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authorJulien Grall <julien.grall@linaro.org>2013-12-03 15:40:37 +0000
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2013-12-13 10:04:51 -0500
commit380108d891acf8db5cf0d477176c7ed2b62b7928 (patch)
tree3c51e85dec23023766c9ad0e442c932cc6ff6006 /include/xen
parenta7892f32cc3534d4cc0e64b245fbf47a8e364652 (diff)
downloadlinux-380108d891acf8db5cf0d477176c7ed2b62b7928.tar.bz2
xen/block: Correctly define structures in public headers on ARM32 and ARM64
On ARM (32 bits and 64 bits), the double-word is 8-bytes aligned. This will result on different structure from Xen and Linux repositories. As Linux is using __packed__ attribute, it must have a 4-bytes padding before each "id" field. This change breaks guest block support with older kernel. IMHO, it's acceptable because Xen on ARM is still on Tech Preview and the hypercall ABI is not yet freezed. Only one architecture (x86_32) doesn't have 64-bit ABI for the block interface. Don't add padding if Linux is compiled for this architecture. Signed-off-by: Julien Grall <julien.grall@linaro.org> Acked-by: Roger Pau Monne <roger.pau@citrix.com> Acked-by: David Vrabel <david.vrabel@citrix.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Ian Campbell <ian.campbell@citrix.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> [I had asked for confirmation that it did not break x86 and Ian went beyound the call of duty to confirm it. Also a internal regression bucket with 32/64 dom0 with 32/64 domU (PV and HVM) confirmed no regressions. ABI changes are a drag..] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'include/xen')
-rw-r--r--include/xen/interface/io/blkif.h10
1 files changed, 5 insertions, 5 deletions
diff --git a/include/xen/interface/io/blkif.h b/include/xen/interface/io/blkif.h
index 65e12099ef89..ae665ac59c36 100644
--- a/include/xen/interface/io/blkif.h
+++ b/include/xen/interface/io/blkif.h
@@ -146,7 +146,7 @@ struct blkif_request_segment_aligned {
struct blkif_request_rw {
uint8_t nr_segments; /* number of segments */
blkif_vdev_t handle; /* only for read/write requests */
-#ifdef CONFIG_X86_64
+#ifndef CONFIG_X86_32
uint32_t _pad1; /* offsetof(blkif_request,u.rw.id) == 8 */
#endif
uint64_t id; /* private guest value, echoed in resp */
@@ -163,7 +163,7 @@ struct blkif_request_discard {
uint8_t flag; /* BLKIF_DISCARD_SECURE or zero. */
#define BLKIF_DISCARD_SECURE (1<<0) /* ignored if discard-secure=0 */
blkif_vdev_t _pad1; /* only for read/write requests */
-#ifdef CONFIG_X86_64
+#ifndef CONFIG_X86_32
uint32_t _pad2; /* offsetof(blkif_req..,u.discard.id)==8*/
#endif
uint64_t id; /* private guest value, echoed in resp */
@@ -175,7 +175,7 @@ struct blkif_request_discard {
struct blkif_request_other {
uint8_t _pad1;
blkif_vdev_t _pad2; /* only for read/write requests */
-#ifdef CONFIG_X86_64
+#ifndef CONFIG_X86_32
uint32_t _pad3; /* offsetof(blkif_req..,u.other.id)==8*/
#endif
uint64_t id; /* private guest value, echoed in resp */
@@ -184,7 +184,7 @@ struct blkif_request_other {
struct blkif_request_indirect {
uint8_t indirect_op;
uint16_t nr_segments;
-#ifdef CONFIG_X86_64
+#ifndef CONFIG_X86_32
uint32_t _pad1; /* offsetof(blkif_...,u.indirect.id) == 8 */
#endif
uint64_t id;
@@ -192,7 +192,7 @@ struct blkif_request_indirect {
blkif_vdev_t handle;
uint16_t _pad2;
grant_ref_t indirect_grefs[BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST];
-#ifdef CONFIG_X86_64
+#ifndef CONFIG_X86_32
uint32_t _pad3; /* make it 64 byte aligned */
#else
uint64_t _pad3; /* make it 64 byte aligned */