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From: Roman Bolshakov <r.bolshakov@yadro.com>
To: Cameron Esfahani <dirty@apple.com>
Cc: pbonzini@redhat.com, qemu-devel@nongnu.org
Subject: Re: [PATCH v1 3/3] hvf: Support AVX512 guests on capable hardware
Date: Wed, 8 Apr 2020 16:56:39 +0300	[thread overview]
Message-ID: <20200408135639.GA17172@SPB-NB-133.local> (raw)
In-Reply-To: <1da0fc0a4f119e951ae11b29ff26ee587f4748aa.1585607927.git.dirty@apple.com>

On Mon, Mar 30, 2020 at 05:16:06PM -0700, Cameron Esfahani wrote:
> macOS lazily enables AVX512.  Explicitly enable it if the processor
> supports it.
> 
> cpu_x86_cpuid() tries to handle OSXSAVE but refers to env->cr[4] for the
> guest copy of CR4.  HVF doesn't support caching CPUID values like KVM,
> so we need to track it ourselves.
> 

Hi Cameron,

Side question, how did you test it? I tried the latest ubuntu and
archlinux iso with -cpu host and noticed that kernel complains about TSC
misbehaviour early during boot.

Also, I didn't look thoroughly into it but do you happen to know if
there could be a case that we're getting AVX512 support without AVX2
support? Wouldn't that be an issue?

Thanks,
Roman


      parent reply	other threads:[~2020-04-08 13:57 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-31  0:16 [PATCH v1 0/3] hvf: Support AVX512 guests and cleanup Cameron Esfahani via
2020-03-31  0:16 ` [PATCH v1 1/3] hvf: use standard CR0 and CR4 register definitions Cameron Esfahani via
2020-04-05 17:58   ` Roman Bolshakov
2020-04-08  6:09     ` Cameron Esfahani via
2020-04-08  8:28       ` Paolo Bonzini
2020-03-31  0:16 ` [PATCH v1 2/3] hvf: Make long mode enter and exit code clearer Cameron Esfahani via
2020-04-05 18:51   ` Roman Bolshakov
2020-04-08  6:13     ` Cameron Esfahani via
2020-03-31  0:16 ` [PATCH v1 3/3] hvf: Support AVX512 guests on capable hardware Cameron Esfahani via
2020-04-06 10:00   ` Paolo Bonzini
2020-04-08 13:56   ` Roman Bolshakov [this message]

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