuilds.org>2020-06-06 10:07:54 +0700
commit90a270d8f0670502b0e69f73c95859401d1e5558 (patch)
tree664e17a36ea8f9ca6d53c9e0545d5b73ad21119a /system/xen
parent61d34fa64d109651462eaa0249c2244e6e63c455 (diff)
system/xen: Updated for version 4.13.1.
Signed-off-by: Mario Preksavec <mario@slackware.hr> Signed-off-by: Willy Sudiarto Raharjo <willysr@slackbuilds.org>
Diffstat (limited to 'system/xen')
-rw-r--r--system/xen/dom0/README.dom02
-rw-r--r--system/xen/dom0/kernel-xen.sh2
-rw-r--r--system/xen/xen.SlackBuild2
-rw-r--r--system/xen/xen.info6
-rw-r--r--system/xen/xsa/xsa312.patch93
-rw-r--r--system/xen/xsa/xsa313-1.patch26
-rw-r--r--system/xen/xsa/xsa313-2.patch132
-rw-r--r--system/xen/xsa/xsa314-4.13.patch121
-rw-r--r--system/xen/xsa/xsa316-xen.patch30
-rw-r--r--system/xen/xsa/xsa318.patch39
10 files changed, 6 insertions, 447 deletions
diff --git a/system/xen/dom0/README.dom0 b/system/xen/dom0/README.dom0
index f798e2ddc7def..68dbf815fb75b 100644
--- a/system/xen/dom0/README.dom0
+++ b/system/xen/dom0/README.dom0
@@ -46,7 +46,7 @@ Xen EFI binary.
To make things a bit easier, a copy of Xen EFI binary can be found here:
- http://slackware.hr/~mario/xen/xen-4.13.0.efi.gz
+ http://slackware.hr/~mario/xen/xen-4.13.1.efi.gz
If an automatic boot to Xen kernel is desired, the binary should be renamed and
copied to the following location: /boot/efi/EFI/BOOT/bootx64.efi
diff --git a/system/xen/dom0/kernel-xen.sh b/system/xen/dom0/kernel-xen.sh
index 483d6460c28cd..754cf6fcf5644 100644
--- a/system/xen/dom0/kernel-xen.sh
+++ b/system/xen/dom0/kernel-xen.sh
@@ -6,7 +6,7 @@
# Modified by Mario Preksavec <mario@slackware.hr>
KERNEL=${KERNEL:-4.4.217}
-XEN=${XEN:-4.13.0}
+XEN=${XEN:-4.13.1}
BOOTLOADER=${BOOTLOADER:-lilo}
ROOTMOD=${ROOTMOD:-ext4}
diff --git a/system/xen/xen.SlackBuild b/system/xen/xen.SlackBuild
index 262ff9996a4cf..80aac0a098d88 100644
--- a/system/xen/xen.SlackBuild
+++ b/system/xen/xen.SlackBuild
@@ -23,7 +23,7 @@
# ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
PRGNAM=xen
-VERSION=${VERSION:-4.13.0}
+VERSION=${VERSION:-4.13.1}
BUILD=${BUILD:-1}
TAG=${TAG:-_SBo}
diff --git a/system/xen/xen.info b/system/xen/xen.info
index fa9672aace6b5..c74e7f07d1beb 100644
--- a/system/xen/xen.info
+++ b/system/xen/xen.info
@@ -1,7 +1,7 @@
PRGNAM="xen"
-VERSION="4.13.0"
+VERSION="4.13.1"
HOMEPAGE="http://www.xenproject.org/"
-DOWNLOAD="http://mirror.slackware.hr/sources/xen/xen-4.13.0.tar.gz \
+DOWNLOAD="http://mirror.slackware.hr/sources/xen/xen-4.13.1.tar.gz \
http://mirror.slackware.hr/sources/xen-extfiles/ipxe-git-1dd56dbd11082fb622c2ed21cfaced4f47d798a6.tar.gz \
http://mirror.slackware.hr/sources/xen-extfiles/lwip-1.3.0.tar.gz \
http://mirror.slackware.hr/sources/xen-extfiles/zlib-1.2.3.tar.gz \
@@ -13,7 +13,7 @@ DOWNLOAD="http://mirror.slackware.hr/sources/xen/xen-4.13.0.tar.gz \
http://mirror.slackware.hr/sources/xen-extfiles/tpm_emulator-0.7.4.tar.gz \
