From 5249fe526e66a92e293bc638ab53eb3d8cd68881 Mon Sep 17 00:00:00 2001
From: "Daniel P. Berrange" <berrange@redhat.com>
Date: Wed, 24 Apr 2019 09:56:40 +0100
Subject: [PATCH 6/9] crypto: convert xts_mult_x to use xts_uint128 type
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RH-Author: Daniel P. Berrange <berrange@redhat.com>
Message-id: <20190424095643.796-7-berrange@redhat.com>
Patchwork-id: 85879
O-Subject: [RHEL-8.1.0 qemu-kvm PATCH 6/9] crypto: convert xts_mult_x to use xts_uint128 type
Bugzilla: 1680231
RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
RH-Acked-by: John Snow <jsnow@redhat.com>
RH-Acked-by: Eric Blake <eblake@redhat.com>
Using 64-bit arithmetic increases the performance for xts-aes-128
when built with gcrypt:
Encrypt: 355 MB/s -> 545 MB/s
Decrypt: 362 MB/s -> 568 MB/s
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
(cherry picked from commit 7dac0dd67426753646df0c23c819609b9e704f59)
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
crypto/xts.c | 40 ++++++++++++++++++++++++++++------------
1 file changed, 28 insertions(+), 12 deletions(-)
diff --git a/crypto/xts.c b/crypto/xts.c
index 0ad231f..10ec83f 100644
--- a/crypto/xts.c
+++ b/crypto/xts.c
@@ -24,6 +24,7 @@
*/
#include "qemu/osdep.h"
+#include "qemu/bswap.h"
#include "crypto/xts.h"
typedef union {
@@ -39,19 +40,34 @@ static inline void xts_uint128_xor(xts_uint128 *D,
D->u[1] = S1->u[1] ^ S2->u[1];
}
-static void xts_mult_x(uint8_t *I)
+static inline void xts_uint128_cpu_to_les(xts_uint128 *v)
{
- int x;
- uint8_t t, tt;
+ cpu_to_le64s(&v->u[0]);
+ cpu_to_le64s(&v->u[1]);
+}
- for (x = t = 0; x < 16; x++) {
- tt = I[x] >> 7;
- I[x] = ((I[x] << 1) | t) & 0xFF;
- t = tt;
- }
- if (tt) {
- I[0] ^= 0x87;
+static inline void xts_uint128_le_to_cpus(xts_uint128 *v)
+{
+ le64_to_cpus(&v->u[0]);
+ le64_to_cpus(&v->u[1]);
+}
+
+static void xts_mult_x(xts_uint128 *I)
+{
+ uint64_t tt;
+
+ xts_uint128_le_to_cpus(I);
+
+ tt = I->u[0] >> 63;
+ I->u[0] <<= 1;
+
+ if (I->u[1] >> 63) {
+ I->u[0] ^= 0x87;
}
+ I->u[1] <<= 1;
+ I->u[1] |= tt;
+
+ xts_uint128_cpu_to_les(I);
}
@@ -79,7 +95,7 @@ static void xts_tweak_encdec(const void *ctx,
xts_uint128_xor(dst, dst, iv);
/* LFSR the tweak */
- xts_mult_x(iv->b);
+ xts_mult_x(iv);
}
@@ -134,7 +150,7 @@ void xts_decrypt(const void *datactx,
if (mo > 0) {
xts_uint128 S, D;
memcpy(&CC, &T, XTS_BLOCK_SIZE);
- xts_mult_x(CC.b);
+ xts_mult_x(&CC);
/* PP = tweak decrypt block m-1 */
memcpy(&S, src, XTS_BLOCK_SIZE);
--
1.8.3.1