From 623c720fc8da3f8fd4b4afc7a9ba3d3de53e1767 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Thu, 11 Feb 2016 16:46:11 +0100 Subject: [PATCH] x86: use CLFLUSHOPT when available Also drop an unnecessary va adjustment in the code being touched. Signed-off-by: Jan Beulich Reviewed-by: Andrew Cooper --- xen/arch/x86/flushtlb.c | 8 +++++--- xen/include/asm-x86/cpufeature.h | 1 + 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/xen/arch/x86/flushtlb.c b/xen/arch/x86/flushtlb.c index 5d5d79c401..90a004f88f 100644 --- a/xen/arch/x86/flushtlb.c +++ b/xen/arch/x86/flushtlb.c @@ -139,10 +139,12 @@ void flush_area_local(const void *va, unsigned int flags) c->x86_clflush_size && c->x86_cache_size && sz && ((sz >> 10) < c->x86_cache_size) ) { - va = (const void *)((unsigned long)va & ~(sz - 1)); + alternative(ASM_NOP3, "sfence", X86_FEATURE_CLFLUSHOPT); for ( i = 0; i < sz; i += c->x86_clflush_size ) - asm volatile ( "clflush %0" - : : "m" (((const char *)va)[i]) ); + alternative_input("rex clflush %0", + "data16 clflush %0", + X86_FEATURE_CLFLUSHOPT, + "m" (((const char *)va)[i])); } else { diff --git a/xen/include/asm-x86/cpufeature.h b/xen/include/asm-x86/cpufeature.h index e7e369b313..442f0a8045 100644 --- a/xen/include/asm-x86/cpufeature.h +++ b/xen/include/asm-x86/cpufeature.h @@ -152,6 +152,7 @@ #define X86_FEATURE_ADX (7*32+19) /* ADCX, ADOX instructions */ #define X86_FEATURE_SMAP (7*32+20) /* Supervisor Mode Access Prevention */ #define X86_FEATURE_PCOMMIT (7*32+22) /* PCOMMIT instruction */ +#define X86_FEATURE_CLFLUSHOPT (7*32+23) /* CLFLUSHOPT instruction */ /* Intel-defined CPU features, CPUID level 0x00000007:0 (ecx), word 8 */ #define X86_FEATURE_PKU (8*32+ 3) /* Protection Keys for Userspace */ -- 2.39.5