http://mirror.slackware.hr/sources/xen-seabios/seabios-1.12.1.tar.gz \
http://mirror.slackware.hr/sources/xen-ovmf/xen-ovmf-20190606_20d2e5a125.tar.bz2"
-MD5SUM="d3b13c4c785601be2f104eaddd7c6a00 \
+MD5SUM="e26fe8f9ce39463734e6ede45c6e11b8 \
b3ab0488a989a089207302111d12e1a0 \
36cc57650cffda9a0269493be2a169bb \
debc62758716a169df9f62e6ab2bc634 \
diff --git a/system/xen/xsa/xsa312.patch b/system/xen/xsa/xsa312.patch
deleted file mode 100644
index ae3fa4041ba06..0000000000000
--- a/system/xen/xsa/xsa312.patch
+++ /dev/null
@@ -1,93 +0,0 @@
-From 9f807cf84a9a7a011cf1df7895c54d6031a7596d Mon Sep 17 00:00:00 2001
-From: Julien Grall <julien@xen.org>
-Date: Thu, 19 Dec 2019 08:12:21 +0000
-Subject: [PATCH] xen/arm: Place a speculation barrier sequence following an
- eret instruction
-
-Some CPUs can speculate past an ERET instruction and potentially perform
-speculative accesses to memory before processing the exception return.
-Since the register state is often controlled by lower privilege level
-at the point of an ERET, this could potentially be used as part of a
-side-channel attack.
-
-Newer CPUs may implement a new SB barrier instruction which acts
-as an architected speculation barrier. For current CPUs, the sequence
-DSB; ISB is known to prevent speculation.
-
-The latter sequence is heavier than SB but it would never be executed
-(this is speculation after all!).
-
-Introduce a new macro 'sb' that could be used when a speculation barrier
-is required. For now it is using dsb; isb but this could easily be
-updated to cater SB in the future.
-
-This is XSA-312.
-
-Signed-off-by: Julien Grall <julien@xen.org>
----
- xen/arch/arm/arm32/entry.S | 1 +
- xen/arch/arm/arm64/entry.S | 3 +++
- xen/include/asm-arm/macros.h | 9 +++++++++
- 3 files changed, 13 insertions(+)
-
-diff --git a/xen/arch/arm/arm32/entry.S b/xen/arch/arm/arm32/entry.S
-index 31ccfb2631..b228d44b19 100644
---- a/xen/arch/arm/arm32/entry.S
-+++ b/xen/arch/arm/arm32/entry.S
-@@ -426,6 +426,7 @@ return_to_hypervisor:
- add sp, #(UREGS_SP_usr - UREGS_sp); /* SP, LR, SPSR, PC */
- clrex
- eret
-+ sb
-
- /*
- * struct vcpu *__context_switch(struct vcpu *prev, struct vcpu *next)
-diff --git a/xen/arch/arm/arm64/entry.S b/xen/arch/arm/arm64/entry.S
-index d35855af96..175ea2981e 100644
---- a/xen/arch/arm/arm64/entry.S
-+++ b/xen/arch/arm/arm64/entry.S
-@@ -354,6 +354,7 @@ guest_sync:
- */
- mov x1, xzr
- eret
-+ sb
-
- check_wa2:
- /* ARM_SMCCC_ARCH_WORKAROUND_2 handling */
-@@ -393,6 +394,7 @@ wa2_end:
- #endif /* !CONFIG_ARM_SSBD */
- mov x0, xzr
- eret
-+ sb
- guest_sync_slowpath:
- /*
- * x0/x1 may have been scratch by the fast path above, so avoid
-@@ -457,6 +459,7 @@ return_from_trap:
- ldr lr, [sp], #(UREGS_SPSR_el1 - UREGS_LR) /* CPSR, PC, SP, LR */
-
- eret
-+ sb
-
- /*
- * Consume pending SError generated by the guest if any.
