[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 02/10] x86/gen-cpuid: Clarify the intended meaning of AVX wrt feature dependencies
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> --- CC: Jan Beulich <JBeulich@xxxxxxxx> --- xen/tools/gen-cpuid.py | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/xen/tools/gen-cpuid.py b/xen/tools/gen-cpuid.py index 5cab6db..6531ca8 100755 --- a/xen/tools/gen-cpuid.py +++ b/xen/tools/gen-cpuid.py @@ -225,9 +225,13 @@ def crunch_numbers(state): XSAVE: [XSAVEOPT, XSAVEC, XGETBV1, XSAVES, AVX, MPX, PKU, LWP], - # AVX is taken to mean hardware support for VEX encoded instructions, - # 256bit registers, and the instructions themselves. Each of these - # subsequent instruction groups may only be VEX encoded. + # AVX is taken to mean hardware support for 256bit registers (which in + # practice depends on the VEX prefix to encode), and the instructions + # themselves. + # + # AVX is not taken to mean support for the VEX prefix itself. + # VEX-encoded GPR instructions, such as those from the BMI{1,2} sets + # function fine in the absence of any enabled xstate. AVX: [FMA, FMA4, F16C, AVX2, XOP], # CX16 is only encodable in Long Mode. LAHF_LM indicates that the -- 2.1.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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