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From: <sv...@va...> - 2015-10-01 12:31:26
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Author: mjw
Date: Thu Oct 1 13:31:19 2015
New Revision: 3197
Log:
Don't advertise RDRAND in cpuid for Core-i7-4910-like avx2 machine.
Bug#353370. In amd64g_dirtyhelper_CPUID_avx2 we set the RDRAND bit
but we don't implement support for RDRAND. Turn the bit off so programs
don't try to use RDRAND when running under valgrind.
Modified:
trunk/priv/guest_amd64_helpers.c
Modified: trunk/priv/guest_amd64_helpers.c
==============================================================================
--- trunk/priv/guest_amd64_helpers.c (original)
+++ trunk/priv/guest_amd64_helpers.c Thu Oct 1 13:31:19 2015
@@ -3101,7 +3101,8 @@
SET_ABCD(0x0000000d, 0x756e6547, 0x6c65746e, 0x49656e69);
break;
case 0x00000001:
- SET_ABCD(0x000306c3, 0x02100800, 0x7ffafbff, 0xbfebfbff);
+ /* Don't advertise RDRAND support, bit 30 in ECX. */
+ SET_ABCD(0x000306c3, 0x02100800, 0x3ffafbff, 0xbfebfbff);
break;
case 0x00000002:
SET_ABCD(0x76036301, 0x00f0b6ff, 0x00000000, 0x00c10000);
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