-diff --git a/xen/include/asm-arm/macros.h b/xen/include/asm-arm/macros.h
-index 91ea3505e4..4833671f4c 100644
---- a/xen/include/asm-arm/macros.h
-+++ b/xen/include/asm-arm/macros.h
-@@ -20,4 +20,13 @@
- .endr
- .endm
-
-+ /*
-+ * Speculative barrier
-+ * XXX: Add support for the 'sb' instruction
-+ */
-+ .macro sb
-+ dsb nsh
-+ isb
-+ .endm
-+
- #endif /* __ASM_ARM_MACROS_H */
---
-2.17.1
-
diff --git a/system/xen/xsa/xsa313-1.patch b/system/xen/xsa/xsa313-1.patch
deleted file mode 100644
index 95fde7ead4db3..0000000000000
--- a/system/xen/xsa/xsa313-1.patch
+++ /dev/null
@@ -1,26 +0,0 @@
-From: Jan Beulich <jbeulich@suse.com>
-Subject: xenoprof: clear buffer intended to be shared with guests
-
-alloc_xenheap_pages() making use of MEMF_no_scrub is fine for Xen
-internally used allocations, but buffers allocated to be shared with
-(unpriviliged) guests need to be zapped of their prior content.
-
-This is part of XSA-313.
-
-Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
-Signed-off-by: Jan Beulich <jbeulich@suse.com>
-Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
-Reviewed-by: Wei Liu <wl@xen.org>
-
---- a/xen/common/xenoprof.c
-+++ b/xen/common/xenoprof.c
-@@ -253,6 +253,9 @@ static int alloc_xenoprof_struct(
- return -ENOMEM;
- }
-
-+ for ( i = 0; i < npages; ++i )
-+ clear_page(d->xenoprof->rawbuf + i * PAGE_SIZE);
-+
- d->xenoprof->npages = npages;
- d->xenoprof->nbuf = nvcpu;
- d->xenoprof->bufsize = bufsize;
diff --git a/system/xen/xsa/xsa313-2.patch b/system/xen/xsa/xsa313-2.patch
deleted file mode 100644
index d81b8232d2df0..0000000000000
--- a/system/xen/xsa/xsa313-2.patch
+++ /dev/null
@@ -1,132 +0,0 @@
-From: Jan Beulich <jbeulich@suse.com>
-Subject: xenoprof: limit consumption of shared buffer data
-
-Since a shared buffer can be written to by the guest, we may only read
-the head and tail pointers from there (all other fields should only ever
-be written to). Furthermore, for any particular operation the two values
-must be read exactly once, with both checks and consumption happening
-with the thus read values. (The backtrace related xenoprof_buf_space()
-use in xenoprof_log_event() is an exception: The values used there get
-re-checked by every subsequent xenoprof_add_sample().)
-
-Since that code needed touching, also fix the double increment of the
-lost samples count in case the backtrace related xenoprof_add_sample()
-invocation in xenoprof_log_event() fails.
-
-Where code is being touched anyway, add const as appropriate, but take
-the opportunity to entirely drop the now unused domain parameter of
-xenoprof_buf_space().
-
-This is part of XSA-313.
