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Re: [Qemu-devel] [PATCH] target/i386: Disable MPX support on named CPU m
Re: [Qemu-devel] [PATCH] target/i386: Disable MPX support on named CPU models
Thu, 20 Dec 2018 15:25:02 +0100
Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.1
On 20/12/18 15:18, Wainer dos Santos Moschetta wrote:
> On 12/20/2018 10:11 AM, Paolo Bonzini wrote:
>> MPX support is being phased out by Intel; GCC has dropped it, Linux
>> is also going to do that. Even though KVM will have special code
>> to support MPX after the kernel proper stops enabling it in XCR0,
>> we probably also want to deprecate that in a few years. As a start,
>> do not enable it by default for any named CPU model starting with
>> the 4.0 machine types; this include Skylake, Icelake and Cascadelake.
>> Signed-off-by: Paolo Bonzini <address@hidden>
>> include/hw/i386/pc.h | 29 +++++++++++++++++++++++++++++
>> target/i386/cpu.c | 14 +++++++-------
>> 2 files changed, 36 insertions(+), 7 deletions(-)
> Side question: I didn't find on QEMU's user manual any reference to
> deprecated features for CPU models. Does that information exists
> somewhere? If not, should it be documented for the users?
It's not deprecated yet, as it won't be removed until pc-*-3.1 is
deprecated. It may be deprecated together with pc-*-3.1, or maybe not
since TCG does implement MPX.