-
-Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
-Signed-off-by: Jan Beulich <jbeulich@suse.com>
-Reviewed-by: George Dunlap <george.dunlap@citrix.com>
-Reviewed-by: Wei Liu <wl@xen.org>
-
---- a/xen/common/xenoprof.c
-+++ b/xen/common/xenoprof.c
-@@ -479,25 +479,22 @@ static int add_passive_list(XEN_GUEST_HA
-
-
- /* Get space in the buffer */
--static int xenoprof_buf_space(struct domain *d, xenoprof_buf_t * buf, int size)
-+static int xenoprof_buf_space(int head, int tail, int size)
- {
-- int head, tail;
--
-- head = xenoprof_buf(d, buf, event_head);
-- tail = xenoprof_buf(d, buf, event_tail);
--
- return ((tail > head) ? 0 : size) + tail - head - 1;
- }
-
- /* Check for space and add a sample. Return 1 if successful, 0 otherwise. */
--static int xenoprof_add_sample(struct domain *d, xenoprof_buf_t *buf,
-+static int xenoprof_add_sample(const struct domain *d,
-+ const struct xenoprof_vcpu *v,
- uint64_t eip, int mode, int event)
- {
-+ xenoprof_buf_t *buf = v->buffer;
- int head, tail, size;
-
- head = xenoprof_buf(d, buf, event_head);
- tail = xenoprof_buf(d, buf, event_tail);
-- size = xenoprof_buf(d, buf, event_size);
-+ size = v->event_size;
-
- /* make sure indexes in shared buffer are sane */
- if ( (head < 0) || (head >= size) || (tail < 0) || (tail >= size) )
-@@ -506,7 +503,7 @@ static int xenoprof_add_sample(struct do
- return 0;
- }
-
-- if ( xenoprof_buf_space(d, buf, size) > 0 )
-+ if ( xenoprof_buf_space(head, tail, size) > 0 )
- {
- xenoprof_buf(d, buf, event_log[head].eip) = eip;
- xenoprof_buf(d, buf, event_log[head].mode) = mode;
-@@ -530,7 +527,6 @@ static int xenoprof_add_sample(struct do
- int xenoprof_add_trace(struct vcpu *vcpu, uint64_t pc, int mode)
- {
- struct domain *d = vcpu->domain;
-- xenoprof_buf_t *buf = d->xenoprof->vcpu[vcpu->vcpu_id].buffer;
-
- /* Do not accidentally write an escape code due to a broken frame. */
- if ( pc == XENOPROF_ESCAPE_CODE )
-@@ -539,7 +535,8 @@ int xenoprof_add_trace(struct vcpu *vcpu
- return 0;
- }
-
-- return xenoprof_add_sample(d, buf, pc, mode, 0);
-+ return xenoprof_add_sample(d, &d->xenoprof->vcpu[vcpu->vcpu_id],
-+ pc, mode, 0);
- }
-
- void xenoprof_log_event(struct vcpu *vcpu, const struct cpu_user_regs *regs,
-@@ -570,17 +567,22 @@ void xenoprof_log_event(struct vcpu *vcp
- /* Provide backtrace if requested. */
- if ( backtrace_depth > 0 )
- {
-- if ( (xenoprof_buf_space(d, buf, v->event_size) < 2) ||
-- !xenoprof_add_sample(d, buf, XENOPROF_ESCAPE_CODE, mode,
-- XENOPROF_TRACE_BEGIN) )
-+ if ( xenoprof_buf_space(xenoprof_buf(d, buf, event_head),
-+ xenoprof_buf(d, buf, event_tail),
-+ v->event_size) < 2 )
- {
- xenoprof_buf(d, buf, lost_samples)++;
- lost_samples++;
- return;
- }
-+
-+ /* xenoprof_add_sample() will increment lost_samples on failure */
-+ if ( !xenoprof_add_sample(d, v, XENOPROF_ESCAPE_CODE, mode,
-+ XENOPROF_TRACE_BEGIN) )
-+ return;
- }
-
-- if ( xenoprof_add_sample(d, buf, pc, mode, event) )
-+ if ( xenoprof_add_sample(d, v, pc, mode, event) )
- {
- if ( is_active(vcpu->domain) )
- active_samples++;
---- a/xen/include/xen/xenoprof.h
-+++ b/xen/include/xen/xenoprof.h
-@@ -61,12 +61,12 @@ struct xenoprof {
-
- #ifndef CONFIG_COMPAT
- #define XENOPROF_COMPAT(x) 0
--#define xenoprof_buf(d, b, field) ((b)->field)
-+#define xenoprof_buf(d, b, field) ACCESS_ONCE((b)->field)
- #else
- #define XENOPROF_COMPAT(x) ((x)->is_compat)
--#define xenoprof_buf(d, b, field) (*(!(d)->xenoprof->is_compat ? \
-- &(b)->native.field : \
-- &(b)->compat.field))
-+#define xenoprof_buf(d, b, field) ACCESS_ONCE(*(!(d)->xenoprof->is_compat \
-+ ? &(b)->native.field \
-+ : &(b)->compat.field))
- #endif
-
- struct domain;
diff --git a/system/xen/xsa/xsa314-4.13.patch b/system/xen/xsa/xsa314-4.13.patch
deleted file mode 100644
index 67e006681e0ce..0000000000000
--- a/system/xen/xsa/xsa314-4.13.patch
+++ /dev/null
@@ -1,121 +0,0 @@
-From ab49f005f7d01d4004d76f2e295d31aca7d4f93a Mon Sep 17 00:00:00 2001
-From: Julien Grall <jgrall@amazon.com>
-Date: Thu, 20 Feb 2020 20:54:40 +0000
-Subject: [PATCH] xen/rwlock: Add missing memory barrier in the unlock path of
- rwlock
-
-The rwlock unlock paths are using atomic_sub() to release the lock.
-However the implementation of atomic_sub() rightfully doesn't contain a
-memory barrier. On Arm, this means a processor is allowed to re-order
-the memory access with the preceeding access.
-
-In other words, the unlock may be seen by another processor before all
-the memory accesses within the "critical" section.
-
-The rwlock paths already contains barrier indirectly, but they are not
-very useful without the counterpart in the unlock paths.
-
-The memory barriers are not necessary on x86 because loads/stores are
-not re-ordered with lock instructions.
-
-So add arch_lock_release_barrier() in the unlock paths that will only
-add memory barrier on Arm.
-
-Take the opportunity to document each lock paths explaining why a
-barrier is not necessary.
-
-This is XSA-314.
-
-Signed-off-by: Julien Grall <jgrall@amazon.com>
-Reviewed-by: Jan Beulich <jbeulich@suse.com>
-Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
-
----
- xen/include/xen/rwlock.h | 29 ++++++++++++++++++++++++++++-
- 1 file changed, 28 insertions(+), 1 deletion(-)
-
-diff --git a/xen/include/xen/rwlock.h b/xen/include/xen/rwlock.h
-index 3dfea1ac2a..516486306f 100644
---- a/xen/include/xen/rwlock.h
-+++ b/xen/include/xen/rwlock.h
-@@ -48,6 +48,10 @@ static inline int _read_trylock(rwlock_t *lock)
- if ( likely(!(cnts & _QW_WMASK)) )
- {
- cnts = (u32)atomic_add_return(_QR_BIAS, &lock->cnts);
-+ /*
-+ * atomic_add_return() is a full barrier so no need for an
-+ * arch_lock_acquire_barrier().
-+ */
- if ( likely(!(cnts & _QW_WMASK)) )
- return 1;
- atomic_sub(_QR_BIAS, &lock->cnts);
-@@ -64,11 +68,19 @@ static inline void _read_lock(rwlock_t *lock)
- u32 cnts;
-
- cnts = atomic_add_return(_QR_BIAS, &lock->cnts);
-+ /*
-+ * atomic_add_return() is a full barrier so no need for an
-+ * arch_lock_acquire_barrier().
-+ */
- if ( likely(!(cnts & _QW_WMASK)) )
- return;
-
- /* The slowpath will decrement the reader count, if necessary. */
- queue_read_lock_slowpath(lock);
-+ /*
-+ * queue_read_lock_slowpath() is using spinlock and therefore is a
-+ * full barrier. So no need for an arch_lock_acquire_barrier().
-+ */
- }
-
- static inline void _read_lock_irq(rwlock_t *lock)
-@@ -92,6 +104,7 @@ static inline unsigned long _read_lock_irqsave(rwlock_t *lock)
- */
- static inline void _read_unlock(rwlock_t *lock)
- {
-+ arch_lock_release_barrier();
- /*
- * Atomically decrement the reader count
- */
-@@ -121,11 +134,20 @@ static inline int _rw_is_locked(rwlock_t *lock)
- */
- static inline void _write_lock(rwlock_t *lock)
- {
-- /* Optimize for the unfair lock case where the fair flag is 0. */
-+ /*
-+ * Optimize for the unfair lock case where the fair flag is 0.
-+ *
-+ * atomic_cmpxchg() is a full barrier so no need for an
-+ * arch_lock_acquire_barrier().
-+ */
- if ( atomic_cmpxchg(&lock->cnts, 0, _QW_LOCKED) == 0 )
- return;
-
- queue_write_lock_slowpath(lock);
-+ /*
-+ * queue_write_lock_slowpath() is using spinlock and therefore is a
-+ * full barrier. So no need for an arch_lock_acquire_barrier().
-+ */
- }
-
- static inline void _write_lock_irq(rwlock_t *lock)
-@@ -157,11 +179,16 @@ static inline int _write_trylock(rwlock_t *lock)
- if ( unlikely(cnts) )
- return 0;
-
-+ /*
-+ * atomic_cmpxchg() is a full barrier so no need for an
-+ * arch_lock_acquire_barrier().
-+ */
- return likely(atomic_cmpxchg(&lock->cnts, 0, _QW_LOCKED) == 0);
- }
-
- static inline void _write_unlock(rwlock_t *lock)
- {
-+ arch_lock_release_barrier();
- /*
- * If the writer field is atomic, it can be cleared directly.
- * Otherwise, an atomic subtraction will be used to clear it.
---
-2.17.1
-
diff --git a/system/xen/xsa/xsa316-xen.patch b/system/xen/xsa/xsa316-xen.patch
deleted file mode 100644
index 4962b4e7161cb..0000000000000
--- a/system/xen/xsa/xsa316-xen.patch
+++ /dev/null
@@ -1,30 +0,0 @@
-From: Ross Lagerwall <ross.lagerwall@citrix.com>
-Subject: xen/gnttab: Fix error path in map_grant_ref()
-
-Part of XSA-295 (c/s 863e74eb2cffb) inadvertently re-positioned the brackets,
-changing the logic. If the _set_status() call fails, the grant_map hypercall
-would fail with a status of 1 (rc != GNTST_okay) instead of the expected
-negative GNTST_* error.
-
-This error path can be taken due to bad guest state, and causes net/blk-back
-in Linux to crash.
-
-This is XSA-316.
-
-Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
-Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
-Reviewed-by: Julien Grall <jgrall@amazon.com>
-
-diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
-index 9fd6e60416..4b5344dc21 100644
---- a/xen/common/grant_table.c
-+++ b/xen/common/grant_table.c
-@@ -1031,7 +1031,7 @@ map_grant_ref(
- {
- if ( (rc = _set_status(shah, status, rd, rgt->gt_version, act,
- op->flags & GNTMAP_readonly, 1,
-- ld->domain_id) != GNTST_okay) )
-+ ld->domain_id)) != GNTST_okay )
- goto act_release_out;
-
- if ( !act->pin )
diff --git a/system/xen/xsa/xsa318.patch b/system/xen/xsa/xsa318.patch
deleted file mode 100644
index f4becdf81e7a7..0000000000000
--- a/system/xen/xsa/xsa318.patch
+++ /dev/null
@@ -1,39 +0,0 @@
-From: Jan Beulich <jbeulich@suse.com>
-Subject: gnttab: fix GNTTABOP_copy continuation handling
-
-The XSA-226 fix was flawed - the backwards transformation on rc was done
-too early, causing a continuation to not get invoked when the need for
-preemption was determined at the very first iteration of the request.
-This in particular means that all of the status fields of the individual
-operations would be left untouched, i.e. set to whatever the caller may
-or may not have initialized them to.
-
-This is part of XSA-318.
-
-Reported-by: Pawel Wieczorkiewicz <wipawel@amazon.de>
-Tested-by: Pawel Wieczorkiewicz <wipawel@amazon.de>
-Signed-off-by: Jan Beulich <jbeulich@suse.com>
-Reviewed-by: Juergen Gross <jgross@suse.com>
-
---- a/xen/common/grant_table.c
-+++ b/xen/common/grant_table.c
-@@ -3576,8 +3576,7 @@ do_grant_table_op(
- rc = gnttab_copy(copy, count);
- if ( rc > 0 )
- {
-- rc = count - rc;
-- guest_handle_add_offset(copy, rc);
-+ guest_handle_add_offset(copy, count - rc);
- uop = guest_handle_cast(copy, void);
- }
- break;
-@@ -3644,6 +3643,9 @@ do_grant_table_op(
- out:
- if ( rc > 0 || opaque_out != 0 )
- {
-+ /* Adjust rc, see gnttab_copy() for why this is needed. */
-+ if ( cmd == GNTTABOP_copy )
-+ rc = count - rc;
- ASSERT(rc < count);
- ASSERT((opaque_out & GNTTABOP_CMD_MASK) == 0);
- rc = hypercall_create_continuation(__HYPERVISOR_grant_table_op, "ihi",